Document Outline
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Quad, 16-Bit DAC with 5 ppm/C
On-Chip Reference in 14-Lead TSSOP
AD5666
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
2005 Analog Devices, Inc. All rights reserved.
FEATURES
Low power quad 16-bit DAC
14-lead TSSOP
On-chip 1.25 V/2.5 V, 5 ppm/C reference
Power down to 400 nA @ 5 V, 200 nA @ 3 V
2.7 V to 5.5 V power supply
Guaranteed monotonic by design
Power-on reset to zero scale or midscale
3 power-down functions
Hardware LDAC with LDAC override function
CLR function to programmable code
SDO daisy-chaining option
Rail-to-rail operation
APPLICATIONS
Process control
Data acquisition systems
Portable battery-powered instruments
Digital gain and offset adjustment
Programmable voltage and current sources
Programmable attenuators
FUNCTIONAL BLOCK DIAGRAM
INTERFACE
LOGIC
INPUT
REGISTER
DIN
LDAC
GND
V
DD
LDAC
V
REFIN
/V
REFOUT
SYNC
SCLK
AD5666
CLR
1.25V/2.5V
REF
V
OUT
A
V
OUT
B
V
OUT
C
V
OUT
D
DAC
REGISTER
STRING
DAC A
BUFFER
INPUT
REGISTER
DAC
REGISTER
STRING
DAC B
BUFFER
INPUT
REGISTER
DAC
REGISTER
STRING
DAC C
BUFFER
INPUT
REGISTER
DAC
REGISTER
STRING
DAC D
BUFFER
SDO
POR
POWER-DOWN
LOGIC
POWER-ON
RESET
05298
-
001
Figure 1.
GENERAL DESCRIPTION
The AD5666 is a low power, quad, 16-bit, buffered voltage-
output DAC. The part operates from a single 2.7 V to 5.5 V
supply and is guaranteed monotonic by design.
The AD5666 has an on-chip reference with an internal gain of 2.
The AD5666-1 has a 1.25 V 5 ppm/C reference, giving a full-scale
output of 2.5 V; the AD5666-2 has a 2.5 V 5 ppm/C reference,
giving a full-scale output of 5 V. The on-board reference is off at
power-up, allowing the use of an external reference. The internal
reference is turned on by writing to the DAC.
The part incorporates a power-on reset circuit that ensures that
the DAC output powers up to 0 V (POR pin low) or to midscale
(POR pin high) and remains powered up at this level until a valid
write takes place. The part contains a power-down feature that
reduces the current consumption of the device to 400 nA at 5 V
and provides software-selectable output loads while in power-down
mode for any or all DAC channels.
The outputs of all DACs can be updated simultaneously using
the LDAC function, with the added functionality of user-select-
able DAC channels to simultaneously update. There is also an
asynchronous CLR that clears all DACs to a software-selectable
code--0 V, midscale, or full scale.
The AD5666 utilizes a versatile 3-wire serial interface that operates
at clock rates of up to 50 MHz and is compatible with standard
SPI, QSPITM, MICROWIRETM, and DSP interface standards. The
on-chip precision output amplifier enables rail-to-rail output
swing.
PRODUCT HIGHLIGHTS
1.
Quad, 16-bit DAC.
2.
On-chip 1.25 V/2.5 V, 5 ppm/C reference.
3.
Available in 14-lead TSSOP.
4.
Selectable power-on reset to 0 V or midscale.
5.
Power-down capability. When powered down, the DAC
typically consumes 200 nA at 3 V and 400 nA at 5 V.
AD5666
Rev. A | Page 2 of 28
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Product Highlights ........................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
AC Characteristics........................................................................ 7
Timing Characteristics ................................................................ 8
Absolute Maximum Ratings.......................................................... 10
ESD Caution................................................................................ 10
Pin Configuration and Function Descriptions........................... 11
Typical Performance Characteristics ........................................... 12
Terminology .................................................................................... 18
Theory of Operation ...................................................................... 20
D/A Section................................................................................. 20
Resistor String............................................................................. 20
Internal Reference ...................................................................... 20
Output Amplifier........................................................................ 21
Serial Interface ............................................................................ 21
Input Shift Register .................................................................... 22
SYNC Interrupt .......................................................................... 22
Daisy-Chaining........................................................................... 23
Internal Reference Register ....................................................... 23
Power-On Reset.......................................................................... 23
Power-Down Modes .................................................................. 23
Clear Code Register ................................................................... 25
LDAC Function .......................................................................... 25
Power Supply Bypassing and Grounding................................ 25
Outline Dimensions ....................................................................... 27
Ordering Guide .......................................................................... 27
REVISION HISTORY
11/05--Rev. 0 to Rev. A
Change to General Description ...................................................... 1
Change to Specifications.................................................................. 3
10/05--Revision 0: Initial Version
AD5666
Rev. A | Page 3 of 28
SPECIFICATIONS
V
DD
= 4.5 V to 5.5 V, R
L
= 2 k to GND, C
L
= 200 pF to GND, V
REFIN
= V
DD
. All specifications T
MIN
to T
MAX
, unless otherwise noted.
Table 1.
A
Grade
1
B Grade
1
Parameter
Min Typ Max Min Typ Max Unit Conditions/Comments
STATIC PERFORMANCE
2
Resolution
16
16
Bits
Relative
Accuracy
32
16
LSB
See
Figure 6
Differential
Nonlinearity
1
1
LSB
Guaranteed monotonic by design
(see Figure 7)
Zero-Code Error
1
9
1
9
mV
All 0s loaded to DAC register (see Figure 13)
Zero-Code
Error
Drift
2
2
V/C
Full-Scale Error
-0.2
-1
-0.2
-1
% FSR
All 1s loaded to DAC register (see Figure 12)
Gain
Error
1
1
%
FSR
Gain
Temperature
Coefficient
2.5
2.5
ppm
Of
FSR/C
Offset
Error
1 9
1 9 mV
DC Power Supply Rejection
Ratio
80
80
dB V
DD
10%
DC Crosstalk
(External Reference)
10
10
V Due to full-scale output change,
R
L
= 2 k to GND or V
DD
5
5
V/mA
Due to load current change
10
10
V
Due to powering down (per channel)
DC Crosstalk
(Internal Reference)
25
25
V Due to full-scale output change,
R
L
= 2 k to GND or V
DD
10
10
V/mA
Due to load current change
OUTPUT CHARACTERISTICS
3
Output Voltage Range
0
V
DD
0
V
DD
V
Capacitive
Load
Stability 2
2
nF R
L
=
10
10
nF R
L
= 2 k
DC
Output
Impedance 0.5
0.5
Short-Circuit
Current
30
30
mA
V
DD
= 5 V
Power-Up Time
4
4
s
Coming out of power-down mode V
DD
= 5 V
REFERENCE
INPUTS
Reference Input Voltage
V
DD
V
DD
V
Reference
Current
20 30
20 30 A V
REF
= V
DD
= 5.5 V
Reference Input Range
0
V
DD
0
V
DD
V
Reference Input Impedance
14.6
14.6
k
Per DAC channel
REFERENCE
OUTPUT
Output
Voltage
2.495
2.505 2.495
2.505 V
At
ambient
Reference TC
3
5 10
5 10
ppm/C
Reference Output
Impedance
7.5
7.5
k
LOGIC INPUTS
3
Input Current
3
3
A
All digital inputs
Input Low Voltage, V
INL
0.8
0.8
V V
DD
= 5 V
Input High Voltage, V
INH
2
2
V V
DD
= 5 V
Pin
Capacitance
3
3
pF
AD5666
Rev. A | Page 4 of 28
A
Grade
1
B Grade
1
Parameter
Min Typ Max Min Typ Max Unit Conditions/Comments
LOGIC OUTPUTS (SDO)
3
Output Low Voltage, V
OL
0.4
0.4
V I
SINK
= 2 mA
Output High Voltage, V
OH
V
DD
-
1
V
DD
-
1
I
SOURCE
= 2 mA
High Impedance Leakage
Current
0.25
0.25
A
High Impedance Output
Capacitance
2
2
pF
POWER
REQUIREMENTS
V
DD
4.5
5.5 4.5
5.5 V
All digital inputs at 0 or V
DD
,
DAC active, excludes load current
I
DD
(Normal Mode)
4
V
IH
= V
DD
and V
IL
= GND
V
DD
= 4.5 V to 5.5 V
0.7
0.9
0.7
0.9
mA
Internal reference off
V
DD
= 4.5 V to 5.5 V
1.3
1.6
1.3
1.6
mA
Internal reference on
I
DD
(All Power-Down Modes)
5
V
DD
= 4.5 V to 5.5 V
0.4
1
0.4
1
A
V
IH
= V
DD
and V
IL
= GND
1
Temperature range is -40C to +105C, typical at 25C.
2
Linearity calculated using a reduced code range of 512 to 65,024. Output unloaded.
3
Guaranteed by design and characterization; not production tested.
4
Interface inactive. All DACs active. DAC outputs unloaded.
5
All four DACs powered down.
AD5666
Rev. A | Page 5 of 28
V
DD
= 2.7 V to 3.6 V, R
L
= 2 k to GND, C
L
= 200 pF to GND, V
REFIN
= V
DD
. All specifications T
MIN
to T
MAX
, unless otherwise noted.
Table 2.
A
Grade
1
B Grade
1
Parameter Min
Typ
Max
Min
Typ
Max
Unit
Conditions/Comments
STATIC PERFORMANCE
2
Resolution 16
16
Bits
Relative Accuracy
32
16
LSB
See Figure 5
Differential Nonlinearity
1
1
LSB
Guaranteed monotonic by design (see Figure 6)
Zero-Code Error
1
9
1
9
mV
All 0s loaded to DAC register (see Figure 13)
Zero-Code Error Drift
2
2
V/C
Full-Scale Error
-0.2
-1
-0.2
-1
% FSR
All 1s loaded to DAC register (see Figure 12)
Gain Error
1
1
% FSR
Gain Temperature
Coefficient
2.5
2.5
ppm Of
FSR/C
Offset Error
1
9
1
9
mV
DC Power Supply Rejection
Ratio
80
80
dB V
DD
10%
DC Crosstalk
(External Reference)
10
10
V Due to full-scale output change,
R
L
= 2 k to GND or V
DD
5
5
V/mA
Due to load current change
10
10
V
Due to powering down (per channel)
DC Crosstalk
(Internal Reference)
25
25
V Due to full-scale output change,
R
L
= 2 k to GND or V
DD
10
10
V/mA
Due to load current change
OUTPUT CHARACTERISTICS
3
Output Voltage Range
0
V
DD
0 V
DD
V
Capacitive Load Stability
2
2
nF
R
L
=
10
10
nF
R
L
= 2 k
DC Output Impedance
0.5
0.5
Short-Circuit Current
30
30
mA
V
DD
= 3 V coming out of power-down mode
Power-Up Time
4
4
s
Coming out of power-down V
DD
= 3 V
REFERENCE INPUTS
Reference Input Voltage
V
DD
V
DD
V
Reference Current
40
50
40
50
A
V
REF
= V
DD
= 3.6 V
Reference Input Range
0
V
DD
0 V
DD
Reference Input Impedance
14.6
14.6
k
Per DAC channel
REFERENCE OUTPUT
Output Voltage
1.247
1.253
1.247
1.253
V
At ambient
Reference TC
3
5
15
5
15
ppm/C
Reference Output
Impedance
7.5
7.5
k
LOGIC INPUTS
3
Input Current
3
3
A
Input Low Voltage, V
INL
0.8
0.8
V
V
DD
= 3 V
Input High Voltage, V
INH
2
2
V
V
DD
= 3 V
Pin Capacitance
3
3
pF
LOGIC OUTPUTS (SDO)
3
Output Low Voltage, V
OL
0.4
0.4 V
I
SINK
= 2 mA
Output High Voltage, V
OH
V
DD
-
0.5
V
DD
-
0.5
I
SOURCE
= 2 mA
High Impedance Leakage
Current
0.25
0.25
A
High Impedance Leakage
Current
2
2
pF
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