TI ADS7869IPZTR Analog motor control front-end with simultaneous sampling on seven s/h capacitors and three 1msps, 12-bit, 12-channel Datasheet

ADS7869
Analog Motor Control Front-End
with Simultaneous Sampling
on Seven S/H Capacitors and
Three 1MSPS, 12-Bit, 12-Channel
ADCs
Data Manual
Literature Number: SBAS253B
May 2003 − Revised November 2004
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
Contents
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4
Package Dissipation Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.5
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.6
Pinout Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.7
Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.8
Basic Circuit Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.9
Typical Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.10
Typical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.11
Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2 Analog Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1
Fully Differential Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.1
Analog-to-Digital Converter Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.2
Window Comparator Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.3
Sign Comparator Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2
Analog-To-Digital Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2.1
HOLD1, HOLD2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2.2
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.3
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.4
Gain Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.5
Offset Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.6
Transition Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3
Sign Comparators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.4
Window Comparators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.5
8-Bit Digital-to-Analog Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.6
Internal Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.7
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.8
Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
v
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
3
vi
Digital Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2
VECANA Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.1
Input Channel Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.2
VECANA Timing Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.3
WINCLK Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3
Serial Peripheral Interface (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.1
SPI Timing Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4
Parallel Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.1
Parallel Read and Write Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.2
Mode 10 Bus Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.3
Mode 11 Bus Access (Standard Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.4
Mode 11 Bus Access (TMS320c54xx DSP Family-Compatible Mode) . . . . . . . . . . . . . .
3.5
Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6
Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.1
FIFO Data Register (00H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.2
Offset Registers (01H – 0CH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.3
Gain Registers (0DH to 18H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.4
WINDAC Register (19H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.5
Control Register (1AH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.6
Counter Control/Status Register (1BH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.7
Edge Count Register (1CH, 1DH, 20H and 21H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.8
Edge Period Register (1EH and 22H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.9
Edge Time Period Register (1FH and 23H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.10
FIFO Test Register (24H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.11
Comparator Test Register (25H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.12
Interrupt Register (26H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.13
Parallel Register (27H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.14
Reset Register (28H) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.7
FIFO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.7.1
DAV Timing Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.8
Digital Counter Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.8.1
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.8.2
Digital Noise Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.8.3
Binary Counters and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.9
Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.10
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.10.1
Reset Timing Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23
23
24
25
26
27
27
29
30
30
31
33
35
37
39
39
40
40
40
41
42
43
43
44
44
45
46
47
48
49
51
52
52
53
56
58
58
58
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
List of Illustrations
1−1. Typical Motor Control Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−2. Functional Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−3. Equivalent Input Circuit to the ADCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−4. Equivalent Input Circuit of the Window Comparators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−5. Histogram of 8000 Conversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−6. Typical Transfer Function of a Sign Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−7. Position Sensor Comparator Overdrive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−8. Current Sign Comparator Overdrive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−9. Typical Transfer Function of a Window Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−10. VECANA Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−11. One SPI Transfer Cycle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−12. Continuous SPI Transfer Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−13. SPI Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−14. Mode 10 Read Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−15. Mode 10 Write Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−16. Mode 11 Read Access (Standard Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−17. Mode 11 Write Access (Standard Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−18. Mode 11 Read Access (TMS320c54xx mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−19. Mode 11 Write Access (TMS320c54xx mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−20. FIFO Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−21. FIFO Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−22. Timing of the DAV Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−23. Block Diagram of a Counter Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−24. Digital Noise Filter Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−25. Timing Diagram of the Counter Signals with the Digital Noise Filter Enabled . . . . . . . . . . . . . . . . . . . . . .
1−26. Timing Diagram of the Counter Signals with the Digital Noise Filter Disabled . . . . . . . . . . . . . . . . . . . . . .
1−27. Detail Counter Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−28. Detail Counter Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−29. Timing Diagram of the Reset Signal RST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
15
16
17
19
19
20
20
21
26
27
28
29
31
32
33
34
35
36
49
50
51
52
53
54
55
56
57
58
vii
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
List of Tables
1−1. Selection of Interface Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−2. Mode vs Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−3. DAC Input/Output Relationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−4. VECANA Gain Select Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−5. 13-bit VECANA ADIN Word Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−6. Controls for Input Multiplexers and Sample Holds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−7. Window Comparator Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−8. SPI Write 24-bit Word Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−9. Host Parallel Port Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−10. Register Map Write 16-bit Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−11. Register Map Read 16-bit Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−12. FIFO Output Word Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−13. Offset Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−14. Gain Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−15. WINDAC Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−16. Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−17. Counter/Control Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−18. Synchronous Latched Edge Count Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−19. Asynchronous Latched Edge Count Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−20. Edge Period Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−21. Edge Time Period Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−22. FIFO Test Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−23. Comparator Test Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−24. Interrupt Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−25. Parallel Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−26. Reset Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1−27. FIFO 16-bit Data Read Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
viii
23
23
24
24
25
25
27
27
30
37
38
39
40
40
40
41
42
43
43
43
44
44
45
46
47
48
49
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
FEATURES
D Seven Simultaneously-Sampling Sample-and-Hold (S/H) Capacitors
D Fully Differential Inputs
D Flexible Digital Interface with Four Modes
− One Mode 100% Software-Compatible to VECANA01
− SPI and Two Parallel Modes
D Two Up—Down Counter Modules On-Chip
D 12-Bit System Gain Adjustment for Every Channel
D 12-Bit Accurate System Offset Adjustment for Every Channel
APPLICATIONS
D Motor Control
DESCRIPTION
The ADS7869 is a motor control front-end that includes three analog-to-digital converters (ADCs) with a total
of seven sample-and-hold capacitors and 12 fully differential input channels. There are four sign comparators
connected to four input channels. There are also three additional fully differential inputs; each input is
connected to a window comparator and a sign comparator.
In addition, the ADS7869 also offers a very flexible digital interface with a parallel port that can be configured
to different standards. Furthermore, a serial peripheral interface (SPI) and a specialized serial interface with
three data lines (VECANA01 mode) are provided. This allows the ADS7869 to interface with most digital signal
processors (DSPs) or microcontrollers. The chip is specialized for motor-control applications. For the position
sensor analysis, two up—down counters are added on the silicon. This feature ensures that the analog input
of the encoder is held at the same point of time as the counter value.
MUX1
SH1
ADC1
12−Bit
MUX2
SH2
ADC2
12−Bit
MUX3
SH3
ADC3
12−Bit
2.5V
Ref
Encoder
Counters
Flexible
Interface
Controllogic
DAC
8−Bit
4
3
1
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
1.1
ORDERING INFORMATION(1)
PRODUCT
MAXIMUM
INTEGRAL
LINEARITY
ERROR (LSB)
NO MISSING
CODES
ERROR (LSB)
±2
ADS7869I
PACKAGELEAD
11
PACKAGE
DESIGNATOR
TQFP-100
PZT
SPECIFIED
TEMPERATURE
RANGE
ORDERING
NUMBER
TRANSPORT
MEDIA,
QUANTITY
ADS7869IPZTT
Tape and Reel,
250
ADS7869IPZTR
Tape and Reel,
1000
−40°C to +85°C
(1) For the most current package and ordering information, see the Package Option Addendum located at the end of this data manual.
1.2
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted(1)
Supply voltage, AVDD to AGND
Supply voltage, BVDD to BGND
ADS7869I
UNIT
−0.3 to 6
V
−0.3 to 6
V
Analog input voltage with respect to AGND
AGND – 0.3 to AVDD + 0.3
V
Reference input voltage with respect to AGND
AGND – 0.3 to AVDD + 0.3
BGND – 0.3 to BVDD + 0.3
V
Digital input voltage with respect to BGND
Ground voltage difference AGND to BGND
± 0.3
V
Input current to any pin except supply
−10 to +10
mA
Operating virtual junction temperature range, TJ
−40 to +150
_C
Operating free-air temperature range, TA
−40 to +85
_C
Storage temperature range, TSTG
−65 to +150
_C
+260
_C
Lead temperature 1,6mm (1/16-inch) from case for 10 seconds
V
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only,
and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is
not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
1.3
RECOMMENDED OPERATING CONDITIONS
Supply Voltage, AGND to AVDD
Supply Voltage, BGND to BVDD
MAX
UNIT
5
5.5
V
2.7
3.6
V
5V Logic Levels
4.5
5
5.5
V
2.475
2.5
2.525
V
−REF_ADC
+REF_ADC
V
−40
+85
°C
+IN – (−IN)
Operating junction temperature range, TJ
1.4
NOM
4.5
Low-Voltage Levels
Reference Input Voltage
Analog Inputs (also see
Fully DIfferential Analog Inputs section)
MIN
PACKAGE DISSIPATION RATINGS
RQJA
DERATING FACTOR
ABOVE TA = 25°C
TA ≤ 25°C
POWER RATING
TA = 70°C
POWER RATING
TA = 85°C
POWER RATING
3.5_C/W
45_C/W
22.222mW/_C
2778mW
1778mW
1444mW
3.5_C/W
2.82_C/W
35.461mW/_C
4433mW
2837mW
2305mW
BOARD
PACKAGE
RQJC
Low-K(1)
High-K(2)
PZT
PZT
(1) The JEDEC Low-K (1s) board design used to derive this data was a 3-inch x 3-inch, two-layer board with 2-ounce copper traces on top of
the board.
(2) The JEDEC High-K (2s2p) board design used to derive this data was a 3-inch x 3-inch, multilayer board with 1-ounce internal power and
ground planes and 2-ounce copper traces on the top and bottom of the board.
2
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
1.5
ELECTRICAL CHARACTERISTICS
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3.3V, VREF = internal +2.5V, fCLK = 16MHz,
fSAMPLE = 1 MSPS, unless otherwise noted.
ADS7869I
PARAMETER
CONDITION
Resolution
MIN
TYP(1)
MAX
12
UNIT
Bit
Analog Input
Full-scale Voltage, Differential
Input Capacitance
Input Leakage Current
CMRR
See Gain Adjustment
−REF_ADC
At DC
DC Accuracy
No Missing Codes
INL Integral Linearity Error
DNL Differential Linearity Error
VOS Bipolar Offset Error
VOS Bipolar Offset Error
VOS Bipolar Offset Match
VOS Bipolar Offset Match
VOS Bipolar Offset Match
TCVOS Bipolar Offset Error Drift
Gain Error
Gain Error
Gain Error Drift
PSRR Power-Supply Rejection Ratio
+REF_ADC
10
±1
64
11
±1
±0.65
2
5
2.5
0.5
0.5
1
0.05
1.5
3
70
Synchronous Channels
AX and BX Channels
IU, IV, and IW Channels
A1, B1, A2, and B2 Channels
AX and BX Channels
Max Input Range, Related to REFIN
Every Other Input Range
Max Input Range, Related to REFIN
4.5V < AVDD < 5.5V
±2.5
±2
±6
±8
6
3
3
1
4
V
pF
nA
dB
Bit
LSB
LSB
LSB
LSB
LSB
LSB
LSB
µV/°C
%
%
ppm/°C
dB
Sampling Dynamics
16MHz ≤ fCLK ≤ 1MHz
tCONV Conversion Time per ADC
tAQ Acquisition Time
Throughput Rate
Aperture Delay
Aperture Delay Matching
Aperture Jitter
Clock Frequency
AC Accuracy
Total Harmonic Distortion
Signal-to-Noise Distortion
Signal-to-Noise + Distortion
Digital Inputs(2)
0.75
250
12
1000
20
1
50
1
THD
SNR
SINAD
Logic Family
VIH High-Level Input Voltage
VIL Low-Level Input Voltage
IIN Input Current
CI Input Capacitance
Digital Outputs(2)
Logic Family
VOH High-Level Output Voltage
VOL Low-Level Output Voltage
IOZ High-Impedance-State Output Current
CO Output Capacitance
CL Load Capacitance
VIN = ±2.5VPP at 10kHz
VIN = ±2.5VPP at 10kHz
VIN = ±2.5VPP at 10kHz
16
−78
71
70
µS
ns
kSPS
ns
ns
ps
MHz
dB
dB
dB
CMOS
0.7SVDD
−0.3
BVDD + 0.3
0.3SVDD
±50
BVDD to BGND
5
V
V
nA
pF
CMOS
BVDD = 4.5V, IOH = −100µA
BVDD = 4.5V, IOL = +100µA
VI = BVDD to BGND
4.44
0.5
±50
5
30
V
V
nA
pF
pF
(1) All values are at TA = +25_C.
(2) Applies for 5.0V nominal supply: 4.5V < BVDD < 5.5V.
(3) Applies for 3.0V nominal supply: 2.7V < BVDD < 3.6V.
3
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
1.5
ELECTRICAL CHARACTERISTICS (continued)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3.3V, VREF = internal +2.5V, fCLK = 16MHz,
fSAMPLE = 1 MSPS, unless otherwise noted.
ADS7869I
PARAMETER
Digital Inputs(3)
Logic Family
VIH High-Level Input Voltage
VIL Low-Level Input Voltage
IIN Input Current
CI Input Capacitance
Digital Outputs(3)
Logic Family
VOH High-Level Output Voltage
VOL Low-Level Output Voltage
IOZ High-Impedance-State Output Current
CO Output Capacitance
CL Load Capacitance
CONDITION
MIN
BVDD = 3.6V
BVDD = 2.7V
VI = BVDD to BGND
2
−0.3
MAX
UNIT
BVDD + 0.3
0.8
±50
V
V
nA
pF
LVCMOS
5
LVCMOS
BVDD = 2.7V, IOH = −100µA
BVDD = 2.7V, IOL = +100µA
VI = BVDD to BGND
BVDD − 0.2
0.2
±50
5
30
Power Supply
AVDD Analog Supply Voltage
BVDD Buffer I/O Supply Voltage
AIDD Analog Supply Current
BIDD Buffer I/O Supply Voltage
Power Dissipation
Reference Output
VREF Reference Output Voltage
VREF Reference Output Voltage
dVREF/dT Reference Voltage Drift
PSRR Power-Supply Rejection Ratio
IOUT Output Current
ISC Short-Circuit Current
tON Turn-On Setting Time
TYP(1)
4.5
2.7
45
2
5.5
5.5
50
250
−40°C > t > +85°C
at 25°C
2.475
2.480
2.500
2.500
±20
60
DC Current
2.525
2.520
1
1
100
Reference Input
VIN Reference Input Voltage
Input Resistance
Input Capacitance
2.475
2.5
100
5
2.525
V
V
nA
pF
pF
V
V
mA
mA
mW
V
V
ppm/°C
dB
µA
mA
µs
V
MΩ
pF
Digital-to-Analog Converter
Resolution
Output Range
INL Integral Linearity Error
DNL Differential Linearity Error
Offset Error
Full-Scale Error
IOUT Output Current
Output Settling Time
Position Sensor Sign Comparator
Input Range
Offset Range
Hysteresis
Delay Time
IOUT = 0
0.2
2.49
±1
±2
1
±1
0.5
1
Bits
V
LSB
LSB
LSB
%
µA
µs
±5
75
25
AVDD − 1.8
±30
100
150
V
mV
mV
ns
0.5
FS = Internal Reference Voltage − 1LSB
to 0.5LSB, no load capacitance
Lower Voltage of Differential Inputs
(1) All values are at TA = +25_C.
(2) Applies for 5.0V nominal supply: 4.5V < BVDD < 5.5V.
(3) Applies for 3.0V nominal supply: 2.7V < BVDD < 3.6V.
4
8
0
0
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
1.5
ELECTRICAL CHARACTERISTICS (continued)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3.3V, VREF = internal +2.5V, fCLK = 16MHz,
fSAMPLE = 1 MSPS, unless otherwise noted.
ADS7869I
PARAMETER
Current Sign Comparator
Input Range
Offset Range
Hysteresis
Delay Time
Window Comparator
Input Range
Offset Range
Hysteresis
Delay Time
Threshold Voltage Input Range
CONDITION
MIN
Lower Voltage of Differential Inputs
0
TYP(1)
MAX
UNIT
±2
10
25
AVDD − 1.8
±20
30
150
V
mV
mV
ns
AVDD + 0.3
±30
80
375
2.5
V
mV
mV
ns
V
−0.3
60
fCLK = 16MHz
(DAIN pin)
0.5
±10
70
250
(1) All values are at TA = +25_C.
(2) Applies for 5.0V nominal supply: 4.5V < BVDD < 5.5V.
(3) Applies for 3.0V nominal supply: 2.7V < BVDD < 3.6V.
5
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
1.6
PINOUT DRAWING
BGND
CLK
BVD D
RST
M1
M0
AGND
DAV
NC
AVD D
HOLD2
HOLD1
CNTB1
A2
CNTA1
A1
NC
NC
NC
AGND
REFOUT
REFIN
AVD D
A2n
A2p
TQFP Package
100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76
A1n
1
75 DATA0
A1p
2
74 DATA1
IUn
3
73 DATA2
IUp
4
72 DATA3
AGND
5
71 DATA4
AXn
6
70 DATA5
AXp
7
69 DATA6
AVD D
8
68 DATA7
AN3n
9
67 DATA8
AN3p 10
66 DATA9
AN2n 11
65 DATA10
AN2p 12
64 DATA11
ADS7869
SGND 13
63 DATA12
AN1n 14
62 DATA13
AN1p 15
61 DATA14
IWn 16
60 DATA15
IWp 17
59 RD
AVD D 18
58 WR
BXp 19
57 CS
BXn 20
56 ADDR0
AGND 21
55 ADDR1
IVp 22
54 ADDR2
IVn 23
53 ADDR3
B1p 24
52 ADDR4
B1n 25
51 ADDR5
6
BGND
INT
BVDD
W_ILIM
V_ILIM
U_ILIM
V_COMP
W_COMP
U_COMP
CNTB2
B2
CNTA2
B1
AGND
W_Cn
V_Cn
W_Cp
V_Cp
U_Cn
DAIN
U_Cp
DAOUT
AVDD
B2n
B2p
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
1.7
PIN FUNCTIONS
TQFP Package
SIGNAL
PIN NUMBER
TYPE
DESCRIPTION
ANALOG SIGNALS
Analog Input Signals of Position Sensors
A1p
2
Analog In
Position Sensor 1, Analog Input of SIN, Positive Input
A1n
1
Analog In
Position Sensor 1, Analog Input of SIN, Negative Input
B1p
24
Analog In
Position Sensor 1, Analog Input of COS, Positive Input
B1n
25
Analog In
Position Sensor 1, Analog Input of COS, Negative Input
AXp
7
Analog In
Position Sensor x, Asynchronous Analog Input of SIN, Positive Input
AXn
6
Analog In
Position Sensor x, Asynchronous Analog Input of SIN, Negative Input
A2p
100
Analog In
Position Sensor 2, Analog Input of SIN, Positive Input
A2n
99
Analog In
Position Sensor 2, Analog Input of SIN, Negative Input
B2p
26
Analog In
Position Sensor 2, Analog Input of COS, Positive Input
B2n
27
Analog In
Position Sensor 2, Analog Input of COS, Negative Input
BXp
19
Analog In
Position Sensor X, Asynchronous Analog Input of COS, Positive Input
BXn
20
Analog In
Position Sensor X, Asynchronous Analog Input of COS, Negative Input
A1
91
Digital Out
Sign of SIN Signal, Position Sensor 1
B1
38
Digital Out
Sign of COS Signal, Position Sensor 1
A2
89
Digital Out
Sign of SIN Signal, Position Sensor 2
B2
40
Digital Out
Sign of COS Signal, Position Sensor 2
CNTA1
90
Digital In
Input Signal SIN to 16-bit Up/Down Counter 1
CNTB1
88
Digital In
Input Signal COS to 16-bit Up/Down Counter 1
CNTA2
39
Digital In
Input Signal SIN to 16-bit Up/Down Counter 2
CNTB2
41
Digital In
Input Signal COS to 16-bit Up/Down Counter 2
Counter Signals of Position Sensors
Analog Input Signals of Phase Currents
IUp
4
Analog In
Phase U Current, Positive Input
IUn
3
Analog In
Phase U Current, Negative Input
IVp
22
Analog In
Phase V Current, Positive Input
IVn
23
Analog In
Phase V Current, Negative Input
IWp
17
Analog In
Phase W Current, Positive Input
IWn
16
Analog In
Phase W Current, Negative Input
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TQFP Package
SIGNAL
PIN NUMBER
TYPE
DESCRIPTION
Comparator Signals of Phase Currents
DAOUT
29
Analog Out
DAIN
30
Analog In
8-Bit DAC Output for Over-Current Limit Value
Over-Current Limit Value as Input for Window Comparators
U_Cp
31
Analog In
Phase U Current Signal Input for Sign and Window Comparator, Positive Input
U_Cn
32
Analog In
Phase U Current Signal Input for Sign and Window Comparator, Negative Input
V_Cp
33
Analog In
Phase V Current Signal Input for Sign and Window Comparator, Positive Input
V_Cn
34
Analog In
Phase V Current Signal Input for Sign and Window Comparator, Negative Input
W_Cp
35
Analog In
Phase W Current Signal Input for Sign and Window Comparator, Positive Input
W_Cn
36
Analog In
Phase W Current Signal Input for Sign and Window Comparator, Negative Input
U_COMP
42
Digital Out
Sign of Phase U Current
V_COMP
43
Digital Out
Sign of Phase V Current
W_COMP
44
Digital Out
Sign of Phase W Current
U_ILIM
45
Digital Out
Over-current Output of Phase U, Active Low Output
V_ILIM
46
Digital Out
Over-current Output of Phase V, Active Low Output
W_ILIM
47
Digital Out
Over-current Output of Phase W, Active Low Output
Other Analog Signals
AN(x)p
15, 12, 10
Analog In
Auxiliary Analog Input Channel (x), Positive Input
AN(x)n
14, 11, 9
Analog In
Auxiliary Analog Input Channel (x), Negative Input
REFIN
97
Analog In
Reference Voltage Input Pin
96
Analog Out
84, 92, 93, 94
—
REFOUT
NC
Reference Voltage Output Pin
No connection (should be left open)
DIGITAL INTERFACE SIGNALS
Address Decode Input(1)
ADDR(x)
56 – 51
Digital In
DATA(xx)
75 – 60
Digital In/Out
CS
57
Digital In
RD
59
Digital In
WR
58
Digital In
Active Low Read Signal(1)
Active Low Write Signal(1)
CLK
77
Digital In
System Clock
INT
49
Digital Out
RST
79
Digital In
M(x)
81, 80
Digital In
DAV
83
Digital Out
HOLD1
87
Digital In
Active Low Convert Start and Synchronous Hold Signal for Sample-and-Hold
Amplifiers
HOLD2
86
Digital In
Active Low Asynchronous Hold Signal for Sample-and-Hold Amplifiers
AVDD
BVDD
8, 18, 28, 85, 98
Power
Analog Power Supply
48, 78
Power
Interface Power Supply
AGND
5, 21, 37, 82, 95
BGND
50, 76
SGND
13
Bidirectional 3-state Data Bus(1)
Active Low Chip-Select Signal(1)
Active High Interrupt Output
Active Low Reset Input
Mode Select Pins(1)
Data Available Signal
POWER SUPPLY
Analog Ground
Interface Ground
Signal Ground
(1) See Digital section for detailed information about the different modes.
8
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Asynchronous Reset
Mode Select
+5V Analog Supply
+5V Analog Supply
Enco der
Counter1
Inputs
Asynchronous Hold
BASIC CIRCUIT CONFIGURATION
C onvert Start
1.8
+2.7V to +5.5V
D igita l Supply
10 µ F
+
10 µ F
+
0.1 µ F
0.1 µ F
0.1 µ F
0.1 µ F
System C lock
C LK
BGND
BV DD
RST
M1
M0
AGND
DAV
AV DD
H OLD2
CN TB1
H OLD1
A2
A1
CN TA1
AGND
REFOU T
AV DD
R EFIN
A1 p/n
A2 p/n
Data Available
IU p/n
AGN D
+5V
Analog Supply
AXp/n
AV DD
0.1 µ F
AN 3p/n
DATA
AN 2p/n
A DS7869
SGN D
AN 1p/n
+5V
Analog Supply
RD
Read
WR
Write
CS
IW p/n
Data Bus
AD DR
Chip Sele ct
Address Bus
AV DD
BXp/n
BGN D
IN T
BV DD
W _ILIM
V_ILIM
U _ILIM
W _C OMP
V_COM P
U _C OM P
C NTB2
B2
C NTA2
B1
AGN D
W _C p/n
V_Cp/n
U _C p/n
D AIN
B1 p/n
AV DD
IVp/n
D AOUT
AGN D
B2p/n
0.1 µ F
Comparator Outputs
1 0µ F
+
0.1 µ F
+5V
Analog Su pply
0.1 µ F
3 Differential
Inpu ts to
Com parators
0.1 µ F
Interrupt
Encoder
Counter2
Inputs
+2.7V to +5.5V
Digital Supply
9
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1.9
TYPICAL APPLICATION CIRCUIT
DC Link
Voltage
DC Link Voltage Sensor
R
S
T
IGBTs
Current Sensor IU
Current Sensor IV
Current Sensor IW
3·2
OPA354
UC
OPA364
AN1
VC
OPA364
AC Motor
Analog
Input
IU
WC
Sign and
Over−Current
Comparators
IV
3 ADCs
7 S&H
12 Channels
IW
A1/B1
OPA364
2
·2
Positioning
Sensor1
at Motor
8−Bit DAC
OPA364
AN2
2.5V
Reference
Counters
Flexible
Interface
A2/B2
OPA364
2
OPA364
AN3
ADS7869
AX/BX
OPA364
·2
Load with
Positioning
Sensor2
Figure 1−1. Typical Motor Control Application
Figure 1−1 shows an example of a typical motor control circuit. The IU, IV and IW channels measure the
currents of the motor. The position (speed) of the motor and load are measured simultaneously by A1, B1 and
A2, B2, respectively, using resolver or analog encoder sensors. The asynchronous inputs AX and BX can be
used to capture the reference signal of encoders to derive the absolute position. Channel AN1 measures the
differential DC link voltage. AN3 measures the temperature of the motor. An auxiliary voltage can be measured
with channel AN2. The counter inputs connect to the appropriate comparator outputs (A1 to CNTA1, B1 to
CNTB1 and so on). The level input of the window comparators, DAIN, should be connected to the 8-bit DAC
output DAOUT.
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1.10 TYPICAL CHARACTERISTICS
At TA = +25_C, AVDD = 5V, BVDD = 3.3V, VREF = internal +2.5V, fCLK = 16MHz, fSAMPLE = 1 MSPS, unless otherwise noted.
REFERENCE VOLTAGE vs TEMPERATURE
ANALOG SUPPLY CURRENT vs TEMPERATURE
2.500
50
2.498
Voltage (V)
Current (mA)
48
46
44
2.494
2.492
42
40
2.496
2.490
−40
25
85
−40
25
85
Temperature (_C)
Temperature (_C)
ADC OFFSET MATCH
vs TEMPERATURE FOR ALL CHANNELS
ADC OFFSET ERROR vs TEMPERATURE
3.0
6.0
Offset Match (LSB)
Offset Error (LSB)
2.8
2.6
2.4
5.0
4.5
2.2
2.0
5.5
−40
4.0
25
85
−40
Temperature (_C)
85
ADC GAIN ERROR AT 5V/V GAIN
vs TEMPERATURE
0.07
4
0.06
3
Gain Error (%)
Gain Error (%)
ADC GAIN ERROR AT 1V/V GAIN
vs TEMPERATURE
0.05
0.04
0.03
25
Temperature (_C)
2
1
−40
25
Temperature (_C)
85
0
−40
25
85
Temperature (_C)
11
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TYPICAL CHARACTERISTICS (Continued)
At TA = +25_C, AVDD = 5V, BVDD = 3.3V, VREF = internal +2.5V, fCLK = 16MHz, fSAMPLE = 1 MSPS, unless otherwise noted.
ADC DIFFERENTIAL LINEARITY
vs TEMPERATURE
ADC DIFFERENTIAL LINEARITY ERROR
vs CODE
1.0
1.0
Max
0.5
DNL (LSB)
DNL (LSB)
0.5
0
−0.5
0
−0.5
Min
−1.0
−40
25
−1.0
85
0
1024
Temperature (_C)
2048
3072
4095
Code
ADC INTEGRAL LINEARITY ERROR
vs TEMPERATURE
ADC INTEGRAL LINEARITY ERROR
vs CODE
2
2
Max
1
0
INL (LSB)
INL (LSB)
1
−1
Min
−2
0
−1
−2
−3
−40
25
−3
85
0
Temperature (_C)
1024
2048
3072
4095
Code
CHANGE IN OFFSET ERROR
vs OFFSET ADJUSTMENT
GAIN ERROR vs GAIN ADJUSTMENT
4
2.0
1.5
1.0
Offset Error (mV)
Gain Error (%)
3
2
1
0.5
0
−0.5
−1.0
0
−1.5
1
4095
2997
1899
Code
12
801
−2.0
−511
0
Code
511
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TYPICAL CHARACTERISTICS (Continued)
At TA = +25_C, AVDD = 5V, BVDD = 3.3V, VREF = internal +2.5V, fCLK = 16MHz, fSAMPLE = 1 MSPS, unless otherwise noted.
DAC GAIN ERROR vs TEMPERATURE
0
0.8
−0.05
−0.10
Gain Error (%)
Offset Error (LSB)
DAC OFFSET ERROR vs TEMPERATURE
1.0
0.6
0.4
−0.15
−0.20
0.2
0
−0.25
−0.30
−40
25
85
− 40
25
85
Temperature (_ C)
Temperature (_C)
DAC DIFFERENTIAL LINEARITY ERROR
vs TEMPERATURE
DAC DIFFERENTIAL LINEARITY ERROR
vs CODE
0.6
0.3
0.4
0.2
DNL (LSB)
DNL (LSB)
Max
0.2
0
0.1
0
−0.1
−0.2
Min
−0.2
−0.4
−0.3
−0.6
−40
25
0
85
51
102
204
255
DAC INTEGRAL LINEARITY ERROR
vs CODE
DAC INTEGRAL LINEARITY ERROR
vs TEMPERATURE
0.6
0.4
0.3
0.2
Max
INL (LSB)
INL (LSB)
153
Code
Temperature (_ C)
0
0
−0.2
−0.3
Min
−0.6
−40
−0.4
25
Temperature (_C)
85
0
51
102
153
204
255
Code
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TYPICAL CHARACTERISTICS (Continued)
At TA = +25_C, AVDD = 5V, BVDD = 3.3V, VREF = internal +2.5V, fCLK = 16MHz, fSAMPLE = 1 MSPS, unless otherwise noted.
ENCODER COMPARATOR OFFSET
vs TEMPERATURE
75
5
73
4
Offset (mV)
Hysteresis (mV)
ENCODER COMPARATOR HYSTERESIS
vs TEMPERATURE
72
69
3
2
67
65
1
−40
25
0
85
−40
25
Temperature (_C)
SIGN COMPARATOR OFFSET
vs TEMPERATURE
SIGN COMPARATOR HYSTERESIS
vs TEMPERATURE
3.0
11.0
2.5
Offset (mV)
Hysteresis (mV)
10.8
10.6
10.4
2.0
1.5
1.0
10.2
10.0
0.5
0
−40
25
85
−40
25
85
Temperature (_C)
Temperature (_ C)
WINDOW COMPARATOR HYSTERESIS
vs TEMPERATURE
WINDOW COMPARATOR OFFSET
vs TEMPERATURE
74
−7
72
−8
DAIN 0.5V
Offset (mV)
Hysteresis (mV)
85
Temperature (_C)
DAIN 2.4V
70
68
DAIN 0.5V
−9
−10
DAIN 2.4V
66
−40
25
Temperature (_C)
14
85
−11
−40
25
Temperature (_C)
85
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1.11
FUNCTIONAL BLOCK DIAGRAM
IUp
IUn
Offset
A1p
A1n
A2p
A2n
Gain
SH 1
DAC 1
12−Bit
RAM
DAC 2
12−Bit
FIFO
MUX 1
ADC 1
12−Bit
SH 2
ADDR <0.5>
Input
Select
MUX 4
Axp
Axn
SH 6
C onv
IVp
IVn
Offset
B1p
B1n
B2p
B2n
Gain
SH 3
DAC 3
12−Bit
DAC 4
12−Bit
MUX 2
D ATA<0.15>
ADC 2
12−Bit
SH 4
MUX 5
Bxp
Bxn
SH 7
C LK
C onv
R ST
Offset
Gain
IWp
IWn
AN 1p
AN 1n
AN 2p
AN 2n
AN 3p
AN 3n
DAC 5
12−Bit
DAC 6
12−Bit
INT
SH 5
ADC 3
12−Bit
D AV
MUX 3
C onv
REFOUT
Control
Logic
Internal
2.5V
Reference
H OLD1
H OLD2
Conv
Up/D own Counter 1
16−Bit
R EFIN
Ref
Up/D own Counter 2
16−Bit
D AOUT
DAC 7
8−Bit
CS
RD
WR
M1
M0
C NTA2
C NTB2
C NTA1
C NTB1
U_Cp
U _COMP
U_Cn
A1
A2
V_Cp
V_COMP
V_Cn
B1
B2
W_Cp
W_COMP
W_Cn
U _ILIM
V_ILIM
W_ILIM
D AIN
Figure 1−2. Functional Diagram
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2
Analog Section
The analog section addresses the Analog-to-Digital Converters, including the gain and offset adjustment.
There is also a discussion of the analog inputs, the seven sign comparators, three window comparators, the
8-bit Digital-to-Analog Converter (DAC), the reference voltage, grounding, and the supply voltage.
2.1
2.1.1
Fully Differential Analog Inputs
Analog-to-Digital Converter Inputs
The 12 inputs to the ADCs, as well as the three inputs (U_C, V_C and W_C) to the comparators, are fully
differential and provide a good common-mode rejection of 60dB at 50kHz. This is very important to suppress
noise in difficult environments.
The seven sample-and-hold circuits from the ADC contain a 5pF capacitor (Cs in Figure 1−3) that is connected
via a switch to the analog inputs. Opening the switch holds the data. The switch closes when the conversion
is finished. The capacitor is then loaded to an initial voltage that is equal to the reference at the ADC, which
is selected with the gain adjustment.
The voltage of the input pin is usually different from the voltage of the sample capacitor when the input switch
closes. The sample capacitor needs to be recharged to the 12-bit accuracy, one-half of a least significant bit
(LSB), within an acquisition time (tAQ) of at least 200ns.
The minimum −3dB bandwidth of the driving operational amplifier can be calculated to:
ln(2) @ (n ) 1)
2p @ t AQ
f 3db +
(1)
where n is equal to 12, the resolution of the ADC (in the case of the ADS7869). When tAQ = 200ns, the minimum
bandwidth of the driving amplifier is 7MHz. The bandwidth can be relaxed if the acquisition time is increased
by the application.
The OPA364 from Texas Instruments is recommended; besides the necessary bandwidth, it provides a low
offset in a small package at a low price.
The phase margin of the driving operational amplifier is usually reduced by the sampling capacitor of the ADC.
A resistor between the capacitor and the amplifier reduces this effect; therefore, an internal 300Ω resistor
(RSER) is in series with the switch. The resistance of the closed switch (RSW) is approximately 80Ω. See
Figure 1−3.
RSER
300Ω
RSW
80Ω
IN+
CPAR
5pF
CS
5pF
CPAR
5pF
CS
5pF
IN−
RSER
300Ω
RSW
80Ω
Figure 1−3. Equivalent Input Circuit to the ADCs
The differential input range (positive minus negative input) of the ADC is ±REF_ADC, the reference of the
converter, which is selected with the gain adjustment.
It is important that the voltage to all inputs does not exceed more than 0.3V above the analog supply or 0.3V
below the ground. There is no DC current flow through the inputs. Current is only necessary when recharging
the sample-and-hold capacitors, CS.
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2.1.2
Window Comparator Inputs
A sampling architecture was selected for the window comparators. The sampling time is two clock cycles with
a minimum tAQ (see Equation 1) of 125ns. The necessary accuracy is 10mV (see 8-bit DAC section) with a
5V input range. The required bandwidth of the driving amplifier is 8.8MHz (see Equation 1). The OPAx354
from Texas Instruments is recommended.
The input circuit of the window comparator is similar to the ADC inputs. The only difference is that the sampling
capacitors are reduced to 2.5pF. (See Figure 1−4.)
RSER
300Ω
RSW
80Ω
IN+
CPAR
5pF
CS
2.5pF
CPAR
5pF
CS
2.5pF
IN−
RSER
300Ω
RSW
80Ω
Figure 1−4. Equivalent Input Circuit of the Window Comparators
2.1.3
Sign Comparator Inputs
Four sign comparators are connected to the ADC inputs (A1, B1, A2 and B2); three of the sign comparators
are wired to the window comparator inputs (U_C, V_C, and W_C).
The sample capacitors of the ADCs and the window comparators could produce voltage glitches; therefore,
it is important to drive the inputs with low impedance.
The lower voltage of the differential input should remain within the range of 0 to AVDD−1.8V.
2.2
Analog-To-Digital Converter
The ADS7869 includes three, SAR-type, 1MSPS, 12-bit ADCs, and three pairs of S/H capacitors, which are
each connected to ADC1 and ADC2. A single S/H capacitor is connected to ADC3. Gain and offset adjustments
are added to each ADC. (See Figure 1−2 on page 15.)
2.2.1
HOLD1, HOLD2
The analog inputs are held when the HOLDx signals go low. The charges of the synchronous
sample-and-holds (S/H1−5) are frozen on the falling edge of HOLD1. The setup time of HOLD1, against the
rising edge of the system clock, is typically 25ns. The conversion will automatically start on the next rising edge
of the clock. The S/Hs are switched back into the sample mode when the conversion is finished, 12 clock
cycles later. This point of time is indicated by DAV. (See Figure 1−10 on page 26.) HOLD1 must go high at
the latest at the 13th falling clock after conversion start.
The asynchronous sample and holds (S/H6−7) are triggered by the active low HOLD2 signal. The setup time
of HOLD2, against the falling edge of HOLD1, is 0ns; see Figure 1−10. The conversion of these S/H circuits
is initiated when they are selected through the digital interface and the HOLD1 signal goes low. The inputs
are connected back to the S/H capacitor when the HOLD2 signal goes high. HOLD2 needs to be low during
the whole conversion. It is possible to connect HOLD1 and HOLD2 together.
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2.2.2
Clock
The ADC uses the external clock CLK, which needs to be in the range of 1MHz to 16MHz. 12 clock cycles
are necessary for a conversion, with a minimum of four clock cycles for the acquisition. Therefore, the
maximum throughput rate of 1MSPS is achieved with a 16MHz clock and 16 clock cycles per complete
conversion cycle. The duty cycle should be 50%; however, the ADS7869 will still function properly with a duty
cycle between 30% and 70%.
2.2.3
Reset
A reset condition stops any ongoing conversion and reconnects the synchronous S/Hs to the inputs; see the
Reset Section.
2.2.4
Gain Adjustment
The output of a 12-bit DAC (REF_ADC) is used as the reference voltage for the ADC. There is one DAC for
each ADC. The voltage range is between 0V (code 000H) and the 2.5V of REFIN (code FFFH). The ADC
operates correctly if the selected voltage is in the range of 0.5V to 2.5V. The output voltage of the DAC sets
the differential input range of the ADC, which is ±REF_ADC. The desired input range can be adjusted in
1.22mV steps.
In the VECANA mode, the gain information contained in the digital input word ADIN automatically sets the
DAC value. See the Vecana Interface section for further information.
In all other modes, there is a register for every input channel inside the digital interface, which stores the gain
information for any given channel. When a particular channel is selected by the application, the value of this
register is automatically written to the DAC and the DAC output is adjusted to the desired value. The DAC
settles to this value within 250ns (equivalent to the minimum acquisition time).
The gain information inside the registers is set to zero when a reset condition occurs. These registers need
to be set to the selected value before the ADCs are used.
In VECANA mode, the DAC is initially set to Full-Scale and the differential input range is equal to ±(voltage
at the REFIN pin).
2.2.5
Offset Adjustment
The offset can be adjusted, similar to the gain, to a 12-bit level with respect to the actual input voltage range
of the ADC. For example, if the input range is ±1V, the offset can be adjusted in increments of 488µV. The
maximum adjustment is ±12.5% of the input range.
There is a register inside the digital interface for each input channel. This registers store the offset adjustment
value for each channel. When a channel is selected for conversion, the offset is automatically adjusted. The
selected channel and the related register information must not be changed during the conversion.
Setting the register to 201H results in a –12.5% adjustment, 000H results in no adjustment, and 1FFH results
in a +12.5% adjustment. The offset adjustment value 200H is not allowed.
The offset adjustment cannot be used in VECANA mode. A reset condition will set the offset adjustment to
zero.
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2.2.6
Transition Noise
The transition noise of the ADS7869 itself is low, as shown in Figure 1−5. Applying a low-noise DC input and
initiating 8000 conversions generated this histogram.
10000
7986
Number of Occurrences
8000
6000
4000
2000
0
13
3030
3031
1
0
3033
3034
0
3032
Code (decimal)
Figure 1−5. Histogram of 8000 Conversions
2.3
Sign Comparators
The ADS7869 includes two sets of sign comparators that differ in their hysteresis. The first set, which is used
for the position sensor inputs in motor control applications, is connected to the inputs A1, B1, A2, and B2. The
hysteresis of these comparators is typically 75mV. In motor control applications, these comparators are used
to measure the signs of the position sensor input signals.
The second set is in parallel to the window comparators at the U_C, V_C, and W_C pins. The hysteresis of
these components is typically 10mV. In motor control applications, these comparators are used to measure
the sign of the main currents.
The sign comparator switches from 0 to 1 if the differential input voltage is above +1/2 of the hysteresis. If the
output is 1, the sign comparator switches back to 0 if the differential input voltage is below −1/2 of the
hysteresis. See Figure 1−6.
+Half Hysteresis
0V
−Half Hysteresis
Comparator
Output
Figure 1−6. Typical Transfer Function of a Sign Comparator
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The input range of the comparators is limited. The lower voltage of the differential inputs should always be
within the range of 0 to AVDD−1.8V.
On every comparator, the output is delayed to the input voltage. This delay is dependent on the overdrive of
the comparator inputs. The overdrive is the input voltage (VIN) minus one-half of the hysteresis.
If the differential input voltage of the position sensor sign comparator is switching from –40mV to +40mV (step
function, 2.5mV overdrive), then the delay time of the output is typically 100ns. The delay is reduced to typically
25ns if the comparator is switching between –100mV and +100mV (72.5mV overdrive). For the delay times
as a function of step size with different overdrives, see Figure 1−7 and Figure 1−8.
100
Delay Time (ns)
80
60
40
20
0
2 .5
12 .5
2 2.5
3 2 .5
4 2.5
5 2 .5
62.5
72 .5
82.5
9 2 .5 10 2.5 112 .5
Overdrive (mV)
Figure 1−7. Position Sensor Comparator Overdrive
100
Delay Time (ns)
80
60
40
20
0
5
10
15
20
25
30
35
40
45
50
55
60
65
Overdrive (mV)
Figure 1−8. Current Sign Comparator Overdrive
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2.4
Window Comparators
The window comparators test if the input voltage is within a certain range; this range is ±(voltage applied to
DAIN, pin 30). If the differential input voltage remains within this range, then the output of the window
comparator is 1. If the voltage is outside this range, then the output is set to 0. The window comparator has
a hysteresis that is turned on when the output is 0. The comparator outputs switch back to 1 when the input
voltage is within in the range of ±(DAIN −60mV). (See Figure 1−9.) The voltage at DAIN needs to be in a range
of 0.5V to 2.5V.
The window comparator has a switched capacitor circuitry, similar to the ADC architecture, but different from
other window comparators. This design dramatically increases the accuracy; due to the additional accuracy,
a proper front-end of the input signal is required. (See the Window Comparator Inputs section.)
+DAIN
DAIN − 60mV
0V
− DAIN + 60mV
− DAIN
Comparator
Output
Figure 1−9. Typical Transfer Function of a Window Comparator
Two clock cycles are used to sample the inputs. The next two clock cycles are used to test the lower and the
upper voltage limit. Every four clock cycles (or every 250ns with a 16MHz clock) the output of the window
comparator is updated. In a worst-case scenario, it takes six clock cycles for the window comparator to detect
a current limit. The window comparators need a continuous clock to operate properly.
In motor control applications, the window comparators are used to monitor the main currents for failures.
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2.5
8-Bit Digital-to-Analog Converter
A voltage between 0.5V to 2.5V is required at DAIN (pin 30) to set the range of the window comparators; this
can be accomplished with the 8-bit DAC. The DAC value is programmed via the digital interface. Input code
00H corresponds to a DAC output voltage of 0V. The full-scale value (FFH) is at 2.49V (internal reference minus
1LSB).
The impedance of the output is typically 10kΩ; the output impedance is independent of the output voltage.
The DAC output is connected to DAOUT (pin 29). The settling time (ts) is dependent on the external
capacitance (Ce) on this pin, and can be calculated to:
t s + 10kW @ C e @ (n ) 1) @ ln(2)
(2)
In this equation, n is equal to 8, the resolution of the DAC. The output impedance also limits the output current.
This current should not exceed 0.5µA (0.5µAS10kΩ = 5mV).
DAOUT and DAIN can be shorted. A capacitor (typically 0.1µF) can be used to low-pass the DAC output;
however, this low-pass configuration is not required.
2.6
Internal Reference
The internal reference, REFOUT (pin 96), provides the 2.5V required for the reference input of the ADCs at
REFIN (pin 97). An internal buffer with a high impedance output drives the reference output pin. This internal
buffer is optimized to reject glitches at the reference pin. Any capacitor can be connected to the REFOUT pin
in able to reduce noise. It is recommended that a 0.1µF capacitor be connected between the REFOUT (pin
96) and the SGND (pin 13). The Signal ground, SGND, is used internally as a negative reference. The
reference voltage is considered a differential voltage between this ground and REFOUT.
Normally, the REFOUT and REFIN pins are both shorted. The internal reference provides an excellent
temperature drift, typically 20ppm, and an initial accuracy of 2.5V±20mV at 25°C. If this does not provide the
required accuracy for an application, then an external reference can be connected to the REFIN pin.
2.7
Grounding
Optimal test results were achieved with a solid ground plane: linearity, offset, and noise performance each
showed improvement. During PCB layout, care should be taken that the return currents do not cross any
sensitive areas or signals.
Digital signals that interface with the ADS7869 are referenced to the solid ground plane. ESD protection
diodes, inside the ADS7869, start conducting if the grounds are separated and the digital inputs go below
–0.3V; this includes short glitches. Current will flow through the substrate of the ADS7869 and will disturb the
analog performance.
2.8
Supply
The ADS7869 has two separate supplies, BVDD (pins 48 and 78) and AVDD (pins 8, 18, 28, 85 and 98).
BVDD is used as a digital pad supply only, and is in the range of 2.7V to 5.5V. This allows the ADS7869 to
interface with all state-of-the-art processors and controllers. BVDD should be filtered in order to limit the noise
energy from the external digital circuitry to the ADS7869. The current through BVDD is far below 5mA;
depending on the external load, a 10Ω to 100Ω resistor can be placed between the external digital circuitry
and the ADS7869. Bypass capacitors (two 0.1µF and one 10µF) should be placed between the two BVDD pins
and the ground plane.
AVDD supplies the internal circuitry, and can vary from 4.5 to 5.5V. It is not possible to use a passive filter
between the digital board supply of the application and the AVDD pins, because the supply current of the
ADS7869 is typically 45mA. In order to generate the analog supply voltage for the ADS7869 and the
necessary analog front-end, a linear regulator (7805 family) is recommended. Bypass capacitors of 0.1µF
should be placed between all AVDD pins and the ground plane. Bypass capacitors of 10µF should be placed
between two AVDD pins and the ground plane.
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3
Digital Section
3.1
Introduction
The ADS7869 can interface with a DSP or µC in four different ways. The M1 and M0 pins determine in which
mode the ADS7869 will communicate; see Table 1−1. It can be connected as a standard VECANA01
interface, as an SPI, or as two different parallel interfaces.
Table 1−1. Selection of Interface Mode
M1
0
0
1
1
M0
0
1
0
1
MODE
VECANA mode
SPI mode
Parallel 1
Parallel 2
As a function of the selected mode, some pins will have different assignment as shown in Table 1−2.
Table 1−2. Mode vs Pin Functions
Pin No.
80, 81 (M1, M0)
VECANA Mode(1)
00
SPI(1)
01
Parallel 1
10
Parallel 2
11
56
NC
NC
ADDR0 (LSB)
ADDR0 (LSB)
55
NC
NC
ADDR1
ADDR1
54
NC
NC
ADDR2
ADDR2
53
S1
NC
ADDR3
ADDR3
52
S0
NC
ADDR4
ADDR4
51
WINCLK
NC
ADDR5 (MSB)
ADDR5 (MSB)
75
NC
NC
DATA0 (LSB)
DATA0 (LSB)
74
NC
NC
DATA1
DATA1
73
NC
NC
DATA2
DATA2
72
NC
NC
DATA3
DATA3
71
NC
NC
DATA4
DATA4
ADOUT1(3)
ADOUT2(3)
NC
DATA5
DATA5
NC
DATA6
DATA6
ADOUT3(3)
ADIN(3)
SPISOMI
DATA7
DATA7
SPISIMO
DATA8
DATA8
70
ADOUT1
69
ADOUT2
68
ADOUT3
67
ADIN
66
NC
SPICLK
DATA9
DATA9
65
NC
NC
DATA10
DATA10
64
NC
NC
DATA11
DATA11
63
NC
NC
DATA12
DATA12
62
NC
NC
DATA13
DATA13
61
NC
NC
DATA14
DATA14
60
NC
NC
DATA15 (MSB)
DATA15 (MSB)
57
NC
SPISTE
CS
CS
59
NC
NC
R/W
RD / − (2)
WR / R/W (2)
58
NC
77
CLK
79
RST
49
NC
83
DAV
87
86
ADCLK(3)
NC
WE
CLK
CLK
CLK
RST
RST
RST
INT
INT
INT
DAV
DAV
DAV
HOLD1
ADBUSY(3)
ADCONV(3)
HOLD1
HOLD1
HOLD1
HOLD2
NPSH(3)
HOLD2
HOLD2
HOLD2
(1) NC means no connection. The NC pins in VECANA01 and SPI modes should be grounded with a pull-down resistor.
(2) For parallel mode 11 there is one sub-mode for compatibility with the TMS320c54xx DSP family; see Mode 11 Bus Access
(TMS320c54xx DSP family-compatible mode) section.
(3) Original VECANA01 pin names.
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3.2
VECANA Interface
The VECANA01 mode of the ADS7869 interface acts exactly like the original VECANA01 interface. This mode
was added to the ADS7869 for backward-compatibility purposes.
Sampling and conversion are controlled with the HOLD1 and CLK inputs. The ADS7869 is designed to
operate with an external clock supplied to the CLK input. This allows the conversion to be synchronous with
the system clock, thus reducing transient noise effects. The DAV signal indicates when a conversion is taking
place with a low-level pulse. The DAV signal is equivalent to the ADBUSY signal in the VECANA01.
The typical clock frequency for the specified accuracy is 16MHz. This results in a complete conversion cycle,
S/H acquisition and analog-to-digital (A/D) conversion of 1µs. It is possible to stop the clock after 14 clock
cycles and start it again when the next conversion starts (after HOLD1 goes low); see the WINCLK Selection
section.
When power is applied to the ADS7869, one conversion cycle is required for initialization before valid digital
data is transmitted on the second cycle. The first conversion after power is applied is performed with
indeterminate configuration values in the Input Setup Register. The second conversion uses those values to
perform proper conversions and to output valid digital data from each of the ADCs.
The setup word received by the ADS7869 is used for the next conversion cycle while the ADCs are converting
and transmitting their serial digital data for one conversion cycle. The 13-bit word is supplied to ADIN (pin 67),
and is stored in the buffered Input Setup Register.
Configuration parameters are:
•
DAC output voltage;
•
Programmable gain/input voltage range;
•
Input multiplexer; and
•
sample-and-hold selection.
The DAC Input portion of the ADIN word (bits DAC [7...0]) determines the value of the DAC output voltage;
see Table 1−5. The 8-bit DAC has 256 possible output steps from 0V to +2.490V. The value of 1LSB is 9.76mV
(see Table 1−3 for input/output relationships).
Table 1−3 to Table 1−6 show information regarding these parameters.
Table 1−3. DAC Input/Output Relationships
DAC Input Code
Analog Output
00H
01H
0000 0000B
0V
0000 0001B
+0.010V
...
...
...
...
...
...
FFH
1111 1111B
+2.490V
Table 1−4. VECANA Gain Select Information
24
Gain Select Bits
Gain Setting
Input Voltage Range
0H
1H
5.0V/V
±0.5V
2.5V/V
±1.0V
2H
3H
1.25V/V
±2.0V
1.0V/V
±2.5V
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The Gain Select portion (bits GAIN [1..0]) determines the programmable gain of the ADIN word; see
Table 1−5. The gain for all three ADCs is set by one gain input parameter. The gain values and allowable
full-scale inputs are shown in Table 1−4.
The gain setting and input voltage range for the channels AN1, AN2, and AN3 at ADC3 are always 1.0V/V
with respect to ±2.5V.
Table 1−5. 13-bit VECANA ADIN Word Format
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
DAC7
DAC6
DAC5
DAC4
DAC3
DAC2
DAC1
DAC0
GAIN1
GAIN0
IN2
IN1
IN0
3.2.1
Input Channel Selection
Table 1−6 shows the relationships between the value of the input select bits and the input channels that are
converted.
Table 1−6. Controls for Input Multiplexers and Sample Holds
INPUT SELECT, BITS 2−0
ANALOG SIGNAL CONNECTED TO ADCX
HEX CODE
BINARY CODE
ADC1
ADC2
ADC3
0H
1H
000
—
—
—
—
AN3
SH5
001
AX
SH6
BX
SH7
AN3
SH5
2H
010
A2
SH1
B2
SH3
AN2
SH5
3H
011
A2
SH2
B2
SH4
AN2
SH5
4H
100
A1
SH1
B1
SH3
AN1
SH5
5H
101
A1
SH1
B1
SH3
AN1
SH5
6H
110
A1
SH1
B1
SH3
AN1
SH5
7H
111
IU
SH1
IV
SH3
IW
SH5
Input Select = 0H
The synchronous sample-and-hold, SH5, samples AN3 (only), then ADC3 converts it on the signal HOLD1.
Input Select = 1H
AX is sampled by the asynchronous sample-and-hold, SH6, with the signal HOLD2; ADC1 converts it on the
signal HOLD1. BX is sampled by the asynchronous sample-and-hold, SH7, with the signal HOLD2; ADC2
converts it on the signal HOLD1. AN3 is sampled by the synchronous sample-and-hold, SH5, then ADC3
converts it on the signal HOLD1.
The signal HOLD2 must be low during the entire conversion. If HOLD2 is high before a conversion starts,
ADC1 and ADC2 will not convert.
Input Select = 2H
A2 is sampled by the synchronous sample-and-hold, SH1; ADC1 converts it on the signal HOLD1. B2 is
sampled by the synchronous sample-and-hold, SH3; ADC2 converts it on the signal HOLD1. AN2 is sampled
by the synchronous sample-and-hold, SH5; ADC3 converts it on the signal HOLD1.
Input Select = 3H
A2 is converted by ADC1 on the signal HOLD1. A2 is sampled on SH2 in a preceding conversion with Input
Select 4H, 5H, or 6H. B2 is converted by ADC2 on the signal HOLD1. B2 is sampled on SH4 in a preceding
conversion with Input Select 4H, 5H, or 6H. AN2 is sampled by the synchronous sample-and-hold, SH5; ADC3
converts it on the signal HOLD1.
Input Select = 4H, 5H and 6H
A1 is sampled by the synchronous sample-and-hold, SH1; ADC1 converts it on the signal HOLD1. B1 is
sampled by the synchronous sample-and-hold, SH3; ADC2 converts it on the signal HOLD1. AN1 is sampled
by the synchronous sample-and-hold, SH5; ADC3 converts it on the signal HOLD1. A2 is sampled by the
synchronous sample-and-hold, SH2, on the signal HOLD1. B2 is sampled by the synchronous
sample-and-hold, SH4, on the signal HOLD1.
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Input Select = 7H
IU is sampled by the synchronous sample-and-hold, SH1; ADC1 converts it on the signal HOLD1. IV is
sampled by the synchronous sample-and-hold, SH3; ADC2 converts it on the signal HOLD1. IW is sampled
by the synchronous sample-and-hold, SH5; ADC3 converts it on the signal HOLD1.
3.2.2
VECANA Timing Characteristics (1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
MIN
ADCLK Period
tC1
62.5
ns
ADCLK HIGH or LOW Time
tW1
20
ns
HOLD1 Signal Setup Time
tSU1
25
HOLD1 Signal Hold Time
tH1
20
HOLD2 Signal Setup Time
tSU2
0
HOLD2 Signal Hold Time
tH2
0
Delay Time from ADCLK Rising to DAV Falling Edge
tD1
15
ns
Output Data Delay Time
tD2
10
ns
Input Data Setup Time
tSU3
10
Input Data Hold Time
tH3
10
Delay Time from ADCLK Rising to DAV Rising Edge
tD3
Sampling Time
MAX
UNIT
ns
15 + 12.5tC1
ns
ns
ns
ns
ns
15
tSAMPLE
ns
4
tC1
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
t C1
CLK
1
2
3
4
12
13
14
1
2
t W1
HO LD1
t SU1
t SAMPLE
t H1
HO LD2
t SU2
t H2
DAV
t D1
t D2
t D3
AD OU T1
Data O UT
D11 (MSB)
D10
AD OU T2
Data O UT
D11 (MSB)
D10
AD OU T3
Data O UT
D11 (MSB)
D1
Data O UT
D0 (LSB)
Data O U T
D11 (M SB)
D1
Data O UT
D0 (LSB)
Data O U T
D11 (M SB)
D1
Data O UT
D0 (LSB)
t D4
t SU3
ADIN
D10
t H3
Data IN
D12 (M SB)
D1 1
D 10
D1
Data IN
D0 (LSB)
Figure 1−10. VECANA Access
26
Data O U T
D11 (M SB)
D ata IN
D 12 (LSB)
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3.2.3
WINCLK Selection
It is possible to apply a separate clock for the window comparators at the WINCLK (pin 51) in VECANA01
mode. By using the pins S0 (pin 52) and S1 (pin 53) as decoder inputs, the window comparators can be
supplied with the system clock, an external clock (supplied by the WINCLK), and two divided external clocks;
see Table 1−7.
Table 1−7. Window Comparator Clock
S1
S0
Clock to Window Comparators
0
0
Synchronous system clock
0
1
External WINCLK clock
1
0
External WINCLK clock / 2
1
1
External WINCLK clock / 4
The system clock, provided by CLK (pin 77), drives the window comparators in the other modes (SPI and
parallel modes).
The window comparator clock, WINCLK, must be synchronous with the system clock, provided by CLK (pin
77). The window comparators can be supplied with a 6MHz clock when the system runs with a 15MHz clock.
In order to provide the window comparators with a maximum of 1µs detection time, a minimum clock of 6MHz
must be supplied. See the Window Comparator section. It is necessary to operate the window comparators
with a continuous clock.
3.3
Serial Peripheral Interface (SPI)
The SPI runs fully asynchronous to the rest of the system. The four signals of the SPI are SPICLK, SPISIMO,
SPISOMI and SPISTE. The maximum speed of the SPI is 25MHz. When the select signal SPISTE is HIGH,
the entire SPI, except the address and the data registers, is in reset state. The SPI clock SPICLK and the serial
data input SPISIMO are disabled when SPISTE is HIGH. The incoming data is strobed by the SPI on the falling
edge of the SPICLK. Outgoing data is put on the output SPISOMI on the rising edge of the SPICLK (see
Figure 1−11). For a transmission of one 16-bit data word, 24 bits are required. The first incoming bit to the
ADS7869 determines if the whole transmission is a read or a write operation. A ‘1’ means a read and a ‘0’
means a write operation. There are seven address bits, but only the six LSBs are used. Then the 16 data bits
are transmitted or received (see Table 1−8).
1
2
3 4
5
SPISTE
SPICLK
SPISIMO
SPISOMI
Figure 1−11. One SPI Transfer Cycle.
Table 1−8. SPI Write 24-bit Word Format
A23
A22
R/W
X
A21
A20
A19
A18
Address
A17
A16
A15
A14
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
Data
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One 16-bit transfer is accomplished, as follows:
1. On the first falling edge of SPICLK, the read/write bit is strobed.
2. On the third falling edge of SPICLK, the MSB of the address (bit 5) is strobed.
3. On the eighth falling edge of SPICLK, the LSB of the address (bit 0) is strobed and the corresponding data of the register
map is read.
4. On the ninth rising edge, the data read from the register map is latched into a shift register and shifted one position
each rising edge of the SPICLK. This data is always sent out, even when a write operation is performed.
5. On the 24th falling edge of SPICLK, the last data bit is shifted in from SPISIMO and a write pulse is generated to write
the data into the register map, if a write operation was performed.
During continuous read or write (see Figure 1−12), the address is decrementing after each read or write; see
the indicating arrows. When the address is set to 00H, in the beginning, the FIFO can be read out fast. The
data is written into the register map on the 16th SPICLK of a data word. If the SPISTE is inactive before the
16th SPICLK in a data word, the data is not written into the register map; therefore, the data is lost.
SPIST E
SPIC LK
SPISIM O
SPISOMI
8 SPICLKs
Address
Don’t C are
8 SPICL Ks
8 SPICLKs
8 SPIC LKs
8 SPIC LKs
8 SPICLKs
8 SPICLKs
8 SPICLKs
1st Data to W rite
2nd D ata to W rite
3rd D ata to W rite
4th Data to W rite
1st R ead D ata
2nd Read D ata
3rd Rea d Data
4th Read D ata
Figure 1−12. Continuous SPI Transfer Cycle
28
8 SPICLKs
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3.3.1
SPI Timing Characteristics (1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
MIN
SPICLK Period
tC1
40
ns
SPICLK HIGH or LOW Time
tW1
10
ns
Delay Time from SPISTE Falling to SPICLK Rising Edge
tD1
15
Delay Time from SPISTE Falling to SPISOMI not Tristate
tD2
Data Setup Time
tSU1
10
Input Data Hold Time
tH1
10
Output Data Delay Time
tD3
Enable Lag Time
tD4
SPISOMI Disable Time
tD5
Sequential Transfer Delay
tW2
MAX
UNIT
ns
15
ns
ns
ns
10
ns
15
ns
15
ns
30
ns
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
SPISTE
tC 1
1
SPICLK
2
tD 1
tS U 1
3
8
9
10
Don’t
Care
Address
A5
Address
A0
Data IN
D15 (MSB)
tH 1
24
D14
Data IN
D0 (LSB)
tD 3
Data OUT
D15 (MSB)
SPISOMI
tW 2
tW 1
Command Bit
R/W
SPISIMO
tD 4
D14
tD 5
Data OUT
D0 (LSB)
tD 2
Figure 1−13. SPI Access
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3.4
Parallel Interface
The Parallel Interface has the following major capabilities:
1. Data words:
•
Data path with a width of 16 bits is supported.
2. Bus handshaking:
•
Separate RD and WR style control signals.
•
Separate R/W and WE style control signals.
3. Mapping
•
The ADS7869 appears as a memory-mapped peripheral. See Table 1−10 on page 37 and Table 1−11 on
page 38.
•
Internal registers are directly mapped into consecutive locations in the external bus address space.
3.4.1
Parallel Read and Write Control
Reading from and writing to the ADS7869 is controlled by the chip select input (CS, pin 57), the write input
(WR, pin 58) and the read input (RD, pin 59). There is a control bit for mode 11, which can be reset to activate
a special compatibility mode. (See Mode 11 Bus Access [DSP-compatible mode] section.) The read and write
pins can be configured as a combined Read/Write and Write enable depending on the needs of the host
processor. The mode pins M0 and M1 determine the method by which the ADS7869 is accessed by the host
(see Table 1−9).
Table 1−9. Host Parallel Port Operation
[M1, M0]
PIN NAME
PIN NO.
FUNCTION
OPERATION
R/W
59
Read/Write Signal
0: Data can be written to ADS7869; see WE
1: Data from ADS7869 is written to the Data Bus
WE
58
Write Enable
0: Data Bus is read by ADS7869 at rising edge
1: ADS7869 Write function is disabled
,10‘
RD
59
Read Signal
,11‘
standard
0: Data from ADS7869 is written to the Data Bus
1: ADS7869 Read function is disabled
WR
58
Write Signal
0: Data Bus is read by ADS7869 at rising edge
1: ADS7869 Write function is disabled
,11‘TMS
—
59
—
Signal is ignored by ADS7869
R/W
58
Read/Write Signal
0: Data Bus is read by ADS7869 at rising edge of CS
1: Data from ADS7869 is written to the Data Bus
30
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3.4.2
Mode 10 Bus Access
When M1 = 1 and M0 = 0 (mode 10), the host port uses the RD (pin 59) as a read/write signal (R/W) and the
WR (pin 58) as a write-enable signal WE. The current cycle is only processed when the chip select input CS
(pin 57) of the ADS7869 is active low.
R/W determines the direction of the transfer during a bus cycle; see Figure 1−14. When R/W is high, data is
placed on the databus by ADS7869, according to the address, as long as CS is low.
For a write cycle, a low-level signal (on WE) indicates to the ADS7869 that the data on the bus is valid. With
the rising edge of WE the data is latched into the ADS7869. When the host sets CS to low, a valid access to
the ADS7869 is detected (see Figure 1−15).
3.4.2.1
Read Timing Characteristics(1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
MAX
UNIT
Delay time from CS LOW to output data not in tri-state mode(2)
SYMBOL
tD1
MIN
8
ns
Access time from address valid to output data valid
tA1
10
ns
Delay time from address not valid to output data not valid(3)
Delay time from CS HIGH to output data in tri-state mode(4)
tD2
8
ns
8
ns
0
tD3
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
(2) Refer to CS signal or RW signal whichever occurs last.
(3) One or more read cycles can be performed in one CS cycle.
(4) Refer to CS signal or RW signal whichever occurs first.
CS
R/W
WE
tA1
tA1
A (5:0)
tD1
tD2
tD2
D (15:0)
Figure 1−14. Mode 10 Read Access
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3.4.2.2
Write Timing Characteristics(1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
MIN
Delay time from R/W LOW to CS LOW
tD1
0
MAX
ns
Access time from CS LOW to WE HIGH
tA1
25
ns
Width time for WE LOW
tW1
20
ns
Width time for WE HIGH(2)
tW2
10
ns
Setup time, address valid before rising edge of WE
tSU1
10
ns
Hold time, address valid after rising edge of WE
tH1
5
ns
Setup time, data valid before rising edge of WE
tSU2
10
ns
Hold time, data valid after rising edge of WE
tH2
5
ns
Delay time from WE HIGH to CS HIGH
tD2
10
ns
Delay time from CS HIGH to R/W HIGH
tD3
0
ns
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
(2) One or more write cycles can be performed in one CS cycle.
CS
tD1
tA1
tD3
R/W
tW1
tW2
tD2
WE
tSU1
tH1
tSU1
tH1
A (5:0)
tSU2
tH2
tSU2
D (15.0)
Figure 1−15. Mode 10 Write Access
32
tH2
UNIT
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3.4.3
Mode 11 Bus Access
(Standard Mode)
When M1 = 1 and M0 = 1 (mode 11), the host port uses WR (pin 58) and RD (pin 59) for independent write
and read access to the ADS7869. The current cycle is processed only when the CS (pin 57) input of the
ADS7869 is an active low. Bit 0 of the PARALLEL register (Address 27H) must have a reset value of 1 to use
the standard mode.
In Mode 11 operation, RD indicates to the ADS7869 that the host processor has requested a data transfer
(see Figure 1−16). The ADS7869 outputs data to the host. The address can be changed within a CS low cycle,
and more than one data can be read.
To configure the registers in the ADS7869, the host issues a WR signal to indicate that valid data is available
on the bus. With the rising edge of the WR the data is latched into the ADS7869; see Figure 1−17. The address
for the ADS7869 must be valid before the write operation takes place. The CS signal can stay low between
two consecutive writes.
3.4.3.1
Read Timing Characteristics(1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
MAX
UNIT
Delay time from CS LOW to output data not in tri-state mode(2)
SYMBOL
tD1
8
ns
Access time from address valid to output data valid
tA1
10
ns
Delay time from address not valid to output data not valid(3)
Delay time from CS HIGH to output data in tri-state mode(4)
tD2
8
ns
8
ns
PARAMETER
MIN
0
tD3
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
(2) Refer to CS signal or RD signal whichever occurs last.
(3) One or more read cycles can be performed in one CS cycle.
(4) Refer to CS signal or RD signal whichever occurs first.
CS
RD
WR
tA1
tA1
A (5:0)
tD1
tD2
tD3
D (15:0)
Figure 1−16. Mode 11 Read Access (Standard Mode)
33
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3.4.3.2
Write Timing Characteristics(1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
MIN
Access time from CS LOW to WR HIGH
tA1
15
MAX
ns
Width time for WR LOW
tW1
10
ns
Width time for WR HIGH(2)
tW2
10
ns
Setup time, address valid before rising edge of WR
tSU1
10
ns
Hold time, address valid after rising edge of WR
tH1
5
ns
Setup time, data valid before rising edge of WR
tSU2
10
ns
Hold time, data valid after rising edge of WR
tH2
5
ns
Delay time from WR HIGH to CS HIGH
tD1
10
ns
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
(2) One or more write cycles can be performed in one CS cycle.
CS
tA1
RD
tW1
tW2
tD1
WR
tSU1
tH1
tSU1
tH1
A (5:0)
tSU2
tH2
tSU2
tH2
D (15:0)
Figure 1−17. Mode 11 Write Access (Standard Mode)
34
UNIT
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3.4.4
Mode 11 Bus Access
(TMS320c54xx DSP Family-Compatible Mode)
In the TMS320c54xx DSP family-compatible mode (M1 = 1 and M0 = 1), the host port uses CS (pin 57)
together with WR (pin 57) as an R/W for independent read and write access to the ADS7869. Bit 0 of the
PARALLEL register (address 27H) must have a value of 0 to use this compatible mode.
In this mode, CS, together with the R/W (which remains high), indicates to the ADS7869 that the host
processor has requested a read data transfer (see Figure 1−18). The ADS7869 will output data to the host
as long as the CS is an active low.
To configure the registers, in the ADS7869 the host puts the R/W signal to low to indicate that valid data is
available on the bus. With the rising edge of the CS, the data is latched into the ADS7869 (see Figure 1−19).
The address for the ADS7869 must be valid before the CS is set to low.
Before using this mode, the register bit 0 at address 27H must be reset. The reset can be performed with a
TMS320C54xx DSP write operation with the original mode 11, because the write access is similar to the write
access of mode 11. (See Mode 11 Bus Access [standard mode] section.) This mode can perform read
operations, after bit 0 is reset, as mentioned above.
3.4.4.1
Read Timing Characteristics(1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
MAX
UNIT
Delay time from CS LOW to output data not in tri-state mode
SYMBOL
tD1
MIN
8
ns
Access time from address valid to output data valid
tA1
10
ns
Delay time from address not valid to output data not valid(2)
tD2
8
ns
Delay time from CS HIGH to output data in tri-state mode
tD3
8
ns
0
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
(2) One or more read cycles can be performed in one CS cycle.
CS
R/W
tA1
tA1
A (5:0)
tD1
tD2
tD3
D (15:0)
Figure 1−18. Mode 11 Read Access (TMS320c54xx mode)
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3.4.4.2
Write Timing Characteristics(1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
MIN
Setup time from R/W LOW to CS LOW
tSU1
0
MAX
ns
Hold time from CS HIGH to R/W HIGH
tH1
5
ns
Setup time from address valid to CS LOW
tSU2
10
ns
Hold time from CS HIGH to address not valid
tH2
5
ns
Setup time from data valid to CS HIGH
tSU3
10
ns
Hold time from CS HIGH to data not valid
tH3
5
ns
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
CS
tH1
tSU1
R/W
tSU2
tH2
A (5:0)
tSU3
tH3
D (15:0)
Figure 1−19. Mode 11 Write Access (TMS320c54xx mode)
36
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3.5
Register Map
Table 1−10. Register Map Write 16-bit Data
ADDRESS
D15
D14
D13
D12
D11
D10
01H
x
x
x
x
x
x
Channel IU, write 10-bit offset DAC-value
02H
x
x
x
x
x
x
Channel A1, write 10-bit offset DAC-value
03H
x
x
x
x
x
x
Channel A2, write 10-bit offset DAC-value
04H
x
x
x
x
x
x
Channel IV, write 10-bit offset DAC-value
05H
x
x
x
x
x
x
Channel B1, write 10-bit offset DAC-value
06H
x
x
x
x
x
x
Channel B2, write 10-bit offset DAC-value
07H
x
x
x
x
x
x
Channel IW, write 10-bit offset DAC-value
08H
x
x
x
x
x
x
Channel AN1, write 10-bit offset DAC-value
09H
x
x
x
x
x
x
Channel AN2, write 10-bit offset DAC-value
0AH
x
x
x
x
x
x
Channel AN3, write 10-bit offset DAC-value
0BH
x
x
x
x
x
x
Channel AX, write 10-bit offset DAC-value
0CH
x
x
x
x
x
x
Channel BX, write 10-bit offset DAC-value
0DH
x
x
x
x
Channel IU, write 12-bit gain DAC-value
0EH
x
x
x
x
Channel A1, write 12-bit gain DAC-value
0FH
x
x
x
x
Channel A2, write 12-bit gain DAC-value
10H
x
x
x
x
Channel IV, write 12-bit gain DAC-value
11H
x
x
x
x
Channel B1, write 12-bit gain DAC-value
12H
x
x
x
x
Channel B2, write 12-bit gain DAC-value
13H
x
x
x
x
Channel IW, write 12-bit gain DAC-value
14H
x
x
x
x
Channel AN1, write 12-bit gain DAC-value
15H
x
x
x
x
Channel AN2, write 12-bit gain DAC-value
16H
x
x
x
x
Channel AN3, write 12-bit gain DAC-value
17H
x
x
x
x
Channel AX, write 12-bit gain DAC-value
18H
x
x
x
x
Channel BX, write 12-bit gain DAC-value
19H
x
x
x
x
x
x
x
x
1AH
x
x
x
x
x
x
x
x
x
x
x
DAV
1BH
x
x
x
x
x
x
x
x
x
x
x
x
00H
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Unwriteable (don’t care)
1CH
Over current, write 8-bit window DAC-value
x
INPUT
Write 4-bit counter control
Unwriteable (don’t care)
1DH
Counter 1, write 16-bit value in EDGECOUNT1 counter
1EH
Unwriteable (don’t care)
1FH
Unwriteable (don’t care)
20H
Unwriteable (don’t care)
21H
Counter 2, write 16-bit value in EDGECOUNT2 counter
22H
Unwriteable (don’t care)
23H
Unwriteable (don’t care)
24H
write 16-bit value in FIFO_TEST register
25H
write 16-bit value in COMP_TEST register
26H
Counter interrupt enables
x
x
x
x
x
x
x
x
x
x
27H
x
x
x
x
x
x
x
x
x
x
x
x
x
x
28H
write 16-bit value in RESET register
29H−3FH
Unwriteable (don’t care)
FIFO interrupt enables
x
PARALLEL
NOTE: ‘x’ means unwriteable (don’t care)
37
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Table 1−11. Register Map Read 16-bit Data
ADDRESS
D15
D14
D13
D12
D11
D10
00H
FIFO data
01H
Channel IU, read 10-bit offset DAC-value (1)
Channel A1, read 10-bit offset DAC-value (1)
02H
03H
04H
05H
06H
07H
08H
09H
0AH
0BH
0CH
D9
D8
D6
D5
D2
D1
D0
Channel IW, read 10-bit offset DAC-value (1)
Channel AN1, read 10-bit offset DAC-value (1)
Channel AN2, read 10-bit offset DAC-value (1)
Channel AN3, read 10-bit offset DAC-value (1)
Channel AX, read 10−bit offset DAC−value (1)
Channel BX, read 10-bit offset DAC-value (1)
0
0
0
0
Channel IU, read 12-bit gain DAC-value
0EH
0
0
0
0
Channel A1, read 12-bit gain DAC-value
0FH
0
0
0
0
Channel A2, read 12-bit gain DAC-value
10H
0
0
0
0
Channel IV, read 12-bit gain DAC-value
11H
0
0
0
0
Channel B1, read 12-bit gain DAC-value
12H
0
0
0
0
Channel B2, read 12-bit gain DAC-value
13H
0
0
0
0
Channel IW, read 12-bit gain DAC-value
14H
0
0
0
0
Channel AN1, read 12-bit gain DAC-value
15H
0
0
0
0
Channel AN2, read 12-bit gain DAC-value
16H
0
0
0
0
Channel AN3, read 12-bit gain DAC-value
17H
0
0
0
0
Channel AX, read 12-bit gain DAC-value
18H
0
(3)
0
(3)
0
(3)
0
(3)
0
0
0
0
1AH
Channel BX, read 12-bit gain DAC-value
(3)
(3)
(3)
(3) Over current, read 8-bit window DAC-value
0
0
0
0
0
0
0
B2
B1
A2
A1
UC
VC
0
0
0
0
0
0
1BH
Read counter control and status register
1CH
Counter 1, read 16-bit value in ASEDGCNT1 register
1DH
Counter 1, read 16-bit value in SYEDGCNT1 register
1EH
Counter 1, read 16-bit value in SYEDGPRD1 register
1FH
Counter 1, read 16-bit value in SYEDGTIME1 register
20H
Counter 2, read 16-bit value in ASEDGCNT2 register
21H
Counter 2, read 16-bit value in SYEDGCNT2 register
22H
Counter 2, read 16-bit value in SYEDGPRD2 register
23H
Counter 2, read 16-bit value in SYEDGTIME2 register
24H
Read 16-bit value in FIFO_TEST register
Read 6 MSB of COMP register
26H
Read INTERRUPT register
27H
0
28H
Read 0000H
29H−3FH
D3
Channel B1, read 10-bit offset DAC-value (1)
Channel B2, read 10-bit offset DAC-value (1)
0DH
25H (2)
D4
Channel A2, read 10-bit offset DAC-value (1)
Channel IV, read 10-bit offset DAC-value (1)
19H
0
0
0
0
0
Unused (read 0000H)
(1) MSB is copied to upper bits to achieve 16-bit two’s complement values.
(2) The lower 10 bits are the comparator outputs.
(3) The MSB of the 8-bit DAC is copied in the upper 8 bits.
38
D7
DAV
0
WC
0
INPUT
UI
0
VI
0
WI
PARALLEL
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3.6
Register Descriptions
The following table shows the symbols that are used in this section. The last number in the symbol represents
the reset value.
3.6.1
R
Readable Bit
W
Writeable Bit
U
Unused
0/1
Value After Reset
FIFO Data Register (00H )
The FIFO Data Register is at address 00H in the register map. The output word of the FIFO is in16-bit format.
The resolution of the ADCs is 12 bits. Output data from each of the ADCs is in binary two’s complement format.
The four MSBs are used for channel identification. The format of the output word is shown in Table 1−12.
There are three words stored in the FIFO for each conversion. There must be three read accesses to this
register to get all three conversion values out of the FIFO.
Table 1−12. FIFO Output Word Format
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
CA3
CA2
CA1
CA0
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
CA3−0: INPUT CHANNEL ADDRESS BITS
Bit 15−12:
0000 = Data from IU input
0001 = Data from A1 input
0010 = Data from A2 input
0011 = Data from IV input
0100 = Data from B1 input
0101 = Data from B2 input
0110 = Data from IW input
0111 = Data from AN1 input
1000 = Data from AN2 input
1001 = Data from AN3 input
1010 = Data from AX input
1011 = Data from BX input
1100 = Unused
1101 = Unused
1110 = Unused
1111 = Unused
Bit 11−0:
DATA11−0: The output from the ADCs
In test mode, the upper four bits are copied from Bit 11 of the written data; see the FIFO Test Register (24H )
section.
39
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3.6.2
Offset Registers (01H – 0CH )
The Offset Registers are stored at the addresses 01H to 0CH. The Offset Registers are 10 bits wide and
represented in the two’s complement format. The sign bit is copied in bit locations 15 to 10. This copy is only
performed by a read access (that is, bits 15 to 10 must not be correctly set, in order to achieve the copy of
the sign bit). The data format is shown in Table 1−13. The valid offset adjustment values are from –511 (201H)
to +511 (1FFH). The value –512 (200H) is not allowed.
Table 1−13. Offset Registers
R0
R0
R0
R0
R0
R0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
D9
D9
D9
D9
D9
D9
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−9:
D9: The MSB of the offset
Bit 8−0:
D9−0: The 10 bits of the offset value
3.6.3
RW0
Gain Registers (0DH to 18H )
The Gain Registers are stored at the addresses 0DH to 18H. The Gain Registers are 12 bits wide. The gain
value is stored in a straight binary format. The data format is shown in Table 1−14.
Table 1−14. Gain Registers
R0
R0
R0
R0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
0
0
0
0
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−12:
Always read as ‘0’; don’t care at write
Bit 11−0:
D11−0: The 12 bits of the gain value
3.6.4
RW0
WINDAC Register (19H )
The WINDAC Register is located in address 19H. The WINDAC Register sets the output of the 8-bit DAC used
by the window comparators. The word is in 8-bit straight binary format. The output voltage is a function of the
register value and the internal reference voltage. (See Table 1−3.) The format of the data word is shown in
Table 1−15.
Table 1−15. WINDAC Register
R0
R0
R0
R0
R0
R0
R0
R0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
D7
D7
D7
D7
D7
D7
D7
D7
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−8:
D7: MSB from DAC input data
Bit 7−0:
D7−0: The 8 bits input to Digital-to-Analog Converter
40
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3.6.5
Control Register (1AH )
The Control Register is located in address 1AH. The control register contains the input selection and the DAV pin
control. (See the FIFO section for additional information.) The format of the Control Register is shown in Table 1−16.
For more about the input selection, see the Vecana Interface section.
Table 1−16. Control Registers
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
RW0
R0
RW0
RW0
0
0
0
0
0
0
0
0
0
0
0
DAV
0
I2
I1
I0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−5, 3:
Unused (read as ‘0’); don’t care at write
Bit 4:
DAV: The 8 bits input to Digital-to-Analog Converter
1 = DAV signal active HIGH
0 = DAV signal active LOW
Bit 2−0:
I2−0: Input channel selection bits
RW0
000 = AN3 for ADC3
001 = AX for ADC1, BX for ADC2, and AN3 for ADC3
010 = A2 via SH1 for ADC1, B2 via SH3 for ADC2 and AN2 for ADC3
011 = A2 via SH2 for ADC1, B2 via SH4 for ADC2 and AN2 for ADC3
100, 101, 110 = A1 for ADC1, B1 for ADC2 and AN1 for ADC3
111 = IU for ADC1, IV for ADC2 and IW for ADC3
41
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
3.6.6
Counter Control/Status Register (1BH )
The Counter Control/Status Register is located in address 1BH. The counter control/status register
CCTRLSTAT is a combined control register for the filtered input of the counters and a status register for the
over- or under-flow status of the counters and the filtered input signals strobed by HOLD1. See the Digital
Counters section for more information on this topic.
When the filter bits FxxE are set, the appropriate input is synchronized with the system clock and a digital filter
processes the input signal. If the bit is reset, the signals are just synchronized.
The overflow states EOx/TOx are set when the appropriate counter has reached the value FFFFH. This
indicates when the time, between two edges of the input signals, is greater than 4ms at 16MHz. Only the time
counter keeps its value until a counter reset is performed. See the Reset Register section for additional
information.
The filtered values of the counter inputs CNTA2, CNTA1, CNTB2 and CNTB1 are sampled with the
synchronous signal HOLD1 and are stored in the appropriate bits FB1, FA1, FB2 and FA2. The format of the
Counter Control/Status Register is described in Table 1−17.
Table 1−17. Counter Control/Status Register
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
RW1
RW1
RW1
RW1
FA1
FB1
FA2
FB2
0
0
0
0
EO2
TO2
EO1
TO1
FA2E
FB2E
FA1E
FB1E
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15:
FA1: Synchronously strobed and filtered CNTA1 signal
Bit 14:
FB1: Synchronously strobed and filtered CNTB1 signal
Bit 13:
FA2: Synchronously strobed and filtered CNTA2 signal
Bit 12:
FB2: Synchronously strobed and filtered CNTB2 signal
Bit 7:
EO2: EDGECNT2, over- or under-flow state
1 = when EDGECNT1 reached FFFFH
0 = when EDGECNT1 is other than FFFFH
Bit 6:
TO2: TIMECOUNT2, over- or under-flow state
1 = when TIMECOUNT1 reached FFFFH
0 = when TIMECOUNT1 is other than FFFFH
Bit 5:
EO1: EDGECNT1, over- or under-flow state
1 = when EDGECNT0 reached FFFFH
0 = when EDGECNT0 is other than FFFFH
Bit 4:
TO1: TIMECOUNT1, over- or under-flow state
1 = when TIMECOUNT0 reached FFFFH
0 = when TIMECOUNT0 is other than FFFFH
Bit 3:
FA2E: Enable of digital filter input CNTA2
1 = Input signal of CNTA2 will be filtered
0 = Input signal of CNTA2 will not be filtered
Bit 2:
FB2E: Enable of digital filter input CNTB2
1 = Input signal of CNTB2 will be filtered
0 = Input signal of CNTB2 will not be filtered
Bit 1:
FA1E: Enable of digital filter input CNTA1
1 = Input signal of CNTA1 will be filtered
0 = Input signal of CNTA1 will not be filtered
Bit 0:
FB1E: Enable of digital filter input CNTB1
1 = Input signal of CNTB1 will be filtered
0 = Input signal of CNTB1 will not be filtered
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3.6.7
Edge Count Register (1CH , 1DH , 20H and 21H )
There are four shadow registers for the two edge counters. The registers SYEDGCNT1 and SYEDGCNT2,
synchronous edge count 1 (in address 1DH), and synchronous edge count 2 (in address 21H), latch the values,
from the edge counters, when the synchronous hold signal HOLD1 is set to low.
Registers ASEDGCNT1, ASEDGCNT2, asynchronous edge count 1 (in address 1CH), and asynchronous
edge count 2 (in address 20H), latch the values from the edge counters when the asynchronous hold signal
HOLD2 is set to low.
An initial value is given to the edge counter 1, EDGECNT1, by writing into the register SYEDGCNT1. An initial
value is given to the edge counter 2, EDGECNT2, by writing into the register SYEDGCNT2; see Table 1−18.
Table 1−18. Synchronous Latched Edge Count Register
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
R−
R−
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−2:
D15−2: The 14 MSBs of the synchronous latched edge counters
Bit 1−0:
D1−0: The 2 LSBs of the synchronous latched edge counters. The value is adjusted to the value of the CNTAx
and CNTBx by a write access to these registers or a reset condition.
CNTAx
CNTBx
EDGECNTx bit 1
EDGECNTx bit 0
Position of the Angle
0
0
0
0
1st Quadrant
1
0
0
1
2nd Quadrant
1
1
1
0
3rd Quadrant
0
1
1
1
4th Quadrant
The data can only be read from the asynchronous latched registers ASEDGCNT1 and ASEDGCNT2; see
Table 1−19.
Table 1−19. Asynchronous Latched Edge Count Register
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−0:
3.6.8
D15−0: The 16 bits of the asynchronous latched edge counters
Edge Period Register (1EH and 22H )
There are two read-only shadow registers for the two edge-period registers. The registers SYEDGPRD1 and
SYEDGPRD2, synchronous edge period 1 (in address 1EH) and synchronous edge period 2 (in address 22H),
latch the values from the edge period registers when the synchronous hold signal HOLD1 is set to low. The
Edge Period Register is described in Table 1−20.
Table 1−20. Edge Period Register
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−0:
D15−0: The 16 bits of the synchronous latched edge period registers
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SBAS253B − MAY 2003 − REVISED NOVEMBER 2004
3.6.9
Edge Time Period Register (1FH and 23H )
There are two read-only shadow registers for the two edge time counters. The registers SYEDGTIME1 and
SYEDGTIME2, synchronous edge time 1 (in address 1FH) and synchronous edge time 2 (in address 23H),
latch the values from the edge time counters when the synchronous hold signal HOLD1 is set to low. The Edge
Time Register is described in Table 1−21.
Table 1−21. Edge Time Period Register
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−0:
D15−0: The 16 bits of the synchronous latched edge time counters
3.6.10 FIFO Test Register (24H )
The purpose of the FIFO Test Register, in address 24H, is to test the FIFO during production test; the FIFO
is filled with a defined pattern via this register. The internal FIFO structure can be verified by reading the
patterns of the FIFO data register. When the FIFO test is enabled, the multiplexers are switched and lead the
data (of the FIFO test register) into the FIFO, instead of the normal ADC data; to simulate the three ADCs,
the data is latched into the FIFO three times. To distinguish between the channels, the first data is unchanged
to simulate ADC1, the second data is inverted to simulate ADC2, and the six LSBs of the third data are inverted
to simulate ADC3. While the FIFO test is enabled, a total of three data words will be stored in the FIFO, with
one write instruction. In order to fill the entire FIFO register with test data, 10 writes must be performed. The
test data is written into the FIFO only when the four enable bits have the value AH. This register should not
be used in normal operation. The format of the output word is shown in Table 1−22.
Table 1−22. FIFO Test Register
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
RW0
E3
E2
E1
E0
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−12:
E3−0: Input channel address bits
0000 = Disable FIFO test
...
1001 = Disable FIFO test
1010 = Enable FIFO test write procedure
1011 = Disable FIFO test
...
1111 = Disable FIFO test
Bit 11−0:
DATA11−0: The input data that will be written into the FIFO registers
In FIFO test mode the four channel bits are copied from Bit 11 of the written data.
44
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3.6.11
Comparator Test Register (25H )
The purpose of the Comparator Test Register, in address 25H, is to apply a defined pattern to the comparator
output pins. This feature is for testing algorithms in the DSP or testing the hardware controlled by the
comparator outputs. To enable the comparator test, the enable part of the register must contain the value 0CH.
This register should not be used in normal operation. By reading the Comparator Test register, the
comparator outputs are sent back in order to allow the host to read the actual comparator outputs in one cycle.
The format of the output word is shown in Table 1−23.
Table 1−23. Comparator Test Register
RW0
RW0
RW0
RW0
RW0
RW0
RW−
RW−
RW−
RW−
RW−
RW−
RW−
RW−
RW−
E5
E4
E3
E2
E1
E0
A1/B2
B1
A2
B2/A1
UC
VC
WC
UI
VI
WI
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−10:
RW−
E5−0: Input channel address bits
000000 = Disable COMPARATOR_TEST
...
001011 = Disable COMPARATOR_TEST
001100 = Enable COMPARATOR_TEST write procedure
001101 = Disable COMPARATOR_TEST
...
111111 = Disable COMPARATOR_TEST
Bit 9:
A1: Control bit of position sensor, sign comparator A1 output
1 = Comparator output A1, set HIGH
0 = Comparator output A1, set LOW
By reading this bit, comparator output B2 is read
Bit 8:
B1: Control bit of position sensor, sign comparator B1 output
1 = Comparator output B1, set HIGH
0 = Comparator output B1, set LOW
Bit 7:
A2: Control bit of position sensor, sign comparator A2 output
1 = Comparator output A2, set HIGH
0 = Comparator output A2, set LOW
Bit 6:
B2: Control bit of position sensor, sign comparator B2 output
1 = Comparator output B2, set HIGH
0 = Comparator output B2, set LOW
By reading this bit, comparator output A1 is read
Bit 5:
UC: Control bit phase U current sign comparator
1 = Comparator output U_COMP, set HIGH
0 = Comparator output U_COMP, set LOW
Bit 4:
VC: Control bit phase V current sign comparator
1 = Comparator output V_COMP, set HIGH
0 = Comparator output V_COMP, set LOW
Bit 3:
WC: Control bit phase W current sign comparator
1 = Comparator output W_COMP, set HIGH
0 = Comparator output W_COMP, set HIGH
Bit 2:
UI: Control bit phase U current window comparator
1 = Comparator output U_ILIM, set HIGH
0 = Comparator output U_ILIM, set LOW
Bit 1:
VI: Control bit phase V current window comparator
1 = Comparator output V_ILIM, set HIGH
0 = Comparator output V_ILIM, set LOW
Bit 0:
WI: Control bit phase W current window comparator
1 = Comparator output W_ILIM, set HIGH
0 = Comparator output W_ILIM, set LOW
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3.6.12 Interrupt Register (26H )
The Interrupt Register, in address 26H, contains the interrupt source and interrupt control bits. The bits xOxF
are set when a particular counter had an over- or under-flow. The bits remain set until the Interrupt register
is read; this is independent of whether the counter over- or under-flow states remain or not. The counter overor under-flow interrupt is enabled when the appropriate xOxE bits are set.
The FFF bit, FIFO full flag, will be set when the FIFO is (or was) full and remains set until the Interrupt register
is read, independent of whether the FIFO is full or not. The FF bit, FIFO full, indicates whether the FIFO is
full or not. The FFF bit is cleared when the Interrupt register is read. The FIFO full interrupt is enabled when
the bit FFE (or FIFO full enable) is set.
The FEF bit, FIFO empty flag, will be set when the FIFO is (or was) empty and remains set until the Interrupt
register is read, independent of whether the FIFO is empty or not. The FE bit, FIFO empty, indicates if the FIFO
is empty or not. The bit FEF is cleared when the Interrupt register is read. The FIFO empty interrupt is enabled
when the FEE bit , FIFO empty enable, is set. For more information about the Interrupt pin, see the Interrupt
section. Table 1−24 describes the Interrupt register.
Table 1−24. Interrupt Register
RW0
RW0
RW0
RW0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
RW0
RW0
EO2E
TO2E
EO1E
TO1E
EO2F
TO2F
EO1F
TO1F
0
0
FF
FE
FFF
FEF
FFE
FEE
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15:
EO2E: Edge counter 2, EDGECNT2, over- or under-flow interrupt enable bit
1 = Interrupt enable
0 = Interrupt disable
Bit 14:
TO2E: Time counter 2, TIMECOUNT2, over- or under-flow interrupt enable bit
1 = Interrupt enable
0 = Interrupt disable
Bit 13:
EO1E: Edge counter 1, EDGECNT1, over- or under-flow interrupt enable bit
1 = Interrupt enable
0 = Interrupt disable
Bit 12:
TO1E: Time counter 1, TIMECOUNT1, over- or under-flow interrupt enable bit
1 = Interrupt enable
0 = Interrupt disable
Bit 11:
EO2F: Edge counter 2, EDGECNT2, over- or under-flow flag
1 = EDGECNT2 over- or under-flow occurred
0 = EDGECNT2 over- or under-flow did not occur
Bit 10:
TO2F: Time counter 2, TIMECOUNT2, over- or under-flow flag
1 = TIMECOUNT2 over- or under-flow occurred
0 = TIMECOUNT2 over- or under-flow did not occur
Bit 9:
EO1F: Edge counter 1, EDGECNT1, over- or under-flow flag
1 = EDGECNT1 over- or under-flow occurred
0 = EDGECNT1 over- or under-flow did not occur
Bit 8:
TO1F: Time counter 1, TIMECOUNT1, over- or under-flow flag
1 = TIMECOUNT1 over- or under-flow occurred
0 = TIMECOUNT1 over- or under-flow did not occur
Bit 7−6:
Unused (read as ‘0’)
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Interrupt Register, continued
Bit 5:
FF: FIFO full state
1 = FIFO is full
0 = FIFO is not full
Bit 4:
FE: FIFO empty state
1 = FIFO is empty
0 = FIFO is not empty
Bit 3:
FFF: FIFO full flag
1 = FIFO is or was full
0 = FIFO is not or was not full
Bit 2:
FEF: FIFO empty flag
1 = FIFO is or was empty
0 = FIFO is not or was not empty
Bit 1
FFE: FIFO full interrupt enable bit
1 = Interrupt enable
0 = Interrupt disable
Bit 0:
FEE: FIFO empty interrupt enable bit
1 = Interrupt enable
0 = Interrupt disable
3.6.13 Parallel Register (27H )
The Parallel Register, in address 27H, controls the parallel interface mode 11; see the Mode 11 Bus Access
sections. The Parallel Register has no effect on modes 00, 01, and 10. There is only one bit present in the
Parallel Register, the M bit. The format of the Parallel Register is shown in Table 1−25.
Table 1−25. Parallel Register
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
R0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
M
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−1:
Unused (read as ‘0’)
Bit 0:
M: Set up the type of the parallel interface
1 = Parallel interface, mode 11 (default)
0 = TMS320c54xx DSP family-compatible parallel interface
RW1
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3.6.14 Reset Register (28H )
The Reset Register, in address 28H, can either reset the ADS7869 entirely, or simply reset the counters.
Writing an AAH pattern to the CX bits will reset both counter 1 and counter 2, and all registers related to the
counters. Writing an AAH pattern to the SX bits forces the ADS7869 into a reset state; both the digital and the
analog sections are reset. The reset register is a write-only register. If the Reset register is read, the data 0000H
will be received. The format of the input word is shown in Table 1−26. To reset the complete ADS7869, the
pattern AAAAH should be written to the Reset register.
Once the Reset register activates a system reset, the register must not be rewritten to in order to deactivate
the reset condition. Writing another pattern to the CX bits (other than AAH) deactivates a reset condition of the
counters or a reset condition of the device.
For more information about reset conditions, see the Reset section.
Table 1−26. Reset Register
W0
W0
W0
W0
W0
W0
W0
W0
W0
W0
W0
W0
W0
W0
W0
S7
S6
S5
S4
S3
S2
S1
S0
C7
C6
C5
C4
C3
C2
C1
C0
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Bit 15−8:
S7−0: Reset control of entire ADS7869 (both digital and analog sections)
00000000 = No effect on ADS7869
...
10101001 = No effect on ADS7869
10101010 = Reset entire ADS7869
10101011 = No effect on ADS7869
...
11111111 = No effect on ADS7869
Bit 7−0:
C7−0: Reset control of both counters and related registers of ADS7869
00000000 = No effect on ADS7869
...
10101001 = No effect on ADS7869
10101010 = Reset both counters in ADS7869
10101011 = No effect on ADS7869
...
11111111 = No effect on ADS7869
48
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3.7
FIFO
The FIFO of the ADS7869 is organized as a 32-word ring buffer with 16 bits per word, shown in Figure 1−20.
30
31 32
1
2
3
4
29
28
5
Read Pointer
6
27
7
26
25
8
24
9
23
10
22
11
21
Data in FIFO
12
20
13
19
18
17 16 15
14
Free
Write Pointer
Figure 1−20. FIFO Structure
The converted data of the ADS7869 is automatically written into the FIFO. To control the writing and reading
process, a write pointer and a read pointer are used. The read pointer always shows the location that contains
the last read data. The write pointer indicates the location that contains the last written sample. The converted
values are written in a predefined sequence to the circular buffer, beginning with ADC1 and ending with ADC3.
The channel number is stored with the ADC data. The data of the FIFO is read through the FIFO register at
address 00H; its format is presented in Table 1−27. The table shows that the channel information for the
converted channel data, is continually maintained. The address 00H in the register map shows only the data
to which the read pointer is directed.
The FIFO generates the DAV signal; see Figure 1−22 on page 51. In VECANA mode, this signal is low; it
indicates that the ADS7869 is converting data (see Figure 1−10 on page 26). In the other modes, the DAV
indicates that data in the FIFO is available. The DAV signal can be configured as either a positive or negative
signal; see the Control Register section.
Table 1−27. FIFO 16-bit Data Read Format
ADDRESS
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
00H
0
0
0
0
ADC1 value, channel IU, included offset and gain compensation
00H
0
0
0
1
ADC1 value, channel A1, included offset and gain compensation
00H
0
0
1
0
ADC1 value, channel A2, included offset and gain compensation
00H
0
0
1
1
ADC2 value, channel IV, included offset and gain compensation
00H
0
1
0
0
ADC2 value, channel B1, included offset and gain compensation
00H
0
1
0
1
ADC2 value, channel B2, included offset and gain compensation
00H
0
1
1
0
ADC3 value, channel IW, included offset and gain compensation
00H
0
1
1
1
ADC3 value, channel AN1, included offset and gain compensation
00H
1
0
0
0
ADC3 value, channel AN2, included offset and gain compensation
00H
1
0
0
1
ADC3 value, channel AN3, included offset and gain compensation
00H
1
0
1
0
ADC1 value, channel AX, included offset and gain compensation
00H
1
0
1
1
ADC2 value, channel BX, included offset and gain compensation
00H
1
1
0
0
Not existing
00H
1
1
0
1
Not existing
00H
1
1
1
0
Not existing
00H
1
1
1
1
Not existing
D1
D0
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The DAV signal becomes active when the write pointer is ahead of the read pointer. The DAV signal becomes
inactive again when the read pointer equals the write pointer (that is, when the FIFO is empty).
When the ADCs are writing data into the FIFO, and the write pointer is more than 32 steps ahead of the read
pointer, a FF (FIFO Full) state will be set. FF is cleared when the first FIFO read operation is performed. To
synchronize the pointers after an FF state, the FIFO should be read out until a FE (FIFO Empty) occurs.
If a read is attempted, while the read and write pointers are equal, the read pointer will not increase; the same
data (the data with the same channel number) is read again. When this occurs, an FE state is set. The FE
state is cleared when new data is written into the FIFO. The read pointer will not go beyond the write pointer.
Both FF and FE go into the Interrupt section. The functional block diagram of the FIFO is shown in Figure 1−21.
The purpose of the test data is to verify the FIFO structure for the development of an application. This is
described in the FIFO Test Register section. This register should not be used in normal operation.
READ ADC
FIFO CONTROL
FIFO_FULL
INT
FIFO_EMPTY
ADC BUSY
DAV
TEST CLOCK
READ and W RITE
POINTER
TEST ENABLE
ADC1
ADC2
ADC3
FIFO
SHIFT
REG ISTER
FIFO M EM ORY
32 x 16
TEST DATA
Figure 1−21. FIFO Block Diagram
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DAV Timing Characteristics(1)
3.7.1
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
Delay time from 14th rising CLK to falling DAV(2)
tD1
Setup time from RD HIGH to next rising CLK
Delay time from rising CLK to rising DAV(2)(3)
tSU1
Setup time from CS HIGH to next rising CLK
Delay time from rising CLK to rising DAV(2)(3)
tSU2
Setup time from SPISTE HIGH to next rising CLK
Delay time from rising CLK to rising DAV(2)(3)
tSU3
MIN
MAX
UNIT
50
ns
8
ns
tD2
50
ns
8
ns
tD3
50
ns
8
ns
tD4
50
ns
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
(2) With the DAV bit in the Control register (14H), the DAV signal can have opposite polarity.
(3) Only applicable when the last data is read from the FIFO
CLK
1
2
3
4
12
13
14
HOLD
15
t D1
DAV
CLK
CS (1)
RD(1)
tSU1
DAV (1)
t D2
CS (2)
tSU2
DAV (2)
t D3
SPISTE (3)
t SU3
DAV (3)
t D4
(1) Parallel mode 11.
(2) Parallel mode 10 and TMS320C54xx mode.
(3) SPI mode.
Figure 1−22. Timing of the DAV Signal
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3.8
Digital Counter Modules
The interface of the ADS7869 for the analog position sensors has the following features:
•
Up to 16MHz operation frequency
•
Error-safe state machine for fully four−quadrant decoding
•
High noise immunity:
−
Differential signal inputs
−
Analog input comparators with hysteresis
−
Schmitt trigger digital inputs
•
Digital Noise Filter
•
16-bit binary Up/Down counters with over- and under-flow detection
•
Synchronous to the system clock
•
Asynchronous and synchronous latching of the counter values at the same time as the ADC values are sampled
and held
•
Five shadow registers
Digital Filter
State Machine
16−Bit
Binary Counters
16−Bit
Registers
A1p
A1n
A1
CNTA1
B1
CNTB1
FiltA1
EDGE
FiltB1
U/D
B1p
B1n
HOLD2
HOLD1
CLK
Figure 1−23. Block Diagram of a Counter Module
3.8.1
Operation
Analog position sensors have two signals on the output, sine and cosine. Both signals are differential and
positioned at 90 electrical degrees to each other. The sign comparators, with typically 75mV hysteresis,
process the position sensor output differential signal. This dramatically reduces the common-mode noise,
which is present in motor control applications. The digital output signal from the comparator is connected to
the counter input. Extra noise suppression is obtained with Schmitt trigger inputs. The digital signals are
carried through a programmable digital filter. The filtered, glitch-free signals are processed by a state machine,
which increments or decrements the counters. The counter values are then latched into corresponding
registers by the synchronous or asynchronous hold signals HOLD1 and HOLD2.
There is a counter module implemented for each pair of position sensor signals (A1, B1 and A2, B2). These
counters can count upwards or downwards, depending on the direction of the position sensor signal (that is,
the phase difference of the signals A1 and B1, respectively, or A2 and B2). These counter values are stored
in shadow registers when the ADC channels are sampled and held. The four position sensor channels and
the counter values are all sampled at the same time on the HOLD1 or HOLD2 signal.
With a 16MHz system clock, the maximum data rate that the counters will operate at is 2MHz.
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3.8.2
Digital Noise Filter
A digital noise filter rejects noise on the incoming quadrature signal. The digital noise filter rejects large, short
duration, noise spikes; false counts, triggered by noise or spikes, are also significantly suppressed. See
Figure 1−24.
FiltA1
Clk
CNTA1
Q
D
Clk
Q
D
Clk
Q
D
Clk
Q
D
Clk
CLK
FiltB1
Clk
CNTB1
Q
Clk
D
Q
Clk
D
Q
Clk
D
Q
D
Clk
CLK
Figure 1−24. Digital Noise Filter Block Diagram
The input signals, CntXY, are sampled on the rising clock edge. Before the signals are passed to the state
machine, the signals must be stable for a minimum of three consecutive rising clock edges. Pulses shorter
than two clock periods are rejected; glitches between rising clock edges are also ignored. See Figure 1−25.
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Filtered Timing Characteristics(1)
3.8.2.1
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
MIN
CLK Period
tC1
62.5
MAX
ns
Counter input signal, CNTA1 or CNTB1, Period
tC2
8
tC1
Counter input signal, CNTA1 or CNTB1, HIGH or LOW time
tW2
4
tC1
Delay between CNTA1 or CNTB1 signal, any combination
tD1
2
Filtered noise spike on CNTA1 or CNTB1 input HIGH or LOW Time
tW3
tC1
2
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
A1p
A1n
B1p
B1n
A1
B1
tC2
CNTA1
tW3
tW2
CNTB1
t D1
CLK
tC1
FiltA1
FiltB1
EDGE
U/D
Figure 1−25. Timing Diagram of the Counter Signals with the Digital Noise Filter Enabled
54
UNIT
tC1
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Unfiltered Timing Characteristics(1)
3.8.2.2
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
MIN
CLK Period
tC1
62.5
MAX
UNIT
ns
Counter input signal, CNTA1 or CNTB1, Period
tC2
8
tC1
Counter input signal, CNTA1 or CNTB1, HIGH or LOW time
tW2
4
tC1
Delay between CNTA1 or CNTB1 signal, any combination
tD1
2
tC1
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
A1p
A1n
B1p
B1n
A1
B1
tC2
CNTA1
t W2
CNTB1
t D1
CLK
tC1
FiltA1
FiltB1
EDGE
U/D
Figure 1−26. Timing Diagram of the Counter Signals with the Digital Noise Filter Disabled
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3.8.3
Binary Counters and Registers
The complete up/down counter includes two 16-bit counters and five 16-bit shadow registers. The first counter
is a 16-bit up/down counter, which counts upwards or downwards on the EDGE input signal as a function of
the U/D signal. This is the coarse angle counter, and it is called EDGECNT. For the fine angle computation,
the second 16-bit counter, TIMECOUNT, is implemented. This counter increments with the system clock and
resets when the EDGE signal occurs. The TIMECOUNT counter cannot be decremented. The system is
shown in Figure 1−27 and the timing is shown in Figure 1−28. The U/D signal is high, counting upwards, when
B1 runs before A1. The U/D signal is low, counting downwards, when A1 runs before B1. The EDGE signal
is set by every filtered edge of A1 and B1.
HOLD2
16−Bit
Register
LE
16−Bit UP/DN
Binary Counter
U/D
ASEDGCNT
UP/DN
HOLD1
EDGE
16−Bit
Register
CNT
EDGECNT
LE
SYEDGCNT
HOLD1
16−Bit UP/DN
Binary Counter
CLR
16−Bit
Register
LE
16−Bit
Register
LE
CLK
TIMECOUNT
EDGEPRD
SYEDGPRD
HOLD1
16−Bit
Register
LE
SYEDGTIME
Figure 1−27. Detail Counter Block Diagram
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When EDGECNT cause an over- or under-flow, the corresponding bit in the Interrupt Register is set. The
counter continues to increment or decrement in value. When the EDGE signal rises, the TIMECOUNT value
is latched into the shadow register EDGEPRD. The value of EDGEPRD is the number of system clocks
between two valid edges of the input signals from the comparators. This value is reciprocally proportional to
the angular speed of the position sensor. The value in the EDGEPRD register is latched in the SYEDGPRD
Register on the synchronous hold signal, HOLD1.
The EDGECNT and TIMECOUNT counter values are stored into the shadow registers (SYEDGCNT and
SYEDGPRD) with the synchronous hold signal, HOLD1, which samples the analog inputs. The value of the
SYEDGTIME Register represents the time between the last EDGE signal and the synchronous hold signal
HOLD1. The EDGECNT counter value is stored into a shadow register ASEDGCNT on the asynchronous
sample signal HOLD2.
The shadow registers SYEDGCNT, ASEDGCNT, SYEDGPRD and SYEDGTIME can be read through the
register map. The counter EDGECNT can be written through the address of the SYEDGCNT Register in the
register map. The 14 MSBs of the written data are stored in the EDGECNT register. The two LSBs are
determined from the inputs FiltA1 and FiltB1; see the Edge Count Register section. This is to prevent
inconsistency between the EDGECNT counters and the ADC data of the position sensor input signals.
F iltA1
F iltB1
EDGE
U/D
EDGECNT
N−2
N−1
N
N−1
N−2
N−3
N−4
N−5
HOLD1
N−2
SYEDGCNT
HOLD2
N−4
ASEDGCNT
CLK
EPNClk
T IM ECOUNT
EPTim e
EDGEPRD
EPNClk
EPNClk
EPNClk
EPNClk
EPNClk
SYEDGPRD
EPNClk
SYEDG TIME
EP Time
EPNClk
EPNClk
EPNClk
Figure 1−28. Detail Counter Timing Diagram
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3.9
Interrupt
The interrupt can have several sources:
•
FIFO full status
•
FIFO empty status
•
Two TIMECOUNT over- or under-flows
•
Two EDGECOUNT over- or under-flows
These six sources are combined into one interrupt signal. The interrupt signal is active high; when the interrupt
pin INT is high, one of the six sources is also high.
To reset an interrupt, the Interrupt Register must be read (see Interrupt Register section), in order to allow the
host to determine which source, or sources, caused the interrupt.
3.10 Reset
The ADS7869 can be forced into a reset state in three different ways:
•
Power−on.
•
Pulling the RST pin (reset pin 79) low.
•
Writing to the Reset Register.
In addition, the digital counters can be reset via the reset register, without resetting the entire ADS7869.
In a reset state, the analog inputs are sampled, the registers (in the register map) are forced into their reset
values, and the FIFO and the counters are cleared. One rising clock pulse during a reset condition is
necessary to reset the synchronous counters.
It takes one clock cycle for the ADS7869 to begin the normal operation after the last reset condition is cleared.
(See Figure 1−29.)
3.10.1 Reset Timing Characteristics (1)
Over recommended operating free-air temperature range at –40_C to +85_C, AVDD = 5V, BVDD = 3V − 5V.
PARAMETER
SYMBOL
MIN
Setup time from RST LOW to rising CLK
tSU1
10
MAX
ns
Hold time from rising CLK to RST HIGH
tH1
5
ns
(1) All input signals are specified with tR = tF = 5ns (10% to 90% of BVDD) and timed from a voltage level of (VIL + VIH)/2.
CLK
t SU1
tH1
RST
Figure 1−29. Timing Diagram of the Reset Signal RST
58
UNIT
PACKAGE OPTION ADDENDUM
www.ti.com
1-Nov-2004
PACKAGING INFORMATION
ORDERABLE DEVICE
STATUS(1)
PACKAGE TYPE
PACKAGE DRAWING
PINS
PACKAGE QTY
ADS7869IPZTR
ACTIVE
TQFP
PZT
100
1000
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
MECHANICAL DATA
MTQF012B – OCTOBER 1994 – REVISED DECEMBER 1996
PZT (S-PQFP-G100)
PLASTIC QUAD FLATPACK
0,27
0,17
0,50
75
0,08 M
51
76
50
100
26
0,13 NOM
25
1
12,00 TYP
Gage Plane
14,20
SQ
13,80
16,20
SQ
15,80
0,25
0,05 MIN
1,05
0,95
0°– 7°
0,75
0,45
Seating Plane
1,20 MAX
0,08
4073179 / B 11/96
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Falls within JEDEC MS-026
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1