2.5 V to 5.5 V, 400 μA, Quad Voltage Output,
8-/10-/12-Bit DACs in 16-Lead TSSOP
AD5307/AD5317/AD5327
Rev. C
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
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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.
FEATURES
AD5307: 4 buffered 8-bit DACs in 16-lead TSSOP
A version: ±1 LSB INL; B version: ±0.625 LSB INL
AD5317: 4 buffered 10-bit DACs in 16-lead TSSOP
A version: ±4 LSB INL; B version: ±2.5 LSB INL
AD5327: 4 buffered 12-bit DACs in 16-lead TSSOP
A version: ±16 LSB INL; B version: ±10 LSB INL
Low power operation: 400 μA @ 3 V, 500 μA @ 5 V
2.5 V to 5.5 V power supply
Guaranteed monotonic by design over all codes
Power down to 90 nA @ 3 V, 300 nA @ 5 V (LDAC pin)
Double-buffered input logic
Buffered/unbuffered reference input options
Output range: 0 V to VREF or 0 V to 2 VREF
Power-on reset to 0 V
Simultaneous update of outputs (LDAC pin)
Asynchronous clear facility (CLR pin)
Low power, SPI®-, QSPI™-, MICROWIRE™-, and DSP-
compatible 3-wire serial interface
SDO daisy-chaining option
On-chip rail-to-rail output buffer amplifiers
Temperature range of −40°C to +105°C
APPLICATIONS
Portable battery-powered instruments
Digital gain and offset adjustment
Programmable voltage and current sources
Programmable attenuators
Industrial process control
GENERAL DESCRIPTION
The AD5307/AD5317/AD53271 are quad 8-,10-,12-bit buffered
voltage-output DACs in 16-lead TSSOP that operate from single
2.5 V to 5.5 V supplies and consume 400 A at 3 V. Their on-
chip output amplifiers allow the outputs to swing rail-to-rail with
a slew rate of 0.7 V/s. The AD5307/AD5317/AD5327 utilize
versatile 3-wire serial interfaces that operate at clock rates up to
30 MHz; these parts are compatible with standard SPI, QSPI,
MICROWIRE, and DSP interface standards.
The references for the four DACs are derived from two reference
pins (one per DAC pair). These reference inputs can be configured
as buffered or unbuffered inputs. Each part incorporates a power-
on reset circuit, ensuring that the DAC outputs power up to 0 V
and remain there until a valid write to the device takes place.
There is also an asynchronous active low CLR pin that clears all
DACs to 0 V. The outputs of all DACs can be updated simul-
taneously using the asynchronous LDAC input. Each part
contains a power-down feature that reduces the current
consumption of the device to 300 nA @ 5 V (90 nA @ 3 V). The
parts can also be used in daisy-chaining applications using the
SDO pin.
All three parts are offered in the same pinout, allowing users to
select the amount of resolution appropriate for their application
without redesigning their circuit board.
FUNCTIONAL BLOCK DIAGRAM
VDD VREFAB
VREFCD
POWER-ON
RESET POWER-DOWN
LOGIC
GND
AD5307/AD5317/AD5327
LDAC
PDLDAC CLRDCEN
SDO
DIN
SYNC
SCLK
BUFFER
BUFFER
BUFFER
BUFFER
INPUT
REGISTER
DAC
REGISTER
STRING
DAC D
INPUT
REGISTER
DAC
REGISTER
STRING
DAC C
INPUT
REGISTER
DAC
REGISTER
STRING
DAC B
INPUT
REGISTER
DAC
REGISTER
STRING
DAC A
VOUTD
VOUTC
VOUTB
VOUTA
GAIN-SELECT
LOGIC
INTERFACE
LOGIC
02067-001
Figure 1.
1 Protected by U.S. Patent No. 5,969,657; other patents pending.
AD5307/AD5317/AD5327
Rev. C | Page 2 of 28
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
General Description ......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
AC Characteristics........................................................................ 5
Timing Characteristics ................................................................ 5
Absolute Maximum Ratings............................................................ 7
ESD Caution.................................................................................. 7
Pin Configuration and Function Descriptions............................. 8
Typical Performance Characteristics ............................................. 9
Ter mi nol o g y .................................................................................... 13
Transfer Function ........................................................................... 14
Functional Description .................................................................. 15
Digital-to-Analog Section ......................................................... 15
Resistor String............................................................................. 15
DAC Reference Inputs ............................................................... 15
Output Amplifier........................................................................ 16
Power-On Reset .......................................................................... 16
Serial Interface ................................................................................ 17
Input Shift Register .................................................................... 17
Control Bits................................................................................. 17
Low Power Serial Interface ....................................................... 18
Daisy Chaining ........................................................................... 18
Double-Buffered Interface ........................................................ 18
Load DAC Input (LDAC).......................................................... 18
Power-Down Mode .................................................................... 18
Microprocessor Interfacing....................................................... 19
Applications..................................................................................... 20
Typical Application Circuit ....................................................... 20
Driving VDD from the Reference Voltage ................................ 20
Bipolar Operation....................................................................... 20
Opto-Isolated Interface for Process-Control Applications... 21
Decoding Multiple AD5307/AD5317/AD5327 Devices....... 21
AD5307/AD5317/AD5327 as Digitally Programmable
Window Detectors ..................................................................... 21
Daisy Chaining ........................................................................... 22
Power Supply Bypassing and Grounding................................ 22
Outline Dimensions ....................................................................... 24
Ordering Guide .......................................................................... 25
REVISION HISTORY
3/06—Rev. B to Rev. C
Changes to Table 3............................................................................ 5
Changes to Ordering Guide .......................................................... 25
10/05—Rev. A to Rev. B
Updated Format..................................................................Universal
Changes to Bipolar Operation Section ........................................ 21
Changes to Ordering Guide .......................................................... 25
8/03—Rev. 0 to Rev. A
Added A Version ................................................................Universal
Changes to Features ..........................................................................1
Changes to Specifications.................................................................2
Changes to Absolute Maximum Ratings........................................6
Changes to Ordering Guide.............................................................6
Changes to TPC 21......................................................................... 12
Added Octals section to Table II .................................................. 20
Updated Outline Dimensions....................................................... 21
AD5307/AD5317/AD5327
Rev. C | Page 3 of 28
SPECIFICATIONS
VDD = 2.5 V to 5.5 V, VREF = 2 V, RL = 2 k to GND, CL = 200 pF to GND. All specifications TMIN to TMAX, unless otherwise noted.
Table 1.
A Version1B Version
Parameter2Min Typ Max Min Typ Max Unit Conditions/Comments
DC PERFORMANCE3, 4
AD5307
Resolution 8 8 Bits
Relative Accuracy ±0.15 ±1 ±0.15 ±0.625 LSB
Differential Nonlinearity ±0.02 ±0.25 ±0.02 ±0.25 LSB Guaranteed monotonic by design
over all codes
AD5317
Resolution 10 10 Bits
Relative Accuracy ±0.5 ±4 ±0.5 ±2.5 LSB
Differential Nonlinearity ±0.05 ±0.5 ±0.05 ±0.5 LSB Guaranteed monotonic by design
over all codes
AD5327
Resolution 12 12 Bits
Relative Accuracy ±2 ±16 ±2 ±10 LSB
Differential Nonlinearity ±0.2 ±1 ±0.2 ±1 LSB Guaranteed monotonic by design
over all codes
Offset Error ±5 ±60 ±5 ±60 mV VDD = 4.5 V, gain = 2; see Figure 29
and Figure 30
Gain Error ±0.3 ±1.25 ±0.3 ±1.25 % FSR VDD = 4.5 V, gain = 2; see Figure 29
and Figure 30
Lower Dead Band5 10 60 10 60 mV See Figure 29, lower dead band
exists only if offset error is negative
Upper Dead Band 10 60 10 60 mV See Figure 30, upper dead band
exists only if VREF = VDD and offset
plus gain error is positive
Offset Error Drift6 −12 −12 ppm of
FSR/°C
Gain Error Drift −5 −5 ppm of
FSR/°C
DC Power Supply Rejection Ratio −60 −60 dB ∆VDD = ±10%
DC Crosstalk 200 200 mV RL = 2 kΩ to GND or VDD
DAC REFERENCE INPUTS
VREF Input Range 1 VDD 1 VDD V Buffered reference mode
0.25 VDD 0.25 VDD V Unbuffered reference mode
VREF Input Impedance (RDAC) >10 >10 Buffered reference mode and
power-down mode
74 90 74 90 Unbuffered reference mode,
0 V to VREF output range
37 45 37 45 Unbuffered reference mode,
0 V to 2 VREF output range
Reference Feedthrough −90 −90 dB Frequency = 10 kHz
Channel-to-Channel Isolation −75 −75 dB Frequency = 10 kHz
OUTPUT CHARACTERISTICS
Minimum Output Voltage7 0.001 0.001 V A measure of the minimum drive
capability of the output amplifier
Maximum Output Voltage V
DD
0.001
V
DD
0.001
V A measure of the maximum drive
capability of the output amplifier
DC Output Impedance 0.5 0.5 Ω
Short-Circuit Current 25 25 mA VDD = 5 V
16 16 mA VDD = 3 V
Power-Up Time 2.5 2.5 μs Coming out of power-down mode,
VDD = 5 V
5 5 μs Coming out of power-down mode,
VDD = 3 V
AD5307/AD5317/AD5327
Rev. C | Page 4 of 28
A Version1B Version
Parameter2Min Typ Max Min Typ Max Unit Conditions/Comments
LOGIC INPUTS
Input Current ±1 ±1 mA
Input Low Voltage, VIL 0.8 0.8 V VDD = 5 V ± 10%
0.6 0.6 V VDD = 3 V ± 10%
0.5 0.5 V VDD = 2.5 V
Input High Voltage, VIH
(Excluding DCEN)
1.7 1.7 V VDD = 2.5 V to 5.5 V; TTL and
1.8 V CMOS compatible
Input High Voltage, VIH
(DCEN)
2.4 2.4 VDD = 5 V ± 10%
2.1 2.1 V VDD = 3 V ± 10%
2.0 2.0 V VDD = 2.5 V
Pin Capacitance 3 3 pF
LOGIC OUTPUT (SDO)
VDD = 4.5 V to 5.5 V
Output Low Voltage, VOL 0.4 0.4 V ISINK = 2 mA
Output High Voltage, VOH VDD − 1 VDD − 1 V ISOURCE = 2 mA
VDD = 2.5 V to 3.6 V
Output Low Voltage, VOL 0.4 0.4 V ISINK = 2 mA
Output High Voltage, VOH VDD
0.5
V
DD
0.5
V ISOURCE = 2 mA
Floating State Leakage Current ±1 ±1 μA DCEN = GND
Floating State Output Capacitance 3 3 pF DCEN = GND
POWER REQUIREMENTS
VDD 2.5 5.5 2.5 5.5 V
IDD (Normal Mode)8 V
IH = VDD and VIL = GND
VDD = 4.5 V to 5.5 V 500 900 500 900 μA
VDD = 2.5 V to 3.6 V 400 750 400 750 μA
All DACs in unbuffered mode; in
buffered mode, extra current is
typically x mA per DAC, where
x = 5 mA + VREF/RDAC
IDD (Power-Down Mode) VIH = VDD and VIL = GND
VDD = 4.5 V to 5.5 V 0.3 1 0.3 1 μA
VDD = 2.5 V to 3.6 V 0.09 1 0.09 1 μA
1 Temperature range (A, B versions): −40°C to +105°C; typical at +25°C.
2 See the Terminology section.
3 DC specifications tested with the outputs unloaded, unless otherwise noted.
4 Linearity is tested using a reduced code range: AD5307 (Code 8 to Code 255); AD5317 (Code 28 to Code 1023); AD5327 (Code 115 to Code 4095).
5 This corresponds to x codes, where x = deadband voltage/LSB size.
6 Guaranteed by design and characterization; not production tested.
7 For the amplifier output to reach its minimum voltage, offset error must be negative. For the amplifier output to reach its maximum voltage, VREF = VDD and offset plus
gain error must be positive.
8 Interface inactive. All DACs active. DAC outputs unloaded.
AD5307/AD5317/AD5327
Rev. C | Page 5 of 28
AC CHARACTERISTICS
VDD = 2.5 V to 5.5 V, RL = 2 k to GND, CL = 200 pF to GND. All specifications TMIN to TMAX, unless otherwise noted.
Table 2.
A, B Versions1
Parameter2, 3Min Typ Max Unit Conditions/Comments
Output Voltage Settling Time VREF = VDD = 5 V
AD5307 6 8 μs 1/4 scale to 3/4 scale change (0x40 to 0xC0)
AD5317 7 9 μs 1/4 scale to 3/4 scale change (0x100 to 0x300)
AD5327 8 10 μs 1/4 scale to 3/4 scale change (0x400 to 0xC00)
Slew Rate 0.7 V/μs
Major-Code Change Glitch Energy 12 nV-s 1 LSB change around major carry
Digital Feedthrough 0.5 nV-s
SDO Feedthrough 4 nV-s Daisy-chain mode; SDO load is 10 pF
Digital Crosstalk 0.5 nV-s
Analog Crosstalk 1 nV-s
DAC-to-DAC Crosstalk 3 nV-s
Multiplying Bandwidth 200 kHz VREF = 2 V ± 0.1 V p-p; unbuffered mode
Total Harmonic Distortion −70 dB VREF = 2.5 V ± 0.1 V p-p; frequency = 10 kHz
1 Temperature range (A, B versions): −40°C to +105°C; typical at +25°C.
2 Guaranteed by design and characterization; not production tested.
3 See the Terminology section.
TIMING CHARACTERISTICS
VDD = 2.5 V to 5.5 V; all specifications TMIN to TMAX, unless otherwise noted.
Table 3.
A, B Versions
Parameter1, , 2
3
Limit at TMIN, TMAX Unit Conditions/Comments
t1 33 ns min SCLK cycle time
t2 13 ns min SCLK high time
t3 13 ns min SCLK low time
t4 13 ns min SYNC to SCLK falling edge set-up time
t5 5 ns min Data set-up time
t6 4.5 ns min Data hold time
t7 5 ns min SCLK falling edge to SYNC rising edge
t8 50 ns min Minimum SYNC high time
t9 20 ns min LDAC pulse width
t10 20 ns min SCLK falling edge to LDAC rising edge
t11 20 ns min CLR pulse width
t12 0 ns min SCLK falling edge to LDAC falling edge
t134, 520 ns max SCLK rising edge to SDO valid (VDD = 3.6 V to 5.5 V)
25 ns max SCLK rising edge to SDO valid (VDD = 2.5 V to 3.5 V)
t14 5 ns min SCLK falling edge to SYNC rising edge
t15 8 ns min SYNC rising edge to SCLK rising edge
t16 0 ns min SYNC rising edge to LDAC falling edge
1 Guaranteed by design and characterization; not production tested.
2 All input signals are specified with tR = tF = 5 ns (10% to 90% of VDD) and timed from a voltage level of (VIL + VIH)/2.
3 See Figure 3 and Figure 4.
4 This is measured with the load circuit of Figure 2. t13 determines maximum SCLK frequency in daisy-chain mode.
5 Daisy-chain mode only.
AD5307/AD5317/AD5327
Rev. C | Page 6 of 28
2mA I
OL
2mA I
OH
V
OH (MIN)
TO OUTPUT
PIN C
L
50pF
02067-002
Figure 2. Load Circuit for Digital Output (SDO) Timing Specifications
02067-003
SCLK
DIN DB15 DB0
t
4
t
1
t
3
t
2
t
8
t
7
t
9
t
12
t
10
t
11
t
6
t
5
LDAC
1
LDAC
2
CLR
SYNC
NOTES
1
ASYNCHRONOUS LDAC UPDATE MODE.
2
SYNCHRONOUS LDAC UPDATE MODE.
Figure 3. Serial Interface Timing Diagram
SCLK
DIN DB15 DB0 DB15' DB0'
DB0
SDO
INPUT WORD FOR DAC N INPUT WORD FOR DAC (N+1)
UNDEFINED INPUT WORD FOR DAC N
DB15
t
1
SYNC
LDAC
t
2
t
3
t
4
t
5
t
6
t
8
t
9
t
13
t
14
t
15
t
16
02067-004
Figure 4. Daisy-Chaining Timing Diagram
AD5307/AD5317/AD5327
Rev. C | Page 7 of 28
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 4.
Parameter1Ratings
VDD to GND −0.3 V to +7 V
Digital Input Voltage to GND −0.3 V to VDD + 0.3 V
Digital Output Voltage to GND −0.3 V to VDD + 0.3 V
Reference Input Voltage to GND −0.3 V to VDD + 0.3 V
VOUTA − VOUTD to GND −0.3 V to VDD + 0.3 V
Operating Temperature Range
Industrial (A, B Versions) −40°C to +105°C
Storage Temperature Range −65°C to +150°C
Junction Temperature (TJ max) 150°C
16-Lead TSSOP
Power Dissipation (TJ max − TA)/θJA
θJA Thermal Impedance 150.4°C/W
Reflow Soldering
Peak Temperature 220°C
Time at Peak Temperature 10 sec to 40 sec
1 Transient currents of up to 100 mA do not cause SCR latch-up.
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.
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.
AD5307/AD5317/AD5327
Rev. C | Page 8 of 28
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
TOP VIEW
(Not to Scale)
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
V
DD
V
OUT
A
V
OUT
B
V
OUT
C
V
REF
AB
V
REF
CD
SDO
SCLK
DIN
GND
V
OUT
D
DCEN
AD5307/
AD5317/
AD5327
CLR
LDAC
PD
SYNC
02067-005
Figure 5. Pin Configuration
Table 5. Pin Function Descriptions
Pin
No. Mnemonic Description
1 CLR Active Low Control Input. Loads all 0s to all input and DAC registers. Therefore, the outputs also go to 0 V.
2 LDAC Active Low Control Input. Transfers the contents of the input registers to their respective DAC registers. Pulsing this
pin low allows any or all DAC registers to be updated if the input registers have new data. This allows simultaneous
update of all DAC outputs. Alternatively, this pin can be tied permanently low.
3 VDD Power Supply Input. These parts can be operated from 2.5 V to 5.5 V, and the supply should be decoupled with a 10 μF
capacitor in parallel with a 0.1 μF capacitor to GND.
4 VOUTA Buffered Analog Output Voltage from DAC A. The output amplifier has rail-to-rail operation.
5 VOUTB Buffered Analog Output Voltage from DAC B. The output amplifier has rail-to-rail operation.
6 VOUTC Buffered Analog Output Voltage from DAC C. The output amplifier has rail-to-rail operation.
7 VREFAB Reference Input Pin for DAC A and DAC B. It can be configured as a buffered or unbuffered input to each or both of
the DACs, depending on the state of the BUF bits in the serial input words to DAC A and DAC B. It has an input range
of 0.25 V to VDD in unbuffered mode and 1 V to VDD in buffered mode.
8 VREFCD Reference Input Pin for DAC C and DAC D. It can be configured as a buffered or unbuffered input to each or both of
the DACs, depending on the state of the BUF bits in the serial input words to DAC C and DAC D. It has an input range
of 0.25 V to VDD in unbuffered mode and 1 V to VDD in buffered mode.
9 DCEN Enables the Daisy-Chaining Option. It should be tied high if the part is being used in a daisy chain, and tied low if it is
being used in standalone mode.
10 PD Active Low Control Input. It acts like a hardware power-down option. All DACs go into power-down mode when this
pin is tied low. The DAC outputs go into a high impedance state, and the current consumption of the part drops to
300 nA @ 5 V (90 nA @ 3 V).
11 VOUTD Buffered Analog Output Voltage from DAC D. The output amplifier has rail-to-rail operation.
12 GND Ground Reference Point for All Circuitry on the Part.
13 DIN Serial Data Input. These devices each have a 16-bit shift register. Data is clocked into the register on the falling edge of
the serial clock input. The DIN input buffer is powered down after each write cycle.
14 SCLK Serial Clock Input. Data is clocked into the input shift register on the falling edge of the serial clock input. Data can be
transferred at rates of up to 30 MHz. The SCLK input buffer is powered down after each write cycle.
15 SYNC Active Low Control Input. This is the frame synchronization signal for the input data. When SYNC goes low, it powers
on the SCLK and DIN buffers and enables the input shift register. Data is transferred in on the falling edges of the
following 16 clocks. If SYNC is taken high before the 16th falling edge, the rising edge of SYNC acts as an interrupt and
the write sequence is ignored by the device.
16 SDO Serial Data Output. Can be used for daisy-chaining a number of these devices together or for reading back the data in
the shift register for diagnostic purposes. The serial data is transferred on the rising edge of SCLK and is valid on the
falling edge of the clock.
AD5307/AD5317/AD5327
Rev. C | Page 9 of 28
TYPICAL PERFORMANCE CHARACTERISTICS
02067-006
0 50 100 150 200
–1.0
–0.5
0
0.5
1.0
250
CODE
INL ERROR (LSB)
T
A
= 25°C
V
DD
= 5V
Figure 6. AD5307 INL
02067-007
0 200 400 600 900
–3
–2
–1
0
1
2
3
1000
CODE
INL ERROR (LSB)
T
A
= 25°C
V
DD
= 5V
Figure 7. AD5317 INL
02067-008
0 1000 2000 3000
–12
–8
–4
0
4
8
12
4000
CODE
INL ERROR (LSB)
T
A
= 25°C
V
DD
= 5V
Figure 8. AD5327 INL
02067-009
0 50 100 150 200
–0.3
–0.2
–0.1
0
0.1
0.2
0.3
250
CODE
DNL ERROR (LSB)
T
A
= 25°C
V
DD
= 5V
Figure 9. AD5307 DNL
02067-010
0 200 400 600 800
–0.6
–0.4
–0.2
0
0.2
0.4
0.6
1000
CODE
DNL ERROR (LSB)
T
A
= 25°C
V
DD
= 5V
Figure 10. AD5317 DNL
02067-011
0 1000 2000 3000
–1.0
–0.5
0
0.5
1.0
4000
CODE
DNL ERROR (LSB)
T
A
= 25°C
V
DD
= 5V
Figure 11. AD5327 DNL
AD5307/AD5317/AD5327
Rev. C | Page 10 of 28
02067-012
0123
–0.50
–0.25
0
0.25
0.50
45
VREF (V)
ERROR (LSB)
MAX INL
MIN INL
MIN INL
TA = 25°C
VDD = 5V
MAX DNL
Figure 12. AD5307 INL Error and DNL Error vs. VREF
02067-013
–40 0 40 80
–0.5
–0.4
–0.3
–0.2
–0.1
0
0.4
0.3
0.2
0.1
0.5
120
TEMPERATURE (°C)
ERROR (LSB)
MAX INL
MAX DNL
VDD = 5V
VREF = 3V
MIN INL
MIN DNL
Figure 13. AD5307 INL Error and DNL Error vs. Temperature
02067-014
–40 0 40 80
–1.0
–0.5
0
0.5
1.0
120
TEMPERATURE (°C)
ERROR (% FSR)
VDD = 5V
VREF = 2V
GAIN ERROR
OFFSET ERROR
Figure 14. AD5307 Offset Error and Gain Error vs. Temperature
02067-015
012345
–0.6
–0.5
–0.4
–0.3
–0.2
–0.1
0.1
0
6
VDD (V)
ERROR (% FSR)
GAIN ERROR
OFFSET ERROR
0.2
TA = 25°C
VREF = 2V
Figure 15. Offset Error and Gain Error vs. VDD
02067-016
012345
0
1
2
3
4
5
6
SINK/SOURCE CURRENT (mA)
V
OUT
(V)
5V SOURCE
3V SOURCE
5V SINK 3V SINK
Figure 16. VOUT Source and Sink Current Capability
02067-017
ZERO SCALE
0
100
200
300
400
500
FULL SCALE
CODE
I
DD
(µA)
T
A
= 25°C
V
DD
= 5V
V
REF
= 2V
600
Figure 17. Supply Current vs. DAC Code
AD5307/AD5317/AD5327
Rev. C | Page 11 of 28
02067-018
0
100
200
300
400
500
V
DD
(V)
I
DD
(µA)
600
2.5 3.0 3.5 4.0 4.5 5.0 5.5
+25°C
–40°C
+105°C
Figure 18. Supply Current vs. Supply Voltage
02067-019
0
0.1
0.2
0.3
0.4
0.5
V
DD
(V)
I
DD
(µA)
2.5 3.0 3.5 4.0 4.5 5.0 5.5
+105°C
+25°C
–40°C
Figure 19. Power-Down Current vs. Supply Voltage
02067-020
300
400
500
600
700
800
V
LOGIC
(V)
I
DD
(µA)
01 2 345
INCREASING
T
A
= 25°C
DECREASING
V
DD
= 5V
INCREASING
DECREASING
V
DD
= 3V
Figure 20. Supply Current vs. Logic Input Voltage for SCLK and DIN Increasing
and Decreasing
02067-021
CH2
CH1
CH1 1V, CH2 5V, TIME BASE = 1µs/DIV
T
A
= 25°C
V
DD
= 5V
V
REF
= 5V
V
OUT
A
SCLK
Figure 21. Half-Scale Settling (1/4 to 3/4 Scale Code Change)
CH1 2.00V, CH2 200mV, TIME BASE = 200µs/DIV
02067-022
T
A
= 25°C
V
DD
= 5V
V
REF
= 2V
V
OUT
A
V
DD
CH1
CH2
Figure 22. Power-On Reset to 0 V
02067-023
T
A
= 25°C
V
DD
= 5V
V
REF
= 2V
CH1 500MV, CH2 5.00V, TIME BASE = 1µs/DIV
CH1
CH2
V
OUT
A
PD
Figure 23. Exiting Power-Down to Midscale
AD5307/AD5317/AD5327
Rev. C | Page 12 of 28
02067-024
350 400 450 500 550 600
I
DD
(µA)
FREQUENCY
V
DD
= 5V
V
DD
= 3V
Figure 24. IDD Histogram with VDD = 3 V and VDD = 5 V
02067-025
2.47
2.48
2.49
2.50
1µs/DIV
V
OUT
(V)
Figure 25. AD5327 Major-Code Transition Glitch Energy
02067-026
10 100 1k 10k 100k 1M
–60
–50
–40
–30
–20
–10
0
10
10M
FREQUENCY (Hz)
(dB)
Figure 26. Multiplying Bandwidth (Small-Signal Frequency Response)
02067-027
012345
–0.02
0.02
6
–0.01
0
0.01
V
REF
(V)
FULL-SCALE ERROR (V)
V
DD
= 5V
T
A
= 25°C
Figure 27. Full-Scale Error vs. VREF
02067-028
150ns/DIV
1mV/DIV
Figure 28. DAC-to-DAC Crosstalk
AD5307/AD5317/AD5327
Rev. C | Page 13 of 28
TERMINOLOGY
Relative Accuracy
For the DAC, relative accuracy, or integral nonlinearity (INL), is
a measure of the maximum deviation in LSB from a straight line
passing through the endpoints of the DAC transfer function.
Figure 6 through Figure 8 show plots of typical INL vs. code.
Differential Nonlinearity
Differential nonlinearity (DNL) is the difference between the
measured change and the ideal 1 LSB change between any two
adjacent codes. A specified differential nonlinearity of ±1 LSB
maximum ensures monotonicity. This DAC is guaranteed
monotonic by design. Figure 9 through Figure 11 show plots of
typical DNL vs. code.
Offset Error
Offset error is a measure of the deviation in the output voltage
from 0 V when zero-code is loaded to the DAC (see Figure 29
and Figure 30.) It can be negative or positive. It is expressed in
millivolts.
Gain Error
Gain error is a measure of the span error of the DAC. It is the
deviation in slope of the actual DAC transfer characteristic from
the ideal expressed as a percentage of the full-scale range.
Offset Error Drift
Offset error drift is a measure of the change in offset error
with changes in temperature. It is expressed in (ppm of full-
scale range)/°C.
Gain Error Drift
Gain error drift is a measure of the change in gain error
with changes in temperature. It is expressed in (ppm of full-
scale range)/°C.
DC Power Supply Rejection Ratio (PSRR)
PSRR indicates how the output of the DAC is affected by
changes in the supply voltage. It is the ratio of the change in
VOUT to a change in VDD for full-scale output of the DAC. It is
measured in decibels. VREF is held at 2 V, and VDD is varied ±10%.
DC Crosstalk
DC crosstalk is the dc change in the output level of one DAC in
response to a change in the output of another DAC. It is measured
with a full-scale output change on one DAC while monitoring
another DAC. It is expressed in microvolts.
Reference Feedthrough
Reference feedthrough is the ratio of the amplitude of the signal at
the DAC output to the reference input when the DAC output is not
being updated (that is, LDAC is high). It is expressed in decibels.
Channel-to-Channel Isolation
Channel-to-channel isolation is the ratio of the amplitude of the
signal at the output of one DAC to a sine wave on the reference
input of another DAC. It is measured in decibels.
Major-Code Transition Glitch Energy
Major-code transition glitch energy is the energy of the impulse
injected into the analog output when the code in the DAC
register changes state. It is normally specified as the area of the
glitch in nV-s and is measured 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).
Digital Feedthrough
Digital feedthrough is a measure of the impulse injected into
the analog output of a DAC from the digital input pins of the
device, but it is measured when the DAC is not being written to
(SYNC held high). It is specified in nV-s and is measured with a
full-scale change on the digital input pins, that is, from all 0s to
all 1s or vice versa.
Digital Crosstalk
Digital crosstalk is the glitch impulse transferred to the output
of one DAC at midscale in response to a full-scale code change
(all 0s to all 1s or vice versa) in the input register of another DAC.
It is measured in standalone mode and is expressed in nV-s.
Analog Crosstalk
Analog crosstalk is the glitch impulse transferred to the output
of one DAC due to a change in the output of another DAC. It is
measured by loading one of the input registers with a full-scale
code change (all 0s to all 1s or vice versa) while keeping LDAC
high, and then pulsing LDAC low and monitoring the output of
the DAC whose digital code has not changed. The area of the
glitch is expressed in nV-s.
DAC-to-DAC Crosstalk
DAC-to-DAC crosstalk is the glitch impulse transferred to the
output of one DAC due to a digital code change and subsequent
output change of another DAC. This includes both digital and
analog crosstalk. It is measured by loading one of the DACs
with a full-scale code change (all 0s to all 1s or vice versa) with
LDAC low while monitoring the output of another DAC. The
energy of the glitch is expressed in nV-s.
Multiplying Bandwidth
The amplifiers within the DAC have a finite bandwidth, and the
multiplying bandwidth is a measure of this. A sine wave on the
reference (with full-scale code loaded to the DAC) appears on
the output. The multiplying bandwidth is the frequency at
which the output amplitude falls to 3 dB below the input.
Total Harmonic Distortion (THD)
THD is the difference between an ideal sine wave and its attenuated
version using the DAC. The sine wave is used as the reference for
the DAC, and the THD is a measure of the harmonics present
on the DAC output. It is measured in decibels.
AD5307/AD5317/AD5327
Rev. C | Page 14 of 28
TRANSFER FUNCTION
DAC CODE
GAIN ERROR
+
OFFSET ERRO
R
OUTPUT
VOLTAGE
NEGATIVE
OFFSET
ERROR
NEGATIVE
OFFSET
ERROR
AMPLIFIER
FOOTROOM
LOWER
DEAD BAND
CODES
02067-029
ACTUAL
IDEAL
Figure 29. Transfer Function with Negative Offset
02067-030
ACTUAL
IDEAL
DAC CODE FULL SCALE
POSITIVE
OFFSET
ERROR
OUTPUT
V
OLTAGE
GAIN ERROR
+
OFFSET ERROR
UPPER
DEADBAND
CODES
Figure 30. Transfer Function with Positive Offset (VREF = VDD)
AD5307/AD5317/AD5327
Rev. C | Page 15 of 28
FUNCTIONAL DESCRIPTION
The AD5307/AD5317/AD5327 are quad resistor-string DACs
fabricated on a CMOS process with resolutions of 8, 10, and 12
bits respectively. Each contains four output buffer amplifiers
and is written to via a 3-wire serial interface. They operate from
single supplies of 2.5 V to 5.5 V, and the output buffer amplifiers
provide rail-to-rail output swing with a slew rate of 0.7 V/µs.
DAC A and DAC B share a common reference input, VREFAB.
DAC C and DAC D share a common reference input, VREFCD.
Each reference input can be buffered to draw virtually no
current from the reference source, or can be unbuffered to give
a reference input range of 0.25 V to VDD. The devices have a
power-down mode in which all DACs can be completely turned
off with a high impedance output.
DIGITAL-TO-ANALOG SECTION
The architecture of one DAC channel consists of a resistor-
string DAC followed by an output buffer amplifier. The voltage
at the VREF pin provides the reference voltage for the
corresponding DAC. Figure 31 shows a block diagram of the
DAC architecture. Because the input coding to the DAC is
straight binary, the ideal output voltage is given by
N
REF
OUT
DV
V
2
×
=
where:
D is the decimal equivalent of the binary code that is loaded to
the DAC register:
0 to 255 for AD5307 (8 bits).
0 to 1023 for AD5317 (10 bits).
0 to 4095 for AD5327 (12 bits).
N is the DAC resolution.
INPUT
REGISTER
DAC
REGISTER
RESISTOR
STRING
OUTPUT
BUFFER AMPLIFIER
REFERENCE
BUFFER
BUF
GAIN MODE
(GAIN = 1 OR 2)
V
REF
AB
V
OUT
A
02067-031
Figure 31. Single DAC Channel Architecture
RESISTOR STRING
The resistor string section is shown in Figure 32. It is simply a
string of resistors, each of value R. The digital code loaded to
the DAC register determines at which node on the string the
voltage is tapped off to be fed into the output amplifier. The
voltage is tapped off by closing one of the switches connecting
the string to the amplifier. Because it is a string of resistors, it is
guaranteed monotonic.
DAC REFERENCE INPUTS
There is a reference pin for each pair of DACs. The reference
inputs are buffered but can also be individually configured as
unbuffered. The advantage with the buffered input is the high
impedance it presents to the voltage source driving it. However,
if the unbuffered mode is used, the user can have a reference
voltage as low as 0.25 V and as high as VDD, because there is no
restriction due to headroom and footroom of the reference
amplifier.
R
R
R
R
R
TO OUTPUT
AMPLIFIER
02067-032
Figure 32. Resistor String
If there is a buffered reference in the circuit (for example, REF192),
there is no need to use the on-chip buffers of the AD5307/AD5317/
AD5327. In unbuffered mode, the input impedance is still large
at typically 90 k per reference input for 0 V to VREF mode and
45 k or 0 V to 2 VREF mode.
The buffered/unbuffered option is controlled by the BUF bit in
the data-word. The BUF bit setting applies to whichever DAC is
selected.
AD5307/AD5317/AD5327
Rev. C | Page 16 of 28
OUTPUT AMPLIFIER
The output buffer amplifier is capable of generating output
voltages to within 1 mV of either rail. Its actual range depends
on the value of VREF, GAIN, offset error, and gain error.
If a gain of 1 is selected (GAIN = 0), the output range is 0.001 V
to VREF.
If a gain of 2 is selected (GAIN = 1), the output range is 0.001 V
to 2 VREF. Because of clamping, however, the maximum output
is limited to VDD − 0.001 V.
The output amplifier is capable of driving a load of 2 k to GND
or VDD in parallel with 500 pF to GND or VDD. The source and
sink capabilities of the output amplifier can be seen in Figure 16.
The slew rate is 0.7 V/s, with a half-scale settling time to
±0.5 LSB (at eight bits) of 6 s.
POWER-ON RESET
The AD5307/AD5317/AD5327 are each provided with a power-
on reset function so that they power up in a defined state. The
power-on state is
Normal operation
Reference inputs unbuffered
0 V to VREF output range
Output voltage set to 0 V
Both input and DAC registers are filled with 0s until a valid
write sequence is made to the device. This is particularly useful
in applications where it is important to know the state of the
DAC outputs while the device is powering up.
AD5307/AD5317/AD5327
Rev. C | Page 17 of 28
SERIAL INTERFACE
The AD5307/AD5317/AD5327 are controlled over versatile 3-wire
serial interfaces that operate at clock rates of up to 30 MHz and
are compatible with SPI, QSPI, MICROWIRE, and DSP
interface standards.
INPUT SHIFT REGISTER
The input shift register is 16 bits wide. Data is loaded into the
device as a 16-bit word under the control of a serial clock input,
SCLK. The timing diagram for this operation is shown in
Figure 3. The 16-bit word consists of four control bits followed
by 8, 10, or 12 bits of DAC data, depending on the device type.
Data is loaded MSB first (Bit 15), and the first two bits
determine whether the data is for DAC A, DAC B, DAC C, or
DAC D. Bit 13 and Bit 12 control the operating mode of the
DAC. Bit 13 is GAIN, which determines the output range of the
part. Bit 12 is BUF, which controls whether the reference inputs
are buffered or unbuffered.
Table 6. Address Bits for the AD53x7
A1 (Bit 15) A0 (Bit 14) DAC Addressed
0 0 DAC A
0 1 DAC B
1 0 DAC C
1 1 DAC D
CONTROL BITS
GAIN controls the output range of the addressed DAC.
0: output range of 0 V to VREF.
1: output range of 0 V to 2 VREF.
BUF controls whether reference of the addressed DAC is
buffered or unbuffered.
0: unbuffered reference.
1: buffered reference.
The AD5327 uses all 12 bits of DAC data; the AD5317 uses
10 bits and ignores the 2 LSBs. The AD5307 uses eight bits and
ignores the last four bits. The data format is straight binary, with
all 0s corresponding to 0 V output and all 1s corresponding to
full-scale output (VREF − 1 LSB).
The SYNC input is a level-triggered input that acts as a frame
synchronization signal and chip enable. Data can be transferred
into the device only while SYNC is low. To start the serial data
transfer, SYNC should be taken low, observing the minimum
SYNC to SCLK falling edge set-up time, t4. After SYNC goes
low, serial data is shifted into the devices input shift register on
the falling edges of SCLK for 16 clock pulses. In standalone
mode (DCEN = 0), any data and clock pulses after the 16th
falling edge of SCLK are ignored, and no further serial data
transfer can occur until SYNC is taken high and low again.
SYNC can be taken high after the falling edge of the 16th SCLK
pulse, observing the minimum SCLK falling edge to SYNC
rising edge time, t7.
After the end of serial data transfer, data is automatically trans-
ferred from the input shift register to the input register of the
selected DAC. If SYNC is taken high before the 16th falling
edge of SCLK, the data transfer is aborted and the DAC input
registers are not updated.
When data has been transferred into the input register of a DAC,
the corresponding DAC register and DAC output can be updated
by taking LDAC low. CLR is an active low, asynchronous clear
that clears the input registers and DAC registers to all 0s.
BIT 15
(MSB)
BIT 0
(LSB)
A1 BUF D7 D6 D5 D4 D3 D2 D1 D0GAINA0 XXXX
DATA BITS
02067-033
Figure 33. AD5307 Input Shift Register Contents
BIT 15
(MSB)
BIT 0
(LSB)
A1 BUF D9 D8 D7 D6 D5 D4 D3 D2GAINA0 D1 D0 X X
DATA BITS
02067-034
Figure 34. AD5317 Input Shift Register Contents
BIT 15
(MSB)
BIT 0
(LSB)
A1 BUF D11 D10 D9 D8 D7 D6 D5 D4GAINA0 D3 D2 D1 D0
DATA BITS
02067-035
Figure 35. AD5327 Input Shift Register Contents
AD5307/AD5317/AD5327
Rev. C | Page 18 of 28
LOW POWER SERIAL INTERFACE
To minimize the power consumption of the device, the interface
powers up fully only when the device is being written to, that is,
on the falling edge of SYNC. The SCLK and DIN input buffers
are powered down on the rising edge of SYNC.
DAISY CHAINING
For systems that contain several DACs, or where the user
wishes to read back the DAC contents for diagnostic purposes,
the SDO pin can be used to daisy-chain several devices together
and provide serial readback.
By connecting the DCEN (daisy-chain enable) pin high, the
daisy-chain mode is enabled. It is tied low in the case of
standalone mode. 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 16 clock
pulses are applied, the data ripples out of the shift register and
appears on the SDO 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 DAC in the chain, a
multi-DAC interface is constructed. Each DAC in the system
requires 16 clock pulses; therefore, the total number of clock
cycles must equal 16N, where N is the total number of devices
in the chain. When the serial transfer to all devices is complete,
SYNC should be taken high. This prevents any further data
from being clocked into the input shift register.
A continuous SCLK source can be used if SYNC is held low for
the correct number of clock cycles. Alternatively, a burst clock
containing the exact number of clock cycles can be used and
SYNC can be taken high some time later.
When the transfer to all input registers is complete, a common
LDAC signal updates all DAC registers and all analog outputs
are updated simultaneously.
DOUBLE-BUFFERED INTERFACE
The AD5307/AD5317/AD5327 DACs have double-buffered
interfaces consisting of two banks of registers: input registers
and DAC registers. The input registers are connected directly to
the input shift register and the digital code is transferred to the
relevant input register on completion of a valid write sequence.
The DAC registers contain the digital code used by the resistor
strings.
Access to the DAC registers is controlled by the LDAC pin.
When the LDAC pin is high, the DAC registers are latched and
the input registers can change state without affecting the
contents of the DAC registers. When LDAC is brought low,
however, the DAC registers become transparent and the
contents of the input registers are transferred to them.
The double-buffered interface is useful if the user requires
simultaneous updating of all DAC outputs. The user can write
to three of the input registers individually and then, by bringing
LDAC low when writing to the remaining DAC input register,
all outputs update simultaneously.
These parts each contain an extra feature whereby a DAC
register is not updated unless its input register has been updated
since the last time LDAC was brought low. Normally, when LDAC
is brought low, the DAC registers are filled with the contents of
the input registers. In the case of the AD5307/AD5317/AD5327,
the DAC register updates only if the input register has changed
since the last time the DAC register was updated, thereby removing
unnecessary digital crosstalk.
LOAD DAC INPUT (LDAC)
LDAC transfers data from the input registers to the DAC
registers and therefore updates the outputs. Use of the LDAC
function enables double buffering of the DAC data, GAIN, and
BUF. There are two LDAC modes: synchronous and asynchronous.
Synchronous Mode
In this mode, the DAC registers are updated after new data is
read from on the falling edge of the 16th SCLK pulse. LDAC
can be tied permanently low or pulsed as in Figure 3.
Asynchronous Mode
In this mode, the outputs are not updated at the same time that
the input registers are written to. When LDAC goes low, the DAC
registers are updated with the contents of the input register.
POWER-DOWN MODE
The AD5307/AD5317/AD5327 have low power consumption,
typically dissipating 1.2 mW with a 3 V supply and 2.5 mW with
a 5 V supply. Power consumption can be further reduced when
the DACs are not in use by putting them into power-down mode,
which is selected by taking the PD pin low.
When the PD pin is high, all DACs work normally with a typical
power consumption of 500 A at 5 V (400 A at 3 V). However,
in power-down mode, the supply current falls to 300 nA at 5 V
(90 nA at 3 V) when all DACs are powered down. Not only does
the supply current drop, but the output stage is also internally
switched from the output of the amplifier, making it an open
circuit. This has the advantage that the output is three-state
while the part is in power-down mode and provides a defined
input condition for whatever is connected to the output of the
DAC amplifier. The output stage is illustrated in Figure 36.
The bias generator, output amplifiers, resistor string, and all
other associated linear circuitry are shut down when the power-
down mode is activated. However, the contents of the registers
are unaffected when in power-down. In fact, it is possible to
load new data to the input registers and DAC registers during
power-down. The DAC outputs update as soon as PD goes high.
AD5307/AD5317/AD5327
Rev. C | Page 19 of 28
The time to exit power-down is typically 2.5 s for VDD = 5 V
and 5 s when VDD = 3 V. This is the time from the rising edge
of PD to when the output voltage deviates from its power-down
voltage. See Figure 23 for a plot.
RESISTOR
STRING DAC
POWER-DOWN
CIRCUITRY
AMPLIFIER
V
OUT
02067-036
Figure 36. Output Stage During Power-Down
MICROPROCESSOR INTERFACING
ADSP-2101/ADSP-2103-to-
AD5307/AD5317/AD5327 Interface
Figure 37 shows a serial interface between the AD5307/AD5317/
AD5327 and the ADSP-2101/ADSP-2103. The ADSP-2101/
ADSP-2103 should be set up to operate in the SPORT transmit
alternate framing mode. The ADSP-2101/ADSP-2103 SPORT is
programmed through the SPORT control register and should be
configured as follows: internal clock operation, active low framing,
16-bit word length. Transmission is initiated by writing a word
to the Tx register after SPORT is enabled. The data is clocked
out on each rising edge of the DSP’s serial clock and clocked
into the AD5307/AD5317/AD5327 on the falling edge of the
DACs SCLK.
SCLK
DIN
SYNC
TFS
DT
SCLK
ADSP-2101/
ADSP-2103
1
1
ADDITIONAL PINS OMITTED FOR CLARITY.
02067-037
AD5307/
AD5317/
AD5327
1
Figure 37. ADSP-2101/ADSP-2103-to-AD5307/AD5317/AD5327 Interface
68HC11/68L11-to-AD5307/AD5317/AD5327 Interface
Figure 38 shows a serial interface between the AD5307/AD5317/
AD5327 and the 68HC11/68L11 microcontroller. SCK of the
68HC11/68L11 drives the SCLK of the AD5307/AD5317/
AD5327, and the MOSI output drives the serial data line (DIN)
of the DAC. The SYNC signal is derived from a port line (PC7).
The set-up conditions for correct operation of this interface are as
follows: The 68HC11/68L11 should be configured so that its CPOL
bit is 0 and its CPHA bit is 1. When data is being transmitted to the
DAC, the SYNC line is taken low (PC7). With this configuration,
data appearing on the MOSI output is valid on the falling edge
of SCK. Serial data from the 68HC11/68L11 is transmitted in
8-bit bytes, with only eight falling clock edges occurring in the
transmit cycle. Data is transmitted MSB first. To load data to
the AD5307/AD5317/AD5327, PC7 is left low after the first
eight bits are transferred and a second serial write operation
is performed to the DAC. PC7 is taken high at the end of this
procedure.
DIN
SCLK
SYNC
PC7
SCK
MOSI
68HC11/68L11
1
1
ADDITIONAL PINS OMITTED FOR CLARITY.
02067-038
AD5307/
AD5317/
AD5327
1
Figure 38. 68HC11/68L11-to-AD5307/AD5317/AD5327 Interface
80C51/80L51-to-AD5307/AD5317/AD5327 Interface
Figure 39 shows a serial interface between the AD5307/AD5317/
AD5327 and the 80C51/80L51 microcontroller. The setup for
the interface is as follows: TxD of the 80C51/80L51 drives SCLK
of the AD5307/AD5317/AD5327, and RxD drives the serial data
line of the part. The SYNC signal is again derived from a bit-
programmable pin on the port. In this case, Port Line P3.3 is
used. When data is to be transmitted to the AD5307/AD5317/
AD5327, P3.3 is taken low. The 80C51/80L51 transmits data only
in 8-bit bytes; therefore, only eight falling clock edges occur in
the transmit cycle. To load data to the DAC, P3.3 is left low after
the first eight bits are transmitted, and a second write cycle is
initiated to transmit the second byte of data. P3.3 is taken high
following the completion of this cycle. The 80C51/80L51 outputs
the serial data LSB first. The AD5307/AD5317/AD5327 require
their data with the MSB as the first bit received. The
80C51/80L51 transmit routine should take this into account.
DIN
SCLK
P3.3
TxD
RxD
80C51/80L51
1
02067-039
SYNC
AD5307/
AD5317/
AD5327
1
1
ADDITIONAL PINS OMITTED FOR CLARITY.
Figure 39. 80C51/80L51-to-AD5307/AD5317/AD5327 Interface
MICROWIRE-to-AD5307/AD5317/AD5327 Interface
Figure 40 shows an interface between the AD5307/AD5317/
AD5327 and a MICROWIRE-compatible device. Serial data is
shifted out on the falling edge of the serial clock, SK, and is
clocked into the AD5307/AD5317/AD5327 on the rising edge
of SK, which corresponds to the falling edge of the DAC’s SCLK.
DIN
SCLK
SK
SO
MICROWIRE1
1ADDITIONAL PINS OMITTED FOR CLARITY.
02067-040
CS SYNC
AD5307/
AD5317/
AD5327
1
Figure 40. MICROWIRE-to-AD5307/AD5317/AD5327 Interface
AD5307/AD5317/AD5327
Rev. C | Page 20 of 28
APPLICATIONS
TYPICAL APPLICATION CIRCUIT
The AD5307/AD5317/AD5327 can be used with a wide range
of reference voltages and offer full, one-quadrant multiplying
capability over a reference range of 0.25 V to VDD. More typically,
these devices are used with a fixed precision reference voltage.
Suitable references for 5 V operation are the AD780 and REF192
(2.5 V references). For 2.5 V operation, a suitable external refer-
ence would be the AD589, a 1.23 V band gap reference. Figure 41
shows a typical setup for the AD5307/AD5317/AD5327 when
using an external reference.
1µF
10µF
SCLK
DIN
GND
AD5307/AD5317/
AD5327
SERIAL
INTERFACE
EXT
REF
02067-041
V
DD
= 2.5V TO 5.5
V
AD780/REF192
WITH V
DD
= 5V
OR AD589 WITH
V
DD
= 2.5V
V
IN
V
OUT
SYNC
V
OUT
A
V
OUT
B
V
OUT
C
V
OUT
D
V
REF
AB
V
REF
CD
0.1µF
Figure 41. AD5307/AD5317/AD5327 Using a 2.5 V External Reference
DRIVING VDD FROM THE REFERENCE VOLTAGE
If an output range of 0 V to VDD is required when the reference
inputs are configured as unbuffered, the simplest solution is to
connect the reference input to VDD. Because this supply can be
noisy and not very accurate, the AD5307/AD5317/AD5327 can
be powered from the reference voltage, for example, from a 5 V
reference such as the REF195, which outputs a steady supply
voltage. The typical current required from the REF195 with no
load on the DAC outputs is 500 A supply current and ≈112 A
into the reference inputs (if unbuffered). When the DAC
outputs are loaded, the REF195 also needs to supply the current
to the loads. The total current required with a 10 k load on
each output is
612 A + 4 (5 V/10 k) = 2.6 mA
The load regulation of the REF195 is typically 2 ppm/mA,
which results in an error of 5.2 ppm (26 V) for the 2.6 mA
current drawn from it. This corresponds to a 0.0013 LSB error
at eight bits and a 0.021 LSB error at 12 bits.
BIPOLAR OPERATION
The AD5307/AD5317/AD5327 are designed for single-supply
operation, but a bipolar output range is also possible using the
circuit shown in Figure 42. This circuit provides an output
voltage range of 5 V. Rail-to-rail operation at the amplifier
output is achievable by using an AD820 or an OP295 as the
output amplifier.
The output voltage for any input code can be calculated as
follows:
(
)
)/(
1
)(2/ R1R2REFIN
R
R2R1DREFIN
V
N
OUT ×
+××
=
where:
D is the decimal equivalent of the code loaded to the DAC.
N is the DAC resolution.
REFIN is the reference voltage input.
When REFIN = 5 V, R1 = R2 = 10 k,
VOUT = (10 × D/2N) − 5 V
+5V
AD820/
OP295
±5V
+5V
R1
10k
R2
10k
SCLK
GND
SERIAL
INTERFACE
–5V
+6V TO +16V
AD5307/AD5317/
AD5327
DIN
02067-042
SYNC
V
OUT
A
V
OUT
B
V
OUT
C
V
OUT
D
V
REF
AB
V
REF
CD
10µF 0.1µF
GND
REF195
V
IN
V
OUT
1µF
V
DD
Figure 42. Bipolar Operation with the AD5307/AD5317/AD5327