AD AD5663RBRMZ-5

Dual 12-/14-/16-Bit nanoDAC® with
5 ppm/°C On-Chip Reference
AD5623R/AD5643R/AD5663R
FEATURES
FUNCTIONAL BLOCK DIAGRAM
VDD
VREFIN /VREFOUT
1.25V/2.5V
REFERENCE
LDAC
SCLK
SYNC
INPUT
REGISTER
DAC
REGISTER
STRING
DAC A
BUFFER
VOUTA
INPUT
REGISTER
DAC
REGISTER
STRING
DAC B
BUFFER
VOUTB
INTERFACE
LOGIC
DIN
AD5623R/AD5643R/AD5663R
POWER-ON
RESET
POWER-DOWN
LOGIC
GND
LDAC CLR
05858-001
Low power, smallest pin-compatible, dual nanoDAC
AD5663R: 16 bits
AD5643R: 14 bits
AD5623R: 12 bits
User-selectable external or internal reference
External reference default
On-chip 1.25 V/2.5 V, 5 ppm/°C reference
10-lead MSOP and 3 mm × 3 mm LFCSP
2.7 V to 5.5 V power supply
Guaranteed monotonic by design
Power-on reset to zero scale
Per channel power-down
Serial interface up to 50 MHz
Hardware LDAC and CLR functions
Figure 1.
APPLICATIONS
Process control
Data acquisition systems
Portable battery-powered instruments
Digital gain and offset adjustment
Programmable voltage and current sources
Programmable attenuators
Table 1. Related Devices
Part No.
AD5663
Description
2.7 V to 5.5 V, dual 16-bit nanoDAC, with external
reference
GENERAL DESCRIPTION
The AD5623R/AD5643R/AD5663R, members of the nanoDAC
family, are low power, dual 12-, 14-, and 16-bit buffered voltageout digital-to-analog converters (DAC) that operate from a single
2.7 V to 5.5 V supply and are guaranteed monotonic by design.
The AD5623R/AD5643R/AD5663R have an on-chip reference.
The AD5623R-3/AD5643R-3/AD5663R-3 have a 1.25 V, 5 ppm/°C
reference, giving a full-scale output of 2.5 V; and the AD5623R-5/
AD5643R-5/AD5663R-5 have a 2.5 V, 5 ppm/°C reference,
giving a full-scale output of 5 V. The on-chip reference is off at
power-up, allowing the use of an external reference; and all
devices can be operated from a single 2.7 V to 5.5 V supply.
The internal reference is turned on by writing to the DAC.
The parts incorporate a power-on reset circuit that ensures the
DAC output powers up to 0 V and remains there until a valid
write takes place. The part contains a power-down feature that
reduces the current consumption of the device to 480 nA at 5 V
and provides software-selectable output loads while in powerdown mode.
The low power consumption of this part in normal operation
makes it ideally suited to portable, battery-operated equipment.
The AD5623R/AD5643R/AD5663R use a versatile, 3-wire serial
interface that operates at clock rates up to 50 MHz, and they are
compatible with standard SPI®, QSPI™, MICROWIRE™, and
DSP interface standards. The on-chip precision output amplifier
enables rail-to-rail output swing to be achieved.
PRODUCT HIGHLIGHTS
1. Dual 12-, 14-, and 16-bit DAC.
2. On-chip 1.25 V/2.5 V, 5 ppm/°C reference.
3. Available in 10-lead MSOP and 10-lead, 3 mm ×
3 mm LFCSP.
4. Low power; typically consumes 0.6 mW at 3 V and
1.25 mW at 5 V.
5. 4.5 μs maximum settling time for the AD5623R.
Rev. A
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.
AD5623R/AD5643R/AD5663R
TABLE OF CONTENTS
Features .............................................................................................. 1
Output Amplifier........................................................................ 20
Applications....................................................................................... 1
Internal Reference ...................................................................... 20
General Description ......................................................................... 1
External Reference ..................................................................... 20
Functional Block Diagram .............................................................. 1
Serial Interface ............................................................................ 20
Product Highlights ........................................................................... 1
Input Shift Register .................................................................... 21
Revision History ............................................................................... 2
SYNC Interrupt .......................................................................... 21
Specifications..................................................................................... 3
Power-On Reset.......................................................................... 22
AD5623R-5/AD5643R-5/AD5663R-5 ....................................... 3
Software Reset............................................................................. 22
AD5623R-3/AD5643R-3/AD5663R-3 ....................................... 5
Power-Down Modes .................................................................. 22
AC Characteristics........................................................................ 6
LDAC Function .......................................................................... 23
Timing Characteristics ................................................................ 7
Internal Reference Setup ........................................................... 24
Timing Diagram ........................................................................... 7
Microprocessor Interfacing....................................................... 25
Absolute Maximum Ratings............................................................ 8
Applications Information .............................................................. 26
ESD Caution.................................................................................. 8
Using a Reference as a Power Supply....................................... 26
Pin Configuration and Function Descriptions............................. 9
Bipolar Operation Using the AD5663R .................................. 26
Typical Performance Characteristics ........................................... 10
Using the AD5663R with a Galvanically Isolated Interface . 26
Terminology .................................................................................... 18
Power Supply Bypassing and Grounding................................ 27
Theory of Operation ...................................................................... 20
Outline Dimensions ....................................................................... 28
Digital-to-Analog Section ......................................................... 20
Ordering Guide .......................................................................... 28
Resistor String ............................................................................. 20
REVISION HISTORY
12/06—Rev. 0 to Rev. A
Changes to Table 2............................................................................ 3
Changes to Table 3............................................................................ 5
Changes to Figure 3.......................................................................... 9
Changes to Ordering Guide .......................................................... 28
4/06—Revision 0: Initial Version
Rev. A | Page 2 of 28
AD5623R/AD5643R/AD5663R
SPECIFICATIONS
AD5623R-5/AD5643R-5/AD5663R-5
VDD = 4.5 V to 5.5 V; RL = 2 kΩ to GND; CL = 200 pF to GND; VREFIN = VDD; all specifications TMIN to TMAX, unless otherwise noted.
Table 2.
Parameter
STATIC PERFORMANCE 2
AD5663R
Resolution
Relative Accuracy
Differential Nonlinearity
AD5643R
Resolution
Relative Accuracy
Differential Nonlinearity
AD5623R
Resolution
Relative Accuracy
Differential Nonlinearity
Zero-Scale Error
Offset Error
Full-Scale Error
Gain Error
Zero-Scale Error Drift
Gain Temperature Coefficient
DC Power Supply Rejection Ratio
DC Crosstalk (External Reference)
Min
DC Output Impedance
Short-Circuit Current
Power-Up Time
REFERENCE INPUTS
Reference Current
Reference Input Range
Reference Input Impedance
REFERENCE OUTPUT
Output Voltage
Reference Temperature Coefficient3
Output Impedance
Unit
Conditions/Comments
±16
±1
Bits
LSB
LSB
Guaranteed monotonic by design
±4
±0.5
Bits
LSB
LSB
Guaranteed monotonic by design
16
±8
14
±2
12
±2
±2.5
−100
10
Bits
LSB
LSB
mV
mV
% of FSR
% of FSR
μV/°C
ppm
dB
μV
10
5
25
μV/mA
μV
μV
20
10
μV/mA
μV
±0.5
+2
±1
−0.1
DC Crosstalk (Internal Reference)
OUTPUT CHARACTERISTICS 3
Output Voltage Range
Capacitive Load Stability
B Grade 1
Typ
Max
0
±1
±0.25
+10
±10
±1
±1.5
VDD
2
10
0.5
30
4
170
0.75
±5
±10
7.5
All 1s loaded to DAC register
Of FSR/°C
DAC code = midscale ; VDD = 5 V ± 10%
Due to full-scale output change;
RL = 2 kΩ to GND or VDD
Due to load current change
Due to powering down (per channel)
Due to full-scale output change;
RL = 2 kΩ to GND or VDD
Due to load current change
Due to powering down (per channel)
RL = ∞
RL = 2 kΩ
VDD = 5 V
Coming out of power-down mode; VDD = 5 V
200
VDD
μA
V
kΩ
VREF = VDD = 5.5 V
2.505
±10
V
ppm/°C
ppm/°C
kΩ
At ambient
MSOP package models
LFCSP package models
26
2.495
V
nF
nF
Ω
mA
μs
Guaranteed monotonic by design
All 0s loaded to DAC register
Rev. A | Page 3 of 28
AD5623R/AD5643R/AD5663R
Parameter
LOGIC INPUTS3
Input Current
Input Low Voltage (VINL)
Input High Voltage (VINH)
Pin Capacitance
POWER REQUIREMENTS
VDD
IDD (Normal Mode) 4
VDD = 4.5 V to 5.5 V
VDD = 4.5 V to 5.5 V
IDD (All Power-Down Modes) 5
VDD = 4.5 V to 5.5 V
Min
B Grade 1
Typ
Max
Unit
Conditions/Comments
3
μA
V
V
pF
All digital inputs
VDD = 5 V
VDD = 5 V
DIN, SCLK, and SYNC
19
pF
LDAC and CLR
±2
0.8
2
4.5
5.5
V
0.25
0.8
0.45
1
mA
mA
VIH = VDD and VIL = GND
Internal reference off
Internal reference on
0.48
1
μA
VIH = VDD and VIL = GND
1
Temperature range: B grade = −40°C to +105°C.
Linearity calculated using a reduced code range: AD5663R (Code 512 to Code 65,024), AD5643R (Code 128 to Code 16,256), and AD5623R (Code 32 to Code 4064).
Output unloaded.
3
Guaranteed by design and characterization, not production tested.
4
Interface inactive. All DACs active. DAC outputs unloaded.
5
Both DACs powered down.
2
Rev. A | Page 4 of 28
AD5623R/AD5643R/AD5663R
AD5623R-3/AD5643R-3/AD5663R-3
VDD = 2.7 V to 3.6 V; RL = 2 kΩ to GND; CL = 200 pF to GND; VREFIN = VDD; all specifications TMIN to TMAX, unless otherwise noted.
Table 3.
Parameter
STATIC PERFORMANCE 2
AD5663R
Resolution
Relative Accuracy
Differential Nonlinearity
AD5643R
Resolution
Relative Accuracy
Differential Nonlinearity
AD5623R
Resolution
Relative Accuracy
Differential Nonlinearity
Zero-Scale Error
Offset Error
Full-Scale Error
Gain Error
Zero-Scale Error Drift
Gain Temperature Coefficient
DC Power Supply Rejection Ratio
DC Crosstalk (External Reference)
Min
DC Output Impedance
Short Circuit Current
Power-Up Time
REFERENCE INPUTS
Reference Current
Reference Input Range
Reference Input Impedance
REFERENCE OUTPUT
Output Voltage
Reference Temperature Coefficient3
Output Impedance
Unit
Conditions/Comments
±16
±1
Bits
LSB
LSB
Guaranteed monotonic by design
±4
±0.5
Bits
LSB
LSB
Guaranteed monotonic by design
16
±8
14
±2
12
±2
±2.5
−100
10
Bits
LSB
LSB
mV
mV
% of FSR
% of FSR
μV/°C
ppm
dB
μV
10
5
25
μV/mA
μV
μV
20
10
μV/mA
μV
±0.5
+2
±1
−0.1
DC Crosstalk (Internal Reference)
OUTPUT CHARACTERISTICS 3
Output Voltage Range
Capacitive Load Stability
B Grade 1
Typ
Max
0
±1
±0.25
+10
±10
±1
±1.5
VDD
2
10
0.5
30
4
170
0.75
±5
±10
7.5
All 1s loaded to DAC register
Of FSR/°C
DAC code = midscale; VDD = 3 V ± 10%
Due to full-scale output change;
RL = 2 kΩ to GND or VDD
Due to load current change
Due to powering down (per channel)
Due to full-scale output change;
RL = 2 kΩ to GND or VDD
Due to load current change
Due to powering down (per channel)
RL = ∞
RL = 2 kΩ
VDD = 3 V
Coming out of power-down mode; VDD = 3 V
200
VDD
μA
V
kΩ
VREF = VDD = 3.6 V
1.253
±15
V
ppm/°C
ppm/°C
kΩ
At ambient
MSOP package models
LFCSP package models
26
1.247
V
nF
nF
Ω
mA
μs
Guaranteed monotonic by design
All 0s loaded to DAC register
Rev. A | Page 5 of 28
AD5623R/AD5643R/AD5663R
Parameter
LOGIC INPUTS3
Input Current
VINL, Input Low Voltage
VINH, Input High Voltage
Pin Capacitance
B Grade 1
Typ
Max
Min
Unit
Conditions/Comments
3
μA
V
V
pF
All digital inputs
VDD = 3 V
VDD = 3 V
DIN, SCLK, and SYNC
19
pF
LDAC and CLR
±2
0.8
2
POWER REQUIREMENTS
VDD
IDD (Normal Mode) 4
VDD = 2.7 V to 3.6 V
VDD = 2.7 V to 3.6 V
IDD (All Power-Down Modes) 5
VDD = 2.7 V to 3.6 V
2.7
3.6
V
200
800
425
900
μA
μA
VIH = VDD and VIL = GND
Internal reference off
Internal reference on
0.2
1
μA
VIH = VDD and VIL = GND
1
Temperature range: B grade = −40°C to +105°C.
Linearity calculated using a reduced code range: AD5663R (Code 512 to Code 65,024), AD5643R (Code 128 to Code 16,256), and AD5623R (Code 32 to Code 4064).
Output unloaded.
3
Guaranteed by design and characterization, not production tested.
4
Interface inactive. All DACs active. DAC outputs unloaded.
5
Both DACs powered down.
2
AC CHARACTERISTICS
VDD = 2.7 V to 5.5 V; RL = 2 kΩ to GND; CL = 200 pF to GND; VREFIN = VDD; all specifications TMIN to TMAX, unless otherwise noted.
Table 4.
Parameter 1, 2
Output Voltage Settling Time
AD5623R
AD5643R
AD5663R
Slew Rate
Digital-to-Analog Glitch Impulse
Digital Feedthrough
Reference Feedthrough
Digital Crosstalk
Analog Crosstalk
DAC-to-DAC Crosstalk
Multiplying Bandwidth
Total Harmonic Distortion
Output Noise Spectral Density
Output Noise
Min
Typ
Max
Unit
Conditions/Comments 3
3
3.5
4
1.8
10
0.1
−90
0.1
1
4
1
4
340
−80
120
100
15
4.5
5
7
μs
μs
μs
V/μs
nV-s
nV-s
dB
nV-s
nV-s
nV-s
nV-s
nV-s
kHz
dB
nV/√Hz
nV/√Hz
μV p-p
¼ to ¾ scale settling to ±0.5 LSB
¼ to ¾ scale settling to ±0.5 LSB
¼ to ¾ scale settling to ±2 LSB
1
Guaranteed by design and characterization, not production tested.
See the Terminology section.
3
Temperature range: B grade = −40°C to +105°C, typical at +25°C.
2
Rev. A | Page 6 of 28
1 LSB change around major carry
VREF = 2 V ± 0.1 V p-p, frequency 10 Hz to 20 MHz
External reference
Internal reference
External reference
Internal reference
VREF = 2 V ± 0.1 V p-p
VREF = 2 V ± 0.1 V p-p, frequency = 10 kHz
DAC code = midscale, 1 kHz
DAC code = midscale, 10 kHz
0.1 Hz to 10 Hz
AD5623R/AD5643R/AD5663R
TIMING CHARACTERISTICS
All input signals are specified with tR = tF = 1 ns/V (10% to 90% of VDD) and timed from a voltage level of (VIL + VIH)/2.
VDD = 2.7 V to 5.5 V; all specifications TMIN to TMAX, unless otherwise noted. 1
Table 5.
Parameter
Limit at TMIN, TMAX
VDD = 2.7 V to 5.5 V
Unit
Conditions/Comments
t1 2
20
ns min
SCLK cycle time
t2
t3
t4
t5
t6
t7
9
9
13
5
5
0
ns min
ns min
ns min
ns min
ns min
ns min
SCLK high time
SCLK low time
SYNC to SCLK falling edge setup time
Data setup time
Data hold time
SCLK falling edge to SYNC rising edge
t8
15
ns min
Minimum SYNC high time
t9
13
ns min
SYNC rising edge to SCLK fall ignore
t10
0
ns min
SCLK falling edge to SYNC fall ignore
t11
10
ns min
LDAC pulse width low
t12
15
ns min
SCLK falling edge to LDAC rising edge
t13
5
ns min
CLR pulse width low
t14
0
ns min
SCLK falling edge to LDAC falling edge
t15
300
ns max
CLR pulse activation time
1
2
Guaranteed by design and characterization, not production tested.
Maximum SCLK frequency is 50 MHz at VDD = 2.7 V to 5.5 V.
TIMING DIAGRAM
t10
t1
t9
SCLK
t8
t3
t4
t2
t7
SYNC
t5
DIN
t6
DB23
DB0
t14
t11
LDAC1
t12
LDAC2
VOUT
t13
t15
05858-002
CLR
1ASYNCHRONOUS LDAC UPDATE MODE.
2SYNCHRONOUS LDAC UPDATE MODE.
Figure 2. Serial Write Operation
Rev. A | Page 7 of 28
AD5623R/AD5643R/AD5663R
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 6.
Parameter
VDD to GND
VOUT to GND
VREFIN/VREFOUT to GND
Digital Input Voltage to GND
Operating Temperature Range
Industrial
Storage Temperature Range
Junction Temperature (TJ max)
Power Dissipation
LFCSP Package (4-Layer Board)
θJA Thermal Impedance
MSOP Package (4-Layer Board)
θJA Thermal Impedance
θJC Thermal Impedance
Reflow Soldering Peak Temperature
Pb-Free
Rating
−0.3 V to +7 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−40°C to +105°C
−65°C to +150°C
150°C
(TJ max − TA)/θJA
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
61°C/W
142°C/W
43.7°C/W
260(+0/−5)°C
Rev. A | Page 8 of 28
AD5623R/AD5643R/AD5663R
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
VOUTB 2
GND 3
LDAC 4
CLR 5
AD5623R/
AD5643R/
AD5663R
TOP VIEW
(Not to Scale)
10
VREFIN/VREFOUT
9
VDD
8
DIN
7
SCLK
6
SYNC
NOTE:
EXPOSED PAD TIED TO GND ON
LFCSP PACKAGE.
05858-003
VOUTA 1
Figure 3. Pin Configuration
Table 7. Pin Function Descriptions
Pin No.
1
2
3
4
Mnemonic
VOUTA
VOUTB
GND
LDAC
5
CLR
6
SYNC
7
SCLK
8
DIN
9
VDD
10
VREFIN/VREFOUT
Description
Analog Output Voltage from DAC A. The output amplifier has rail-to-rail operation.
Analog Output Voltage from DAC B. The output amplifier has rail-to-rail operation.
Ground. Reference point for all circuitry on the part.
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.
Asynchronous Clear Input. The CLR input is falling edge sensitive. While CLR is low, all LDAC pulses are
ignored. When CLR is activated, zero scale is loaded to all input and DAC registers. This clears the output to 0 V.
The part exits clear code mode on the 24th falling edge of the next write to the part. If CLR is activated during
a write sequence, the write is aborted.
Level-Triggered Control Input (Active Low). This is the frame synchronization signal for the input data.
When SYNC goes low, it enables the input shift register, and data is transferred in on the falling edges of the
following clocks. The DAC is updated following the 24th clock cycle unless SYNC is taken high before this edge,
in which case the rising edge of SYNC acts as an interrupt and the write sequence is ignored by the DAC.
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 up to 50 MHz.
Serial Data Input. This device has a 24-bit shift register. Data is clocked into the register on the falling edge
of the serial clock input.
Power Supply Input. These parts can be operated from 2.7 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.
Common Reference Input/Reference Output. When the internal reference is selected, this is the reference output
pin. When using an external reference, this is the reference input pin. The default for this pin is a reference input.
Rev. A | Page 9 of 28
AD5623R/AD5643R/AD5663R
TYPICAL PERFORMANCE CHARACTERISTICS
1.0
VDD = VREF = 5V
TA = 25°C
0.6
4
0.4
DNL ERROR (LSB)
6
2
0
–2
–4
0.2
0
–0.2
–0.4
–6
–0.6
–8
–0.8
–10
0
VDD = VREF = 5V
TA = 25°C
0.8
5k 10k 15k 20k 25k 30k 35k 40k 45k 50k 55k 60k 65k
CODE
–1.0
05858-005
INL ERROR (LSB)
8
0
10k
20k
30k
CODE
40k
50k
60k
05858-008
10
Figure 7. DNL—AD5663R, External Reference
Figure 4. INL—AD5663R, External Reference
0.5
4
VDD = VREF = 5V
TA = 25°C
3
VDD = VREF = 5V
TA = 25°C
0.4
0.3
DNL ERROR (LSB)
INL ERROR (LSB)
2
1
0
–1
0.2
0.1
0
–0.1
–0.2
–2
0
2.5k
5.0k
7.5k
10.0k
CODE
12.5k
15.0k
–0.5
05858-006
–4
–0.4
0
2.5k
5.0k
7.5k
10.0k
CODE
12.5k
15.0k
05858-009
–0.3
–3
Figure 8. DNL—AD5643R, External Reference
Figure 5. INL—AD5643R, External Reference
1.0
0.20
VDD = VREF = 5V
0.8 TA = 25°C
VDD = VREF = 5V
TA = 25°C
0.15
0.6
0.10
DNL ERROR (LSB)
0.2
0
–0.2
–0.4
0
–0.05
0
0.5k
1.0k
1.5k
2.0k
2.5k
CODE
3.0k
3.5k
4.0k
Figure 6. INL—AD5623R, External Reference
–0.20
0
0.5k
1.0k
1.5k
2.0k
2.5k
CODE
3.0k
3.5k
Figure 9. DNL—AD5623R, External Reference
Rev. A | Page 10 of 28
4.0k
05858-010
–0.15
–0.8
–1.0
0.05
–0.10
–0.6
05858-007
INL ERROR (LSB)
0.4
AD5623R/AD5643R/AD5663R
1.0
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
8
0.6
4
DNL ERROR (LSB)
INL ERROR (LSB)
6
2
0
–2
–4
0.4
0.2
0
–0.2
–0.4
–6
–0.6
–8
–0.8
5k 10k 15k 20k 25k 30k 35k 40k 45k 50k 55k 60k 65k
CODE
–1.0
05858-011
–10
0
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
0.8
0
5k 10k 15k 20k 25k 30k 35k 40k 45k 50k 55k 60k 65k
CODE
Figure 10. INL—AD5663R-5
05858-014
10
Figure 13. DNL—AD5663R-5
4
0.5
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
3
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
0.4
0.3
DNL ERROR (LSB)
INL ERROR (LSB)
2
1
0
–1
0.2
0.1
0
–0.1
–0.2
–2
–0.3
–3
–0.4
–4
16250
CODE
Figure 11. INL—AD5643R-5
05858-015
15000
13750
12500
11250
10000
8750
7500
6250
5000
3750
2500
0
1250
16250
CODE
05858-012
15000
13750
12500
11250
10000
8750
7500
6250
5000
3750
2500
0
1250
–0.5
Figure 14. DNL—AD5643R-5
1.0
0.20
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
0.8
0.6
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
0.15
DNL ERROR (LSB)
0.2
0
–0.2
–0.4
0
–0.05
0
0.5k
1.0k
1.5k
2.0k
2.5k
CODE
3.0k
3.5k
4.0k
Figure 12. INL—AD5623R-5
–0.20
0
0.5k
1.0k
1.5k
2.0k
2.5k
CODE
3.0k
Figure 15. DNL—AD5623R-5
Rev. A | Page 11 of 28
3.5k
4.0k
05858-016
–0.15
–0.8
–1.0
0.05
–0.10
–0.6
05858-013
INL ERROR (LSB)
0.10
0.4
AD5623R/AD5643R/AD5663R
10
1.0
VDD = 3V
VREFOUT = 1.25V
TA = 25°C
8
0.6
4
DNL ERROR (LSB)
2
0
–2
–4
0.4
0.2
0
–0.2
–0.4
–6
–0.6
–8
–0.8
–1.0
0
5k 10k 15k 20k 25k 30k 35k 40k 45k 50k 55k 60k 65k
CODE
05858-017
–10
0
5k 10k 15k 20k 25k 30k 35k 40k 45k 50k 55k 60k 65k
CODE
Figure 16. INL—AD5663R-3
Figure 19. DNL—AD5663R-3
4
0.5
VDD = 3V
V
= 1.25V
3 T REFOUT
A = 25°C
VDD = 3V
VREFOUT = 1.25V
TA = 25°C
0.4
0.3
DNL ERROR (LSB)
2
INL ERROR (LSB)
05858-020
INL ERROR (LSB)
6
VDD = 3V
VREFOUT = 1.25V
TA = 25°C
0.8
1
0
–1
–2
0.2
0.1
0
–0.1
–0.2
–0.3
–3
–0.4
16250
05858-021
15000
13750
12500
11250
8750
10000
7500
0.20
VDD = 3V
VREFOUT = 1.25V
TA = 25°C
0.15
0.6
0.10
DNL ERROR (LSB)
0.4
0.2
0
–0.2
–0.4
0.05
0
–0.05
–0.10
–0.6
–1.0
0
0.5k
1.0k
1.5k
2.0k
2.5k
CODE
3.0k
3.5k
4.0k
Figure 18. INL—AD5623R-3
–0.20
0
0.5k
1.0k
1.5k
2.0k
2.5k
CODE
3.0k
Figure 21. DNL—AD5623R-3
Rev. A | Page 12 of 28
3.5k
4.0k
05858-022
–0.15
–0.8
05858-019
INL ERROR (LSB)
6250
Figure 20. DNL—AD5643R-3
VDD = 3V
VREFOUT = 1.25V
TA = 25°C
0.8
5000
CODE
Figure 17. INL—AD5643R-3
1.0
3750
2500
0
1250
16250
CODE
05858-018
15000
13750
12500
11250
–0.5
10000
8750
7500
6250
5000
3750
2500
0
1250
–4
AD5623R/AD5643R/AD5663R
8
0
6
MAX INL
VDD = VREF = 5V
–0.04
GAIN ERROR
–0.06
MAX DNL
0
MIN DNL
–2
–4
–0.08
–0.10
–0.12
–0.14
MIN INL
–20
0
20
40
60
TEMPERATURE (°C)
80
100
–0.18
120
–0.20
–40
Figure 22. INL Error and DNL Error vs. Temperature
20
40
60
TEMPERATURE (°C)
80
100
1.5
MAX INL
8
1.0
6
VDD = 5V
TA = 25°C
ZERO-SCALE ERROR
0.5
ERROR (mV)
2
MAX DNL
0
MIN DNL
–2
–4
0
–0.5
–1.0
–1.5
–6
OFFSET ERROR
1.25
1.75
2.25
2.75
3.25
VREF (V)
3.75
4.25
05858-081
MIN INL
–8
–10
0.75
0
Figure 25. Gain Error and Full-Scale Error vs. Temperature
10
4
–20
–2.0
4.75
–2.5
–40
Figure 23. INL Error and DNL Error vs. VREF
–20
0
20
40
60
TEMPERATURE (°C)
80
100
05858-024
–8
–40
05858-080
–6
FULL-SCALE ERROR
–0.16
05858-023
2
ERROR (% FSR)
ERROR (LSB)
4
ERROR (LSB)
VDD = 5V
–0.02
Figure 26. Zero-Scale Error and Offset Error vs. Temperature
8
1.0
6
MAX INL
TA = 25°C
0.5
4
ERROR (% FSR)
MAX DNL
0
MIN DNL
–2
–4
0
FULL-SCALE ERROR
–0.5
–1.0
MIN INL
–8
2.7
–1.5
3.2
3.7
4.2
VDD (V)
4.7
–2.0
2.7
5.2
Figure 24. INL Error and DNL Error vs. Supply
3.2
3.7
4.2
VDD (V)
4.7
5.2
Figure 27. Gain Error and Full-Scale Error vs. Supply
Rev. A | Page 13 of 28
05858-025
–6
05858-082
ERROR (LSB)
GAIN ERROR
2
AD5623R/AD5643R/AD5663R
1.0
0.5
TA = 25°C
0.5
0.4
ZERO-SCALE ERROR
DAC LOADED WITH
FULL-SCALE
SOURCING CURRENT
DAC LOADED WITH
ZERO-SCALE
SINKING CURRENT
0.3
ERROR VOLTAGE (V)
–0.5
–1.0
–1.5
0.2
0.1
0
–0.1
–0.2
VDD = 5V
VREFOUT = 2.5V
–0.3
–2.0
OFFSET ERROR
3.2
3.7
4.2
VDD (V)
4.7
5.2
–0.4
–0.5
–10
05858-026
–2.5
2.7
Figure 28. Zero-Scale Error and Offset Error vs. Supply
–8
–6
–4
–2
0
2
CURRENT (mA)
4
6
8
10
Figure 31. Headroom at Rails vs. Source and Sink
6
VDD = 5.5V
TA = 25°C
8
5
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
FULL SCALE
3/4 SCALE
4
6
VOUT (V)
NUMBER OF UNITS
VDD = 3V
VREFOUT = 1.25V
05858-029
ERROR (mV)
0
4
3
MIDSCALE
2
1/4 SCALE
1
2
0.235
0.240
0.245
IDD (mA)
0.250
0.255
–1
–30
Figure 29. IDD Histogram with External Reference
0
10
CURRENT (mA)
20
30
4
VDD = 5.5V
TA = 25°C
3
3
2
VOUT (V)
4
2
1
VDD = 3V
VREFOUT = 1.25V
TA = 25°C
FULL SCALE
3/4 SCALE
MIDSCALE
1
1/4 SCALE
0
0.78
0.80
0.82
IDD (mA)
0.84
05858-091
NUMBER OF UNITS
–10
Figure 32. AD56x3R-5 Source and Sink Capability
5
0
–20
05858-030
0.230
ZERO SCALE
–1
–30
ZERO SCALE
–20
–10
0
10
CURRENT (mA)
20
Figure 33. AD56x3R-3 Source and Sink Capability
Figure 30. IDD Histogram with Internal Reference
Rev. A | Page 14 of 28
30
05858-031
0
05858-090
0
AD5623R/AD5643R/AD5663R
0.30
SYNC
TA = 25°C
VDD = VREFIN = 5V
0.25
1
SLCK
3
VDD = VREFIN = 3V
0.15
0.10
VOUT
0.05
VDD = 5V
–20
0
20
40
60
TEMPERATURE (°C)
80
100
CH1 5.0V
CH3 5.0V
Figure 34. Supply Current vs. Temperature
CH2 500mV
M400ns
A CH1
1.4V
05858-062
0
–40
05858-044
2
Figure 37. Exiting Power-Down to Midscale
VOUT = 909mV/DIV
05858-060
1
TIME BASE = 4µs/DIV
Figure 35. Full-Scale Settling Time, 5 V
2.538
2.537
2.536
2.535
2.534
2.533
2.532
2.531
2.530
2.529
2.528
2.527
2.526
2.525
2.524
2.523
2.522
2.521
VDD = VREF = 5V
TA = 25°C
5ns/SAMPLE NUMBER
GLITCH IMPULSE = 9.494nV
1LSB CHANGE AROUND
MIDSCALE (0x8000 TO 0x7FFF)
05858-058
VOUT (V)
VDD = VREF = 5V
TA = 25°C
FULL-SCALE CODE CHANGE
0x0000 TO 0xFFFF
OUTPUT LOADED WITH 2kΩ
AND 200pF TO GND
0
50
100
150
200 250 300 350
SAMPLE NUMBER
400
450
512
Figure 38. Digital-to-Analog Glitch Impulse (Negative)
2.498
VDD = VREF = 5V
TA = 25°C
VDD = VREF = 5V
TA = 25°C
5ns/SAMPLE NUMBER
ANALOG CROSSTALK = 0.424nV
2.497
VOUT (V)
2.496
VDD
2.495
2.494
1
2.493
MAX(C2)*
420.0mV
05858-059
2.492
2
VOUT
CH1 2.0V
CH2 500mV
M100µs 125MS/s
A CH1
1.28V
8.0ns/pt
2.491
05858-061
IDD (mA)
0.20
0
50
100
150
200 250 300 350
SAMPLE NUMBER
400
450
Figure 39. Analog Crosstalk, External Reference
Figure 36. Power-On Reset to 0 V
Rev. A | Page 15 of 28
512
VDD = 3V
VREFOUT = 1.25V
TA = 25°C
DAC LOADED WITH MIDSCALE
5µV/DIV
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
5ns/SAMPLE NUMBER
ANALOG CROSSTALK = 4.462nV
0
50
100
150
200 250 300 350
SAMPLE NUMBER
400
450
1
05858-065
2.496
2.494
2.492
2.490
2.488
2.486
2.484
2.482
2.480
2.478
2.476
2.474
2.472
2.470
2.468
2.466
2.464
2.462
2.460
2.458
2.456
05858-057
VOUT (V)
AD5623R/AD5643R/AD5663R
512
4s/DIV
Figure 40. Analog Crosstalk, Internal Reference
Figure 43. 0.1 Hz to 10 Hz Output Noise Plot, Internal Reference
800
700
1
600
500
400
300
100
0
100
05858-063
Y AXIS = 2µV/DIV
X AXIS = 4s/DIV
VDD = 5V
VREFOUT = 2.5V
200
Figure 41. 0.1 Hz to 10 Hz Output Noise Plot, External Reference
VDD = 3V
VREFOUT = 1.25V
1k
10k
FREQUENCY (Hz)
1M
05858-066
OUTPUT NOISE (nV/√Hz)
VDD = VREF = 5V
TA = 25°C
DAC LOADED WITH MIDSCALE
TA = 25°C
MIDSCALE LOADED
10M
Figure 44. Noise Spectral Density, Internal Reference
–20
VDD = 5V
VREFOUT = 2.5V
TA = 25°C
DAC LOADED WITH MIDSCALE
–30
–40
VDD = 5V
TA = 25°C
DAC LOADED WITH FULL SCALE
VREF = 2V ± 0.3V p-p
(dB)
10µV/DIV
–50
1
–60
–70
–80
05858-064
5s/DIV
–100
Figure 42. 0.1 Hz to 10 Hz Output Noise Plot, Internal Reference
2k
4k
6k
FREQUENCY (Hz)
8k
Figure 45. Total Harmonic Distortion
Rev. A | Page 16 of 28
10k
05858-067
–90
AD5623R/AD5643R/AD5663R
16
VREF = VDD
TA = 25°C
14
CLR
3
VDD = 3V
12
TIME (µs)
VOUT A
10
VDD = 5V
8
VOUT B
6
0
1
2
3
4
5
6
7
CAPACITANCE (nF)
8
9
10
05858-068
2
4
Figure 46. Settling Time vs. Capacitive Load
5
–5
–10
–15
–20
–25
–30
100k
1M
FREQUENCY (Hz)
10M
05858-069
–35
–40
10k
CH3 5.0V
CH2 1.0V
CH4 1.0V
M200ns A CH3
Figure 48. CLR Pulse Activation Time
VDD = 5V
TA = 25°C
0
(dB)
05858-050
4
Figure 47. Multiplying Bandwidth
Rev. A | Page 17 of 28
1.10V
AD5623R/AD5643R/AD5663R
TERMINOLOGY
Relative Accuracy or Integral Nonlinearity (INL)
For the DAC, relative accuracy or integral nonlinearity is a
measurement of the maximum deviation, in LSBs, from a
straight line passing through the endpoints of the DAC transfer
function. A typical INL vs. code plot is shown in Figure 5.
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 differential nonlinearity of ±1 LSB
maximum ensures monotonicity. This DAC is guaranteed
monotonic by design. A typical DNL vs. code plot is shown in
Figure 9.
Zero-Scale Error
Zero-scale error is the measurement of the output error when
zero code (0x0000) is loaded to the DAC register. Ideally, the
output should be 0 V. The zero-scale error is always positive in
the AD56x3R because the output of the DAC cannot go below
0 V. It is due to a combination of the offset errors in the DAC
and the output amplifier. Zero-scale error is expressed in mV.
A plot of zero-scale error vs. temperature is shown in Figure 26.
Full-Scale Error
Full-scale error is the measurement of the output error when
full-scale code (0xFFFF) is loaded into the DAC register. Ideally,
the output should be VDD − 1 LSB. Full-scale error is expressed
in percent of full-scale range. A plot of full-scale error vs.
temperature is shown in Figure 25.
Gain Error
Gain error is a measure of the span error of the DAC. It is the
deviation in slope of the DAC transfer characteristic from ideal,
expressed as a percent of the full-scale range.
Zero-Scale Error Drift
Zero-scale error drift is the measurement of the change in zeroscale error with a change in temperature. It is expressed in
microvolts/°C (μV/°C).
Gain Temperature Coefficient
Gain temperature coefficient is a measurement of the change in
gain error with changes in temperature. It is expressed in (ppm
of full-scale range)/°C.
Offset Error
Offset error is a measure of the difference between VOUT (actual)
and VOUT (ideal) expressed in mV in the linear region of the
transfer function. Offset error is measured on the AD56x3R
with code 512 loaded in the DAC register. It can be negative or
positive.
DC Power Supply Rejection Ratio (PSRR)
PSRR indicates how the output of the DAC is affected by
changes in the supply voltage. PSRR is the ratio of the change in
VOUT to a change in VDD for full-scale output of the DAC. It
is measured in dB. VREF is held at 2 V, and VDD is varied by
±10%.
Output Voltage Settling Time
Output voltage settling time is the amount of time it takes for
the output of a DAC to settle to a specified level for a 1/4 to 3/4
full-scale input change and is measured from the 24th falling
edge of SCLK.
Digital-to-Analog Glitch Impulse
The impulse injected into the analog output when the input
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 input code is changed by 1 LSB at the major carry
transition (0x7FFF to 0x8000). See Figure 38.
Digital Feedthrough
A measure of the impulse injected into the analog output of the
DAC from the digital inputs of the DAC, digital feedthrough is
measured when the DAC output is not updated. It is specified
in nV-s, and it is measured with a full-scale code change on the
data bus, that is, from all 0s to all 1s and vice versa.
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 (dB).
Noise Spectral Density
Noise spectral density is a measurement of the internally
generated random noise. Random noise is characterized as a
spectral density (nV/√Hz). It is measured by loading the DAC
to midscale and measuring noise at the output. A plot of noise
spectral density is shown in Figure 44.
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 (or soft
power-down and power-up) while monitoring another DAC
kept at midscale. It is expressed in microvolts (μV).
DC crosstalk due to load current change is a measure of the
impact that a change in load current on one DAC has to
another DAC kept at midscale. It is expressed in microvolts/
milliamps (μV/mA).
Rev. A | Page 18 of 28
AD5623R/AD5643R/AD5663R
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 and vice versa) in the input register of another
DAC. It is measured in standalone mode and is expressed
in nanovolts-second (nV-s).
Multiplying Bandwidth
The amplifiers within the DAC have a finite bandwidth. 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.
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 and vice versa) while keeping LDAC
high. Then pulse LDAC low and monitor the output of the DAC
whose digital code was not changed. The area of the glitch is
expressed in nanovolts-second (nV-s).
Total Harmonic Distortion (THD)
Total harmonic distortion 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
measurement of the harmonics present on the DAC output.
It is measured in decibels (dB).
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 and vice versa) with
LDAC low and monitoring the output of another DAC. The
energy of the glitch is expressed in nanovolts-second (nV-s).
Rev. A | Page 19 of 28
AD5623R/AD5643R/AD5663R
THEORY OF OPERATION
DIGITAL-TO-ANALOG SECTION
R
The AD5623R/AD5643R/AD5663R DAC is fabricated on
a CMOS process. The architecture consists of a string DAC
followed by an output buffer amplifier. Figure 49 shows a block
diagram of the DAC architecture.
REF (+)
DAC
REGISTER
TO OUTPUT
AMPLIFIER
R
OUTPUT
AMPLIFIER
(GAIN = +2)
RESISTOR
STRING
REF (–)
GND
VOUT
R
05858-032
VDD
R
Figure 49. DAC Architecture
05858-033
R
Because the input coding to the DAC is straight binary, the ideal
output voltage when using an external reference is given by
D
VOUT = VREFIN × ⎛⎜ N ⎞⎟
⎝2 ⎠
Figure 50. Resistor String
INTERNAL REFERENCE
The ideal output voltage when using the internal reference is
given by
D
VOUT = 2 × VREFOUT × ⎛⎜ N ⎞⎟
⎝2 ⎠
where:
D is the decimal equivalent of the binary code that is loaded to
the DAC register:
0 to 4095 for AD5623R (12-bit)
0 to 16,383 for AD5643R (14-bit)
0 to 65,535 for AD5663R (16-bit)
The AD5623R/AD5643R/AD5663R on-chip reference is off at
power-up and is enabled via a write to a control register. See the
Internal Reference Setup section for details.
The AD56x3R-3 has a 1.25 V, 5 ppm/°C reference, giving a fullscale output of 2.5 V. The AD56x3R-5 has a 2.5 V, 5 ppm/°C
reference, giving a full-scale output of 5 V. The internal reference associated with each part is available at the VREFOUT pin.
A buffer is required if the reference output is used to drive
external loads. When using the internal reference, it is
recommended that a 100 nF capacitor be placed between
reference output and GND for reference stability.
EXTERNAL REFERENCE
N is the DAC resolution.
RESISTOR STRING
The resistor string section is shown in Figure 50. It is simply a
string of resistors, each of Value R. The 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.
OUTPUT AMPLIFIER
The output buffer amplifier can generate rail-to-rail voltages on
its output, which gives an output range of 0 V to VDD. It can drive
a load of 2 kΩ in parallel with 1000 pF to GND. The source and
sink capabilities of the output amplifier can be seen in Figure 31.
The slew rate is 1.8 V/μs with a 1/4 to 3/4 full-scale settling time
of 10 μs.
The VREFIN pins on the AD56x3R-3 and the AD56x3R-5 allows
the use of an external reference if the application requires it.
The on-chip reference is off at power-up, and this is the default
condition. The AD56x3R-3 and the AD56x3R-5 can be operated
from a single 2.7 V to 5.5 V supply.
SERIAL INTERFACE
The AD5623R/AD5643R/AD5663R have a 3-wire serial interface
(SYNC, SCLK, and DIN) that is compatible with SPI, QSPI, and
MICROWIRE interface standards, as well as with most DSPs.
See Figure 2 for a timing diagram of a typical write sequence.
The write sequence begins by bringing the SYNC line low. Data
from the DIN line is clocked into the 24-bit shift register on the
falling edge of SCLK. The serial clock frequency can be as high
as 50 MHz, making the AD5623R/AD5643R/AD5663R compatible
with high speed DSPs. On the 24th falling clock edge, the last
data bit is clocked in and the programmed function is executed,
for example, a change in DAC register contents and/or a change
in the mode of operation.
Rev. A | Page 20 of 28
AD5623R/AD5643R/AD5663R
At this stage, the SYNC line can be kept low or be brought high.
In either case, it must be brought high for a minimum of 15 ns
before the next write sequence, so that a falling edge of SYNC
can initiate the next write sequence.
Table 8. Command Definition
Because the SYNC buffer draws more current when VIN = 2 V
than it does when VIN = 0.8 V, SYNC should be idled low between
write sequences for even lower power operation. As mentioned
previously, it must, however, be brought high again just before
the next write sequence.
INPUT SHIFT REGISTER
The input shift register is 24 bits wide (see Figure 52). The first
two bits are don’t cares. The next three are Command Bit C2 to
Command Bit C0 (see Table 8), followed by the 3-bit DAC
Address A2 to DAC Address A0 (see Table 9), and, finally, the
16-, 14-, and 12-bit data-word.
C2
0
0
0
C1
0
0
1
C0
0
1
0
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
Command
Write to Input Register n
Update DAC Register n
Write to Input Register n, update all
(software LDAC)
Write to and update DAC Channel n
Power down DAC (power up)
Reset
LDAC register setup
Internal reference setup (on/off )
Table 9. Address Command
A2
0
0
0
0
1
The data-word comprises the 16-, 14-, and 12-bit input codes,
followed by zero, two, or four don’t care bits, for the AD5663R,
AD5643R, and AD5623R, respectively (see Figure 51, Figure 52,
and Figure 53). The data bits are transferred to the DAC register
on the 24th falling edge of SCLK.
A1
0
0
1
1
1
A0
0
1
0
1
1
ADDRESS (n)
DAC A
DAC B
Reserved
Reserved
All DACs
SYNC INTERRUPT
In a normal write sequence, the SYNC line is kept low for at
least 24 falling edges of SCLK, and the DAC is updated on the
24th falling edge. However, if SYNC is brought high before the
24th falling edge, this acts as an interrupt to the write sequence.
The shift register is reset, and the write sequence is seen as
invalid. Neither an update of the DAC register contents nor a
change in the operating mode occurs (see Figure 54).
DB23 (MSB)
X
DB0 (LSB)
C2
C1
C0
A2
A1
A0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
05858-034
X
DATA BITS
COMMAND BITS
ADDRESS BITS
Figure 51. AD5663R Input Shift Register Contents
DB23 (MSB)
X
C2
C1
C0
A2
A1
A0
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
D2
D1
D0
X
X
X
X
05858-071
X
DB0 (LSB)
DATA BITS
COMMAND BITS
ADDRESS BITS
Figure 52. AD5643R Input Shift Register Contents
DB23 (MSB)
X
DB0 (LSB)
C2
C1
C0
A2
A1
A0
D11
D10
D9
D8
D7
D6
D5
D4
D3
DATA BITS
COMMAND BITS
X
X
05858-072
X
ADDRESS BITS
Figure 53. AD5623R Input Shift Register Contents
SCLK
SYNC
DB23
DB0
DB23
INVALID WRITE SEQUENCE:
SYNC HIGH BEFORE 24TH FALLING EDGE
DB0
VALID WRITE SEQUENCE, OUTPUT UPDATES
ON THE 24TH FALLING EDGE
Figure 54. SYNC Interrupt Facility
Rev. A | Page 21 of 28
05858-035
DIN
AD5623R/AD5643R/AD5663R
Again, to select which combination of DAC channels to power
up, set the corresponding bits (Bit DB1 and Bit DB0) to 1. See
Table 13 for contents of the input shift register during powerdown/power-up operation.
POWER-ON RESET
The AD5623R/AD5643R/AD5663R contain a power-on reset
circuit that controls the output voltage during power-up. The
AD5623R/AD5643R/AD5663R DACs output power up to 0 V,
and the output remains there until a valid write sequence is
made to the DACs. This is useful in applications where it is
important to know the state of the output of the DACs while
they are in the process of powering up. Any events on LDAC or
CLR during power-on reset are ignored.
The DAC output powers up to the value in the input register
while LDAC is low. If LDAC is high, the DAC ouput powers up
to the value held in the DAC register before power-down.
Table 11. Modes of Operation
SOFTWARE RESET
The AD5623R/AD5643R/AD5663R contain a software reset
function. Command 101 is reserved for the software reset
function (see Table 8). The software reset command contains
two reset modes that are software-programmable by setting bit
DB0 in the control register. Table 10 shows how the state of the
bit corresponds to the mode of operation of the device. Table 12
shows the contents of the input shift register during the
software reset mode of operation.
1 (Power-on Reset)
DB4
0
0
1
1
1
0
1
Operating Mode
Normal operation
Power-down modes
1 kΩ to GND
100 kΩ to GND
Three-state
When both Bit DB1 and Bit DB2 are set to 0, the part works
normally, with its normal power consumption of 250 μA at 5 V.
However, for the three power-down modes, the supply current
falls to 480 nA at 5 V (200 nA at 3 V). Not only does the supply
current fall, but the output stage is also internally switched from
the output of the amplifier to a resistor network of known values.
This has the advantage that the output impedance of the part is
known while the part is in power-down mode. The outputs can
either be connected internally to GND through a 1 kΩ or 100 kΩ
resistor or left open-circuited (three-state) (see Figure 55).
Table 10. Software Reset Modes
DB0
0
DB5
0
Registers Reset to Zero
DAC register
Input register
DAC register
Input register
LDAC register
Power-down register
Internal reference setup register
RESISTOR
STRING DAC
AMPLIFIER
VOUT
The AD5623R/AD5643R/AD5663R contain four separate
modes of operation. Command 100 is reserved for the powerdown function (see Table 8). These modes are softwareprogrammable by setting Bit DB5 and Bit DB4 in the control
register. Table 11 shows how the state of the bits corresponds to
the mode of operation of the device. Any or all DACs (DAC B
and DAC A) can be powered down to the selected mode by
setting the corresponding two bits (Bit DB1 and Bit DB0) to 1.
POWER-DOWN
CIRCUITRY
RESISTOR
NETWORK
05858-036
POWER-DOWN MODES
Figure 55. Output Stage During Power-Down
The bias generator, the output amplifier, the resistor string,
and other associated linear circuitry are shut down when
power-down mode is activated. However, the contents of the
DAC register are unaffected when in power-down. The time
to exit power-down is typically 4 μs for both VDD = 5 V and
VDD = 3 V (see Figure 37).
By executing the same Command 100, any combination of DACs
can be powered up by setting Bit DB5 and Bit DB4 to normal
operation mode.
Table 12. 24-Bit Input Shift Register Contents for Software Reset Command
MSB
DB23 to DB22
DB21
LSB
x
Don’t care
1
0
1
Command bits (C2 to C0)
DB20
DB19
DB18
DB17
DB16
x
x
x
Address bits (A2 to A0)
Rev. A | Page 22 of 28
DB15 to DB1
DB0
x
Don’t care
1/0
Determines software reset mode
AD5623R/AD5643R/AD5663R
Table 13. 24-Bit Input Shift Register Contents of Power Up/Down Function
MSB
DB23 to
DB22
x
Don’t
care
LSB
DB21 DB20 DB19
1
0
0
Command bits (C2 to C0)
DB15 to
DB6
x
Don’t
care
DB18 DB17 DB16
x
x
x
Address bits (A2 to A0)
Don’t care
DB5
DB4
PD1
PD0
Power-down
mode
DB3
DB2
x
x
Don’t care
DB1
DB0
DAC B
DAC A
Power down/Power up
channel selection;
set bit to 1 to select
channel
Table 14. 24-Bit Input Shift Register Contents for LDAC Setup Command
MSB
DB23 to
DB22
x
Don’t care
LSB
DB21
DB20
DB19
1
1
0
Command bits (C2 to C0)
DB110
DB17
x
x
Address bits (A3 to A0)
Don’t care
DB16
DB15 to DB2
DB1
DB0
x
x
Don’t care
DAC B
DAC A
Set DAC to 0 or 1 for required
mode of operation
LDAC FUNCTION
Asynchronous LDAC
The AD5623R/AD5643R/AD5663R DACs have doublebuffered 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.
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.
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 one of the input registers individually and then, by bringing
LDAC low when writing to the other DAC input register, all
outputs will 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
AD5623R/AD5643R/AD5663R, 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.
The outputs of all DACs can be simultaneously updated, using
the hardware LDAC pin.
The LDAC register gives the user full flexibility and control over
the hardware LDAC pin. This register allows the user to select
which combination of channels to simultaneously update when
the hardware LDAC pin is executed. Setting the LDAC bit
register to 0 for a DAC channel means that the update of this
channel is controlled by the LDAC pin. If this bit is set to 1, this
channel synchronously updates; that is, the DAC register is
updated after new data is read in, regardless of the state of the
LDAC pin. It effectively sees the LDAC pin as being pulled low.
See Table 15 for the LDAC register mode of operation. This
flexibility is useful in applications where the user wants to
simultaneously update select channels while the rest of the
channels are synchronously updating.
Writing to the DAC using Command 110 loads the 2-bit LDAC
register [DB1:DB0]. The default for each channel is 0; that is,
the LDAC pin works normally. Setting the bits to 1 means the
DAC register is updated, regardless of the state of the LDAC
pin. See Table 14 for contents of the input shift register during
the LDAC register setup command.
Table 15. LDAC Register Mode of Operation
LDAC Bits
(DB1 to DB0)
0
LDAC Pin
LDAC Operation
1/0
Determined by LDAC pin
1
x = don’t care
The DAC registers are updated
after new data is read in on the
falling edge of the 24th SCLK
pulse.
Synchronous LDAC
The DAC registers are updated after new data is read in on the
falling edge of the 24th SCLK pulse. LDAC can be permanently
low or pulsed as shown in Figure 2.
Rev. A | Page 23 of 28
AD5623R/AD5643R/AD5663R
INTERNAL REFERENCE SETUP
Table 16. Reference Setup Register
The on-chip reference is off at power-up by default. This
reference can be turned on or off by setting a software
programmable bit, DB0, in the control register. Table 16 shows
how the state of the bit corresponds to the mode of operation.
Command 111 is reserved for setting up the internal reference
(see Table 8). See Table 17 for the contents of the input shift
register during the internal reference set-up command.
Internal Reference
Setup Register (DB0)
0
Action
Reference off (default)
1
Reference on
Table 17. 32-Bit Input Shift Register Contents for Reference Setup Function
MSB
DB23 to DB22
x
Don’t care
DB21
DB20
1
1
Command bits (C2 to C0)
DB19
1
DB18
DB17
x
x
Address bits (A2 to A0)
Rev. A | Page 24 of 28
DB16
x
DB15 to DB1
x
Don’t care
LSB
DB0
1/0
Reference
setup register
AD5623R/AD5643R/AD5663R
MICROPROCESSOR INTERFACING
AD5623R/AD5643R/AD5663R to Blackfin® ADSP-BF53X
Interface
Figure 56 shows a serial interface between the AD5623R/
AD5643R/AD5663R and the Blackfin ADSP-BF53X microprocessor. The ADSP-BF53X processor family incorporates two
dual-channel synchronous serial ports, SPORT1 and SPORT0,
for serial and multiprocessor communications. Using SPORT0
to connect to the AD5623R/AD5643R/AD5663R, the setup for
the interface is as follows: DT0PRI drives the DIN pin of the
AD5623R/AD5643R/AD5663R, while TSCLK0 drives the
SCLK of the parts. The SYNC is driven from TFS0.
TFS0
AD5643R/
AD5663R1
SYNC
DTOPRI
DIN
TSCLK0
SCLK
1ADDITIONAL PINS OMITTED FOR CLARITY.
05858-037
ADSP-BF53x1
Data is transmitted MSB first. To load data to the AD5623R/
AD5643R/AD5663R, 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.
AD5623R/AD5643R/AD5663R to 80C51/80L51 Interface
Figure 58 shows a serial interface between the AD5623R/
AD5643R/AD5663R and the 80C51/80L51 microcontroller.
The setup for the interface is as follows: TxD of the 80C51/
80L51 drives SCLK of the AD5623R/AD5643R/AD5663R,
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
AD5623R/AD5643R/AD5663R, P3.3 is taken low. The 80C51/
80L51 transmit data in 8-bit bytes only; thus, 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.
Figure 56. AD5623R/AD5643R/AD5663R to Blackfin ADSP-BF53X Interface
Figure 57 shows a serial interface between the AD5623R/
AD5643R/AD5663R and the 68HC11/68L11 microcontroller.
SCK of the 68HC11/68L11 drives the SCLK of the AD5623R/
AD5643R/AD5663R, and the MOSI output drives the serial
data line of the DAC.
PC7
SYNC
SCK
SCLK
AD5643R/
AD5663R1
P3.3
SYNC
TxD
SCLK
RxD
DIN
1ADDITIONAL PINS OMITTED FOR CLARITY.
Figure 58. AD5623R/AD5643R/AD5663R to 80C512/80L51 Interface
DIN
1ADDITIONAL PINS OMITTED FOR CLARITY.
AD5623R/AD5643R/AD5663R to MICROWIRE Interface
Figure 57. AD5623R/AD5643R/AD5663R to 68HC11/68L11 Interface
The SYNC signal is derived from a port line (PC7). The setup
conditions for correct operation of this interface are as follows:
the 68HC11/68L11 is configured with its CPOL bit as 0, and its
CPHA bit as 1. When data is being transmitted to the DAC, the
SYNC line is taken low (PC7). When the 68HC11/68L11 is
configured as described previously, 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.
Figure 59 shows an interface between the AD5623R/AD5643R/
AD5663R and any MICROWIRE-compatible device. Serial data is
shifted out on the falling edge of the serial clock and is clocked into
the AD5623R/AD5643R/AD5663R on the rising edge of the SK.
Rev. A | Page 25 of 28
MICROWIRE1
AD5643R/
AD5663R1
CS
SYNC
SK
SCLK
SO
DIN
1ADDITIONAL PINS OMITTED FOR CLARITY.
05858-040
MOSI
80C51/80L511
AD5643R/
AD5663R1
05858-038
68HC11/68L111
The 80C51/80L51 output the serial data in a format that has the
LSB first. The AD5623R/AD5643R/AD5663R must receive data
with the MSB first. The 80C51/80L51 transmit routine should
take this into account.
05858-039
AD5623R/AD5643R/AD5663R to 68HC11/68L11
Interface
Figure 59. AD5623R/AD5643R/AD5663R to MICROWIRE Interface
AD5623R/AD5643R/AD5663R
APPLICATIONS INFORMATION
R2 = 10kΩ
USING A REFERENCE AS A POWER SUPPLY
500 μA + (5 V/5 kΩ) = 1.25 mA
The load regulation of the REF195 is typically 2 ppm/mA,
which results in a 3 ppm (15 μV) error for the 1.5 mA current
drawn from it. This corresponds to a 0.196 LSB error.
15V
REF195
SYNC
SCLK
DIN
VDD
AD5623R/
AD5643R/
AD5663R
VOUT = 0V TO 5V
R1 = 10kΩ
AD820/
OP295
VDD
10µF
0.1µF
±5V
VOUT
AD5663R
–5V
THREE-WIRE
SERIAL
INTERFACE
Figure 61. Bipolar Operation with the AD5663R
USING THE AD5663R WITH A
GALVANICALLY ISOLATED INTERFACE
In process control applications in industrial environments,
it is often necessary to use a galvanically isolated interface to
protect and isolate the controlling circuitry from any hazardous
common-mode voltages that can occur in the area where
the DAC is functioning. iCoupler® provides isolation in excess
of 2.5 kV. The AD5663R uses a 3-wire serial logic interface, so
the ADuM1300 3-channel digital isolator provides the required
isolation (see Figure 62). The power supply to the part also
needs to be isolated, which is done by using a transformer. On
the DAC side of the transformer, a 5 V regulator provides the
5 V supply required for the AD5663R.
5V
REGULATOR
05858-041
THREE-WIRE
SERIAL
INTERFACE
5V
+5V
+5V
05858-042
Because the supply current required by the AD5623R/AD5643R/
AD5663R is extremely low, an alternative option is to use a
voltage reference to supply the required voltage to the parts (see
Figure 60). This is especially useful if the power supply is quite
noisy or if the system supply voltages are at some value other
than 5 V or 3 V, for example, 15 V. The voltage reference outputs
a steady supply voltage for the AD5623R/AD5643R/ AD5663R.
If the low dropout REF195 is used, it must supply 500 μA of
current to the AD5623R/AD5643R/AD5663R, with no load on
the output of the DAC. When the DAC output is loaded, the
REF195 also needs to supply the current to the load. The total
current required (with a 5 kΩ load on the DAC output) is
10µF
POWER
0.1µF
Figure 60. REF195 as Power Supply to the AD5623R/AD5643R/AD5663R
BIPOLAR OPERATION USING THE AD5663R
SCLK
VIA
VOA
SCLK
VDD
AD5663R
ADuM1300
SDI
VIB
VOB
SYNC
DATA
VIC
VOC
DIN
VOUT
GND
The output voltage for any input code can be calculated as
follows:
Figure 62. AD5663R with a Galvanically Isolated Interface
⎡
⎛ D ⎞ ⎛ R1 + R2 ⎞
⎛ R2 ⎞⎤
VO = ⎢VDD × ⎜
⎟×⎜
⎟ − VDD × ⎜ ⎟⎥
⎝ R1 ⎠⎦
⎝ 65,536 ⎠ ⎝ R1 ⎠
⎣
where D represents the input code in decimal (0 to 65,535).
With VDD = 5 V, R1 = R2 = 10 kΩ,
⎛ 10 × D ⎞
VO = ⎜
⎟ −5V
⎝ 65,536 ⎠
This is an output voltage range of ±5 V, with 0x0000 corresponding to a −5 V output, and 0xFFFF corresponding to
a +5 V output.
Rev. A | Page 26 of 28
05858-043
The AD5663R has been designed for single-supply operation,
but a bipolar output range is also possible using the circuit in
Figure 61. The circuit gives an output voltage range of ±5 V.
Rail-to-rail operation at the amplifier output is achievable using
an AD820 or an OP295 as the output amplifier.
AD5623R/AD5643R/AD5663R
POWER SUPPLY BYPASSING AND GROUNDING
When accuracy is important in a circuit, it is helpful to carefully
consider the power supply and ground return layout on the
board. The printed circuit board containing the AD5663R
should have separate analog and digital sections, each having its
own area of the board.
If the AD5663R is in a system where other devices require an
AGND-to-DGND connection, the connection should be made at
one point only. This ground point should be as close as possible
to the AD5663R.
The power supply to the AD5663R should be bypassed with
10 μF and 0.1 μF capacitors. The capacitors should be located as
close as possible to the device, with the 0.1 μF capacitor ideally
right up against the device. The 10 μF capacitors are the
tantalum bead type. It is important that the 0.1 μF capacitor
have low effective series resistance (ESR) and effective series
inductance (ESI), which is found, for example, in common
ceramic types of capacitors.
This 0.1 μF capacitor provides a low impedance path to ground
for high frequencies caused by transient currents due to internal
logic switching.
The power supply line itself should have as large a trace as
possible to provide a low impedance path and to reduce glitch
effects on the supply line. Clocks and other fast switching
digital signals should be shielded from other parts of the board
by digital ground. Avoid crossover of digital and analog signals,
if possible. When traces cross on opposite sides of the board,
ensure that they run at right angles to each other to reduce
feedthrough effects through the board. The best board layout
technique is the microstrip technique, where the component
side of the board is dedicated to the ground plane only and the
signal traces are placed on the solder side. However, this is not
always possible with a 2-layer board.
Rev. A | Page 27 of 28
AD5623R/AD5643R/AD5663R
OUTLINE DIMENSIONS
INDEX
AREA
3.10
3.00
2.90
PIN 1
INDICATOR
3.00
BSC SQ
10
1.50
BCS SQ
0.50
BSC
1
2.48
2.38
2.23
EXPOSED
PAD
TOP VIEW
(BOTTOM VIEW)
10
3.10
3.00
2.90
1
6
5
5.15
4.90
4.65
PIN 1
6
0.80
0.75
0.70
SEATING
PLANE
0.80 MAX
0.55 TYP
SIDE VIEW
0.30
0.23
0.18
0.50
0.40
0.30
5
0.50 BSC
0.95
0.85
0.75
1.74
1.64
1.49
0.05 MAX
0.02 NOM
0.15
0.05
1.10 MAX
0.33
0.17
SEATING
PLANE
0.23
0.08
0.80
0.60
0.40
8°
0°
COPLANARITY
0.10
0.20 REF
COMPLIANT TO JEDEC STANDARDS MO-187-BA
Figure 63. 10-Lead Lead Frame Chip Scale Package [LFCSP_WD]
3 mm x 3 mm Body, Very Very Thin, Dual Lead
(CP-10-9)
Dimensions shown in millimeters
Figure 64. 10-Lead Mini Small Outline Package [MSOP]
(RM-10)
Dimensions shown in millimeters
ORDERING GUIDE
Model
AD5623RBCPZ-3R2 1
AD5623RBCPZ-3REEL71
AD5623RBRMZ-31
AD5623RBRMZ-3REEL71
AD5623RBRMZ-51
AD5623RBRMZ-5REEL71
AD5643RBRMZ-31
AD5643RBRMZ-3REEL71
AD5643RBRMZ-51
AD5643RBRMZ-5REEL71
AD5663RBCPZ-3R21
AD5663RBCPZ-3REEL71
AD5663RBRMZ-31
AD5663RBRMZ-3REEL71
AD5663RBRMZ-51
AD5663RBRMZ-5REEL71
EVAL-AD5663REB
1
Temperature
Range
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
−40°C to +105°C
Accuracy
±1 LSB INL
±1 LSB INL
±1 LSB INL
±1 LSB INL
±1 LSB INL
±1 LSB INL
±4 LSB INL
±4 LSB INL
±4 LSB INL
±4 LSB INL
±16 LSB INL
±16 LSB INL
±16 LSB INL
±16 LSB INL
±16 LSB INL
±16 LSB INL
Internal
Reference
1.25 V
1.25 V
1.25 V
1.25 V
2.5 V
2.5 V
1.25 V
1.25 V
2.5 V
2.5 V
1.25 V
1.25 V
1.25 V
1.25 V
2.5 V
2.5 V
Z = Pb-free part.
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05858-0-12/06(A)
Rev. A | Page 28 of 28
Package Description
10-Lead LFCSP_WD
10-Lead LFCSP_WD
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead LFCSP_WD
10-Lead LFCSP_WD
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
Evaluation Board
Package
Option
CP-10-9
CP-10-9
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
CP-10-9
CP-10-9
RM-10
RM-10
RM-10
RM-10
Branding
D85
D85
D85
D85
D86
D86
D81
D81
D7Q
D7Q
D7S
D7S
D7S
D7S
D7H
D7H