4 x12-Bit and 4 x16-Bit Octal DAC with
On-Chip Reference in 14 Lead TSSOP
Preliminary Technical Data
AD5678
FEATURES
Low Power Octal DAC with
4 DACs x 16 Bits
4 DACs x 12 Bits
12-Bit Accuracy Guaranteed
14/16-Lead TSSOP Package
On-chip 1.25/2.5V, 10ppm/C Reference
Power-Down to 200 nA @ 5V, 50 nA @ 3V
3V/5V Power Supply
Guaranteed Monotonic by Design
Power-On-Reset to Zero
Three Power-Down Functions
Hardware /LDAC and /CLR functions
Rail-to-Rail Operation
Temperature Range -40C to +125C
APPLICATIONS
ProcessControl
Data Acquisition Systems
Portable Battery Powered Instruments
Digital Gain and Offset Adjustment
Programmable Voltage and Current Sources
Programmable Attenuators
INTERFACE
LOGIC
I
NPUT
REGISTER
I
NPUT
REGISTER
I
NPUT
REGIS-
TER
I
NPUT
REGISTER
I
NPUT
REGISTER
I
NPUT
REGISTER
I
NPUT
REGISTER
I
NPUT
REGISTER
D
AC
REGISTER
D
AC
REGISTER
D
AC
REGISTER
D
AC
REGISTER
DAC
REGISTER
D
AC
REGISTER
DAC
REGISTER
DAC
REGISTER
STRING
DAC C
STRING
DAC A
STRING
DAC B
STRING
DAC D
STRING
DAC E
STRING
DAC F
STRING
DAC G
STRING
DAC H
BUFFER
BUFFER
BUFFER
BUFFER
BUFFER
BUFFER
BUFFER
BUFFER
DIN
LDAC
POWER-DOWN
LOGIC
GND
VOUTB
VOUTC
VOUTD
VOUTE
VOUTG
VOUTH
VOUTF
VDD
POWER-ON
RESET
LDAC*
VOUTA
V
REF
SYNC
SCLK
AD5678
CLR*
*RU-16 PACKAGE ONLY
1.25/2.5V
Ref
Figure 1. Functional Block Diagram
GENERAL DESCRIPTION
The AD5678 is a low power, octal buffered voltage-out DAC; 4
DACs with 12-bits of resolution and 4 DACs with16-bits of
resolution, in a single package. All devices operate from a
single +2.7V to +5.5V, and are guaranteed monotonic by
design.
The AD5678 has an on-chip reference with an internal gain of
two. The AD5678-1 has a 1.25V 10ppm/C max reference and
the AD5678-2, has a 2.5V 10ppm/C max reference. 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 zero
volts 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 200nA at 5V and provides
software selectable output loads while in power-down mode for
any or all DACs channels.
The outputs of all DACs may be updated simultaneously using
the /LDAC function, with the added functionality of selecting
through software any number of DAC channels to synchronize.
There is also an asynchronous active low /CLR that clears all
DACs to a software selectable code - 0 V, midscale or fullscale .
The AD5678 utilizes a versatile three-wire serial interface that
operates at clock rates up to 50 MHz and is compatible with
standard SPITM, QSPITM, MICROWIRETM and DSP interface
standards. Its on-chip precision output amplifier allows rail-to-
rail output swing to be achieved.
PRODUCT HIGHLIGHTS
1.
Octal 4x12-/4x16-Bit DAC; 12-Bit Accuracy
Guaranteed.
2.
On-chip 1.25/2.5V, 10ppm/C max Reference.
3.
Available in 14/16-lead TSSOP package.
4.
Power-On-Reset to Zero volts.
5.
Power-down capability. When powered down, the
DAC typically consumes 50nA at 3V and 200nA at 5V.
Rev. PrA
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: 781.326.8703
2004 Analog Devices, Inc. All rights reserved.
AD5678
Preliminary Technical Data
Rev.PrA | Page 2 of 24
TABLE OF CONTENTS
Features .......................................................................................... 1
Applications................................................................................... 1
General Description..................................................................... 1
Product Highlights ....................................................................... 1
AD5678Specifications.................................................................... 3
Timing Characteristics..................................................................... 9
Pin Configuration and Function Descriptions........................... 10
Absolute Maximum Ratings.......................................................... 11
ESD Caution................................................................................ 11
Terminology................................................................................ 11
AD5678Typical Performance Characteristics .......................... 13
General Description................................................................... 16
Serial Interface ............................................................................ 16
Microprocessor Interfacing............................................................
Applications .....................................................................................
Outline Dimensions ....................................................................... 23
Ordering Guide ...............................................................................
REVISION HISTORY
Revision 0: Initial Version
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
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: 781.326.8703
2004 Analog Devices, Inc. All rights reserved.
Preliminary Technical Data
AD5678
Rev. PrA| Page 3 of 24
AD5678SPECIFICATIONS
(V
DD
= +4.5 V to +5.5 V; R
L
= 2 k to GND; C
L
= 200 pF to GND; External REFIN = V
DD
; all specifications T
MIN
to T
MAX
unless otherwise
noted)
Table 1.
A Grade
B Grade
Parameter
Min
Typ
Max
Min
Typ
Max
Unit
B Version
1
,
2
Conditions/Comments
STATIC PERFORMANCE
3,4
AD5678 (DAC C, D, E, F)
Resolution
12
12
Bits
Relative Accuracy
0.5
6
0.5
1
LSB
See Figure 4
Differential Nonlinearity
1
1
LSB
Guaranteed Monotonic by Design. See
Figure 5.
AD5678 (DAC A, B, G, H)
Resolution
16
16
Bits
Relative Accuracy
32
16
LSB
See Figure 4
Differential Nonlinearity
1
1
LSB
Guaranteed Monotonic by Design. See
Figure 5.
Load Regulation
2
2
LSB/mA
VDD=Vref=5V, Midscale
Iout=0mA to
15mA sourcing/sinking
Zero Code Error
+1
+9
+1
+9
mV
All Zeroes Loaded to DAC Register. See
Figure 8.
Zero Code Error Drift
3
20
20
V/C
Full-Scale Error
-0.15
-1.25
-0.15
-1.25
% of FSR
All Ones Loaded to DAC Register. See
Figure 8.
Gain Error
0.7
0.7
% of FSR
Gain Temperature
Coefficient
5
5
ppm
of
FSR/C
Offset Error
1
9
1
9
mV
Offset Temperature
Coefficient
1.7
1.7
V/C
DC Power Supply Rejection
Ratio
6
80
80
dB
V
DD
10%
DC Crosstalk
6
(Ext Ref)
10
10
V
R
L
= 2 k. to GND or V
DD
4.5
4.5
V/mA
Due to Load current change
10
10
V
Due to Powering Down (per channel)
DC Crosstalk
6
(Int Ref)
20
20
V
R
L
= 2 k. to GND or V
DD
4.5
4.5
V/mA
Due to Load current change
20
20
V
Due to Powering Down (per channel)
OUTPUT
CHARACTERISTICS
6
Output Voltage Range
0
V
DD
0
V
DD
V
Capacitive Load Stability
2
2
pF
R
L
=
10
10
pF
R
L
=2 k
1
Temperature ranges are as follows: B Version: -40C to +125C, typical at 25C.
2
Linearity calculated using a reduced code range of 485 to 64714. Output unloaded.
3
DC specifications tested with the outputs unloaded unless stated otherwise.
4
Linearity is tested using a reduced code range: AD5628 (Code 48 to Code 4047), AD5648 (Code / to Code /), and AD5678 (Code 485 to 64714).
6
Guaranteed by design and characterization; not production tested.
8
Interface inactive. All DACs active. DAC outputs unloaded.
9
All eight DACs powered down.
Specifications subject to change without notice.
AD5678
Preliminary Technical Data
Rev.PrA | Page 4 of 24
A Grade
B Grade
Parameter
Min
Typ
Max
Min
Typ
Max
Unit
B Version
1
,
2
Conditions/Comments
DC Output Impedance
0.5
0.5
Short Circuit Current
30
30
mA
V
DD
=+5V
Power-Up Time
4
4
s
Coming out of Power-Down Mode.
V
DD
=+5V
REFERENCE INPUTS
3
Reference Input voltage
V
DD
V
DD
V
1% for specified performance
Reference Current
35
45
35
45
A
V
REF
= V
DD
= +5.5V (per DAC channel)
Reference Input Range
0
V
DD
0
V
DD
Reference
Input
Impedance
150
150
k
Per DAC channel
REFERENCE
OUTPUT
Output Voltage
AD5678x-2/3
2.495
2.5
2.505
2.495
2.5
2.505
V
Reference TC
10
10
ppm/C
LOGIC INPUTS
3
Input Current
1
1
A
V
INL
, Input Low Voltage
0.8
0.8
V
V
DD
=+5 V
V
INH
, Input High Voltage
2
2
V
V
DD
=+5 V
Pin Capacitance
3
3
pF
POWER
REQUIREMENTS
V
DD
4.5
5.5
4.5
5.5
V
All Digital Inputs at 0 or V
DD
I
DD
(Normal Mode)
8
DAC Active and Excluding Load Current
V
DD
=4.5 V to +5.5 V
2
4
2
4
mA
V
IH
=V
DD
and V
IL
=GND
I
DD
(All Power-Down
Modes)
9
V
DD
=4.5 V to +5.5 V
0.2
1
0.2
1
A
V
IH
=V
DD
and V
IL
=GND
POWER
EFFICIENCY
I
OUT
/I
DD
89
89
% I
LOAD
=2 mA, V
DD
=+5 V
Preliminary Technical Data
AD5678
Rev. PrA| Page 5 of 24
AC CHARACTERISTICS
1
(V
DD
= +4.5 V to +5.5 V; R
L
= 2 k to GND; C
L
= 200 pF to GND; External REFIN = V
DD
; all
specifications T
MIN
to T
MAX
unless otherwise noted)
NOTES
1
Guaranteed by design and characterization; not production tested.
2
See the Terminology section.
3
Temperature range (Y Version): 40
C to +125C; typical at +25C.
Specifications subject to change without notice.
Parameter
2
Min
Typ
Max
Unit
B Version
1
Conditions/Comments
Output Voltage Settling Time
AD5678 (DAC C, D, E, F)
6
8
s
to scale settling to 2LSB
AD5678 (DAC A, B, G, H)
8
10
s
to scale settling to 2LSB
Settling Time for 1LSB Step
Slew Rate
1.5
V/s
Digital-to-Analog Glitch Impulse
5
nV-s
1 LSB Change Around Major Carry. See Figure 21.
Channel to-Channel Isolation
100
dB
Digital Feedthrough
0.1
nV-s
Digital Crosstalk
0.5
nV-s
Analog Crosstalk
1
nV-s
DAC-to-DAC Crosstalk
3
nV-s
Multiplying Bandwidth
200
kHz
VREF = 2V 0.1 V p-p.
Total Harmonic Distortion
-80
dB
VREF = 2V 0.1 V p-p. Frequency = 10kHz
Output Noise Spectral Density
120
nV/Hz
DAC code=8400
H
, 1kHz
100
nV/Hz
DAC code=8400
H
, 10kHz
Output Noise
15
Vp-p
0.1Hz to 10Hz;
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