ANALOG DEVICES AD5790 Service Manual

System Ready, 20-Bit, ±2LSB INL,
VCCVDDV
Data Sheet

FEATURES

Single 20-bit voltage output DAC, ±2 LSB INL 8 nV/√Hz output noise spectral density
0.1 LSB long-term linearity error stability
±0.018 ppm/°C gain error temperature coefficient
2.5 μs output voltage settling time
3.5 nV-sec midscale glitch impulse Integrated precision reference buffers Operating temperature range: −40°C to +125°C 4 mm × 5 mm LFCSP package Wide power supply range of up to ±16.5 V 35 MHz Schmitt-triggered digital interface
1.8 V compatible digital interface

APPLICATIONS

Medical instrumentation Test and measurement Industrial control Scientific and aerospace instrumentation Data acquisition systems Digital gain and offset adjustment Power supply control
Voltage Output DAC
AD5790

FUNCTIONAL BLOCK DIAGRAM

REFP
6.8k
R1 R
6k
AD5790
6.8k
FB
R
INV
V
FB
OUT
IOV
SDIN
SCLK
SYNC
SDO
LDAC
CLR
RESET
CC
INPUT SHIFT
REGISTE R
AND
CONTROL
LOGIC
POWER-ON-RESET AND CLEAR LOG IC
DGND
20
SS
20
V
REFN
Figure 1.
20-BIT
DAC REG
AGNDV
A1
DAC
Table 1. Related Devices
Part No. Description
AD5791 20-bit, 1 LSB accurate DAC AD5780
18-bit, ±1 LSB INL, voltage output DAC , buffered reference inputs
AD5781
18-bit, ±1 LSB INL, voltage Output DAC ,
unbuffered reference inputs
AD5760 16-bit, ±0.5 LSB INL, voltage Output DAC AD5541A/AD5542A 16-bit, 1 LSB accurate 5 V DAC
10239-001

GENERAL DESCRIPTION

The AD57901 is a single 20-bit, unbuffered voltage-output DAC that operates from a bipolar supply of up to 33 V. The AD5790 accepts a positive reference input in the range of 5 V to V
2.5 V and a negative reference input in the range of V to 0 V. The AD5790 offers a relative accuracy specification of ±2 LSB maximum range, and operation is guaranteed mono­tonic with a −1 LSB to +3 LSB DNL specification.
The part uses a versatile 3-wire serial interface that operates at clock rates of up to 35 MHz and is compatible with standard SPI, QSPI™, MICROWIRE™, and DSP interface standards. Reference buffers are also provided on chip. The part incorpo­rates a power-on reset circuit that ensures the DAC output powers up to 0 V in a known output impedance state and remains in this state until a valid write to the device takes place. The part provides a disable feature that places the output in a defined load state. The part provides an output clamp feature that places the output in a defined load state.
1
Protected by U.S. Patent No. 7,884,747.
Rev. B
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her 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.
DD
+ 2.5 V
SS

PRODUCT HIGHLIGHTS

1. 20-bit resolution.
2. Wide power supply range of up to ±16.5 V.
3. −40°C to +125°C operating temperature range.
4. Low 8 nV/√Hz noise.
5. Low ±0.018 ppm/°C gain error temperature coefficient.

COMPANION PRODUCTS

Output Amplifier Buffer: AD8675, ADA4898-1, ADA4004-1 External Reference: ADR445 DC-to-DC Design Tool: ADIsimPower Additional companion products on the AD5790 product page
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 ©2011-2012 Analog Devices, Inc. All rights reserved.
AD5790 Data Sheet

TABLE OF CONTENTS

Features.............................................................................................. 1
Applications....................................................................................... 1
Functional Block Diagram ..............................................................1
General Description......................................................................... 1
Product Highlights........................................................................... 1
Companion Products....................................................................... 1
Revision History ...............................................................................2
Specifications..................................................................................... 3
Timing Characteristics ................................................................ 5
Absolute Maximum Ratings............................................................ 8
ESD Caution.................................................................................. 8
Pin Configuration and Function Descriptions............................. 9
Typical Performance Characteristics........................................... 10
Terminology.................................................................................... 18
Theory of Operation ......................................................................19
DAC Architecture....................................................................... 19
Serial Interface............................................................................ 19
Standalone Operation................................................................ 20
Hardware Control Pins.............................................................. 20
On-Chip Registers...................................................................... 21
AD5790 Features............................................................................ 24
Power-On to 0 V......................................................................... 24
Configuring the AD5790 .......................................................... 24
DAC Output State ...................................................................... 24
Output Amplifier Configuration.............................................. 24
Applications Information.............................................................. 26
Typical Operating Circuit ......................................................... 26
Evaluation Board........................................................................ 27
Outline Dimensions....................................................................... 28
Ordering Guide .......................................................................... 28

REVISION HISTORY

2/12—Rev. A to Rev. B
Deleted Linearity Compensation Section ................................... 24
12/11—Rev. 0 to Rev. A
Changes to Table 1............................................................................ 1
Changes to Table 2............................................................................ 4
Changes to Figure 48...................................................................... 17
Changes to DAC Register Section................................................ 21
Changes to Table 11........................................................................ 22
Updated Outline Dimensions....................................................... 28
11/11—Revision 0: Initial Version
Rev. B | Page 2 of 28
Data Sheet AD5790

SPECIFICATIONS

VDD = 12.5 V to 16.5 V, VSS = −16.5 V to −12.5 V, V R
= unloaded, CL = unloaded, T
L
MIN
to T
, unless otherwise noted.
MAX
= 10 V, V
REFP
= −10 V, VCC = 2.7 V to +5.5 V, IOVCC = 1.71 V to 5.5 V,
REFN
Table 2.
B Version Parameter Min Typ Max Unit Test Conditions/Comments
STATIC PERFORMANCE2
Resolution 20 Bits Integral Nonlinearity Error (Relative
−2 ±1.2 +2 LSB V
Accuracy)
−3 ±1.2 +3 LSB V
−4 ±1.2 +4 LSB V Differential Nonlinearity Error −1 +2 LSB V
−1 +3 LSB V Long-Term Linearity Error Stability3 0.1 LSB After 750 hours at TA = 135°C Full-Scale Error −12 ±3.8 +12 LSB V
−22 ±2.7 +22 LSB V
−40 ±1.8 +40 LSB V
−9 ±3.8 +9 LSB V
−12 ±2.7 +12 LSB V
−22 ±1.8 +22 LSB V Full-Scale Error Temperature Coefficient ±0.026 ppm/°C V Zero-Scale Error −19 ±1.3 +19 LSB V
−40 ±0.7 +40 LSB V
−82 ±0.9 +82 LSB V
−8 ±1.3 +8 LSB V
−13 ±0.7 +13 LSB V
−22 ±0.9 +22 LSB V Zero-Scale Error Temperature Coefficient ±0.025 ppm/°C V Gain Error −19 ±2.3 +19 ppm FSR V
−35 ±1.9 +35 ppm FSR V
−68 ±0.9 +68 ppm FSR V
−9 ±2.3 +9 ppm FSR V
−15 ±2.9 +15 ppm FSR V
−22 ±0.9 +22 ppm FSR V Gain Error Temperature Coefficient ±0.018 ppm/°C V R1, RFB Matching 0.015 %
OUTPUT CHARACTERISTICS
Output Voltage Range V
V
REFN
Output Voltage Settling Time 2.5 μs 10 V step to 0.02%, using the ADA4898-1 buffer
3.5 μs 500 code step to ±1 LSB4 Output Noise Spectral Density 8 nV/√Hz At 1 kHz, DAC code = midscale 8 nV/√Hz At 10 kHz, DAC code = midscale Output Voltage Noise 1.1 μV p-p DAC code = midscale, 0.1 Hz to 10 Hz bandwidth Midscale Glitch Impulse4
14 nV-sec V
3.5 nV-sec V 4 nV-sec V MSB Segment Glitch Impulse4
14 nV-sec
3.5 nV-sec 4 nV-sec
1
V
REFP
= +10 V, V
REFP
= +10 V, V
REFP
= ±10 V, +10 V, and +5 V
REFx
= +10 V, V
REFP
= ±10 V, +10 V, and +5 V
REFx
= +10 V, V
REFP
= 10 V, V
REFP
= 5 V, V
REFP
= +10 V, V
REFP
= 10 V, V
REFP
= 5 V, V
REFP
= +10 V, V
REFP
= +10 V, V
REFP
= 10 V, V
REFP
= 5 V, V
REFP
= +10 V, V
REFP
= 10 V, V
REFP
= 5 V, V
REFP
= +10 V, V
REFP
= +10 V, V
REFP
= 10 V, V
REFP
= 5 V, V
REFP
= +10 V, V
REFP
= 10 V, V
REFP
= 5 V, V
REFP
= +10 V, V
REFP
= −10 V, TA = 0°C to 105°C
REFN
= −10 V, TA =−40°C to +105°C
REFN
= −10 V, TA = 0°C to 105°C
REFN
= −10 V
REFN
= 0 V
REFN
= 0 V
REFN
= −10 V, TA = 0°C to 105°C
REFN
= 0 V, TA = 0°C to 105°C
REFN
= 0 V, TA = 0°C to 105°C
REFN
= −10 V
REFN
= −10 V
REFN
= 0 V
REFN
= 0 V
REFN
= −10 V, TA = 0°C to 105°C
REFN
= 0 V, TA = 0°C to 105°C
REFN
= 0 V, TA = 0°C to 105°C
REFN
= −10 V
REFN
= −10 V
REFN
= 0 V
REFN
= 0 V
REFN
= −10 V, TA = 0°C to 105°C
REFN
= 0 V, TA = 0°C to 105°C
REFN
= 0 V, TA = 0°C to 105°C
REFN
= −10 V
REFN
in unity-gain mode
REFP
REFP
REFP
V
REFP
V
REFP
V
REFP
= +10 V, V = 10 V, V = 5 V, V
= +10 V, V
= 10 V, V = 5 V, V
= −10 V
REFN
= 0 V
REFN
= 0 V
REFN
= −10 V, see Figure 43
REFN
= 0 V, see Figure 44
REFN
= 0 V, see Figure 45
REFN
Rev. B | Page 3 of 28
AD5790 Data Sheet
B Version
1
Parameter Min Typ Max Unit Test Conditions/Comments
Output Enabled Glitch Impulse 57 nV-sec On removal of output ground clamp
Digital Feedthrough 0.27 nV-sec
DC Output Impedance (Normal Mode) 3.4
DC Output Impedance (Output
6
Clamped to Ground)
REFERENCE INPUTS
V
Input Range 5 VDD − 2.5 V
REFP
V
Input Range VSS + 2.5 0 V
REFN
Input Bias Current −20 −0.63 +20 nA
−4 −0.63 +4 TA = 0°C to 105°C
Input Capacitance 1 pF V
REFP
, V
REFN
LOGIC INPUTS
Input Current5 −1 +1 μA
Input Low Voltage, VIL 0.3 × IOVCC V IOVCC = 1.71 V to 5.5 V
Input High Voltage, VIH 0.7 × IOVCC V IOVCC = 1.71 V to 5.5 V
Pin Capacitance 5 pF LOGIC OUTPUT (SDO)
Output Low Voltage, VOL 0.4 V IOVCC = 1.71 V to 5.5 V, sinking 1 mA
Output High Voltage, VOH IOVCC − 0.5 V IOVCC = 1.71 V to 5.5 V, sourcing 1 mA
High Impedance Leakage Current ±1 μA
High Impedance Output Capacitance 3 pF POWER REQUIREMENTS All digital inputs at DGND or IOVCC
VDD 7.5 VSS + 33 V
VSS V
− 33 −2.5 V
DD
VCC 2.7 5.5 V
IOVCC 1.71 5.5 V IOVCC ≤ VCC
IDD 10.3 14 mA
ISS −10 −14 mA
ICC 600 900 μA
IOICC 52 140 μA SDO disabled
DC Power Supply Rejection Ratio ±7.5 μV/V ∆VDD ± 10%, V
= −15 V
SS
±1.5 μV/V ∆VSS ± 10%, VDD = 15 V
AC Power Supply Rejection Ratio 90 dB ∆VDD ± 200 mV, 50 Hz/60 Hz, V
= −15 V
SS
90 dB ∆VSS ± 200 mV, 50 Hz/60 Hz, VDD = 15 V
1
Temperature range: −40°C to +125°C, typical conditions: TA = +25°C, VDD = +15 V, VSS = −15 V, V
2
Performance characterized with the AD8675ARZ output buffer.
3
Linearity error refers to both INL error and DNL error, either parameter can be expected to drift by the amount specified after the length of time specified.
4
The AD5790 is configured in unity-gain mode with a low-pass RC filter on the output. R = 300 Ω, C = 143 pF (total capacitance seen by the output buffer, lead
capacitance, and so forth).
5
Current flowing in an individual logic pin.
= +10 V, V
REFP
= −10 V.
REFN
Rev. B | Page 4 of 28
Data Sheet AD5790

TIMING CHARACTERISTICS

VCC = 2.7 V to 5.5 V; all specifications T
Table 3.
Parameter
2
t
40 28 ns min SCLK cycle time
1
IOV
= 1.71 V to 3.3 V IOVCC = 3.3 V to 5.5 V
CC
92 60 ns min SCLK cycle time (readback and daisy-chain modes) t2 15 10 ns min SCLK high time t3 9 5 ns min SCLK low time t4 5 5 ns min
t5 2 2 ns min t6 48 40 ns min t7 8 6 ns min t8 9 7 ns min Data setup time t9 12 7 ns min Data hold time t10 13 10 ns min t11 20 16 ns min t12 14 11 ns min t13 130 130 ns typ t14 130 130 ns typ t15 50 50 ns min t16 140 140 ns typ t17 0 0 ns min t18 65 60 ns max t19 62 45 ns max SCLK rising edge to SDO valid (CL = 50 pF) t20 0 0 ns min t21 35 35 ns typ t22 150 150 ns typ
1
All input signals are specified with tR = tF = 1 ns/V (10% to 90% of IOVCC) and timed from a voltage level of (VIL + VIH)/2.
2
Maximum SCLK frequency is 35 MHz for write mode and 16 MHz for readback and daisy-chain modes.
MIN
Limit1
to T
, unless otherwise noted.
MAX
Unit Test Conditions/Comments
to SCLK falling edge setup time
SYNC SCLK falling edge to SYNC Minimum SYNC
rising edge to next SCLK falling edge ignore
SYNC
falling edge to SYNC falling edge
LDAC
rising edge to LDAC falling edge
SYNC
pulse width low
LDAC
falling edge to output response time
LDAC
rising edge to output response time (LDAC tied low)
SYNC
pulse width low
CLR
pulse activation time
CLR
falling edge to first SCLK rising edge
SYNC
rising edge to SDO tristate (CL = 50 pF)
SYNC
rising edge to SCLK rising edge ignore
SYNC
pulse width low
RESET
pulse activation time
RESET
high time
rising edge hold time
Rev. B | Page 5 of 28
AD5790 Data Sheet
t
1
t
7
SCLK
SYNC
SDIN
LDAC
V
OUT
V
OUT
CLR
V
OUT
t
6
t
4
t
8
DB23 DB0
t
10
t
16
t
3
t
9
t
15
2421
t
2
t
5
t
t
11
t
14
12
t
13
SCLK
SYNC
SDIN
SDO
RESET
V
OUT
t
21
t
22
t
17
t
6
t
4
t
8
DB23 DB0
INPUT WORD SPECIFIES
REGISTE R TO BE READ
t
3
t
9
Figure 2. Write Mode Timing Diagram
t
1
t
2
t
7
t
t
5
17
DB23 DB0
REGISTE R CONTENTS CLOCKED OUT
Figure 3. Readback Mode Timing Diagram
NOP CONDI TION
10239-002
t
20
24221241
t
5
t
t
19
18
10239-003
Rev. B | Page 6 of 28
Data Sheet AD5790
t
20
t
5
t
18
10239-004
SCLK
SYNC
SDIN
SDO
t
t
17
12 24 4825
t
6
t
4
t
8
DB23
INPUT WORD FOR DAC N
DB23
t
3
t
9
UNDEFINED
1
26
t
2
DB0 DB23 DB0
INPUTWORDFORDACN–1
t
19
DB0 DB23 DB0
INPUT WORD FOR DAC N
Figure 4. Daisy-Chain Mode Timing Diagram
Rev. B | Page 7 of 28
AD5790 Data Sheet

ABSOLUTE MAXIMUM RATINGS

TA = 25°C, unless otherwise noted. Transient currents of up to 100 mA do not cause SCR latch-up.
Table 4.
Parameter Rating
VDD to AGND −0.3 V to +34 V VSS to AGND −34 V to +0.3 V VDD to VSS −0.3 V to +34 V VCC to DGND −0.3 V to +7 V IOVCC to DGND
−0.3 V to V
+ 3 V or +7 V
CC
(whichever is less)
Digital Inputs to DGND
−0.3 V to IOV
+ 0.3 V or
CC
+7 V (whichever is less)
V
to AGND −0.3 V to VDD + 0.3 V
OUT
V
to AGND −0.3 V to VDD + 0.3 V
REFP
V
to AGND VSS − 0.3 V to + 0.3 V
REFN
DGND to AGND −0.3 V to +0.3 V Operating Temperature Range, TA
Industrial −40°C to +125°C Storage Temperature Range −65°C to +150°C Maximum Junction Temperature,
max
T
J
150°C
Power Dissipation (TJ max − TA)/θJA LFCSP Package
θJA Thermal Impedance 31.0°C/W Lead Temperature JEDEC industry standard
Soldering J-STD-020 ESD (Human Body Model) 1.6 kV
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.
This device is a high performance integrated circuit with an ESD rating of <1.6 kV, and it is ESD sensitive. Proper precautions must be taken for handling and assembly.

ESD CAUTION

Rev. B | Page 8 of 28
Data Sheet AD5790

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

DNC
23
DNC
22
DNC
21
FB
R
20
INV
24
V
1
OUT
V
2
REFP
V
3
DD
RESET
V
DD
CLR
LDAC
NOTES
DO NOT CONNECT. DO NOT CONNECT TO
1. DNC =
2. NEGATIVE ANALOG S A VOLTAGE IN THE RANG
CAN BE CONNECTED. V
AGND. THE PADDLE CAN BE LEFT ELE
TO UNCONNECTED P
CONNECTION IS MADE AT TH
OMMENDED THAT THE PADDLE BE THER
REC CONNECTE THERMAL PERFORMANCE.
D TO A C
AD5790
4
TOP VIEW
5
(Not to Scale)
6 7
9
8
10
CCVCC
DNC
IOV
UPPLY CONNECTION (V
E OF –16.5 V TO –2.5 V
SHOULD BE
SS
ROVIDED THAT A SUP
E VSS PINS. IT IS
OPPER PLANE FOR ENHANCED
11
SDO
19 18 17 16 15 14 13
12
SDIN
DECOUPLED
PLY
AGND V
SS
V
SS
V
REFN
DGND SYNC SCLK
THIS PIN.
).
SS
CTRICALLY
MALLY
10239-005
Figure 5. Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic Description
1 V 2 V 3, 5 VDD Positive Analog Supply Connection. A voltage in the range of 7.5 V to 16.5 V can be connected. VDD must be
4 6
7
8 VCC Digital Supply. Voltage range is from 2.7 V to 5.5 V. VCC should be decoupled to DGND. 9 IOVCC Digital Interface Supply. Digital threshold levels are referenced to the voltage applied to this pin. Voltage range is
10, 21, 22, 23 DNC Do Not Connect. Do not connect to these pins. 11 SDO Serial Data Output. 12 SDIN Serial Data Input. This device has a 24-bit input shift register. Data is clocked into the register on the falling edge
13 SCLK Serial Clock Input. Data is clocked into the input shift register on the falling edge of the serial clock input. Data
14
15 DGND Ground Reference Pin for Digital Circuitry. 16 V 17, 18 VSS Negative Analog Supply Connection. A voltage in the range of −16.5 V to −2.5 V can be connected. VSS must be
19 AGND Ground Reference Pin for Analog Circuitry. 20 RFB 24 INV EPAD VSS Negative Analog Supply Connection (VSS). A voltage in the range of −16.5 V to −2.5 V can be connected. VSS must
Analog Output Voltage.
OUT
Positive Reference Voltage Input. A voltage in the range of 5 V to VDD − 2.5 V can be connected.
REFP
decoupled to AGND. RESET CLR
Active Low Reset. Asserting this pin returns the
AD5790 to its power-on status.
Active Low Input. Asserting this pin sets the DAC register to a user defined value (see
DAC output. The output value depends on the DAC register coding that is being used, either binary or twos
complement. LDAC
Active Low Load DAC Logic Input. This is used to update the DAC register and, consequently, the analog output.
When tied permanently low, the output is updated on the rising edge of
SYNC
. If
LDAC write cycle, the input register is updated, but the output update is held off until the falling edge of LDAC
pin should not be left unconnected.
from 1.71 V to 5.5 V
of the serial clock input.
can be transferred at rates of up to 35 MHz.
SYNC
Negative Reference Voltage Input.
REFN
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 then transferred in on the falling edges of the
following clocks. The DAC is updated on the rising edge of
SYNC
.
decoupled to AGND.
Feedback Connection for External Amplifier. See the Inverting Input Connection for External Amplifier. See the
AD5790 Features section for further details.
AD5790 Features section for further details.
be decoupled to AGND. The paddle can be left electrically unconnected provided that a supply connection is made at the V
pins. It is recommended that the paddle be thermally connected to a copper plane for enhanced
SS
thermal performance.
Table 12) and updates the
is held high during the
LDAC
. The
Rev. B | Page 9 of 28
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