AD AD7641BSTZ

FEATURES
Multiple pins/software programmable input ranges:
±10V, ±5V, 10V, 5V
iCMOS™ process technology
Pins or serial SPI input ranges/mode selection
Throughput:
670kSPS (AD7634)
250kSPS (AD7631)
INL: ± 1.75 LSB (7± ppm of full scale)
DNL: +2/-1 LSB
18-bit resolution with no missing codes
Dynamic range: 102.5 dB typical
SNR: 101 dB typical
THD: -122 dB typical
5V internal reference: typical drift 7ppm/°C; TEMP output
No pipeline delay (SAR architecture)
Parallel (18, 16- or 8-bit bus) and serial 5 V/3.3 V interface
SPI®-/QSPI™-/MICROWIRE™-/DSP-compatible
Power dissipation:
190 mW @ 670kSPS
75 mW @ 250kSPS
Pb-free 48-lead LQFP and LFCSP (7x7mm) packages
Pin compatible with other PulSAR ADCs
APPLICATIONS
Process control
High speed data acquisition
Digital signal processing
Spectrum analysis
Instrumentation
Communications
GENERAL DESCRIPTION
The AD7631/AD7634 is an18-bit, charge redistribution
successive approximation register (SAR) architecture analog-todigital converter (ADC) with programmable input ranges and
mode selection via a dedicated write only serial interface (or by
hardware pin-strapping). The device is fabricated on ADI’s
patented iCMOS high voltage process. The device contains a
high speed 18-bit sampling ADC, an internal conversion clock,
an internal reference (and buffer), and both serial and parallel
system interface ports. Power consumption is automatically
scaled with throughput (AD7634 in Impulse mode), making it
ideal for battery-powered applications. It is available in Pb-free,
48-lead packages with operation specified from −40°C to
+85°C.
FUNCTIONAL BLOCK DIAGRAM
TEMP REFBUFIN REF REFGND VCC VEE
DVDD DGND
OVDD
AD7631/
AD7634
AGND
AVDD
SERIAL
PROGRAMMABLE
PORT
REF AMP
IN+
SWITCHED
CAP DAC
IN-
PDREF
SPPCLK
SPPDATA
HW/SW
SERIAL DATA
PORT
18
D[17:0]
BUSY
CLOCK
PARALLEL
INTERFACE
PDBUF
PD
OGND
SPPEN
REF
CONTROL LOGIC AND
CALIBRATION CIRCUITRY
RD
CS
RESET
D0/OB/2C
CNVST WARP IMPULSE
MODE0
-001
Preliminary Technical Data
18-Bit 250/670 kSPS PulSAR®
Bipolar Programmable Inputs ADC
AD7631/AD7634
MODE1
Figure 1.
Table 1. PulSAR® Selection
Type/kSPS
Pseudo
Differential
True Bipolar
True
Differential
18-Bit
Multichannel/
Simultaneous
100 to
250
AD7651,
AD7660
AD7661
AD7610,
AD7663
AD7675
AD7631
AD7678
500 to
570
AD7650
AD7652
AD7664
AD7666
AD7665
AD7676
AD7679
650 to
1000
AD7653
AD7667
AD7612,
AD7671
AD7677
AD7634
AD7674
>1000
AD7621
AD7622
AD7623
AD7641
AD7643
AD7654
AD7655
PRODUCT HIGHLIGHTS
1.
2.
3.
4.
5.
Programmable input range and mode selection.
Dedicated write only serial port used for selecting input
range and mode select (mode select AD7634 only).
Fast throughput
The AD7634 is 670kSPS and the AD7631 is 250kSPS.
Superior Linearity.
No missing 18-bit code. +/- 1.75 LSB typical INL
Internal Reference.
5 V internal reference with a typical drift of ±7 ppm/°C
and on-chip TEMP sensor.
Serial or Parallel Interface.
Versatile parallel (18, 16- or 8-bit bus) or 2-wire serial
interface arrangement compatible with 3.3 V, or 5 V logic.
Rev. PrC
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2006 Analog Devices, Inc. All rights reserved.
AD7631/AD7634
Preliminary Technical Data
TABLE OF CONTENTS
Features .............................................................................................. 1
Absolute Maximum Ratings ............................................................8
Applications....................................................................................... 1
ESD Caution...................................................................................8
General Description ......................................................................... 1
Pin Configuration and Function Descriptions..............................9
Functional Block Diagram .............................................................. 1
Terminology .................................................................................... 13
Product Highlights ........................................................................... 1
Outline Dimensions ....................................................................... 14
Revision History ............................................................................... 2
Ordering Guide .......................................................................... 14
Specifications..................................................................................... 3
Timing Specifications....................................................................... 6
REVISION HISTORY
Rev. PrC | Page 2 of 14
Preliminary Technical Data
AD7631/AD7634
SPECIFICATIONS
AVDD = DVDD = 5 V; OVDD = 2.7 V to 5.5 V; VCC = 15V; VEE = -15V; VREF = 5 V; all specifications TMIN to TMAX, unless otherwise noted.
Table 2.
Parameter
RESOLUTION
ANALOG INPUT 1
Differential Voltage Range
0 to 5V
0 to 10V
±5V
±10V
Operating Input Voltage Range
0 to 5V
0 to 10V
±5V
±10V
Common Mode Voltage range
0 to 5V
0 to 10V
Bipolar ranges
Analog Input CMRR
Input Current
Input Current
Input Impedance
THROUGHPUT SPEED
Complete Cycle
Throughput Rate
Time between Conversions
Complete Cycle
Throughput Rate
Complete Cycle
Throughput Rate
Complete Cycle
Throughput Rate
DC ACCURACY
Integral Linearity Error 2
No Missing Codes
Differential Linearity Error
Transition Noise
Bipolar Offset Error
Bipolar Offset Error Temperature Drift
Bipolar Full-Scale Error
Bipolar Full-Scale Error Temperature Drift
Power Supply Sensitivity
Conditions
Min
18
Typ
Max
VIN+ - VIN−
VIN+ - VIN−
VIN+ - VIN−
VIN+ - VIN−
-VREF
-2VREF
-2VREF
-4VREF
VREF
2VREF
2VREF
4VREF
(VIN+, VIN−) to AGND
(VIN+, VIN−) to AGND
(VIN+, VIN−) to AGND
(VIN+, VIN−) to AGND
-0.1V
-0.1V
-VREF – 0.1V
-2VREF – 0.1V
VREF + 0.1V
2VREF + 0.1V
VREF + 0.1V
2VREF + 0.1V
VIN+, VIN−
VIN+, VIN−
VIN+, VIN−
fIN = 100 kHz
@ 670 kSPS throughput
@ 250 kSPS throughput
VREF/2 – 0.1V
VREF – 0.2V
–0.1V
Unit
Bits
T
AD7634 in Warp mode
AD7634 in Warp mode
AD7634 in Warp mode
AD7634 in Normal mode
AD7634 in Normal mode
AD7634 in Impulse
AD7634 in Impulse mode
AD7631
AD7631
VREF/2
VREF
0
TBD
TBD
TBD
0
0
0
±1.75
18
−1
AVDD = 5 V ± 5%
Rev. PrC | Page 3 of 14
dB
μA
μA
1.49
670
1
1.75
570
2.22
450
4
250
1
VREF = 5V, PDREF = PDBUF = High
VREF/2 + 0.1V
VREF + 0.2V
0.1V
+2
0.75
10
TBD
±60
TBD
TBD
μs
kSPS
ms
μs
kSPS
μs
kSPS
μs
kSPS
LSB 3
Bits
LSB
LSB
LSB
ppm/°C
LSB
ppm/°C
LSB
AD7631/AD7634
Parameter
AC ACCURACY
Dynamic Range
Signal-to-Noise
Spurious-Free Dynamic Range
Total Harmonic Distortion
Signal-to-(Noise + Distortion)
–3 dB Input Bandwidth
SAMPLING DYNAMICS
Aperture Delay
Aperture Jitter
Transient Response
INTERNAL REFERENCE
Output Voltage
Temperature Drift
Line Regulation
Turn-On Settling Time
REFERENCE BUFFER
REFBUFIN Input Voltage Range
EXTERNAL REFERENCE
Voltage Range
Current Drain
Current Drain
TEMPERATURE PIN
Voltage Output
Temperature Sensitivity
Output Resistance
DIGITAL INPUTS
Logic Levels
VIL
VIH
IIL
IIH
DIGITAL OUTPUTS
Data Format 5
Pipeline Delay 6
VOL
VOH
POWER SUPPLIES
Specified Performance
AVDD
DVDD
OVDD
VCC
VEE
Preliminary Technical Data
Conditions
VIN = ±5V,
VIN = ±5V,
VIN = ±5V,
VIN = ±5V,
VIN = ±5V,
Min
fIN = 2 kHz, -60dB
fIN = 2 kHz
fIN = 2 kHz
fIN = 2 kHz
fIN = 2 kHz
Full-scale step
PDREF = PDBUF = low
REF @ 25°C
–40°C to +85°C
AVDD = 5 V ± 5%
CREF = 10 μF
PDREF = high
Typ
Max
102.5
101
122
-106
100
12
dB 4
dB
dB
dB
dB
MHz
1
5
ns
ps rms
ns
115
4.985
5.000
±7
±15
5
5.015
2.5
PDREF = PDBUF = high
REF
AD7634 @ 670 kSPS throughput
AD7631 @ 250 kSPS throughput
5
TBD
TBD
TEMP @ 25°C
–0.3
2.1
–1
–1
AVDD+0.1
5
5
15
-15
Rev. PrC | Page 4 of 14
V
μA
μA
mV
mV/°C
kΩ
+0.6
OVDD+0.3
+1
+1
V
V
μA
μA
0.4
V
V
5.25
5.25
5.25
V
V
V
V
V
OVDD − 0.6
4.75
4.75
2.7
V
ppm/°C
ppm/V
ms
V
TBD
1
4
ISINK = 500 μA
ISOURCE = −500 μA
Unit
Preliminary Technical Data
Parameter
Operating Current 7
AVDD 8
DVDD
OVDD
VCC
VEE
VCC
VEE
Power Dissipation
With Internal Reference7
With Internal Reference7
Without Internal Reference
Without Internal Reference7
In Power-Down Mode 9
TEMPERATURE RANGE 10
Specified Performance
AD7631/AD7634
Conditions
PDREF = PDBUF = low
AD7631 @ 250kSPS throughput
AD7634 @ 670kSPS throughput
AD7631 @ 250kSPS throughput
AD7634 @ 670kSPS throughput
AD7631 @ 250kSPS throughput
AD7634 @ 670kSPS throughput
AD7631 @ 250kSPS throughput
AD7631 @ 250kSPS throughput
AD7634 @ 670kSPS throughput
AD7634 @ 670kSPS throughput
Min
AD7631 @ 250kSPS throughput
AD7634 @ 670kSPS throughput
AD7631 @ 250kSPS throughput
AD7634 @ 670kSPS throughput
PD = high
TMIN to TMAX
−40
1
Typ
Max
8.5
21
3.5
7
0.1
0.2
1
0.6
2.8
2
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
75
190
62
160
2
mW
mW
mW
μW
+85
The inputs are differential anti-phase. Refer to the Error! Reference source not found. section.
Linearity is tested using endnotes, not best fit.
LSB means least significant bit. With the 0 to 5V input range, 1 LSB 38.15μV.
4
All specifications in dB are referred to a full-scale input FSR. Tested with an input signal at 0.5 dB below full-scale, unless otherwise specified.
5
Parallel or serial 18-bit.
6
Conversion results are available immediately after completed conversion.
7
Tested in parallel reading mode.
8
With internal reference, PDREF and PDBUF are low; without internal reference, PDREF and PDBUF are high.
9
With all digital inputs forced to OVDD.
10
Consult sales for extended temperature range.
2
3
Rev. PrC | Page 5 of 14
Unit
°C
AD7631/AD7634
Preliminary Technical Data
TIMING SPECIFICATIONS
AVDD = DVDD = 5 V; OVDD = 2.7 V to 5.5 V; VCC = 15V; VEE = -15V; VREF = 5 V; all specifications TMIN to TMAX, unless otherwise noted.
Table 3.
Parameter
CONVERSION AND RESET
Convert Pulse Width
Time Between Conversions (Warp Mode/Normal Mode 1 )
AD7631
AD7634 (Warp Mode/Normal Mode/Impulse Mode) 2
CNVST Low to BUSY High Delay
BUSY High All Modes (Except Master Serial Read After Convert)
AD7631
AD7634 (Warp Mode/Normal Mode/Impulse Mode)
Aperture Delay
End of Conversion to BUSY Low Delay
Conversion Time
AD7631
AD7634 (Warp Mode/Normal Mode/Impulse Mode)
Acquisition Time
AD7631
AD7634 (Warp Mode/Normal Mode/Impulse Mode)
RESET Pulse Width
Symbol
Min
Typ
t1
t2
10
ns
ns
4
1.49/1.75/2.22
μs
μs
ns
35
t3
t4
t5
t6
t7
Max
Unit
TBD
TBD
μs
μs
ns
ns
TBD
TBD
μs
μs
2
10
t8
t9
250
250
10
ns
ns
ns
PARALLEL INTERFACE MODES
CNVST Low to DATA Valid Delay
AD7631
AD7634 (Warp Mode/Normal Mode/Impulse Mode)
DATA Valid to BUSY Low Delay
Bus Access Request to DATA Valid
Bus Relinquish Time
t10
1.5
1/1.25/1.5
t11
t12
t13
45
15
μs
μs
ns
ns
ns
10
10
10
ns
ns
ns
12
5
MASTER SERIAL INTERFACE MODES 3
CS Low to SYNC Valid Delay
CS Low to Internal SCLK Valid Delay
CS Low to SDOUT Delay
CNVST Low to SYNC Delay
AD7631
AD7634 (Warp Mode/Normal Mode/Impulse Mode)
SYNC Asserted to SCLK First Edge Delay
Internal SCLK Period 4
Internal SCLK High4
Internal SCLK Low4
SDOUT Valid Setup Time4
SDOUT Valid Hold Time4
SCLK Last Edge to SYNC Delay4
CS High to SYNC HI-Z
CS High to Internal SCLK HI-Z
CS High to SDOUT HI-Z
t14
t15
t16
t17
525
25/275/525
t18
t19
t20
t21
t22
t23
t24
t25
t26
t27
Rev. PrC | Page 6 of 14
3
25
12
7
4
2
3
40
10
10
10
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Preliminary Technical Data
AD7631/AD7634
Parameter
Symbol
Min
Typ
Max
Unit
See
4
BUSY High in Master Serial Read after Convert
CNVST Low to SYNC Asserted Delay (all Modes)
AD7631
AD7634 (Warp Mode/Normal Mode/Impulse Mode)
SYNC Deasserted to BUSY Low Delay
Table 4
t28
t29
t30
SLAVE SERIAL INTERFACE MODES
External SCLK Setup Time
External SCLK Active Edge to SDOUT Delay
SDIN Setup Time
SDIN Hold Time
External SCLK Period
External SCLK High
External SCLK Low
ns
ns
ns
ns
TBD
TBD
25
t31
t32
t33
t34
t35
t36
t37
5
1
5
5
12.5
5
5
8
ns
ns
ns
ns
ns
ns
ns
1
In warp mode only, the maximum time between conversions is 1 ms; otherwise, there is no required maximum time.
In warp mode only, the time between conversions is 1 ms; otherwise, there is no required maximum time.
3
In serial interface modes, the SYNC, SCLK, and SDOUT timings are defined with a maximum load CL of 10 pF; otherwise, the load is 60 pF maximum.
4
In serial master read during convert mode. See Error! Reference source not found. for serial master read after convert mode timing specifications.
2
Table 4. Serial Clock Timings in Master Read After Convert Mode
DIVSCLK[1]
DIVSCLK[0]
SYNC to SCLK First Edge Delay Minimum
Internal SCLK Period Minimum
Internal SCLK Period Maximum
Internal SCLK High Minimum
Internal SCLK Low Minimum
SDOUT Valid Setup Time Minimum
SDOUT Valid Hold Time Minimum
SCLK Last Edge to SYNC Delay Minimum
BUSY High Width Maximum (Warp mode)
BUSY High Width Maximum (Normal mode)
BUSY High Width Maximum (Impulse mode)
Symbol
t18
t19
t19
t20
t21
t22
t23
t24
t28
t28
t28
Rev. PrC | Page 7 of 14
0
0
3
25
40
12
7
4
2
3
1.75
2
2.25
0
1
17
60
80
22
21
18
4
60
2.5
2.75
3
1
0
17
120
160
50
49
18
30
140
4
4.25
4.5
1
1
17
240
320
100
99
18
89
300
7
7.25
7.5
Unit
ns
ns
ns
ns
ns
ns
ns
ns
μs
μs
μs
AD7631/AD7634
Preliminary Technical Data
ABSOLUTE MAXIMUM RATINGS
Table 5.
Parameter
Analog Inputs/Outputs
IN+, IN−, REF, REFBUFIN, TEMP,
INGND, REFGND to AGND
Ground Voltage Differences
AGND, DGND, OGND
Supply Voltages
AVDD, DVDD
OVDD
AVDD to DVDD
AVDD, DVDD to OVDD
Digital Inputs
PDREF, PDBUF
Internal Power Dissipation1
Internal Power Dissipation2
Junction Temperature
Storage Temperature Range
Rating
AVDD + 0.3 V to
AGND − 0.3 V
±0.3 V
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
−0.3 V to +2.7 V
−0.3 V to +3.8 V
±2.8 V
−3.8 V to +2.8 V
−0.3 V to +5.5 V
±20 mA
700 mW
2.5 W
125°C
–65°C to +125°C
1. Specification is for the device in free air:
48-Lead LQFP; θJA = 91°C/W, θJC = 30°C/W.
2. Specification is for the device in free air:
48-Lead LFCSP; θJA = 26°C/W.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
500µA
TO OUTPUT
PIN
IOL
1.4V
CL
50pF
2V
0.8V
tDELAY
tDELAY
2V
0.8V
2V
0.8V
Figure 3. Voltage Reference Levels for Timing
Figure 2. Load Circuit for Digital Interface Timing,
SDOUT, SYNC, and SCLK Outputs, CL = 10 pF
Rev. PrC | Page 8 of 14
04761-003
IOH
04761-002
500µA
NOTE
IN SERIAL INTERFACE MODES, THE SYNC, SCLK, AND
SDOUT TIMING ARE DEFINED WITH A MAXIMUM LOAD
CL OF 10pF; OTHERWISE, THE LOAD IS 60pF MAXIMUM.
Preliminary Technical Data
AD7631/AD7634
REFGND
REF
IN–
VCC
VEE
IN+
AGND
AVDD
PDBUF
PDREF
REFBUFIN
TEMP
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
48 47 46 45 44 43 42 41 40 39 38 37
36 BIPOLAR
PIN 1
IDENTIFIER
35 CNVST
MODE0 3
MODE1 4
D0/OB/2C 5
WARP 6
34 PD
33 RESET
32 CS
AD7631/AD7634
31 RD
TOP VIEW
(Not to Scale)
IMPULSE 7
30 TEN
D1/A0 8
D2/A1 9
29 BUSY
28 D17/SPPEN
D3 10
27 D16/SPPCLK
D4DIVSCLK[0] 11
D5/DIVSCLK[1] 12
25 D14/HW/SW
D13/RDERROR
D11/SCLK
D12/SYNC
DVDD
DGND
D10/SDOUT
OVDD
D9/RDC/SDIN
OGND
13 14 15 16 17 18 19 20 21 22 23 24
D6/EXT/INT
D7/INVSYNC
D8/INVSCLK
NC = NO CONNECT
26 D15/SPPDATA
-004
AGND 1
AVDD 2
Figure 4. Pin Configuration
Table 6. Pin Function Descriptions
Pin
No.
1, 42
2, 44
3, 4
Mnemonic
AGND
AVDD
MODE[0:1]
Type 1
P
P
DI
5
D0/OB/2C
DI/O
6
WARP
DI
7
IMPULSE
DI
8
D1/A0
DI/O
9
D2/A1
DI/O
10
D3
D0
Description
Analog Power Ground Pin.
Input Analog Power Pins. Nominally 5 V.
Data Output Interface Mode Selection.
Interface MODE#
MODE1
MODE0
Description
0
0
0
18-bit interface
1
0
1
16-bit interface
2
1
0
8-bit (byte) interface
3
1
1
Serial interface
When MODE[1:0] = 0 (18-bit interface mode), this pin is Bit 0 of the parallel port data output bus
and the data coding is straight binary. In all other modes, this pin allows the choice of straight
binary/twos complement. When OB/2C is high, the digital output is straight binary; when low,
the MSB is inverted resulting in a twos complement output from its internal shift register.
AD7634: Conversion Mode Selection. When WARP = high and IMPULSE = low, this selects warp mode.
In this mode, the maximum throughput is achievable, and a minimum conversion rate must be applied
to guarantee full specified accuracy.
When WARP = low and IMPULSE = low, this selects normal mode where full accuracy is maintained
independent of the minimum conversion rate.
AD7631: Connect to DGND.
AD7634: Conversion Mode Selection. When IMPULSE = high and WARP = low, this input selects impulse
mode, a reduced power mode. In this mode, the power dissipation is approximately scaled
proportional to the sampling rate.
AD7631: Connect to DGND.
When MODE[1:0] = 0, this pin is Bit 1 of the parallel port data output bus. In all other modes, this
input pin controls the form in which data is output as shown in Table 7.
When MODE[1:0] = 0, this pin is Bit 2 of the parallel port data output bus.
When MODE[1:0] = 1 or 2, this input pin controls the form in which data is output as shown in Table 7.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 3 of the parallel port data output bus.
This pin is always an output, regardless of the interface mode.
Rev. PrC | Page 9 of 14
AD7631/AD7634
Pin
No.
11, 12
Preliminary Technical Data
Mnemonic
D[4:5]
or DIVSCLK[0:1]
Type 1
DI/O
13
D6
or EXT/INT
DI/O
14
D7
or INVSYNC
DI/O
15
D8
or INVSCLK
DI/O
16
D9
or RDC
DI/O
or SDIN
17
18
OGND
OVDD
P
P
19
20
21
DVDD
DGND
D10
or SDOUT
P
P
DO
22
D11
or SCLK
DI/O
23
D12
or SYNC
DO
Description
When MODE[1:0] = 0, 1, or 2, these pins are Bit 4 and Bit 5 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), serial clock division selection. When using serial master read
after convert mode (EXT/INT = low, RDC/SDIN = low), these inputs can be used to slow down the
internally generated serial clock that clocks the data output. In other serial modes, these pins are
high impedance outputs.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 6 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), serial clock source select. This input is used to select the
internally generated (master) or external (slave) serial data clock.
When EXT/INT = low, master mode. The internal serial clock is selected on SCLK output.
When EXT/INT = high, slave mode. The output data is synchronized to an external clock signal,
gated by CS, connected to the SCLK input.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 7 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), invert sync select. In serial master mode (EXT/INT = low), this
input is used to select the active state of the SYNC signal.
When INVSYNC = low, SYNC is active high.
When INVSYNC = high, SYNC is active low.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 8 of the parallel port data output bus.
When MODE[1:0] = 3, invert SCLK select. In all serial modes, this input is used to
invert the SCLK signal.
When MODE[1:0] = 0, 1, or 2, this output is used as bit 9 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), read during convert. When using serial master mode
(EXT/INT = low), RDC is used to select the read mode.
When RDC = high, the previous conversion result is output on SDOUT during conversion and
the period of SCLK changes.
When RDC = low (read after convert), the current result can be output on SDOUT only when
the conversion is complete.
When MODE[1:0] = 3 (serial mode), serial data in. When using serial slave mode, (EXT/INT = high),
SDIN could be used as a data input to daisy-chain the conversion results from two or more ADCs
onto a single SDOUT line. The digital data level on SDIN is output on SDOUT with a delay of 18 SCLK
periods after the initiation of the read sequence.
Input/Output Interface Digital Power Ground.
Input/Output Interface Digital Power. Nominally at the same supply as the supply of the
host interface (2.7 V to 5V).
Digital Power. Nominally at 5 V.
Digital Power Ground.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 10 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), serial data output. In serial mode, this pin is used as the serial
data output synchronized to SCLK. Conversion results are stored in an on-chip register. The ADC
provides the conversion result, MSB first, from its internal shift register. The data format is
determined by the logic level of OB/2C.
In master mode, EXT/INT = low. SDOUT is valid on both edges of SCLK.
In slave mode, EXT/INT = high:
When INVSCLK = low, SDOUT is updated on SCLK rising edge and valid on the next falling edge.
When INVSCLK = high, SDOUT is updated on SCLK falling edge and valid on the next rising edge.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 11 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), serial clock. In all serial modes, this pin is used as the serial
data clock input or output, depending upon the logic state of the EXT/INT pin. The active edge
where the data SDOUT is updated depends on the logic state of the INVSCLK pin.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 12 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), frame synchronization. In serial master mode (EXT/INT= low),
this output is used as a digital output frame synchronization for use with the internal data clock.
Rev. PrC | Page 10 of 14
Preliminary Technical Data
Pin
No.
Mnemonic
Type 1
24
D13
or RDERROR
DO
25
D14
or HW/SW
DI/O
26
D15
or SPPDATA
DI/O
27
D16
or SPPCLK
DI/O
28
D17
or SPPEN
DI/O
29
BUSY
DO
30
TEN
DI
31
RD
DI
32
CS
DI
33
RESET
DI
34
PD
DI
35
CNVST
DI
36
BIP
DI
37
REF
AI/O
AD7631/AD7634
Description
When a read sequence is initiated and INVSYNC = low, SYNC is driven high and remains high
while SDOUT output is valid.
When a read sequence is initiated and INVSYNC = high, SYNC is driven low and remains low
while SDOUT output is valid.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 13 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), read error. In serial slave mode (EXT/INT = high), this output
is used as an incomplete read error flag. If a data read is started and not completed when the
current conversion is complete, the current data is lost and RDERROR is pulsed high.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 14 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode) hardware/software select. This input, part of the serial
programmable port, is used to select hardware or software input ranges and mode selection.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 15 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), serial programmable port data. This input is used to write in the
serial programmable port data when HW/SW = low.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 16 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), serial programmable port clock. This input is used to clock in the
data on SPPDATA. The active edge where the data SPPDATA is updated depends on the logic state of
the INVSCLK pin.
When MODE[1:0] = 0, 1, or 2, this output is used as Bit 17 of the parallel port data output bus.
When MODE[1:0] = 3 (serial mode), serial programmable port enable. Asserting this input enables the
serial programmable port.
Busy Output. Transitions high when a conversion is started and remains high until the conversion
is complete and the data is latched into the on-chip shift register. The falling edge of BUSY can be
used as a data-ready clock signal.
10 Volt Input Range. Refer to Table 8.
When MODE[1:0] = 0, 1, or 2, this input is used to select the 10V input range.
When MODE[1:0] = 3 (serial mode), and
HW/SW = high, driving TEN high selects the 10 Volt input range.
HW/SW = low, the input range is programmed with the serial programmable port and this pin is a
don’t care.
Read Data. When CS and RD are both low, the interface parallel or serial output bus is enabled.
Chip Select. When CS and RD are both low, the interface parallel or serial output bus is enabled.
CS is also used to gate the external clock in slave serial mode.
Reset Input. When high, resets the ADC. Current conversion, if any, is aborted. Falling edge of
RESET enables the calibration mode indicated by pulsing BUSY high. If not used, this pin can be tied to
DGND.
Power-Down Input. When high, power downs the ADC. Power consumption is reduced and
conversions are inhibited after the current one is completed.
Conversion Start. A falling edge on CNVST puts the internal sample-and-hold into the hold state
and initiates a conversion.
Bipolar Input Range. Refer to Table 8.
When MODE[1:0] = 0, 1, or 2, this input is used to select the bipolar input range.
When MODE[1:0] = 3 (serial mode), and
HW/SW = high, driving BIP high selects the bipolar input range.
HW/SW = low, the input range is programmed with the serial programmable port and this pin is a
don’t care.
Reference Output/Input.
When PDREF/PDBUF = low, the internal reference and buffer are enabled producing 5 V on this pin.
When PDREF/PDBUF = high, the internal reference and buffer are disabled allowing an externally
supplied voltage reference up to AVDD volts. Decoupling is required with or without the internal
reference and buffer.
Rev. PrC | Page 11 of 14
AD7631/AD7634
Preliminary Technical Data
Pin
No.
38
39
40
41
43
45
46
Mnemonic
REFGND
IN−
VCC
VEE
IN+
TEMP
REFBUFIN
Type 1
AI
AI
P
P
AI
AO
AI/O
47
PDREF
DI
48
PDBUF
DI
1
Description
Reference Input Analog Ground.
Differential Negative Analog Input; referenced to IN+.
High Voltage Positive Supply.
High Voltage Negative Supply.
Differential Positive Analog Input; referenced to IN-.
Temperature Sensor Analog Output.
Reference Buffer Input.
When using an external reference with the internal buffer (PDBUF = low, PDREF = high), applying 2.5V
on this pin produces 5V on the REF pin.
When using the internal reference (PDBUF = PDREF = low), this pin should not be connected.
Internal Reference Power-Down Input.
When low, the internal reference is enabled (PDBUF also needs to be low).
When high, the internal reference is powered down and an external reference must been used.
Internal Reference Buffer Power-Down Input.
When low, the buffer is enabled (PDREF also needs to be low).
When high, the buffer is powered-down and an external reference must be used.
AI = analog input; AI/O = bidirectional analog; AO = analog output; DI = digital input; DI/O = bidirectional digital; DO = digital output; P = power.
Table 7. Data Bus Interface Definition
MODE
MODE1
MODE0
0
1
0
0
0
1
1
0
1
2
1
0
2
1
0
2
1
0
2
1
0
3
1
1
D0/OB/2C
R[0]
OB/2C
D1/A0
D2/A1
D[3]
D[4:9]
D[10:11]
D[12:15]
D[16:17]
Description
R[1]
A0 = 0
R[2]
R[2]
R[3]
R[3]
R[4:9]
R[4:9]
R[10:11]
R[10:11]
R[12:15]
R[12:15]
R[16:17]
R[16:17]
18-Bit Parallel
16-Bit High Word
OB/2C
OB/2C
A0 = 1
R[0]
R[1]
A0 = 0
A1 = 0
All Hi-Z
R[10:11]
R[12:15]
R[16:17]
8-Bit High Byte
OB/2C
OB/2C
A0 = 0
A1 = 1
All Hi-Z
R[2:3]
R[4:7]
R[8:9]
8-Bit Mid Byte
A0 = 1
A1 = 0
All Hi-Z
R[0:1]
OB/2C
OB/2C
A0 = 1
A1 = 1
All Hi-Z
All Hi-Z
Table 8. Input Range Selection. Parallel Mode and Serial Hardware Mode
1
Range
BIP
TEN
0 - 5V
0 - 10V
±5V
±10V
All Ranges 1
Low
Low
High
High
X
Low
High
Low
High
X
HW/SW (serial
mode)
High
High
High
High
Low
In serial mode (MODE[1:0] = 3) when HW/SW = low, the input ranges are defined by registers.
Rev. PrC | Page 12 of 14
All Zeros
16-Bit Low Word
All Zeros
All Zeros
Serial Interface
R[0:1]
8-Bit Low Byte
8-Bit Low Byte
Serial Interface
Preliminary Technical Data
AD7631/AD7634
TERMINOLOGY
Integral Nonlinearity Error (INL)
Linearity error refers to the deviation of each individual code
from a line drawn from negative full scale through positive full
scale. The point used as negative full scale occurs ½ LSB before
the first code transition. Positive full scale is defined as a level
1½ LSB beyond the last code transition. The deviation is
measured from the middle of each code to the true straight line.
Differential Nonlinearity Error (DNL)
In an ideal ADC, code transitions are 1 LSB apart. Differential
nonlinearity is the maximum deviation from this ideal value. It
is often specified in terms of resolution for which no missing
codes are guaranteed.
Gain Error
The first transition (from 000…00 to 000…01) should occur for
an analog voltage ½ LSB above the nominal negative full scale
(19.073486 V for the 0 to 5V range). The last transition (from
111…10 to 111…11) should occur for an analog voltage
1½ LSB below the nominal full scale (+4.999943 V for the 0 to
5V V range). The gain error is the deviation of the difference
between the actual level of the last transition and the actual
level of the first transition from the difference between the ideal
levels.
Total Harmonic Distortion (THD)
THD is the ratio of the rms sum of the first five harmonic
components to the rms value of a full-scale input signal and is
expressed in decibels.
Signal to (Noise + Distortion) Ratio (SINAD)
SINAD is the ratio of the rms value of the actual input signal to
the rms sum of all other spectral components below the Nyquist
frequency, including harmonics but excluding dc. The value for
SINAD is expressed in decibels.
Spurious-Free Dynamic Range (SFDR)
The difference, in decibels (dB), between the rms amplitude of
the input signal and the peak spurious signal.
Effective Number of Bits (ENOB)
ENOB is a measurement of the resolution with a sine wave
input. It is related to SINAD and is expressed in bits by
ENOB = [(SINADdB − 1.76)/6.02]
Aperture Delay
Aperture delay is a measure of the acquisition performance and
is measured from the falling edge of the CNVST input to when
the input signal is held for a conversion.
Zero Error
The zero error is the difference between the ideal midscale
input voltage (0 V) and the actual voltage producing the
midscale output code.
Transient Response
The time required for the AD7641 to achieve its rated accuracy
after a full-scale step function is applied to its input.
Dynamic Range
It is the ratio of the rms value of the full scale to the rms noise
measured with the inputs shorted together. The value for
dynamic range is expressed in decibels.
It is derived from the typical shift of output voltage at 25°C on a
sample of parts maximum and minimum reference output
voltage (VREF) measured at TMIN, T(25°C), and TMAX. It is
expressed in ppm/°C using
Reference Voltage Temperature Coefficient
Signal-to-Noise Ratio (SNR)
SNR is the ratio of the rms value of the actual input signal to the
rms sum of all other spectral components below the Nyquist
frequency, excluding harmonics and dc. The value for SNR is
expressed in decibels.
TCVREF (ppm/°C ) =
VREF ( Max ) − VREF ( Min)
× 106
VREF (25°C ) × (TMAX − TMIN )
where:
VREF (Max) = Maximum VREF at TMIN, T(25°C), or TMAX
VREF (Min) = Minimum VREF at TMIN, T(25°C), or TMAX
VREF (25°C) = VREF at 25°C
TMAX = +85°C
TMIN = –40°C
Rev. PrC | Page 13 of 14
AD7631/AD7634
Preliminary Technical Data
OUTLINE DIMENSIONS
0.75
0.60
0.45
9.00
BSC SQ
1.60
MAX
37
48
36
1
PIN 1
7.00
BSC SQ
TOP VIEW
1.45
1.40
1.35
0.15
0.05
(PINS DOWN)
0.20
0.09
7°
3.5°
0°
0.08 MAX
COPLANARITY
SEATING
PLANE
25
12
13
24
0.27
0.22
0.17
VIEW A
0.50
BSC
LEAD PITCH
VIEW A
ROTATED 90° CCW
COMPLIANT TO JEDEC STANDARDS MS-026-BBC
Figure 5. 48-Lead Low Profile Quad Flat Package [LQFP]
(ST-48)
Dimensions shown in millimeters
7.00
BSC SQ
0.60 MAX
0.60 MAX
37
36
PIN 1
INDICATOR
TOP
VIEW
12° MAX
PIN 1
INDICATOR
48
5.25
5.10 SQ
4.95
(BOTTOM VIEW)
25
24
13
12
0.25 MIN
5.50
REF
0.80 MAX
0.65 TYP
0.05 MAX
0.02 NOM
0.50 BSC
SEATING
PLANE
1
EXPOSED
PAD
6.75
BSC SQ
0.50
0.40
0.30
1.00
0.85
0.80
0.30
0.23
0.18
0.20 REF
PADDLE CONNECTED TO AGND.
THIS CONNECTION IS NOT
REQUIRED TO MEET THE
ELECTRICAL PERFORMANCES.
COPLANARITY
0.08
COMPLIANT TO JEDEC STANDARDS MO-220-VKKD-2
Figure 6. 48-Lead Lead Frame Chip Scale Package [LFCSP_VQ]
7 mm × 7 mm Body, Very Thin Quad (CP-48-1)
Dimensions shown in millimeters
ORDERING GUIDE
Model
AD7641BCPZ 1
AD7641BCPZRL1
AD7641BSTZ1
AD7641BSTZRL1
EVAL-AD7641CB 2
EVAL-CONTROLBRD3 3
1
2
3
Temperature Range
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
Package Description
48-Lead Lead Frame Chip Scale Package (LFCSP_VQ)
48-Lead Lead Frame Chip Scale Package (LFCSP_VQ)
48-Lead Low Profile Quad Flat Package (LQFP)
48-Lead Low Profile Quad Flat Package (LQFP)
Evaluation Board
Controller Board
Package Option
CP-48-1
CP-48-1
ST-48
ST-48
Z = Pb-free part.
This board can be used as a standalone evaluation board or in conjunction with the EVAL-CONTROL BRD3 for evaluation/demonstration purposes.
This board allows a PC to control and communicate with all Analog Devices, Inc. evaluation boards ending in the CB designators.
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
PR06004-0-6/06(PrC)
T
T
Rev. PrC | Page 14 of 14