AD AD5348 2.5 v to 5.5 v, parallel interface octal voltage output 8-/10-/12-bit dac Datasheet

2.5 V to 5.5 V, Parallel Interface
Octal Voltage Output 8-/10-/12-Bit DACs
AD5346/AD5347/AD5348
FEATURES
GENERAL DESCRIPTION
AD5346: octal 8-bit DAC
AD5347: octal 10-bit DAC
AD5348: octal 12-bit DAC
Low power operation: 1.4 mA (max) @ 3.6 V
Power-down to 120 nA @ 3 V, 400 nA @ 5 V
Guaranteed monotonic by design over all codes
Rail-to-rail output range: 0 V to VREF or 0 V to 2 × VREF
Power-on reset to 0 V
Simultaneous update of DAC outputs via LDAC pin
Asynchronous CLR facility
Readback
Buffered/unbuffered reference inputs
20 ns WR time
38-lead TSSOP/6 mm × 6 mm 40-lead LFCSP packaging
Temperature range: –40°C to +105°C
The AD5346/AD5347/AD53481 are octal 8-, 10-, and 12-bit
DACs, operating from a 2.5 V to 5.5 V supply. These devices
incorporate an on-chip output buffer that can drive the output
to both supply rails, and also allow a choice of buffered or
unbuffered reference input.
APPLICATIONS
An asynchronous CLR input is also provided, which resets the
contents of the input register and the DAC register to all zeros.
These devices also incorporate a power-on reset circuit that
ensures that the DAC output powers on to 0 V and remains
there until valid data is written to the device.
The AD5346/AD5347/AD5348 have a parallel interface. CS
selects the device and data is loaded into the input registers on
the rising edge of WR. A readback feature allows the internal
DAC registers to be read back through the digital port.
The GAIN pin on these devices allows the output range to be
set at 0 V to VREF or 0 V to 2 × VREF.
Input data to the DACs is double-buffered, allowing simultaneous update of multiple DACs in a system using the LDAC pin.
Portable battery-powered instruments
Digital gain and offset adjustment
Programmable voltage and current sources
Optical networking
Automatic test equipment
Mobile communications
Programmable attenuators
Industrial process control
All three parts are pin compatible, which allows users to select
the amount of resolution appropriate for their application
without redesigning their circuit board.
FUNCTIONAL BLOCK DIAGRAM
VDD
AGND
VREFAB
DGND
VREFCD
POWER-ON
RESET
AD5348
BUF
INPUT
REGISTER
DAC
REGISTER
STRING
DAC A
BUFFER
VOUTA
INPUT
REGISTER
DAC
REGISTER
STRING
DAC B
BUFFER
VOUTB
INPUT
REGISTER
DAC
REGISTER
STRING
DAC C
BUFFER
VOUTC
INPUT
REGISTER
DAC
REGISTER
STRING
DAC D
BUFFER
VOUTD
INPUT
REGISTER
DAC
REGISTER
STRING
DAC E
BUFFER
VOUTE
A2
INPUT
REGISTER
DAC
REGISTER
STRING
DAC F
BUFFER
VOUTF
A1
INPUT
REGISTER
DAC
REGISTER
STRING
DAC G
BUFFER
VOUTG
INPUT
REGISTER
DAC
REGISTER
STRING
DAC H
BUFFER
VOUTH
GAIN
DB11
.
.
.
DB0
CS
RD
WR
A0
INTERFACE
LOGIC
POWER-DOWN
LOGIC
LDAC
VREFGH
VREFEF
03331-0-001
CLR
PD
Figure 1.
1
Protected by U.S. Patent No. 5,969,657.
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
© 2003 Analog Devices, Inc. All rights reserved.
AD5346/AD5347/AD5348
TABLE OF CONTENTS
Specifications..................................................................................... 3
Power-On Reset.......................................................................... 17
AC Characteristics............................................................................ 4
Power-Down Mode .................................................................... 17
Timing Characteristics..................................................................... 5
Suggested Data Bus Formats..................................................... 18
Absolute Maximum Ratings............................................................ 6
Applications Information .............................................................. 19
ESD Caution.................................................................................. 6
Typical Application Circuits ..................................................... 19
AD5346 Pin Configurations and Function Descriptions ........... 7
Driving VDD from the Reference Voltage................................. 19
AD5347 Pin Configurations and Function Descriptions ........... 8
Bipolar Operation Using the AD5346/AD5347/AD5348..... 19
AD5348 Pin Configurations and Function Descriptions ........... 9
Decoding Multiple AD5346/AD5347/AD5348s.................... 20
Terminology .................................................................................... 10
AD5346/AD5347/AD5348 as Digitally Programmable
Window Detectors ...................................................................... 20
Typical Performance Characteristics ........................................... 12
Functional Description .................................................................. 16
Programmable Current Source ................................................ 20
Digital-to-Analog Section ......................................................... 16
Coarse and Fine Adjustment Using the
AD5346/AD5347/AD5348 ....................................................... 21
Resistor String ............................................................................. 16
Power Supply Bypassing and Grounding................................ 21
DAC Reference Input................................................................. 16
Outline Dimensions ....................................................................... 23
Output Amplifier ........................................................................ 16
Ordering Guides......................................................................... 24
Parallel Interface ......................................................................... 17
REVISION HISTORY
Revision 0: Initial Version
Rev. 0 | Page 2 of 24
AD5346/AD5347/AD5348
SPECIFICATIONS
Table 1. VDD = 2.5 V to 5.5 V; VREF = 2 V; RL = 2 kΩ to GND; CL = 200 pF to GND; all specifications TMIN to TMAX,
unless otherwise noted
2
Parameter
DC PERFORMANCE3,4
AD5346
Resolution
Relative Accuracy
Differential Nonlinearity
AD5347
Resolution
Relative Accuracy
Differential Nonlinearity
AD5348
Resolution
Relative Accuracy
Differential Nonlinearity
Offset Error
Gain Error
Lower Deadband5
Upper Deadband5
Offset Error Drift6
Gain Error Drift6
DC Power Supply Rejection
Ratio6
DC Crosstalk6
DAC REFERENCE INPUT6
VREF Input Range
VREF Input Range
VREF Input Impedance
Min
B Version1
Typ
Max
±1
±0.25
Bits
LSB
LSB
Guaranteed monotonic by design over all codes
10
±0.5
±0.05
±4
±0.5
Bits
LSB
LSB
Guaranteed monotonic by design over all codes
±16
±1
±3
±1
60
60
200
1
0.25
VDD
VDD
>10
90
45
–90
–75
0.001
VDD –
0.001
0.5
25
16
2.5
5
DC Output Impedance
Short Circuit Current
Power-Up Time
Conditions/Comments
8
±0.15
±0.02
12
±2
±0.2
±0.4
±0.1
10
10
–12
–5
–60
Reference Feedthrough
Channel-to-Channel Isolation
OUTPUT CHARACTERISTICS6
Minimum Output Voltage4, 7
Maximum Output Voltage4, 7
Unit
LOGIC INPUTS
Input Current
VIL, Input Low Voltage
Bits
LSB
LSB
% of FSR
% of FSR
mV
mV
ppm of FSR/°C
ppm of FSR/°C
dB
Guaranteed monotonic by design over all codes
Lower deadband exists only if offset error is negative
VDD = 5 V; upper deadband exists only if VREF = VDD
∆VDD = ±10%
µV
RL = 2 kΩ to GND, 2 kΩ to VDD; CL = 200 pF to GND;
Gain = +1
V
V
MΩ
kΩ
kΩ
dB
dB
Buffered reference mode
Unbuffered reference mode
Buffered reference mode and power-down mode
Gain = +1; input impedance = RDAC
Gain = +2; input impedance = RDAC
Frequency = 10 kHz
Frequency = 10 kHz
V min
V max
Rail-to-rail operation
Ω
mA
mA
µs
µs
VDD = 5 V
VDD = 3 V
Coming out of power-down mode; VDD = 5 V
Coming out of power-down mode; VDD = 3 V
6
VIH, Input High Voltage
Pin Capacitance
±1
0.8
0.7
0.6
1.7
5
µA
V
V
V
V
pF
Rev. 0 | Page 3 of 24
VDD = 5 V ±10%
VDD = 3 V ±10%
VDD = 2.5 V
VDD = 2.5 V to 5.5 V
AD5346/AD5347/AD5348
2
Parameter
LOGIC OUTPUTS6
VDD = 4.5 V to 5.5 V
Output Low Voltage, VOL
Output High Voltage, VOH
VDD = 2.5 V to 3.6 V
Output Low Voltage, VOL
Output High Voltage, VOH
POWER REQUIREMENTS
VDD
IDD (Normal Mode)
VDD = 4.5 V to 5.5 V
VDD = 2.5 V to 3.6 V
B Version1
Typ
Max
Min
Unit
Conditions/Comments
0.4
V
V
ISINK = 200 µA
ISOURCE = 200 µA
0.4
V
V
ISINK = 200 µA
ISOURCE = 200 µA
5.5
V
1
0.8
1.65
1.4
mA
mA
0.4
0.12
1
1
µA
µA
VDD – 1
VDD – 0.5
2.5
IDD (Power-Down Mode)
VDD = 4.5 V to 5.5 V
VDD = 2.5 V to 3.6 V
VIH = VDD, VIL = GND
All DACs in unbuffered mode. In buffered mode,
extra current is typically x µA per DAC, where x = 5 µA +
VREF/RDAC
VIH = VDD, VIL = GND
See footnotes after the AC Characteristics table.
AC CHARACTERISTICS6
Table 2. VDD = 2.5 V to 5.5 V; RL = 2 kΩ to GND; CL = 200 pF to GND; all specifications TMIN to TMAX, unless otherwise noted
2
Parameter
Output Voltage Settling Time
AD5346
AD5347
AD5348
Slew Rate
Major Code Transition Glitch
Energy
Digital Feedthrough
Digital Crosstalk
Analog Crosstalk
DAC-to-DAC Crosstalk
Multiplying Bandwidth
Total Harmonic Distortion
Min
B Version1
Typ
Max
Unit
6
7
8
0.7
µs
µs
µs
V/µs
8
9
10
Conditions/Comments
VREF = 2 V
1/4 scale to 3/4 scale change (40 H to C0 H)
1/4 scale to 3/4 scale change (100 H to 300 H)
1/4 scale to 3/4 scale change (400 H to C00 H)
8
nV-s
1 LSB change around major carry
0.5
1
1
3.5
200
–70
nV-s
nV-s
nV-s
nV-s
kHz
dB
VREF = 2 V ±0.1 V p-p; unbuffered mode
VREF = 2. V ±0.1 V p-p; frequency = 10 kHz; unbuffered mode
1
Temperature range: B Version: –40°C to +105°C; typical specifications are at 25°C.
See Terminology section.
3
Linearity is tested using a reduced code range: AD5346 (Code 8 to 255); AD5347 (Code 28 to 1023); AD5348 (Code 115 to 4095).
4
DC specifications tested with outputs unloaded.
5
This corresponds to x codes. 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
the offset plus gain error must be positive.
2
200µA
VOH(min) + VOL(max)
CL
50pF
2
200µA
IOH
Figure 2. Load Circuit for Digital Output Timing Specifications
Rev. 0 | Page 4 of 24
03331-0-002
TO OUTPUT
PIN
IOL
AD5346/AD5347/AD5348
TIMING CHARACTERISTICS1, 2, 3
Table 3. VDD = 2.5 V to 5.5 V; all specifications TMIN to TMAX, unless otherwise noted
Parameter
Data Write Mode (Figure 3)
t1
t2
t3
t4
t5
t6
t7
t8
t9
t10
t11
t12
t13
t14
t15
Data Readback Mode (Figure 4)
t16
t17
t18
t19
t20
t21
t22
t23
t24
t25
t26
Limit at TMIN, TMAX
Unit
Condition/Comments
0
0
20
5
4.5
5
5
4.5
5
4.5
20
10
20
20
0
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
CS to WR setup time
CS to WR hold time
WR pulse width
Data, GAIN, BUF setup time
Data, GAIN, BUF hold time
Synchronous mode. WR falling to LDAC falling.
Synchronous mode. LDAC falling to WR rising.
Synchronous mode. WR rising to LDAC rising.
Asynchronous mode. LDAC rising to WR rising.
Asynchronous mode. WR rising to LDAC falling.
LDAC pulse width
CLR pulse width
Time between WR cycles
A0, A1, A2 setup time
A0, A1, A2 hold time
0
0
0
20
30
0
22
30
4
30
22
30
30
30
30
50
ns min
ns min
ns min
ns min
ns min
ns min
ns max
ns max
ns min
ns max
ns max
ns max
ns min
ns min
ns min
ns min
A0, A1, A2 to CS setup time
A0, A1, A2 to CS hold time
CS to falling edge of RD
RD pulse width; VDD = 3.6 V to 5.5 V
RD pulse width; VDD = 2.5 V to 3.6 V
CS to RD hold time
Data access time after falling edge of RD; VDD = 3.6 V to 5.5 V
Data access time after falling edge of RD VDD = 2.5 V to 3.6 V
Bus relinquish time after rising edge of RD
CS falling edge to data; VDD = 3.6 V to 5.5 V
CS falling edge to data; VDD = 2.5 V to 3.6 V
Time between RD cycles
Time from RD to WR
Time from WR to RD, VDD = 3.6 V to 5.5 V
Time from WR to RD, VDD = 2.5 V to 3.6 V
1
Guaranteed by design and characterization, not production tested.
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 2.
2
t1
t2
A0–A2
CS
t3
t13
t4
DATA,
GAIN, BUF
LDAC1
t5
CS
t18
t6
t7
t9
t20
t19
t8
t24
RD
t10
t21
t11
LDAC2
CLR
t17
t16
WR
t22
DATA
t23
t12
t14
t15
t25
WR
t26
03331-0-003
NOTES
1. SYNCHRONOUS LDAC UPDATE MODE
2. ASYNCHRONOUS LDAC UPDATE MODE
Figure 3. Parallel Interface Write Timing Diagram
Figure 4. Parallel Interface Read Timing Diagram
Rev. 0 | Page 5 of 24
03331-0-004
A0–A2
AD5346/AD5347/AD5348
ABSOLUTE MAXIMUM RATINGS
Table 4. TA = 25°C, unless otherwise noted
Parameter
VDD to GND
Digital Input Voltage to GND
Digital Output Voltage to GND
Reference Input Voltage to GND
VOUT to GND
Operating Temperature Range
Industrial (B Version)
Storage Temperature Range
Junction Temperature
38-Lead TSSOP Package
Power Dissipation
θJA Thermal Impedance
θJC Thermal Impedance
40-Lead LFCSP Package
Power Dissipation
θJA Thermal Impedance (3-layer
board)
Lead Temperature, Soldering (10 sec)
IR Reflow, Peak Temperature
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
–0.3 V to VDD + 0.3 V
–40°C to +105°C
–65°C to +150°C
150°C
(TJ max − TA)/ θJA mW
98.3°C/W
8.9°C/W
(TJ max − TA)/ θJA mW
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those listed in the operational sections
of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
29.6°C/W
300°C
220°C
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.
Rev. 0 | Page 6 of 24
AD5346/AD5347/AD5348
GAIN
36
WR
37
CLR
38
VREFGH
39
PD
40
VREFCD
36 GAIN
VREFEF
37 CLR
VREFCD 3
VDD
38 PD
1
VREFEF 2
VREFAB
VREFGH
VDD
AD5346 PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
35
34
33
32
31
VDD 4
35 WR
VOUTA 1
30 RD
VREFAB 5
34 RD
VOUTB 2
29 CS
33 CS
VOUTC 3
28 DB7
32 DB7
VOUTD 4
26 DB1
VOUTH 14
25 DB0
DGND 15
24 DGND
BUF 16
23 DGND
LDAC 17
22 DGND
A0 18
21 DGND
A1 19
20 A2
22 DB1
VOUTH 10
21 DB0
11
12
13
14
15
16
17
18
19
20
DGND
VOUTG 13
23 DB2
VOUTG 9
DGND
27 DB2
24 DB3
VOUTF 8
DGND
VOUTF 12
25 DB4
VOUTE 7
A2
28 DB3
26 DB5
TOP VIEW
(Not to Scale)
DGND
VOUTE 11
AD5346
AGND 6
A1
29 DB4
Figure 6. AD5346 Pin Configuration—LFCSP
03331-0-005
AGND 10
27 DB6
8-BIT
AGND 5
03331-0-006
TOP VIEW 31
DB6
(Not to Scale)
9
30 DB5
VOUTD
VOUTC 8
A0
AD5346
LDAC
VOUTB 7
BUF
8-BIT
DGND
VOUTA 6
Figure 5. AD5346 Pin Configuration—TSSOP
Table 5. AD5346 Pin Function Descriptions
Pin Number
TSSOP
LFCSP
1
35
2
36
3
37
4
38, 39
Mnemonic
VREFGH
VREFEF
VREFCD
VDD
VREFAB
VOUTX
Function
Reference Input for DACs G and H.
Reference Input for DACs E and F.
Reference Input for DACs C and D.
Power Supply Pin(s). This part can operate 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. Both VDD pins on the LFCSP
package must be at the same potential.
Reference Input for DACs A and B.
Output of DAC X. Buffered output with rail-to-rail operation.
AGND
DGND
Analog Ground. Ground reference for analog circuitry.
Digital Ground. Ground reference for digital circuitry.
BUF
LDAC
Buffer Control Pin. Controls whether the reference input to the DAC is buffered or unbuffered.
Active Low Control Input. Updates the DAC registers with the contents of the input registers, which
allows all DAC outputs to be simultaneously updated.
LSB Address Pin. Selects which DAC is to be written to.
Address Pin. Selects which DAC is to be written to.
MSB Address Pin. Selects which DAC is to be written to.
Eight Parallel Data Inputs. DB7 is the MSB of these eight bits.
Active Low Chip Select Input. Used in conjunction with WR to write data to the parallel interface, or
with RD to read back data from a DAC.
Active Low Read Input. Used in conjunction with CS to read data back from the internal DACs.
Active Low Write Input. Used in conjunction with CS to write data to the parallel interface.
Gain Control Pin. Controls whether the output range from the DAC is 0 V to VREF or 0 V to 2 × VREF.
Asynchronous Active Low Control Input. Clears all input registers and DAC registers to zeros.
Power-Down Pin. This active low control pin puts all DACs into power-down mode.
5
6–9,
11–14
10
15,
21–24
16
17
40
1–4,
7–10
5, 6
11,
17–20
12
13
18
19
20
25–32
33
14
15
16
21–28
29
A0
A1
A2
DB0–DB7
CS
34
35
36
37
38
30
31
32
33
34
RD
WR
GAIN
CLR
PD
Rev. 0 | Page 7 of 24
AD5346/AD5347/AD5348
GAIN
36
WR
37
CLR
38
VREFGH
39
PD
40
VREFCD
36 GAIN
VREFEF
37 CLR
VREFCD 3
VDD
38 PD
1
VREFEF 2
VREFAB
VREFGH
VDD
AD5347 PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
35
34
33
32
31
VDD 4
35 WR
VOUTA 1
30 RD
VREFAB 5
34 RD
VOUTB 2
29 CS
33 CS
VOUTC 3
28 DB9
32 DB9
VOUTD 4
26 DB3
VOUTH 14
25 DB2
DGND 15
24 DB1
BUF 16
23 DB0
LDAC 17
22 DGND
A0 18
21 DGND
A1 19
20 A2
22 DB3
VOUTH 10
21 DB2
11
12
13
14
15
16
17
18
19
20
DB1
VOUTG 13
23 DB4
VOUTG 9
DB0
27 DB4
24 DB5
VOUTF 8
DGND
VOUTF 12
25 DB6
VOUTE 7
A2
28 DB5
26 DB7
TOP VIEW
(Not to Scale)
DGND
VOUTE 11
AD5347
AGND 6
A1
29 DB6
Figure 8. AD5347 Pin Configuration—LFCSP
03331-0-007
AGND 10
27 DB8
10-BIT
AGND 5
03331-0-008
TOP VIEW 31
DB8
(Not to Scale)
30 DB7
VOUTD 9
VOUTC 8
A0
AD5347
LDAC
VOUTB 7
BUF
10-BIT
DGND
VOUTA 6
Figure 7. AD5347 Pin Configuration—TSSOP
Table 6. AD5347 Pin Function Descriptions
Pin Number
TSSOP
LFCSP
1
35
2
36
3
37
4
38, 39
5
6–9,
11–14
10
15, 21–22
Mnemonic
VREFGH
VREFEF
VREFCD
VDD
VREFAB
VOUTX
Function
Reference Input for DACs G and H.
Reference Input for DACs E and F.
Reference Input for DACs C and D.
Power Supply Pin(s). This part can operate 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. Both VDD pins on the LFCSP package
must be at the same potential.
Reference Input for DACs A and B.
Output of DAC X. Buffered output with rail-to-rail operation.
AGND
DGND
Analog Ground. Ground reference for analog circuitry.
Digital Ground. Ground reference for digital circuitry.
BUF
LDAC
Buffer Control Pin. Controls whether the reference input to the DAC is buffered or unbuffered.
Active Low Control Input. Updates the DAC registers with the contents of the input registers, which
allows all DAC outputs to be simultaneously updated.
LSB Address Pin. Selects which DAC is to be written to.
Address Pin. Selects which DAC is to be written to.
MSB Address Pin. Selects which DAC is to be written to.
Ten Parallel Data Inputs. DB9 Is the MSB of these ten bits.
Active Low Chip Select Input. Used in conjunction with WR to write data to the parallel interface, or
with RD to read back data from a DAC.
Active Low Read Input. Used in conjunction with CS to read data back from the internal DACs.
Active Low Write Input. Used in conjunction with CS to write data to the parallel interface.
Gain Control Pin. Controls whether the output range from the DAC is 0 V to VREF or 0 V to 2 × VREF.
Asynchronous Active Low Control Input. Clears all input registers and DAC registers to zeros.
Power-Down Pin. This active low control pin puts all DACs into power-down mode.
16
17
40
1–4,
7–10
5, 6
11,
17–18
12
13
18
19
20
23–32
33
14
15
16
19–28
29
A0
A1
A2
DB0–DB9
CS
34
35
36
37
38
30
31
32
33
34
RD
WR
GAIN
CLR
PD
Rev. 0 | Page 8 of 24
AD5346/AD5347/AD5348
GAIN
36
WR
37
CLR
38
VREFGH
39
PD
40
VREFCD
36 GAIN
VREFEF
37 CLR
VREFCD 3
VDD
38 PD
1
VREFEF 2
VREFAB
VREFGH
VDD
AD5348 PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
35
34
33
32
31
VDD 4
35 WR
VOUTA 1
30 RD
VREFAB 5
34 RD
VOUTB 2
29 CS
33 CS
VOUTC 3
28 DB11
32 DB11
VOUTD 4
26 DB5
VOUTH 14
25 DB4
DGND 15
24 DB3
BUF 16
23 DB2
LDAC 17
22 DB1
A0 18
21 DB0
A1 19
20 A2
22 DB5
VOUTH 10
21 DB4
11
12
13
14
15
16
17
18
19
20
DB3
VOUTG 13
23 DB6
VOUTG 9
DB2
27 DB6
24 DB7
VOUTF 8
DB1
VOUTF 12
25 DB8
VOUTE 7
A2
28 DB7
26 DB9
TOP VIEW
(Not to Scale)
DB0
VOUTE 11
AD5348
AGND 6
A1
29 DB8
Figure 10. AD5348 Pin Configuration—LFCSP
03331-0-009
AGND 10
27 DB10
12-BIT
AGND 5
03331-0-010
TOP VIEW 31
DB10
(Not to Scale)
30 DB9
VOUTD 9
VOUTC 8
A0
AD5348
LDAC
VOUTB 7
BUF
12-BIT
DGND
VOUTA 6
Figure 9. AD5348 Pin Configuration—TSSOP
Table 7. AD5348 Pin Function Descriptions
Pin Number
TSSOP LFCSP
1
35
2
36
3
37
4
38, 39
Mnemonic
VREFGH
VREFEF
VREFCD
VDD
5
6–9,
11–14
10
15
16
17
40
1–4,
7–10
5, 6
11
12
13
VREFAB
VOUTX
AGND
DGND
BUF
LDAC
18
19
20
21–32
33
14
15
16
17–28
29
A0
A1
A2
DB0–DB11
CS
34
35
36
37
38
30
31
32
33
34
RD
WR
GAIN
CLR
PD
Function
Reference Input for DACs G and H.
Reference Input for DACs E and F.
Reference Input for DACs C and D.
Power Supply Pin(s). This part can operate 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. Both VDD pins on the LFCSP package must be at
the same potential.
Reference Input for DACs A and B.
Output of DAC X. Buffered output with rail-to-rail operation.
Analog Ground. Ground reference for analog circuitry.
Digital Ground. Ground reference for digital circuitry.
Buffer Control Pin. Controls whether the reference input to the DAC is buffered or unbuffered.
Active Low Control Input. Updates the DAC registers with the contents of the input registers, which allows
all DAC outputs to be simultaneously updated.
LSB Address Pin. Selects which DAC is to be written to.
Address Pin. Selects which DAC is to be written to.
MSB Address Pin. Selects which DAC is to be written to.
Twelve Parallel Data Inputs. DB11 is the MSB of these 12 bits.
Active Low Chip Select Input. Used in conjunction with WR to write data to the parallel interface, or with
RD to read back data from a DAC.
Active Low Read Input. Used in conjunction with CS to read data back from the internal DACs.
Active Low Write Input. Used in conjunction with CS to write data to the parallel interface.
Gain Control Pin. Controls whether the output range from the DAC is 0 V to VREF or 0 V to 2 × VREF.
Asynchronous Active Low Control Input. Clears all input registers and DAC registers to zeros.
Power-Down Pin. This active low control pin puts all DACs into power-down mode.
Rev. 0 | Page 9 of 24
AD5346/AD5347/AD5348
TERMINOLOGY
Relative Accuracy
GAIN ERROR
AND
OFFSET
ERROR
For the DAC, relative accuracy or integral nonlinearity (INL) is
a measure of the maximum deviation, in LSBs, from a straight
line passing through the actual endpoints of the DAC transfer
function. Typical INL versus code plots can be seen in Figure 14,
Figure 15, and Figure 16.
Differential Nonlinearity
ACTUAL
OUTPUT
VOLTAGE
IDEAL
POSITIVE
OFFSET
Gain Error
03331-0-012
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. Typical DNL versus code plots can be
seen in Figure 17, Figure 18, and Figure 19.
DAC CODE
This is a measure of the span error of the DAC, including any
error in the gain of the buffer amplifier. It is the deviation in
slope of the actual DAC transfer characteristic from the ideal
and is expressed as a percentage of the full-scale range. This is
illustrated in Figure 11.
Figure 12. Positive Offset Error and Gain Error
Offset Error
GAIN ERROR
AND
OFFSET
ERROR
IDEAL
This is a measure of the offset error of the DAC and the output
amplifier. It is expressed as a percentage of the full-scale range.
If the offset voltage is positive, the output voltage still positive at
zero input code. This is shown in Figure 12. Because the DACs
operate from a single supply, a negative offset cannot appear at
the output of the buffer amplifier. Instead, there is a code close
to zero at which the amplifier output saturates (amplifier
footroom). Below this code there is a dead band over which the
output voltage does not change. This is illustrated in Figure 13.
OUTPUT
VOLTAGE
ACTUAL
NEGATIVE
OFFSET
POSITIVE
GAIN ERROR
NEGATIVE
GAIN ERROR
ACTUAL
DAC CODE
DEADBAND CODES
AMPLIFIER
FOOTROOM
(~1mV)
OUTPUT
VOLTAGE
NEGATIVE
OFFSET
03331-0-013
IDEAL
03331-0-011
DAC CODE
Figure 13. Negative Offset Error and Gain Error
Figure 11. Gain Error
Rev. 0 | Page 10 of 24
AD5346/AD5347/AD5348
Offset Error Drift
Digital Crosstalk
This is a measure of the change in offset error with changes in
temperature. It is expressed in (ppm of full-scale range)/°C.
This 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
expressed in nV-s.
Gain Error Drift
This 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)
This 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 ±10%.
DC Crosstalk
This is the dc change in the output level of one DAC at midscale
in response to a full-scale code change (all 0s to all 1s and vice
versa) and output change of another DAC. It is expressed in µV.
Reference Feedthrough
This 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, i.e., LDAC is high. It is expressed in dB.
Channel-to-Channel Isolation
This is a ratio of the amplitude of the signal at the output of one
DAC to a sine wave on the reference inputs of the other DACs.
It is measured by grounding one VREF pin and applying a 10 kHz,
4 V p-p sine wave to the other VREF pins. It is expressed in dB.
Major-Code Transition Glitch Energy
This is the energy of the impulse injected into the analog output
when the DAC 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).
Analog Crosstalk
This 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 nV-s.
DAC-to-DAC Crosstalk
This 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 the LDAC pin set
low and 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. 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)
This 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 dB.
Digital Feedthrough
This is a measure of the impulse injected into the analog output
of the DAC from the digital input pins of the device, but it is
measured when the DAC is not being written to, CS held high.
It is specified in nV-s and is measured with a full-scale change
on the digital input pins, i.e., from all 0s to all 1s and vice versa.
Rev. 0 | Page 11 of 24
AD5346/AD5347/AD5348
TYPICAL PERFORMANCE CHARACTERISTICS
1.0
0.3
TA = 25°C
VDD = 5V
TA = 25°C
VDD = 5V
0.2
DNL ERROR (LSB)
INL ERROR (LSB)
0.5
0
0.1
0
–0.1
–0.5
–1.0
0
50
100
150
200
03331-0-017
03331-0-014
–0.2
–0.3
250
0
50
100
CODE
Figure 14. AD5346 Typical INL Plot
200
250
800
1000
Figure 17. AD5346 Typical DNL Plot
0.6
3
TA = 25°C
VDD = 5V
TA = 25°C
VDD = 5V
2
0.4
1
0.2
DNL ERROR (LSB)
0
–1
–3
0
200
400
600
800
–0.2
–0.4
03331-0-015
–2
0
03331-0-018
INL ERROR (LSB)
150
CODE
–0.6
0
1000
200
400
600
CODE
CODE
Figure 15. AD5347 Typical INL Plot
Figure 18. AD5347 Typical DNL Plot
1.0
12
TA = 25°C
VDD = 5V
TA = 25°C
VDD = 5V
8
DNL ERROR (LSB)
4
0
–4
0
–12
0
1000
2000
CODE
3000
03331-0-019
–0.5
–8
03331-0-016
INL ERROR (LSB)
0.5
–1.0
0
4000
1000
2000
CODE
3000
Figure 19. AD5348 Typical DNL Plot
Figure 16. AD5348 Typical INL Plot
Rev. 0 | Page 12 of 24
4000
AD5346/AD5347/AD5348
0.2
0.5
VDD = 5V
TA = 25°C
0.4
TA = 25°C
VREF = 2V
0.1
MAX INL
0.3
0
GAIN ERROR
MAX DNL
ERROR (% FSR)
ERROR (LSB)
0.2
0.1
0
–0.1
MIN DNL
–0.1
–0.2
–0.3
–0.2
MIN INL
–0.4
OFFSET ERROR
–0.4
–0.5
0
1
2
3
4
03331-0-034
03331-0-031
–0.3
–0.5
–0.6
5
0
1
VREF(V)
Figure 20. AD5346 INL and DNL Error vs. VREF
2
3
VDD (V)
4
5
6
Figure 23. Offset Error and Gain Error vs. VDD
5
0.5
VDD = 5V
VREF = 2V
0.4
MAX INL
5V SOURCE
0.3
4
0.2
3
VOUT (V)
ERROR (LSB)
3V SOURCE
MAX DNL
0.1
0
–0.1
2
MIN DNL
–0.2
03331-0-032
1
–0.4
–0.5
–40
MIN INL
–20
0
20
40
60
TEMPERATURE (°C)
80
0
0
100
Figure 21. AD5346 INL and DNL Error vs. Temperature
1
2
3
4
SINK/SOURCE CURRENT (mA)
5
6
Figure 24. VOUT Source and Sink Current Capability
1.0
1.0
VDD = 5V
VREF = 2V
0.9
VDD = 5V
TA = 25°C
0.8
0.5
0.7
IDD (mA)
0.6
0
OFFSET ERROR
0.5
0.4
0.3
–0.5
GAIN ERROR
–1.0
–40
–20
0
60
20
40
TEMPERATURE (°C)
80
03331-0-036
0.2
03331-0-033
ERROR (% FSR)
3V SINK
5V SINK
03331-0-035
–0.3
0.1
0
100
ZERO SCALE
Figure 22. AD5346 Offset Error and Gain Error vs. Temperature
HALF SCALE
DAC CODE
FULL SCALE
Figure 25. Supply Current vs. DAC Code
Rev. 0 | Page 13 of 24
AD5346/AD5347/AD5348
1.4
TA = 25°C
VDD = 5V
VREF = 5V
VREF = 2V
GAIN = 1 UNBUFFERED
1.2
TA = –40°C
TA = +25°C
1.0
VOUTA
IDD (mA)
0.8
TA = +105°C
CH1
0.6
LDAC
CH2
03331-0-037
0.2
03331-0-040
0.4
0
2.5
3.0
3.5
4.0
4.5
SUPPLY VOLTAGE (V)
5.0
CH1 1V, CH2 5V, TIME BASE = 1µs/DIV
5.5
Figure 29. Half-Scale Settling (¼ to ¾ Scale Code)
Figure 26. Supply Current vs. Supply Voltage
1.0
0.9
TA = 25°C
VDD = 5V
VREF = 2V
TA = 25°C
CH1
0.7
VDD
0.6
0.5
0.4
VOUTA
0.3
CH2
03331-0-041
0.2
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
03331-0-038
0.1
5.5
VDD (V)
CH1 2V, CH2 200mV, TIME BASE = 200µs/DIV
Figure 30. Power-On Reset to 0 V
Figure 27. Power-Down Current vs. Supply Voltage
2.5
TA = 25°C
VDD = 5V
2.0
VOUT1
CH2
1.5
1.0
PD
VDD = 3V
0
0
1
2
3
VLOGIC (V)
4
03331-0-042
0.5
CH1
03331-0-039
IDD (mA)
IDD POWER-DOWN (µA)
0.8
CH1 2.00V, CH2 1.00V, TIME BASE = 20µs/DIV
5
Figure 31. Exiting Power-Down to Midscale
Figure 28. Supply Current vs. Logic Input Voltage
Rev. 0 | Page 14 of 24
AD5346/AD5347/AD5348
0.02
21
VDD = 5V
TA = 25°C
15
FREQUENCY
VDD = 3V
VDD = 5V
12
9
6
0.01
0
–0.01
03331-0-046
FULL-SCALE ERROR (V)
18
0
0.6
0.8
1.0
1.2
03331-0-043
3
1.4
IDD (mA)
–0.02
0
1
2
3
VREF (V)
4
5
6
Figure 35. Full-Scale Error vs. VREF
Figure 32. IDD Histogram with VDD = 3 V and VDD = 5 V
1.999
2.49
1.998
2.48
1.997
2.47
1.996
1µs/DIV
10
0
–10
dB
–20
–30
–40
03331-0-045
–60
10
100
1k
10k
100k
FREQUENCY (Hz)
1M
10M
Figure 34. Multiplying Bandwidth (Small Signal Frequency Response)
Rev. 0 | Page 15 of 24
511
03331-0-047
Figure 36. DAC-to-DAC Crosstalk
Figure 33. AD5348 Major Code Transition Glitch Energy
–50
0
25
50
75
100
125
150
175
200
225
250
275
300
325
350
375
400
425
450
475
03331-0-044
VOUT (V)
2.50
AD5346/AD5347/AD5348
FUNCTIONAL DESCRIPTION
VREF
The AD5346/AD5347/AD5348 are octal resistor-string DACs
fabricated by a CMOS process with resolutions of 8, 10, and 12
bits, respectively. They are written to using a parallel interface.
They operate from single supplies of 2.5 V to 5.5 V, and the
output buffer amplifiers offer rail-to-rail output swing. The gain
of the buffer amplifiers can be set to 1 or 2 to give an output
voltage range of 0 V to VREF or 0 V to 2 × VREF. The AD5346/
AD5347/AD5348 have reference inputs that may be buffered to
draw virtually no current from the reference source. The devices
have a power-down feature that reduces current consumption
to only 100 nA @ 3 V.
R
R
R
Figure 38. Resistor String
The architecture of one DAC channel consists of a reference
buffer and a resistor-string DAC followed by an output buffer
amplifier. The voltage at the VREF pin provides the reference
voltage for the DAC. Figure 37 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
DAC REFERENCE INPUT
The DACs operate with an external reference. The AD5346/
AD5347/AD5348 have a reference input for each pair of DACs.
The reference inputs may be configured as buffered or
unbuffered. This option is controlled by the BUF pin.
D
× Gain
2N
In buffered mode (BUF = 1), the current drawn from an
external reference voltage is virtually zero because the impedance is at least 10 MΩ. The reference input range is 1 V to VDD.
where:
D is the decimal equivalent of the binary code, which is loaded
to the DAC register:
0–255 for AD5346 (8 bits)
0–1023 for AD5347 (10 bits)
0–4095 for AD5348 (12 bits)
N is the DAC resolution.
Gain is the output amplifier gain (1 or 2).
VREFAB
BUF
If using an external buffered reference (such as REF192), there
is no need to use the on-chip buffer.
The output buffer amplifier is capable of generating output
voltages to within 1 mV of either rail. Its actual range depends
on VREF, GAIN, the load on VOUT, and offset error.
REFERENCE
BUFFER
RESISTOR
STRING
VOUTA
OUTPUT
BUFFER AMPLIFIER
03331-0-020
DAC
REGISTER
In unbuffered mode (BUF = 0), 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. The impedance is still large at typically 90 kΩ for 0 V
to VREF mode and 45 kΩ for 0 V to 2 × VREF mode.
OUTPUT AMPLIFIER
(GAIN = +1 OR +2)
INPUT
REGISTER
03331-0-021
R
DIGITAL-TO-ANALOG SECTION
VOUT = VREF ×
TO OUTPUT
AMPLIFIER
R
Figure 37. Single DAC Channel Architecture
RESISTOR STRING
The resistor string section is shown in Figure 38. It is simply a
string of resistors, each of value R. The digital code loaded to
the DAC register determines at what 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.
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. However, because of clamping, the
maximum output is limited to VDD – 0.001 V.
The output amplifier is capable of driving a load of 2 kΩ 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 24.
The slew rate is 0.7 V/µs with a half-scale settling time to ±0.5 LSB
(at 8 bits) of 6 s with the output unloaded. See Figure 29.
Rev. 0 | Page 16 of 24
AD5346/AD5347/AD5348
where IDYNAMIC =
PARALLEL INTERFACE
The AD5346/AD5347/AD5348 load their data as a single 8-,
10-, or 12-bit word.
Double-Buffered Interface
The AD5346/AD5347/AD5348 DACs all have double-buffered
interfaces consisting of an input register and a DAC register.
DAC data, BUF, and GAIN inputs are written to the input register under control of the Chip Select (CS) and Write (WR) pins.
Access to the DAC register is controlled by the LDAC function.
When LDAC is high, the DAC register is latched and the input
register may change state without affecting the contents of the
DAC register. However, when LDAC is brought low, the DAC
register becomes transparent and the contents of the input
register are transferred to it. The gain and buffer control signals
are also double-buffered and are updated only when LDAC is
taken low.
This is useful if the user requires simultaneous updating of all
DACs and peripherals. The user can write to all input registers
individually and then, by pulsing the LDAC input low, all
outputs update simultaneously.
These parts contain an extra feature whereby the DAC register
is not updated unless its input register has been updated since
the last time that 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 AD5346/
AD5347/AD5348, the part updates the DAC register only if the
input register has been changed since the last time the DAC
register was updated. This removes unnecessary crosstalk.
cvf and
c = capacitance or the data bus
v = VDD
f = readback frequency
Load DAC Input (LDAC)
LDAC transfers data from the input register to the DAC register,
and therefore updates the outputs. The LDAC function enables
double-buffering of the DAC data, GAIN data, and BUF. There
are two LDAC modes:
•
•
Synchronous Mode. In this mode, the DAC register is
updated after new data is read in on the rising edge of the
WR input. LDAC can be tied permanently low or pulsed as
shown in Figure 3.
Asynchronous Mode. In this mode, the outputs are not
updated at the same time that the input register is written
to. When LDAC goes low, the DAC register is updated with
the contents of the input register.
POWER-ON RESET
The AD5346/AD5347/AD5348 have a power-on reset function,
so that they power up in a defined state. The power-on state is
•
•
•
•
Normal operation
Reference input buffered
0 V to VREF output range
Output voltage set to 0 V
Both input and DAC registers are filled with zeros and remain
so 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.
Clear Input (CLR)
POWER-DOWN MODE
CLR is an active low, asynchronous clear that resets the input
and DAC registers.
The AD5346/AD5347/AD5348 have low power consumption,
dissipating typically 2.4 mW with a 3 V supply and 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.
CS is an active low input that selects the device.
Write Input (WR)
WR is an active low input that controls writing of data to the
device. Data is latched into the input register on the rising edge
of WR.
Read Input (RD)
RD is an active low input that controls when data is read back
from the internal DAC registers. On the falling edge of RD, data
is shifted onto the data bus. Under the conditions of a high
capacitive load and high supplies, the user must ensure that the
dynamic current remains at an acceptable level, therefore
ensuring that the die temperature is within specification. The
die temperature can be calculated as
When the PD pin is high, the DACs work normally with a typical power consumption of 1 mA at 5 V (0.8 mA at 3 V). In
power-down mode, however, the supply current falls to 400 nA
at 5 V (120 nA at 3 V) when the 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
open-circuit. This has the advantage that the outputs are threestate while the part is in power-down mode, and provides a
defined input condition for whatever is connected to the outputs
of the DAC amplifiers. The output stage is illustrated in Figure 39.
RESISTOR
STRING DAC
AMPLIFIER
VOUT
POWER-DOWN
CIRCUITRY
TDIE = TAMBIENT + VDD (IDD + IDYNAMIC)θJA
03331-0-022
Chip Select Input (CS)
Figure 39. Output Stage During Power-Down
Rev. 0 | Page 17 of 24
AD5346/AD5347/AD5348
The AD5347 and AD5348 data bus must be at least 10 and 12
bits wide, respectively, and are best suited to a 16-bit data bus
system.
Examples of data formats for putting GAIN and BUF on a
16-bit data bus are shown in Figure 40. Note that any unused
bits above the actual DAC data may be used for GAIN and BUF.
AD5347
SUGGESTED DATA BUS FORMATS
X
X
X
X
BUF GAIN DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
X
X BUF GAIN DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
AD5348
In many applications, the GAIN and BUF pins are hardwired.
However, if more flexibility is required, they can be included in
a data bus. This enables the user to software program GAIN,
giving the option of doubling the resolution in the lower half of
the DAC range. In a bused system, GAIN and BUF may be
treated as data inputs because they are written to the device
during a write operation and take effect when LDAC is taken
low. This means that the reference buffers and the output
amplifier gain of multiple DAC devices can be controlled using
common GAIN and BUF lines. Note that GAIN and BUF are
not read back during an RD operation.
X = UNUSED BIT
Figure 40. AD5347/AD5348 Data Format for Word Load with
GAIN and BUF Data on 16-Bit Bus
Table 8. AD5346/AD5347/AD5348 Truth Table
CLR
LDAC
1
1
1
1
0
X
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
X
1
X
1
X
1
X
1
X
1
X
1
X
1
X
1
0
X
X
X = Don’t Care
CS
WR
RD
1
X
X
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
X
0
X
1
X
0→1
0→1
0→1
0→1
0→1
0→1
0→1
0→1
1
1
1
1
1
1
1
1
X
0
X
1
X
1
1
1
1
1
1
1
1
1→0
1→0
1→0
1→0
1→0
1→0
1→0
1→0
1
0
A2
X
X
X
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
X
X
A1
X
X
X
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
X
X
Rev. 0 | Page 18 of 24
A0
X
X
X
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
X
X
Function
No Data Transfer
No Data Transfer
Clear All Registers
Load DAC A Input Register
Load DAC B Input Register
Load DAC C Input Register
Load DAC D Input Register
Load DAC E Input Register
Load DAC F Input Register
Load DAC G Input Register
Load DAC H Input Register
Read Back DAC Register A
Read Back DAC Register B
Read Back DAC Register C
Read Back DAC Register D
Read Back DAC Register E
Read Back DAC Register F
Read Back DAC Register G
Read Back DAC Register H
Update DAC Registers
Invalid Operation
03331-0-048
The bias generator, the output amplifier, the resistor string, and
all other associated linear circuitry are all shut down when the
power-down mode is activated. However, the contents of the
registers are unaffected when in power-down. The time to exit
power-down is typically 2.5 s for VDD = 5 V and 5 µs when VDD =
3 V. This is the time from a rising edge on the PD pin to when
the output voltage deviates from its power-down voltage. See
Figure 31.
AD5346/AD5347/AD5348
APPLICATIONS INFORMATION
TYPICAL APPLICATION CIRCUITS
The AD5346/AD5347/AD5348 can be used with a wide range
of reference voltages, especially if the reference inputs are
configured as unbuffered, in which case the devices offer full,
one-quadrant multiplying capability over a reference range of
0.25 V to VDD. More typically, these devices may be used with a
fixed, precision reference voltage. Figure 41 shows a typical
setup for the devices when using an external reference
connected to the reference inputs. Suitable references for 5 V
operation are the AD780, ADR381, and REF192 (2.5 V references). For 2.5 V operation, suitable external references are the
AD589 and the AD1580 (1.2 V band gap references).
BIPOLAR OPERATION USING THE
AD5346/AD5347/AD5348
The AD5346/AD5347/AD5348 have been designed for singlesupply operation, but a bipolar output range is also possible by
using the circuit shown in Figure 43. This circuit has an output
voltage range of ±5 V. Rail-to-rail operation at the amplifier
output is achievable using an AD820, an AD8519, or an OP196
as the output amplifier.
5V
R4
20kΩ
0.1µF
VIN
10µF
±5V
VDD
EXT
REF
VIN
–5V
R1
10kΩ
VOUT*
R2
20kΩ
VOUT*
AD5346/AD5347/
AD5348
GND
*ONLY ONE CHANNEL OF VREF AND VOUT SHOWN
03331-0-024
AD780/ADR381/REF192
WITH VDD = 5V
OR AD589/AD1580 WITH
VDD = 2.5V
GND
Figure 43. Bipolar Operation with the AD5346/ AD5347/AD5348
*ONLY ONE CHANNEL OF VREF AND VOUT SHOWN
The output voltage for any input code can be calculated as
follows:
Figure 41. AD5346/AD5347/AD5348 Using an External Reference
DRIVING VDD FROM THE REFERENCE VOLTAGE
If an output range of 0 V to VDD is required, the simplest
solution is to connect the reference inputs to VDD. Because this
supply may not be very accurate and may be noisy, the devices
can be powered from the reference voltage, for example, by
using a 5 V reference such as the ADM663 or ADM666, as
shown in Figure 42.
VOUT = [(1 + R4/R3) × (R2/(R1 + R2) × (2 × VREF × D/2N)] –
R4 × VREF/R3
where:
D is the decimal equivalent of the code loaded to the DAC.
N is the DAC resolution.
VREF is the reference voltage input.
with:
6V TO 16V
0.1µF
VREF = 5 V
R1 = R3 = 10 kΩ
R2 = R4 = 20 kΩ
VDD = 5 V
GAIN = 2
10µF
VIN
ADM663/ADM666
VDD
VREF*
0.1µF
VOUT*
AD5346/AD5347/
AD5348
GND
VOUT = (10 × D/2N) – 5
03331-0-025
SENSE
VOUT(2)
GND SHDN
VSET GND
AD5346/AD5347/
AD5348
03331-0-026
VREF*
GND
EXT
REF
0.1µF
VDD
VOUT
AD820/AD8519/
OP196
VREF*
VOUT
GND
EXT
REF
+5V
R3
10kΩ
VDD = 2.5V to 5.5V
0.1µF
10µF
*ONLY ONE CHANNEL OF VREF AND VOUT SHOWN
Figure 42. Using an ADM663/ADM666 as Power and
Reference to the AD5346/AD5347/AD5348
Rev. 0 | Page 19 of 24
AD5346/AD5347/AD5348
5V
DECODING MULTIPLE AD5346/AD5347/AD5348s
The 74HC139 is used as a 2-line to 4-line decoder to address
any of the DACs in the system. To prevent timing errors from
occurring, the enable input should be brought to its inactive
state while the coded address inputs are changing state.
Figure 44 shows a diagram of a typical setup for decoding
multiple devices in a system. Once data has been written
sequentially to all DACs in a system, all the DACs can be
updated simultaneously using a common LDAC line. A common CLR line can also be used to reset all DAC outputs to 0 V.
AD5346/AD5347
A0 /AD5348
A1
A2
WR
DATA
INPUTS
LD AC
CLR
CS
A0
A1
A2
WR
LDAC
CLR
VIN
VDD
ENABLE
CODED
ADDRESS
1G
VCC
1Y0
1A
1Y1
74HC139
1B
1Y2
1Y3
DGND
AD5346/AD5347
VREFAB
1kΩ
1kΩ
FAIL
PASS
VDD
PASS/
FAIL
1/2
CMP04
AD5346/AD5347/
AD5348
VOUTB
03331-0-028
VOUTA
1/6 74HC05
GND
Figure 45. Programmable Window Detector
PROGRAMMABLE CURRENT SOURCE
Figure 46 shows the AD5346/AD5347/AD5348 used as the
control element of a programmable current source. In this
example, the full-scale current is set to 1 mA. The output
voltage from the DAC is applied across the current setting
resistor of 4.7 kΩ in series with the 470 Ω adjustment
potentiometer, which gives an adjustment of about ±5%.
Suitable transistors to place in the feedback loop of the amplifier include the BC107 and the 2N3904, which enable the
current source to operate from a minimum VSOURCE of 6 V. The
operating range is determined by the operating characteristics
of the transistor. Suitable amplifiers include the AD820 and the
OP295, both having rail-to-rail operation on their outputs. The
current for any digital input code and resistor value can be
calculated as follows:
I = G × VREF
A0 /AD5348
A1
A2
WR
DATA
LD AC INPUTS
CLR
CS
D
mA
(2 × R)
N
where:
G is the gain of the buffer amplifier (1 or 2).
D is the digital input code.
N is the DAC resolution (8, 10, or 12 bits).
R is the sum of the resistor plus adjustment potentiometer in kΩ.
AD5346/AD5347
VDD = 5V
03331-0-027
A0 /AD5348
A1
A2
WR
DATA
INPUTS
LD AC
CLR
CS
VREF
DATA BUS
AD5346/AD5347
A0 /AD5348
A1
A2
WR
DATA
LD AC
INPUTS
CLR
CS
10µF
0.1µF
The CS pin on these devices can be used in applications to
decode a number of DACs. In this application, all DACs in the
system receive the same data and WR pulses, but only the CS to
one of the DACs will be active at any one time, so data will only
be written to the DAC whose CS is low.
0.1µF
Figure 44. Decoding Multiple DAC Devices
10µF
VSOURCE
VIN
A digitally programmable upper/lower limit detector using two
of the DACs in the AD5346/AD5347/AD5348 is shown in
Figure 45. Any pair of DACs in the device may be used, but for
simplicity the description refers to DACs A and B.
The upper and lower limits for the test are loaded to DACs A
and B which, in turn, set the limits on the CMP04. If a signal at
the VIN input is not within the programmed window, an LED
indicates the fail condition.
5V
VDD
EXT
REF
VREF*
VOUT
GND
0.1µF
LOAD
VOUT*
AD5346/AD5347/
AD5348
4.7kΩ
GND
470Ω
*ONLY ONE CHANNEL OF VREF AND VOUT SHOWN
Rev. 0 | Page 20 of 24
Figure 46. Programmable Current Source
03331-0-029
AD5346/AD5347/AD5348 AS DIGITALLY
PROGRAMMABLE WINDOW DETECTORS
AD5346/AD5347/AD5348
COARSE AND FINE ADJUSTMENT USING
THE AD5346/AD5347/AD5348
POWER SUPPLY BYPASSING AND GROUNDING
Two of the DACs in the AD5346/AD5347/AD5348 can be
paired together to form a coarse and fine adjustment function,
as shown in Figure 47. As with the window comparator
previously described, the description refers to DACs A and B.
DAC A provides the coarse adjustment, while DAC B provides
the fine adjustment. Varying the ratio of R1 and R2 changes the
relative effect of the coarse and fine adjustments. With the
resistor values shown, the output amplifier has unity gain for
the DAC A output, so the output range is 0 V to (VREF – 1 LSB).
For DAC B, the amplifier has a gain of 7.6 × 10–3, giving DAC B
a range equal to 2 LSBs of DAC A.
The circuit is shown with a 2.5 V reference, but reference
voltages up to VDD may be used. The op amps indicated allow a
rail-to-rail output swing.
VDD = 5V
0.1µF
10µF
VDD
VOUT
VREFAB
0.1µF
AD5346/AD5347/
AD5348
VOUTB
R1
390Ω
R2
51.2kΩ
AD780/ADR381/REF192
WITH VDD = 5V
GND
Figure 47. Coarse and Fine Adjustment
03331-0-030
VOUTA
VOUT
GND
R3
51.2kΩ
5V
VIN
EXT
REF
R4
390Ω
In any circuit where accuracy is important, careful consideration
of the power supply and ground return layout helps to ensure
the rated performance.
The printed circuit board on which the AD5346/AD5347/
AD5348 is mounted should be designed so that the analog and
digital sections are separated and are confined to certain areas
of the board. This facilitates the use of ground planes that can
be separated easily. A minimum etch technique is generally best
for ground planes because it gives the best shielding. Digital and
analog ground planes should be joined in one place only. If the
AD5346/AD5347/AD5348 is the only device requiring an
AGND-to-DGND connection, then the ground planes should
be connected at the AGND and DGND pins of the AD5346/
AD5347/AD5348. If the AD5346/AD5347/AD5348 is in a
system where multiple devices require AGND-to-DGND
connections, the connection should be made at one point only, a
star ground point that should be established as close as possible
to the AD5346/AD5347/AD5348.
The AD5346/AD5347/AD5348 should have ample supply
bypassing of 10 µF in parallel with 0.1 µF on the supply located
as close to the package as possible, ideally right up against the
device. The 10 µF capacitors are the tantalum bead type. The
0.1 µF capacitor should have low effective series resistance
(ESR) and effective series inductance (ESI), such as the
common ceramic types that provide a low impedance path to
ground at high frequencies to handle transient currents due to
internal logic switching.
The power supply lines of the device should use the largest trace
possible to provide low impedance paths and to reduce the
effects of glitches on the power supply line. Fast switching
signals such as clocks should be shielded with digital ground to
avoid radiating noise to other parts of the board, and should
never be run near the reference inputs. Avoid crossover of
digital and analog signals. Traces on opposite sides of the board
should run at right angles to each other to reduce the effects of
feedthrough through the board. A microstrip technique is by far
the best, but not always possible with a double-sided board. In
this technique, the component side of the board is dedicated to
ground plane, while signal traces are placed on the solder side.
Rev. 0 | Page 21 of 24
AD5346/AD5347/AD5348
Table 9. Overview of AD53xx Parallel Devices
Part No.
SINGLES
AD5330
AD5331
AD5340
AD5341
DUALS
AD5332
AD5333
AD5342
AD5343
QUADS
AD5334
AD5335
AD5336
AD5344
OCTALS
AD5346
AD5347
AD4348
Resolution
DNL
VREF Pins
Settling Time
8
10
12
12
±0.25
±0.5
±1.0
±1.0
1
1
1
1
6 µs
7 µs
8 µs
8 µs
8
10
12
12
±0.25
±0.5
±1.0
±1.0
2
2
2
1
6 µs
7 µs
8 µs
8 µs
8
10
10
12
±0.25
±0.5
±0.5
±1.0
2
2
4
4
6 µs
7 µs
7 µs
8 µs
8
10
12
±0.25
±0.5
±1.0
4
4
4
6 µs
7 µs
8 µs
Additional Pin Functions
BUF
GAIN HBEN CLR
9
Package
Pins
9
9
9
9
9
TSSOP
TSSOP
TSSOP
TSSOP
20
20
24
20
9
9
9
9
9
TSSOP
TSSOP
TSSOP
TSSOP
20
24
28
20
9
9
9
9
TSSOP
TSSOP
TSSOP
TSSOP
24
24
28
28
9
9
9
9
9
9
TSSOP, LFCSP
TSSOP, LFCSP
TSSOP, LFCSP
38, 40
38, 40
38, 40
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
Table 10. Overview of AD53xx Serial Devices
Part No.
SINGLES
AD5300
AD5310
AD5320
AD5301
AD5311
AD5321
DUALS
AD5302
AD5312
AD5322
AD5303
AD5313
AD5323
QUADS
AD5304
AD5314
AD5324
AD5305
AD5315
AD5325
AD5306
AD5316
AD5326
AD5307
AD5317
AD5327
OCTALS
AD5308
AD5318
AD5328
Resolution
DNL
VREF Pins
Settling Time
Interface
Package
Pins
8
10
12
8
10
12
±0.25
±0.5
±1.0
±0.25
±0.5
±1.0
0 (VREF = VDD)
0 (VREF = VDD)
0 (VREF = VDD)
0 (VREF = VDD)
0 (VREF = VDD)
0 (VREF = VDD)
4 µs
6 µs
8 µs
6 µs
7 µs
8 µs
SPI®
SPI
SPI
2-Wire
2-Wire
2-Wire
SOT-23, MSOP
SOT-23, MSOP
SOT-23, MSOP
SOT-23, MSOP
SOT-23, MSOP
SOT-23, MSOP
6, 8
6, 8
6, 8
6, 8
6, 8
6, 8
8
10
12
8
10
12
±0.25
±0.5
±1.0
±0.25
±0.5
±1.0
2
2
2
2
2
2
6 µs
7 µs
8 µs
6 µs
7 µs
8 µs
SPI
SPI
SPI
SPI
SPI
SPI
MSOP
MSOP
MSOP
TSSOP
TSSOP
TSSOP
8
8
8
16
16
16
8
10
12
8
10
12
8
10
12
8
10
12
±0.25
±0.5
±1.0
±0.25
±0.5
±1.0
±0.25
±0.5
±1.0
±0.25
±0.5
±1.0
1
1
1
1
1
1
4
4
4
2
2
2
6 µs
7 µs
8 µs
6 µs
7 µs
8 µs
6 µs
7 µs
8 µs
6 µs
7 µs
8 µs
SPI
SPI
SPI
2-Wire
2-Wire
2-Wire
2-Wire
2-Wire
2-Wire
SPI
SPI
SPI
MSOP
MSOP
MSOP
MSOP
MSOP
MSOP
TSSOP
TSSOP
TSSOP
TSSOP
TSSOP
TSSOP
10
10
10
10
10
10
16
16
16
16
16
16
8
10
12
±0.25
±0.5
±1.0
2
2
2
6 µs
7 µs
8 µs
SPI
SPI
SPI
TSSOP
TSSOP
TSSOP
16
16
16
Rev. 0 | Page 22 of 24
AD5346/AD5347/AD5348
OUTLINE DIMENSIONS
9.80
9.70
9.60
20
38
4.50
4.40
4.30
6.40 BSC
1
19
PIN 1
1.20
MAX
0.15
0.05
COPLANARITY
0.10
0.50
BSC
0.27
0.17
SEATING
PLANE
0.20
0.09
8°
0°
0.70
0.60
0.45
COMPLIANT TO JEDEC STANDARDS MO-153BD-1
Figure 48. 38-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-38)
Dimensions shown in millimeters
6.00
BSC SQ
0.60 MAX
0.60 MAX
PIN 1
INDICATOR
TOP
VIEW
0.50
BSC
5.75
BSC SQ
0.50
0.40
0.30
12° MAX
1.00
0.85
0.80
PIN 1
INDICATOR
31
30
40
1
21
20
10
11
0.25 MIN
4.50
REF
0.80 MAX
0.65 TYP
0.05 MAX
0.02 NOM
SEATING
PLANE
0.30
0.23
0.18
0.20 REF
COPLANARITY
0.08
COMPLIANT TO JEDEC STANDARDS MO-220-VJJD-2
Figure 49. 40-Lead Lead Frame Chip Scale Package [LFCSP]
(CP-40)
Dimensions shown in millimeters
Rev. 0 | Page 23 of 24
4.25
4.10 SQ
3.95
BOTTOM
VIEW
AD5346/AD5347/AD5348
ORDERING GUIDES
Table 11. AD5346 Ordering Guide
Model
AD5346BRU
AD5346BRU-REEL
AD5346BRU-REEL7
AD5346BCP
AD5346BCP-REEL
AD5346BCP-REEL7
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
Package Description
TSSOP (Thin Shrink Small Outline Package)
TSSOP (Thin Shrink Small Outline Package)
TSSOP (Thin Shrink Small Outline Package)
LFCSP (Lead Frame Chip Scale Package)
LFCSP (Lead Frame Chip Scale Package)
LFCSP (Lead Frame Chip Scale Package)
Package Option
RU-38
RU-38
RU-38
CP-40
CP-40
CP-40
Package Description
TSSOP (Thin Shrink Small Outline Package)
TSSOP (Thin Shrink Small Outline Package)
TSSOP (Thin Shrink Small Outline Package)
LFCSP (Lead Frame Chip Scale Package)
LFCSP (Lead Frame Chip Scale Package)
LFCSP (Lead Frame Chip Scale Package)
Package Option
RU-38
RU-38
RU-38
CP-40
CP-40
CP-40
Package Description
TSSOP (Thin Shrink Small Outline Package)
TSSOP (Thin Shrink Small Outline Package)
TSSOP (Thin Shrink Small Outline Package)
LFCSP (Lead Frame Chip Scale Package)
LFCSP (Lead Frame Chip Scale Package)
LFCSP (Lead Frame Chip Scale Package)
Package Option
RU-38
RU-38
RU-38
CP-40
CP-40
CP-40
Table 12. AD5347 Ordering Guide
Model
AD5347BRU
AD5347BRU-REEL
AD5347BRU-REEL7
AD5347BCP
AD5347BCP-REEL
AD5347BCP-REEL7
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
Table 13. AD5348 Ordering Guide
Model
AD5348BRU
AD5348BRU-REEL
AD5348BRU-REEL7
AD5348BCP
AD5348BCP-REEL
AD5348BCP-REEL7
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
© 2003 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C03331–0–11/03(0)
Rev. 0 | Page 24 of 24
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