AD AD5516ABC-3 16-channel, 12-bit voltage-output dac with 14-bit increment mode Datasheet

a
16-Channel, 12-Bit Voltage-Output DAC
with 14-Bit Increment Mode
AD5516*
FEATURES
High Integration:
16-Channel DAC in 12 mm ⴛ 12 mm LFBGA
14-Bit Resolution via Increment/Decrement Mode
Guaranteed Monotonic
Low Power, SPITM, QSPITM, MICROWIRE TM, and DSPCompatible
3-Wire Serial Interface
Output Impedance 0.5 ⍀
Output Voltage Range
ⴞ2.5 V (AD5516-1)
ⴞ5 V (AD5516-2)
ⴞ10 V (AD5516-3)
Asynchronous Reset-Facility (via RESET Pin)
Asynchronous Power-Down Facility (via PD Pin)
Daisy-Chain Mode
Temperature Range: –40ⴗC to +85ⴗC
APPLICATIONS
Level Setting
Instrumentation
Automatic Test Equipment
Optical Networks
Industrial Control Systems
Data Acquisition
Low Cost I/O
GENERAL DESCRIPTION
The AD5516 is a 16-channel, 12-bit voltage-output DAC. The
selected DAC register is written to via the 3-wire serial interface.
DAC selection is accomplished via address bits A3–A0. 14-bit
resolution can be achieved by fine adjustment in Increment/
Decrement Mode (Mode 2). The serial interface operates at
clock rates up to 20 MHz and is compatible with standard SPI,
MICROWIRE, and DSP interface standards. The output voltage range is fixed at ± 2.5 V (AD5516-1), ± 5 V (AD5516-2),
and ± 10 V (AD5516-3). Access to the feedback resistor in each
channel is provided via RFB0 to RFB15 pins.
The device is operated with AVCC = 5 V ± 5%, DVCC = 2.7 V to
5.25 V, VSS = –4.75 V to –12 V, and VDD = +4.75 V to +12 V
and requires a stable 3 V reference on REF_IN.
PRODUCT HIGHLIGHTS
1. Sixteen 12-bit DACs in one package, guaranteed monotonic
2. Available in a 74-lead LFBGA package with a body size of
12 mm ⴛ 12 mm
FUNCTIONAL BLOCK DIAGRAM
DVCC
AVCC
VDD
REF_IN
VBIAS
VSS
ROFFS
R FB
AD5516
VOUT0
DAC
RESET
ROFFS
BUSY
ANALOG
CALIBRATION
LOOP
R FB
DAC
ROFFS
R FB
MODE1
ROFFS
INTERFACE
CONTROL
LOGIC
SCLK
DIN
MODE2
7-BIT BUS
DOUT SYNC
R FB
RFB15
VOUT15
DAC
DCEN
RFB 14
VOUT14
DAC
12-BIT BUS
DGND
RFB1
VOUT1
DACGND
AGND
RFB0
POWER-DOWN
LOGIC
PD
*Protected by U.S. Patent No. 5,969,657; other patents pending
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corporation.
REV. 0
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. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2002
(VDD = +4.75 V to +13.2 V, VSS = –4.75 V to –13.2 V; AVCC = 4.75 V to 5.25 V; DVCC =
AD5516 –SPECIFICATIONS 2.7 V to 5.25 V; AGND = DGND = DACGND = 0 V; REF_IN = 3 V; All outputs unloaded.
All specifications T to T unless otherwise noted.)
MIN
MAX
Parameter1
A Version2
Unit
DAC DC PERFORMANCE
Resolution
Integral Nonlinearity (INL)
Differential Nonlinearity (DNL)
Increment/Decrement Step-Size
Bipolar Zero Error
Positive Full-Scale Error
Negative Full-Scale Error
12
±2
–1/+1.3
± 0.25
±7
± 10
± 10
Bits
LSB max
LSB max
LSB typ
LSB max
LSB max
LSB max
VOLTAGE REFERENCE
REF_IN
Nominal Input Voltage
Input Voltage Range3
Input Current
3
2.875/3.125
±1
V
V min/max
µA max
10
0.5
ppm/°C typ
Ω typ
± 2.5
±5
± 10
5
200
7
–85
120
V typ
V typ
V typ
kΩ min
pF
mA typ
dB typ
µV max
± 10
0.8
0.4
2.4
2
150
10
µA max
V max
V max
V min
V min
mV typ
pF max
5 pF typ
0.4
4
0.4
2.4
±1
5
V max
V min
V max
V min
µA max
pF typ
Sinking 200 µA
Sourcing 200 µA
Sinking 200 µA
Sourcing 200 µA
DCEN = 0
DCEN = 0
+4.75/+15.75
–4.75/–15.75
4.75/5.25
2.7/5.25
V min/max
V min/max
V min/max
V min/max
5
5
17
1.5
mA max
mA max
mA max
mA max
3.5 mA typ. All Channels Full-Scale
3.5 mA typ. All Channels Full-Scale
13 mA typ
1 mA typ
2
3
2
2
105
µA max
µA max
µA max
µA max
mW typ
200 nA typ
200 nA typ
200 nA typ
200 nA typ
VDD = +5 V, VSS = –5 V
ANALOG OUTPUTS (VOUT 0–15)
Output Temperature Coefficient3, 4
DC Output Impedance3
Output Range5
AD5516-1
AD5516-2
AD5516-3
Resistive Load3, 6
Capacitive Load3, 6
Short-Circuit Current3
DC Power-Supply Rejection Ratio3
DC Crosstalk3
DIGITAL INPUTS3
Input Current
Input Low Voltage
Input High Voltage
Input Hysteresis (SCLK and SYNC)
Input Capacitance
Conditions/Comments
Mode 1
± 0.5 LSB typ, Monotonic; Mode 1
Monotonic; Mode 2 Only
< 1 nA typ
of FSR
VDD = +12 V ± 5%, VSS = –12 V ± 5%
± 5 µA typ
DVCC = 5 V ±
DVCC = 3 V ±
DVCC = 5 V ±
DVCC = 3 V ±
5%
10%
5%
10%
3
DIGITAL OUTPUTS (BUSY, DOUT)
Output Low Voltage, DVCC = 5 V
Output High Voltage, DVCC = 5 V
Output Low Voltage, DVCC = 3 V
Output High Voltage, DVCC = 3 V
High Impedance Leakage Current (DOUT only)
High Impedance Output Capacitance (DOUT only)
POWER REQUIREMENTS
Power Supply Voltages
VDD
VSS
AVCC
DVCC
Power Supply Currents7
IDD
ISS
AICC
DICC
Power-Down Currents7
IDD
ISS
AICC
DICC
Power Dissipation7
NOTES
1
See Terminology section.
2
A Version: Industrial temperature range –40°C to +85°C; typical at +25°C.
3
Guaranteed by design and characterization; not production tested.
4
AD780 as reference for the AD5516.
5
Output range is restricted from V SS + 2 V to VDD – 2 V. Output span varies with reference voltage and is functional down to 2 V.
6
Ensure that you do not exceed T J (MAX). See Absolute Maximum Ratings section.
7
Outputs unloaded.
Specifications subject to change without notice.
–2–
REV. 0
AD5516
(VDD = +4.75 V to +13.2 V, VSS = –4.75 V to –13.2 V; AVCC = 4.75 V to 5.25 V; DVCC = 2.7 V to 5.25 V; AGND = DGND
MIN to TMAX unless otherwise noted.)
AC CHARACTERISTICS = DACGND = 0 V; REF_IN = 3 V; All outputs unloaded. All specifications T
Parameter1, 2
4
Output Voltage Settling Time (Mode 1)
Output Voltage Settling Time (Mode 2)4
Slew Rate
Digital-to-Analog Glitch Impulse
Digital Crosstalk
Analog Crosstalk AD5516-1
Digital Feedthrough
Output Noise Spectral Density @ 1 kHz
A Version3
Unit
Conditions/Comments
32
2.5
0.85
1
5
10
1
150
␮s max
␮s max
V/␮s typ
nV-s typ
nV-s typ
nV-s typ
nV-s typ
nV/(Hz)1/2 typ
100 pF, 5 kΩ Load Full-Scale Change
100 pF, 5 kΩ Load, 1 Code Increment
1 LSB Change around Major Carry
AD5516-1
NOTES
1
See Terminology section.
2
Guaranteed by design and characterization; not production tested.
3
A version: Industrial temperature range –40°C to +85°C.
4
Timed from the end of a write sequence.
Specifications subject to change without notice.
TIMING CHARACTERISTICS
(VDD = +4.75 V to +13.2 V, VSS = – 4.75 V to –13.2 V; AVCC = 4.75 V to 5.25 V; DVCC = 2.7 V to 5.25 V;
AGND = DGND = DACGND = 0 V. All specifications TMIN to TMAX unless otherwise noted.)
Parameter1, 2, 3
Limit at TMIN, TMAX
(A Version)
Unit
Conditions/Comments
fUPDATE1
fUPDATE2
fCLKIN
t1
t2
t3
t4
t5
t6
t7
t7MODE2
t8MODE1
t9MODE2
t10
t114
t12
32
750
20
20
20
15
5
5
0
10
400
10
200
10
20
20
kHz max
kHz max
MHz max
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns max
ns min
DAC Update Rate (Mode 1)
DAC Update Rate (Mode 2)
SCLK Frequency
SCLK High Pulsewidth
SCLK Low Pulsewidth
SYNC Falling Edge to SCLK Falling Edge Setup Time
DIN Setup Time
DIN Hold Time
SCLK Falling Edge to SYNC Rising Edge
Minimum SYNC High Time (Standalone Mode)
Minimum SYNC High Time (Daisy-Chain Mode)
BUSY Rising Edge to SYNC Falling Edge
18th SCLK Falling Edge to SYNC Falling Edge (Standalone Mode)
SYNC Rising Edge to SCLK Rising Edge (Daisy-Chain Mode)
SCLK Rising Edge to DOUT Valid (Daisy-Chain Mode)
RESET Pulsewidth
NOTES
1
See Timing Diagrams in Figures 1 and 2.
2
Guaranteed by design and characterization; not production tested.
3
All input signals are specified with tr = tf = 5 ns (10% to 90% of DV CC) and timed from a voltage level of (V IL + VIH)/2.
4
This is measured with the load circuit of Figure 3.
Specifications subject to change without notice.
–3–
AD5516
SERIAL INTERFACE TIMING DIAGRAMS
SCLK
1
2
17
t3
t2
18
t1
t6
t7
SYNC
t9 MODE2
t4
t5
MSB
DIN
LSB
BIT 17
BIT 0
t8 MODE1
BUSY
t12
RESET
Figure 1. Serial Interface Timing Diagram
SCLK
t3
t7 MODE2
t2
t1
t10
t6
SYNC
t4
MSB
DIN
t5
LSB
BIT 17
BIT 0
BIT 17
INPUT WORD FOR DEVICE N
BIT 0
INPUT WORD FOR DEVICE N+1
t11
DOUT
BIT 17
t8 MODE1
UNDEFINED
BIT 0
INPUT WORD FOR DEVICE N
BUSY
Figure 2. Daisy-Chaining Timing Diagram
200␮A
TO OUTPUT
PIN
IOL
1.6V
CL
50pF
200␮A
IOH
Figure 3. Load Circuit for DOUT Timing Specifications
–4–
REV. 0
AD5516
ABSOLUTE MAXIMUM RATINGS 1, 2
(TA = 25°C unless otherwise noted.)
VDD to AGND . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +17 V
VSS to AGND . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V to –17 V
AVCC to AGND, DACGND . . . . . . . . . . . . . . –0.3 V to +7 V
DVCC to DGND . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V
Digital Inputs to DGND . . . . . . . . . . –0.3 V to DVCC + 0.3 V
Digital Outputs to DGND . . . . . . . . . –0.3 V to DVCC + 0.3 V
REF_IN to AGND, DACGND . . . . . –0.3 V to AVCC + 0.3 V
VOUT 0–15 to AGND . . . . . . . . . . . . VSS – 0.3 V to VDD + 0.3 V
AGND to DGND . . . . . . . . . . . . . . . . . . . . –0.3 V to +0.3 V
RFB 0–15 to AGND . . . . . . . . . . . . VSS – 0.3 V to VDD + 0.3 V
Operating Temperature Range, Industrial . . . . . –40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C
Junction Temperature (TJ MAX) . . . . . . . . . . . . . . . . . . . 150°C
74-Lead LFBGA Package, ␪JA Thermal Impedance . . 41°C/W
Reflow Soldering
Peak Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
Time at Peak Temperature . . . . . . . . . . . . .10 sec to 40 sec
NOTES
1
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 listed in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability.
2
Transient currents of up to 100 mA will not cause SCR latch-up.
ORDERING GUIDE
Model
Function
Output Voltage Span
Package Option
AD5516ABC-1
AD5516ABC-2
AD5516ABC-3
16 DACs
16 DACs
16 DACs
± 2.5 V
±5 V
± 10 V
74-Lead LFBGA
74-Lead LFBGA
74-Lead LFBGA
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
the AD5516 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.
REV. 0
–5–
WARNING!
ESD SENSITIVE DEVICE
AD5516
PIN CONFIGURATION
1 2 3 4 5 6 7 8 9 10 11
A
A
B
B
C
C
D
D
E
E
TOP VIEW
F
F
G
G
H
H
J
J
K
L
K
L
1 2 3 4 5 6 7 8 9 10 11
74-LEAD LFBGA BALL CONFIGURATION
LFBGA
Number
Ball
Name
LFBGA
Number
Ball
Name
LFBGA
Number
Ball
Name
LFBGA
Number
Ball
Name
LFBGA
Number
Ball
Name
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
B1
B2
B3
B4
NC
NC
RESET
BUSY
DGND
DVCC
DOUT
DIN
SYNC
NC
NC
NC
NC
NC
DCEN
B5
B6
B7
B8
B9
B10
B11
C1
C2
C6
C10
C11
D1
D2
D10
DGND
DGND
NC
NC
SCLK
NC
REF_IN
VOUT0
DACGND
NC
AVCC1
NC
RFB0
DACGND
AVCC2
D11
E1
E2
E10
E11
F1
F2
F10
F11
G1
G2
G10
G11
H1
H2
NC
VOUT1
NC
AGND1
PD
VOUT2
R FB1
AGND2
RFB14
RFB2
RFB15
VOUT14
RFB13
VOUT3
VOUT15
H10
H11
J1
J2
J6
J10
J11
K1
K2
K3
K4
K5
K6
K7
K8
VOUT13
VOUT12
RFB3
VOUT14
NC
RFB12
RFB11
RFB4
VOUT5
RFB5
NC
VSS2
VSS1
VOUT10
VOUT9
K9
K10
K11
L1
L2
L3
L4
L5
L6
L7
L8
L9
L10
L11
RFB10
RFB9
VOUT11
NC
VOUT6
RFB6
VOUT7
NC
VDD2
VDD1
RFB7
VOUT8
RFB8
NC
NC = Not Internally Connected
PIN FUNCTION DESCRIPTIONS
Mnemonic
Function
AGND (1–2)
AVCC (1–2)
VDD (1–2)
VSS (1–2)
DGND
DVCC
DACGND
REF_IN
VOUT (0–15)
RFB (0–15)
SYNC
Analog GND pins
Analog supply pins. Voltage range from +4.75 V to +5.25 V.
VDD supply pins. Voltage range from +4.75 V to +15.75 V.
VSS supply pins. Voltage range from –4.75 V to –15.75 V.
Digital GND pins
Digital supply pin. Voltage range from 2.7 V to 5.25 V.
Reference GND supply for all 16 DACs.
Reference input voltage for all 16 DACs. The recommended value of REF_IN is 3 V.
Analog output voltages from the 16 DAC channels.
Feedback resistors. For nominal output voltage range connect each RFB to its corresponding VOUT.
Active low input. This is the frame synchronization signal for the serial interface. While SYNC is low, data is
transferred in on the falling edge of SCLK.
Serial clock input. Data is clocked into the shift register on the falling edge of SCLK. This operates at clock
speeds up to 20 MHz.
Serial data input. Data must be valid on the falling edge of SCLK.
SCLK
DIN
–6–
REV. 0
AD5516
PIN FUNCTION DESCRIPTIONS (continued)
Mnemonic
Function
DOUT
Serial data output. DOUT can be used for daisy-chaining a number of devices together or for reading back the
data in the shift register for diagnostic purposes. Data is clocked out on DOUT on the rising edge of SCLK and is
valid on the falling edge of SCLK.
Active high control input. This pin is tied high to enable daisy-chain mode.
Active low control input. This resets all DAC registers to power-on value.
Active high control input. All DACs go into power-down mode when this pin is high. The DAC outputs go into
a high-impedance state.
Active low output. This signal tells the user that the analog calibration loop is active. It goes low during
conversion. The duration of the pulse on BUSY determines the maximum DAC update rate, fUPDATE. Further
writes to the AD5516 are ignored while BUSY is active.
DCEN1
RESET2
PD1
BUSY
NOTES
1
Internal pull-down device on this logic input. Therefore it can be left floating and will default to a logic low condition.
2
Internal pull-up device on this logic input. Therefore it can be left floating and will default to a logic high condition.
TERMINOLOGY
Integral Nonlinearity (INL)
This is a measure of the maximum deviation from a straight line
passing through the endpoints of the DAC transfer function. It is
expressed in LSBs.
Differential Nonlinearity (DNL)
Differential nonlinearity (DNL) is the difference between the
measured change and the ideal 1 LSB change between any two
adjacent codes. A specified DNL of –1 LSB maximum ensures
monotonicity.
DC Crosstalk
This is the dc change in the output level of one DAC at midscale
in response to a full-scale code change (all 0s to all 1s and vice
versa) and output change of another DAC. It is expressed in mV.
Output Settling Time
This is the time taken from when the last data bit is clocked into
the DAC until the output has settled to within ± 0.5 LSB of its
final value (see TPC 7).
Digital-to-Analog Glitch Impulse
Bipolar zero error is the deviation of the DAC output from the ideal
midscale of 0 V. It is measured with 10...00 loaded to the DAC.
It is expressed in LSBs.
This is the area of the glitch injected into the analog output when
the code in the DAC register changes state. It is specified as the
area of the glitch in nV-secs when the digital code is changed by
1 LSB at the major carry transition (011...11 to 100...00 or
100...00 to 011...11).
Positive Full-Scale Error
Digital Crosstalk
This is the error in the DAC output voltage with all 1s loaded to
the DAC. Ideally the DAC output voltage, with all 1s loaded to the
DAC registers, should be 2.5 V – 1 LSB (AD5516-1), 5 V – 1 LSB
(AD5516-2), and 10 V – 1 LSB (AD5516-3). It is expressed in LSBs.
This is the glitch impulse transferred to the output of one DAC at
midscale while a full-scale code change (all 1s to all 0s and vice
versa) is being written to another DAC. It is expressed in nV-secs.
Negative Full-Scale Error
This is the area of the glitch transferred to the output (VOUT) of
one DAC due to a full-scale change in the output (VOUT) of
another DAC. The area of the glitch is expressed in nV-secs.
Bipolar Zero Error
This is the error in the DAC output voltage with all 0s loaded to the
DAC. Ideally the DAC output voltage, with all 0s loaded to the
DAC registers, should be –2.5 V (AD5516-1), –5 V (AD5516-2),
and –10 V (AD5516-3). It is expressed in LSBs.
Output Temperature Coefficient
This is a measure of the change in analog output with changes in
temperature. It is expressed in ppm/°C of FSR.
DC Power Supply Rejection Ratio
DC power supply rejection ratio (PSRR) is a measure of the change
in analog output for a change in supply voltage (VDD and VSS).
It is expressed in dBs. VDD and VSS are varied ± 5%.
REV. 0
Analog Crosstalk
Digital Feedthrough
This is a measure of the impulse injected into the analog outputs
from the digital control inputs when the part is not being written
to, i.e., SYNC is high. It is specified in nV-secs and measured
with a worst-case change on the digital input pins, e.g., from all
0s to all 1s and vice versa.
Output Noise Spectral Density
This is a measure of internally generated random noise. Random
noise is characterized as a spectral density (voltage per root Hertz).
It is measured in nV/(Hz)1/2.
–7–
AD5516 –Typical Performance Characteristics
1.0
REF_IN = 3V
0.8 TA = 25ⴗC
1.0
2.0
REF_IN = 3V
0.8 TA = 25ⴗC
1.5
0.6
0.6
0.4
0.4
REF_IN = 3V
0.2
0
–0.2
–0.4
ERROR – LSB
INL ERROR – LSB
DNL ERROR – LSB
1.0
0.2
0
–0.2
INL
0.5
+VE
DNL
0
–0.5
–VE
DNL
–0.4
–1.0
–0.6
–0.6
–0.8
–0.8
–1.0
–1.0
0
1000
2000
3000
DAC CODE
4000
–1.5
0
1000
–2.0
–40
4000
3
–1
0.006
0
MIDSCALE
–0.006
–0.002
POSITIVE FS ERROR
–20
0
20
40
0.0
–0.004
NEGATIVE FS ERROR
–3
–40
0.002
–0.002
–0.001
–2
–0.008
60
80
–0.003
–40
TEMPERATURE – ⴗC
–20
0
20
40
60
80
–0.01
–8
–6
–4
TEMPERATURE – ⴗC
TPC 5. VOUT vs. Temperature
TPC 4. Bipolar Zero Error and
Full-Scale Error vs. Temperature
3.0
–2
0
2
CURRENT – mA
4
6
8
TPC 6. VOUT Source and Sink
Capability
–0.029
TA = 25ⴗC
REF_IN = 3V
TA = 25ⴗC
REF_IN = 3V
2.0
TA = 25ⴗC
REF_IN = 3V
NEW
VALUE
–0.030
1.0
VOUT – V
80
0.004
VOUT – V
VOUT – V
0
60
40
REF_IN = 3V
TA = 25ⴗC
0.008
0.001
BIPOLAR ZERO ERROR
20
0.01
AVDD = +12V
AVSS = –12V
REF_IN = 3V
MIDSCALE LOADED
0.002
1
0
TPC 3. Typical INL Error and DNL
Error vs. Temperature
0.003
REF_IN = 3V
2
–20
TEMPERATURE – ⴗC
TPC 2. Typical INL Plot
TPC 1. Typical DNL Plot
ERROR – LSB
2000
3000
DAC CODE
PD
5V/DIV
VOUT
2V/DIV
CALIBRATION TIME
0
–0.031
OLD
VALUE
–1.0
TIME BASE = 2.5␮s/DIV
2␮s/DIV
2.5␮s/DIV
–0.032
–2.0
5V
0V
–3.0
TPC 7. Full-Scale Settling Time
–0.033
TPC 8. Exiting Power-Down to
Full Scale
–8–
BUSY
TPC 9. Major Code Transition
Glitch Impulse
REV. 0
AD5516
450
40
40
REF_IN = 3V
TA = 25ⴗC
REF_IN = 3V
TA = 25ⴗC
400
300
250
200
150
FREQUENCY – %
FREQUENCY – %
FREQUENCY
350
20
20
100
50
0
2.4893
2.4896
VOUT – V
2.4899
TPC 10. VOUT Repeatability; Programming the Same Code Multiple Times
0
–10
0
LSBs
0
–10
10
TPC 11. Bipolar Error Distribution
30
0
LSBs
10
TPC 12. Positive Full-Scale
Error Distribution
2.5
REF_IN = 3V
TA = 25ⴗC
REF_IN = 3V
TA = 25ⴗC
20
ERROR – LSB
FREQUENCY – %
2.0
10
1.5
1.0
0.5
0
–10
0
0
LSBs
10
0
TPC 13. Negative Full-Scale Error Distribution
REV. 0
20
40
60
80
STEP SIZE
100
120
130
TPC 14. Increment Step vs. Accuracy
–9–
AD5516
Table I illustrates ideal analog output versus DAC code.
FUNCTIONAL DESCRIPTION
The AD5516 consists of sixteen 12-bit DACs in a single package.
A single reference input pin (REF_IN) is used to provide a 3 V
reference for all 16 DACs. To update a DAC’s output voltage
the required DAC is addressed via the 3-wire serial interface.
Once the serial write is complete, the selected DAC converts the
code into an output voltage. The output amplifiers translate the
DAC output range to give the appropriate voltage range (± 2.5 V,
± 5 V, or ± 10 V) at output pins VOUT0 to VOUT15.
The AD5516 uses a self-calibrating architecture to achieve
12-bit performance. The calibration routine servos to select the
appropriate voltage level on an internal 14-bit resolution DAC.
Noise during the calibration (BUSY low period) can result in
the selection of a voltage within a ± 0.25 LSB band around the
normal selected voltage. See TPC 10.
AD5516-2 VDAC =
AD5516-3 VDAC =
4 × VREF _ IN × 2.5 × D
3×2
N
8 × VREF _ IN × 2.5 × D
3 × 2N
VREF _ IN × 2.5
3
–
2 VREF _ IN × 2.5
3
–
4 VREF _ IN × 2.5
3
VREF_IN × 2.5/3 – 1 LSB
0V
–VREF_IN × 2.5/3
1111 1111 1111
1000 0000 0000
0000 0000 0000
Mode 2 (MODE bits = 01 or 10): Mode 2 operation allows the
user to increment or decrement the DAC output in 0.25 LSB steps,
resulting in a 14-bit monotonic DAC. The amount by which the
DAC output is incremented or decremented is determined by
Mode 2 bits DB6–DB0, e.g., for a 0.25 LSB increment/decrement
DB6...DB0 = 0000001, while for a 2.5 LSB increment/decrement,
DB6...DB0 = 0001010. The MODE bits determine whether the
DAC data is incremented (01) or decremented (10). The maximum
amount that the user is allowed to increment or decrement the DAC
output is 127 steps of 0.25 LSB, i.e., DB6...DB0 = 1111111.
Mode 2 update takes approximately 1 µs. The Mode 2 feature
allows increased resolution but overall increment/decrement accuracy varies with increment/decrement step as shown in TPC 14.
Mode 2 is useful in applications where greater resolution is
required, for example, in servo applications requiring fine-tune
to 14-bit resolution.
The architecture of each DAC channel consists of a resistorstring DAC followed by an output buffer amplifier. The voltage
at the REF_IN Pin provides the reference voltage for the corresponding DAC. The input coding to the DAC is offset binary;
this results in ideal DAC output voltages as follows:
–
Analog Output, VOUT
Mode 1 (MODE bits = 00): The user programs a 12-bit data
word to one of 16 channels via the serial interface. This word is
loaded into the addressed DAC register and is then converted
into an analog output voltage. During conversion the BUSY
output is low and all SCLK pulses are ignored. At the end of a
conversion BUSY goes high indicating that the update of the
addressed DAC is complete. It is recommended that SCLK is
not pulsed while BUSY is low. Mode 1 conversion takes 25 µs typ.
DIGITAL-TO-ANALOG SECTION
3 × 2N
LSB
The AD5516 has two modes of operation.
On power-on, all DACs power up to a reset value (see RESET
section).
2 × VREF _ IN × 2.5 × D
MSB
MODES OF OPERATION
It is essential to minimize noise on REFIN for optimal performance. The AD780’s specified decoupling makes it the ideal
reference to drive the AD5516.
AD5516-1 VDAC =
Table I. DAC Register Contents AD5516-1
Where:
D = decimal equivalent of the binary code that is loaded to
the DAC register, i.e., 0–4096
N = DAC resolution = 12
MSB
0
LSB
0
A3
MODE
BITS
A2
A1
A0
DB11 DB10 DB9
DB8
DB7
ADDRESS
BITS
DB6
DB5
DB4
DB3
DB2
DB1
DB0
DATA
BITS
Figure 4. Mode 1 Data Format
MSB
0
LSB
1
A3
MODE
BITS
A2
A1
A0
0
0
0
0
0
DB6
DB5
ADDRESS
BITS
DB4
DB3
DB2
DB1
MSB
1
DB0
7 INCREMENT
BITS
LSB
0
MODE
BITS
A3
A2
A1
A0
0
0
0
0
0
DB6
DB5
ADDRESS
BITS
DB4
DB3
DB2
DB1
DB0
7 DECREMENT
BITS
Figure 5. Mode 2 Data Format
–10–
REV. 0
AD5516
The user must allow 200 ns (min) between two consecutive
Mode 2 writes in standalone mode and 400 ns (min) between
two consecutive Mode 2 writes in daisy-chain mode.
Daisy-Chain Mode (DCEN = 1)
In daisy-chain mode, the internal gating on SCLK is disabled.
The SCLK is continuously applied to the input shift register
when SYNC is low. If more than 18 clock pulses are applied,
the data ripples out of the shift register and appears on the DOUT
line. This data is clocked out on the rising edge of SCLK and is
valid on the falling edge. By connecting this line to the DIN
input on the next device in the chain, a multidevice interface is
constructed. Eighteen clock pulses are required for each device
in the system. Therefore, the total number of clock cycles must
equal 18N where N is the total number of devices in the chain.
See the timing diagram in Figure 2.
See Figures 4 and 5 for Mode 1 and Mode 2 data formats.
When MODE bits = 11, the device is in No Operation mode.
This may be useful in daisy-chain applications where the user
does not wish to change the settings of the DACs. Simply write
11 to the MODE bits and the following address and data bits
will be ignored.
SERIAL INTERFACE
The AD5516 has a 3-wire interface that is compatible with SPI/
QSPI/MICROWIRE and DSP interface standards. Data is written
to the device in 18-bit words. This 18-bit word consists of two
mode bits, four address bits, and 12 data bits as shown in Figure 4.
When the serial transfer to all devices is complete, SYNC should
be taken high. This prevents any further data being clocked into the
input shift register. A burst clock containing the exact number of
clock cycles may be used and SYNC taken high some time later.
After the rising edge of SYNC, data is automatically transferred
from each device’s input shift register to the addressed DAC.
The serial interface works with both a continuous and burst
clock. The first falling edge of SYNC resets a counter that counts
the number of serial clocks to ensure the correct number of bits
are shifted in and out of the serial shift registers. Any further
edges on SYNC are ignored until the correct number of bits are
shifted in or out. In order for another serial transfer to take
place, the counter must be reset by the falling edge of SYNC.
RESET Function
The RESET function on the AD5516 can be used to reset all
nodes on this device to their power-on reset condition. This is
implemented by applying a low-going pulse of minimum 20 ns
to the RESET Pin on the device.
A3–A0
Four address bits (A3 = MSB Address, A0 = LSB). These are
used to address one of 16 DACs.
Table III. Typical Power-ON Values
Table II. Selected DAC
A3
A2
A1
A0
Selected DAC
0
0
:
1
0
0
:
1
0
0
:
1
0
1
:
1
DAC 0
DAC 1
Output Voltage
AD5516-1
AD5516-2
AD5516-3
–0.073 V
–0.183 V
–0.391 V
BUSY Output
During conversion, the BUSY output is low and all SCLK
pulses are ignored. At the end of a conversion, BUSY goes high
indicating that the update of the addressed DAC is complete. It
is recommended that SCLK is not pulsed while BUSY is low.
DAC 15
DB11–DB0
These are used to write a 12-bit word into the addressed DAC
register. Figures 1 and 2 show the timing diagram for a write
cycle to the AD5516.
MICROPROCESSOR INTERFACING
The AD5516 is controlled via a versatile 3-wire serial interface
that is compatible with a number of microprocessors and DSPs.
SYNC FUNCTION
In both standalone and daisy-chain modes, SYNC is an edgetriggered input that acts as a frame synchronization signal and
chip enable. Data can only be transferred into the device while
SYNC is low. To start the serial data transfer, SYNC should be
taken low observing the minimum SYNC falling to SCLK falling
edge setup time, t3.
AD5516 to ADSP-2106x SHARC DSP Interface
The ADSP-2106x SHARC DSPs are easily interfaced to the
AD5516 without the need for extra logic.
The AD5516 expects a t3 (SYNC falling edge to SCLK falling
edge setup time) of 15 ns min. Consult the ADSP-2106x User
Manual for information on clock and frame sync frequencies for
the SPORT register and contents of the TDIV, RDIV registers.
Standalone Mode (DCEN = 0)
After SYNC goes low, serial data will be shifted into the device’s
input shift register on the falling edges of SCLK for 18 clock
pulses. After the falling edge of the 18th SCLK pulse, data will
automatically be transferred from the input shift register to the
addressed DAC.
SYNC must be taken high and low again for further serial data
transfer. SYNC may be taken high after the falling edge of the
18th SCLK pulse, observing the minimum SCLK falling edge
to SYNC rising edge time, t6. If SYNC is taken high before the
18th falling edge of SCLK, the data transfer will be aborted and
the addressed DAC will not be updated. See the timing diagram
in Figure 1.
REV. 0
Device
–11–
AD5516
A data transfer is initiated by writing a word to the TX register
after the SPORT has been enabled. In write sequences data is
clocked out on each rising edge of the DSP’s serial clock and
clocked into the AD5516 on the falling edge of its SCLK. The
SPORT transmit control register should be set up as follows:
DTYPE
ICLK
TFSR
INTF
LTFS
LAFS
SENDN
SLEN
=
=
=
=
=
=
=
=
AD5516 to PIC16C6x/7x
The PIC16C6x/7x synchronous serial port (SSP) is configured
as an SPI master with the clock polarity bit (CKP) = 0. This is
done by writing to the synchronous serial port control register
(SSPCON). See user PIC16/17 Microcontroller User Manual.
In this example, I/O port RA1 is being used to provide a SYNC
signal and enable the serial port of the AD5516. This microcontroller transfers only eight bits of data during each serial transfer
operation; therefore, three consecutive write operations are
required. Figure 8 shows the connection diagram.
00, Right Justify Data
1, Internal Serial Clock
1, Frame Every Word
1, Internal Frame Sync
1, Active Low Frame Sync Signal
0, Early Frame Sync
0, Data Transmitted MSB First
10011, 18-Bit Data Words (SLEN = Serial Word)
SCLK
Figure 6 shows the connection diagram.
DIN
SYNC
ADSP-2106x*
AD5516*
PIC16C6x/7x*
AD5516*
SCK/RC3
SDI/RC4
RA1
*ADDITIONAL PINS OMITTED FOR CLARITY
SYNC
DIN
TFS
Figure 8. AD5516 to PIC16C6x/7x Interface
DT
AD5516 to 8051
SCLK
SCLK
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 6. AD5516 to ADSP-2106x Interface
AD5516 to MC68HC11
The serial peripheral interface (SPI) on the MC68HC11 is
configured for master mode (MSTR = 1), clock polarity bit
(CPOL) = 0, and the clock phase bit (CPHA) = 1. The SPI is
configured by writing to the SPI control register (SPCR)—see
the 68HC11 User Manual. SCK of the 68HC11 drives the SCLK
of the AD5516, the MOSI output drives the serial data line
(DIN) of the AD5516. The SYNC signal is derived from a port
line (PC7). When data is being transmitted to the AD5516, the
SYNC line is taken low (PC7). Data appearing on the MOSI
output is valid on the falling edge of SCK. Serial data from the
68HC11 is transmitted in 8-bit bytes with only eight falling
clock edges occurring in the transmit cycle. Data is transmitted
MSB first. In order to transmit 18 data bits, it is important to
left justify the data in the SPDR register. PC7 must be pulled
low to start a transfer and taken high and low again before any
further read/write cycles can take place. A connection diagram is
shown in Figure 7.
MC68HC11*
AD5516*
SYNC
PC7
SCLK
SCK
DIN
MOSI
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 7. AD5516 to MC68HC11 Interface
A serial interface between the AD5516 and the 80C51/80L51
microcontroller is shown in Figure 9. The AD5516 requires a
clock synchronized to the serial data. The 8051 serial interface
must therefore be operated in Mode 0. TxD of the microcontroller drives the SCLK of the AD5516, while RxD drives the
serial data line. P3.3 is a bit programmable pin on the serial port
that is used to drive SYNC. The 80C51/80L51 provides the
LSB first, while the AD5516 expects MSB of the 18-bit word
first. Care should be taken to ensure the transmit routine takes
this into account.
8051*
AD5516*
SCLK
TxD
DIN
RxD
SYNC
P1.1
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 9. AD5516 to 8051 Interface
When data is to be transmitted to the DAC, P3.3 is taken
low. Data on RxD is valid on the falling edge of TxD, so the
clock must be inverted as the AD5516 clocks data into the
input shift register on the rising edge of the serial clock. The
80C51/80L51 transmits its data in 8-bit bytes with only eight
falling clock edges occurring in the transmit cycle. As the DAC
requires an 18-bit word, P3.3 must be left low after the first eight
bits are transferred, and brought high after the complete 18 bits
have been transferred. DOUT may be tied to RxD for data verification purposes when the device is in daisy-chain mode.
–12–
REV. 0
AD5516
APPLICATION CIRCUITS
POWER SUPPLY DECOUPLING
The AD5516 is suited for use in many applications, such as level
setting, optical, industrial systems, and automatic test applications. In level setting and servo applications where a fine-tune
adjust is required, the Mode 2 function increases resolution.
The following figures show the AD5516 used in some potential
applications.
In any circuit where accuracy is important, careful consideration
of the power supply and ground return layout helps to ensure the
rated performance. The printed circuit board on which the AD5516
is mounted should be designed so that the analog and digital
sections are separated and confined to certain areas of the board. If
the AD5516 is in a system where multiple devices require an
AGND-to-DGND connection, the connection should be made at
one point only. The star ground point should be established as
close as possible to the device. For supplies with multiple pins
(AVCC1, AVCC2) it is recommended to tie those pins together. The
AD5516 should have ample supply bypassing of 10 µF in parallel
with 0.1 µF on each supply located as closely to the package as
possible, ideally right up against the device. The 10 µF capacitors
are the tantalum bead type. The 0.1 µF capacitor should have low
effective series resistance (ESR) and effective series inductance
(ESI), like the common ceramic types that provide a low-impedance
path to ground at high frequencies, to handle transient currents
due to internal logic switching.
AD5516 in a Typical ATE System
The AD5516 is ideally suited for the level setting function in
automatic test equipment. A number of DACs are required to
control pin drivers, comparators, active loads, parametric measurement units, and signal timing. Figure 10 shows the AD5516
in such a system.
DAC
PARAMETRIC
MEASUREMENT
UNIT
ACTIVE
LOAD
DAC
SYSTEM BUS
DAC
DRIVER
STORED
DATA AND
INHIBIT
PATTERN
DAC
FORMATTER
DUT
DAC
PERIOD
GENERATION
AND
DELAY
TIMING
DAC
COMPARE
REGISTER
DAC
DACs
SYSTEM BUS
COMPARATOR
Figure 10. AD5516 in an ATE System
AD5516 in an Optical Network Control Loop
The AD5516 can be used in optical network control applications that require a large number of DACs to perform a control
and measurement function. In the example shown below, the
outputs of the AD5516 are fed into amplifiers and used to control
actuators that determine the position of MEMS mirrors in an
optical switch. The exact position of each mirror is measured and
the readings are multiplexed into an 8-channel, 14-bit ADC
(AD7865). The increment and decrement modes of the DACs are
useful in this application as it allows the user 14-bit resolution.
The power supply lines of the AD5516 should use as large a trace
as possible to provide low-impedance paths and reduce the effects
of glitches on the power supply line. Fast switching signals such
as clocks should be shielded with digital ground to avoid radiating
noise to other parts of the board, and should never be run near
the reference inputs. A ground line routed between the DIN and
SCLK lines will help reduce crosstalk between them (not required
on a multilayer board as there will be a separate ground plane, but
separating the lines will help). It is essential to minimize noise
on REFIN.
Avoid crossover of digital and analog signals. Traces on opposite
sides of the board should run at right angles to each other. This
reduces the effects of feedthrough through the board. A microstrip technique is by far the best, but not always possible with a
double-sided board. In this technique, the component side of
the board is dedicated to ground plane while signal traces are
placed on the solder side.
As is the case for all thin packages, care must be taken to avoid
flexing the package and to avoid a point load on the surface of
the package during the assembly process.
The control loop is driven by an ADSP-2106x, a 32-bit
SHARC DSP.
0
AD5516
15
0
MEMS
MIRROR
ARRAY
15
S
E
N
S ADG609
ⴛ2
O
R
S
0
AD7865
7
AD8644
ⴛ2
ADSP-2106x
Figure 11. AD5516 in an Optical Control Loop
REV. 0
–13–
AD5516
OUTLINE DIMENSIONS
Dimensions shown in millimeters and (inches)
74-Lead LFBGA
(BC-74)
A1 CORNER
INDEX CORNER
A1 CORNER
INDEX CORNER
10.00 (0.3937) BSC
12.00 (0.4724) BSC
11 10 9 8 7 6 5 4 3 2 1
TOP VIEW
12.00
(0.4724)
BSC
1.00
(0.0394)
BSC
DETAIL A
1.70
(0.0669)
MAX
A
B
C
D
E 10.00
F (0.3937)
G BSC
H
J
K
L
BOT TOM
VIEW
1.00 (0.0394) BSC
DETAIL A
0.50
(0.0197)
MIN
0.63 (0.0248)
BSC
SEATING
PLANE
BALL DIAMETER
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN
COMPLIANT TO JEDEC STANDARDS MO-192
–14–
REV. 0
–15–
–16–
PRINTED IN U.S.A.
C02792–0–5/02(0)
Similar pages