AD5420 [ADI]
Single Channel, 16-Bit, Serial Input, Current Source DAC; 单通道， 16位，串行输入，电流源DAC
| 型号： | AD5420 |
| 厂家： | 
ADI |
| 描述： | Single Channel, 16-Bit, Serial Input, Current Source DAC |
| 文件： | 总29页 (文件大小：277K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Single Channel, 16-Bit, Serial Input,
Current Source DAC
Preliminary Technical Data
AD5420
FEATURES
GENERAL DESCRIPTION
The AD5420 is a low-cost, precision, fully integrated 16-bit
converter offering a programmable current source output
designed to meet the requirements of industrial process control
applications.
16-Bit Resolution and Monotonicity
Current Output Ranges: 4–20mA, 0–20mA or 0–24mA
0.1% typ Total Unadjusted Error (TUE)
5ppm/°C Output Drift
The output current range is programmable to 4mA to 20 mA,
0mA to 20mA or an over range function of 0mA to 24mA.
The output is open circuit protected and can drive inductive
loads of 1H. The device is specified to operate with a power
supply range from 10.8 V to 40V (AD5420BREZ) or 10.8V to
60V (AD5420BCPZ). Output loop compliance is 0 V to AVDD
– 2.5 V.
Flexible Serial Digital Interface
On-Chip Output Fault Detection
On-Chip Reference (10 ppm/°C Max)
Asynchronous CLEAR Function
Power Supply (AVDD) Range
10.8V to 60 V; AD5420BCPZ
The flexible serial interface is SPI and MICROWIRE
compatible and can be operated in 3-wire mode to minimize the
digital isolation required in isolated applications.
The device also includes a power-on-reset function ensuring
that the device powers up in a known state and an
asynchronous CLEAR pin which sets the output to the low end
of the selected current range.
10.8V to 40V; AD5420BREZ
Output Loop Compliance to AVDD – 2.5 V
Temperature Range: -40°C to +85°C
TSSOP and LFCSP Packages
APPLICATIONS
Process Control
Actuator Control
PLC
The total output error is typically ±0.1% FSR.
Table 1. Related Devices
Part Number
Description
AD5422
Single Channel, 16-Bit, Serial
Input Current Source and
Voltage Output DAC
AD5412
AD5410
Single Channel, 12-Bit, Serial
Input Current Source and
Voltage Output DAC
Single Channel, 12-Bit, Serial
Input Current Source DAC
Rev. PrD
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 registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2007 Analog Devices, Inc. All rights reserved.
AD5420
Preliminary Technical Data
TABLE OF CONTENTS
Features .............................................................................................. 1
RESET register............................................................................ 22
Status register.............................................................................. 22
Features............................................................................................ 23
fault alert...................................................................................... 23
Asynchronous Clear (CLEAR)................................................. 23
Internal Reference ...................................................................... 23
External current setting resistor............................................... 23
Digital Power Supply.................................................................. 23
External boost function............................................................. 23
digital Slew rate control............................................................. 24
IOUT Filtering Capacitors............................................................ 24
Applications Information.............................................................. 25
driving inductive loads.............................................................. 25
Transient voltage protection ..................................................... 25
Layout Guidelines....................................................................... 25
Galvanically Isolated Interface ................................................. 25
Microprocessor Interfacing....................................................... 25
Thermal and supply considerations......................................... 26
Outline Dimensions....................................................................... 27
Ordering Guide .......................................................................... 27
Applications....................................................................................... 1
General Description......................................................................... 1
Revision History ............................................................................... 2
Functional Block Diagram .............................................................. 3
Specifications..................................................................................... 4
AC Performance Characteristics................................................ 6
Timing Characteristics ................................................................ 7
Absolute Maximum Ratings............................................................ 9
ESD Caution.................................................................................. 9
Pin Configuration and Function Descriptions........................... 10
Typical Performance Characteristics ........................................... 12
Terminology .................................................................................... 17
Theory of Operation ...................................................................... 18
Architecture................................................................................. 18
Serial Interface ............................................................................ 18
Default configuration................................................................. 21
Transfer Function....................................................................... 21
Data Register............................................................................... 21
Control Register.......................................................................... 21
REVISION HISTORY
PrD – Preliminary Version.
Rev. PrD | Page 2 of 29
Preliminary Technical Data
FUNCTIONAL BLOCK DIAGRAM
DVCC
AD5420
DVCC
CAP1
CAP2
AVDD
SELECT
AD5420
R2
R3
BOOST
CLEAR
INPUT SHIFT
REGISTER
AND
CONTROL
LOGIC
LATCH
SCLK
SDIN
16
/
16-BIT
DAC
I
OUT
SDO
FAULT
R
SET
R1
POWER
ON
VREF
RESET
DGND*
REFIN
AGND
REFOUT
*LFCSP Package
Figure 1.
Rev. PrD | Page 3 of 29
AD5420
Preliminary Technical Data
SPECIFICATIONS
AVDD = 10.8V to 40V/60V1, AGND = DGND = 0 V, REFIN= +5 V external; DVCC = 2.7 V to 5.5 V, RL = 300Ω, HL = 50mH;
all specifications TMIN to TMAX, 0 to 24 mA range unless otherwise noted.
Table 2.
Parameter
Value2
0 to 24
0 to 20
4 to 20
Unit
mA
mA
mA
Test Conditions/Comments
Output Current Ranges
ACCURACY
Resolution
16
Bits
Total Unadjusted Error (TUE)
TUE TC3
Relative Accuracy (INL)
Differential Nonlinearity (DNL)
Offset Error
±0.3
±5
±0.012
±1
±0.05
±5
±0.02
% FSR max
ppm/°C typ
% FSR max
LSB max
% FSR max
µv/°C typ
% FSR max
Over temperature, supplies, and time, typically 0.1% FSR
Guaranteed monotonic
Offset Error Drift
Gain Error
@ 25°C, error at other temperatures obtained using gain
TC
Gain TC3
Full-Scale Error
±±
0.05
ppm FSR/°C max
% FSR max
@ 25°C, error at other temperatures obtained using gain
TC
Full-Scale TC3
±±
ppm FSR/°C
OUTPUT CHARACTERISTICS3
Current Loop Compliance Voltage
Output Current Drift vs. Time
AVDD - 2.5
V max
TBD
TBD
TBD
1
ppm FSR/500 hr typ
ppm FSR/1000 hr typ
Ω max
Resistive Load
Inductive Load
H max
DC PSRR
10
µA/V max
Output Impedance
REFERENCE INPUT/OUTPUT
Reference Input3
50
MΩ typ
Reference Input Voltage
DC Input Impedance
Reference Range
5
30
4 to 5
V nom
kΩ min
V min to V max
±1% for specified performance
Typically 40 kΩ
Reference Output
Output Voltage
Reference TC
Output Noise (0.1 Hz to 10 Hz)3
Noise Spectral Density3
Output Voltage Drift vs. Time3
4.99± to 5.002
±10
1±
120
±40
±50
TBD
5
V min to V max
ppm/°C max
µV p-p typ
nV/√Hz typ
ppm/500 hr typ
ppm/1000 hr typ
nF max
@ 25°C
@ 10 kHz
Capacitive Load
Load Current
mA typ
Short Circuit Current
Line Regulation3
7
10
TBD
TBD
mA typ
ppm/V typ
ppm/mA
Load Regulation3
Thermal Hysteresis3
DIGITAL INPUTS3
VIH, Input High Voltage
VIL, Input Low Voltage
Input Current
ppm
DVCC = 2.7 V to 5.5 V, JEDEC compliant
2
V min
0.±
±1
10
V max
µA max
pF typ
Per pin
Per pin
Pin Capacitance
Rev. PrD | Page 4 of 29
Preliminary Technical Data
AD5420
Parameter
Value2
Unit
Test Conditions/Comments
DIGITAL OUTPUTS 3
SDO
VOL, Output Low Voltage
VOH, Output High Voltage
High Impedance Leakage
Current
0.4
DVCC − 0.5
±1
V max
V min
µA max
sinking 200 µA
sourcing 200 µA
High Impedance Output
Capacitance
5
pF typ
FAULT
VOL, Output Low Voltage
VOL, Output Low Voltage
VOH, Output High Voltage
0.4
0.6
3.6
V max
V typ
V min
10kΩ pull-up resistor to DVCC
@ 2.5 mA
10kΩ pull-up resistor to DVCC
POWER REQUIREMENTS
AVDD
10.± to 60
10.± to 40
V min to V max
V min to V max
AD5420BCPZ
AD5420BREZ
DVCC
Input Voltage
Output Voltage
Output Load Current
Short Circuit Current
AIDD
2.7 to 5.5
4.5
5
20
TBD
1
TBD
TBD
TBD
V min to V max
V typ
mA typ
mA typ
mA
mA max
mW typ
mW typ
mW typ
Internal supply disabled
DVCC can be overdriven up to 5.5V
DICC
VIH = DVCC, VIL = GND, TBD mA typ
AVDD = 40V
AVDD = 60V
Power Dissipation
AVDD = 15V
1 Maximum supply for the AD5420BREZ is 40V, Maximum supply for the AD5420BCPZ is 60V
2 Temperature range: -40°C to +±5°C; typical at +25°C.
3 Guaranteed by design and characterization, not production tested.
Rev. PrD | Page 5 of 29
AD5420
Preliminary Technical Data
AC PERFORMANCE CHARACTERISTICS
AVDD = 10.8V to 40V/60V1, AGND = DGND = 0 V, REFIN= +5 V external; DVCC = 2.7 V to 5.5 V, RL = 300Ω, HL = 50mH;
all specifications TMIN to TMAX, 0 to 24 mA range unless otherwise noted.
Table 3.
Parameter2
Unit
Test Conditions/Comments
DYNAMIC PERFORMANCE
Output Current Settling Time
TBD
TBD
µs typ
µs typ
To 0.1% FSR , L = 1H
To 0.1% FSR , L < 1mH
1 Maximum supply for the AD5420BREZ is 40V, Maximum supply for the AD5420BCPZ is 60V
2 Guaranteed by design and characterization, not production tested.
Rev. PrD | Page 6 of 29
Preliminary Technical Data
AD5420
TIMING CHARACTERISTICS
AVDD = 10.8V to 40V/60V1, AGND = DGND = 0 V, REFIN= +5 V external; DVCC = 2.7 V to 5.5 V, RL = 300Ω, HL = 50mH;
all specifications TMIN to TMAX, 0 to 24 mA range unless otherwise noted.
Table 4.
Parameter2, 3, 4
Limit at TMIN, TMAX
Unit
Description
Write Mode
t1
t2
t3
t4
t5
t5
t6
t7
33
13
13
13
40
5
5
5
40
20
5
ns min
ns min
ns min
ns min
ns min
µs min
ns min
ns min
ns min
ns min
µs max
SCLK cycle time
SCLK low time
SCLK high time
LATCH delay time
LATCH high time
LATCH high time (After a write to the CONTROL register)
Data setup time
Data hold time
LATCH low time
t±
t9
t10
CLEAR pulsewidth
CLEAR activation time
Readback Mode
t11
t12
t13
t14
t15
t16
t17
t1±
±2
33
33
13
40
5
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns max
ns max
SCLK cycle time
SCLK low time
SCLK high time
LATCH delay time
LATCH high time
Data setup time
Data hold time
LATCH low time
5
40
40
33
t19
t20
Serial output delay time (CL SDO5 = 15pF)
LATCH rising edge to SDO tri-state
Daisychain Mode
t21
t22
t23
t24
t25
t26
t27
t2±
t29
±2
33
33
13
40
5
5
40
40
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns max
SCLK cycle time
SCLK low time
SCLK high time
LATCH delay time
LATCH high time
Data setup time
Data hold time
LATCH low time
Serial output delay time (CL SDO5 = 15pF)
1 Maximum supply for the AD5420BREZ is 40V, Maximum supply for the AD5420BCPZ is 60V
2 Guaranteed by characterization. Not production tested.
3 All input signals are specified with tR = tF = 5 ns (10% to 90% of DVCC) and timed from a voltage level of 1.2 V.
4 See Figure 2, Figure 3, and Figure 4.
5 CL SDO = Capacitive load on SDO output.
Rev. PrD | Page 7 of 29
AD5420
Preliminary Technical Data
t1
SCLK
1
2
24
t3
t2
t4
t5
LATCH
t7
t8
t6
SDIN
DB23
DB0
t9
CLEAR
t10
OUTPUT
Figure 2. Write Mode Timing Diagram
t11
2
1
9
23
SCLK
1
2
24
22
24
8
t13
t12
t14
t15
LATCH
SDIN
t17
t18
t16
DB23
DB0
DB23
DB0
NOP CONDITION
INPUT WORD SPECIFIES
REGISTER TO BE READ
t20
t19
SDO
X
X
X
X
DB15
DB0
UNDEFINED DATA
FIRST 8 BITS ARE
DON’T CARE BITS
SELECTED REGISTER
DATA CLOCKED OUT
Figure 3. Readback Mode Timing Diagram
t21
26
48
25
SCLK
1
2
24
t23
t22
t24
t25
LATCH
SDIN
t27
t28
t26
DB23
DB0
DB23
DB0
INPUT WORD FOR DAC N
UNDEFINED
INPUT WORD FOR DAC N-1
t29
DB23
DB0
SDO
DB23
DB0
INPUT WORD FOR DAC N
Figure 4. Daisychain Mode Timing Diagram
Rev. PrD | Page ± of 29
Preliminary Technical Data
ABSOLUTE MAXIMUM RATINGS
AD5420
TA = 25°C unless otherwise noted.
Transient currents of up to 100 mA do not cause SCR latch-up.
Table 5.
Parameter
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.
Rating
AVDD to AGND, DGND
DVCC to AGND, DGND
Digital Inputs to AGND, DGND
−0.3V to 60V
−0.3 V to +7 V
−0.3 V to DVCC + 0.3 V or 7 V
(whichever is less)
−0.3 V to DVCC + 0.3 V or 7V
(whichever is less)
−0.3 V to +7 V
−0.3V to AVDD
-0.3V to +0.3V
Digital Outputs to AGND, DGND
ESD CAUTION
REFIN/REFOUT to AGND, DGND
IOUT to AGND, DGND
AGND to DGND
Operating Temperature Range
Industrial
−40°C to +±51°C
−65°C to +150°C
125°C
Storage Temperature Range
Junction Temperature (TJ max)
24-Lead TSSOP Package
θJA Thermal Impedance
40-Lead LFCSP Package
θJA Thermal Impedance
Power Dissipation
42°C/W
1 Power dissipated on chip must be de-rated to keep junction temperature
below 125°C. Assumption is max power dissipation condition is sourcing
24mA into Ground from AVDD with a 3mA on-chip current.
2±°C/W
(TJ max – TA)/ θJA
JEDEC Industry Standard
J-STD-020
Lead Temperature
Soldering
Rev. PrD | Page 9 of 29
Preliminary Technical Data
AD5420
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
AV
NC
NC
GND
1
2
3
4
5
6
7
8
9
24
23
22
DD
40 39 38 37 36 35 34 33 32 31
DV
CC
NC
FAULT
GND
1
2
30
29
28
27
26
25
24
23
22
21
NC
AD5420
FAULT
GND
CAP2
CAP1
21 NC
20 BOOST
3
GND
4
BOOST
GND
TOP VIEW
(Not to Scale)
5
CLEAR
LATCH
SCLK
SDIN
IOUT
I
AD5420
TOP VIEW
(Not to Scale)
19
CLEAR
LATCH
SCLK
SDIN
OUT
6
NC
18 NC
17 NC
7
NC
8
DVCC SELECT
DV
16
SELECT
SDO
9
NC
NC
CC
15 REFIN
14 REFOUT
NC
10
SDO 10
11 12 13 14 15 16 17 18 19 20
11
12
AGND
GND
R
13
SET
Figure 5. TSSOP Pin Configuration
Figure 6. LFCSP Pin Configuration
Table 6. Pin Function Descriptions
TSSOP Pin No. LFCSP Pin No. Mnemonic
Description
1,4,5,12
2
3
3,4,15,14,37
39
2
GND
DVCC
FAULT
These pins must be connected to 0V.
Digital Supply Pin. Voltage ranges from 2.7 V to 5.5 V.
Fault alert, This pin is asserted low when an open circuit is detected in current mode or
an over temperature is detected. Open drain output, must be connected to a pull-up
resistor.
17,1±,21,22, 23 1,10,11,19,
20,21,22,24,25,
NC
No Connection.
30,31,32,33,34,
35,3±,40
6
7
±
5
6
7
CLEAR
LATCH
SCLK
Active High Input. Asserting this pin will set the current output to the bottom of the
selected range.
Positive edge sensitive latch, a rising edge will parallel load the input shift register data
into the DAC register, also updating the output.
Serial Clock Input. Data is clocked into the shift register on the rising edge of SCLK. This
operates at clock speeds up to 30 MHz.
9
10
±
9
SDIN
SDO
Serial Data Input. Data must be valid on the rising edge of SCLK.
Serial Data Output. Used to clock data from the serial register in daisy-chain or readback
mode. Data is clocked out on the falling edge of SCLK. See Figure 3 and Figure 4.
11
N/A
12
13
AGND
DGND
Ground reference pin for analog circuitry.
Ground reference pin for digital circuitry. (AGND and DGND are internally connected in
TSSOP package).
13
16
RSET
An external, precision, low drift 15kΩ current setting resistor can be connected to this
pin to improve the IOUT temperature drift performance. Refer to Features section.
14
15
17
1±
REFOUT
REFIN
Internal Reference Voltage Output. REFOUT = 5 V ± 2 mV.
External Reference Voltage Input. Reference input range is 4 V to 5 V. REFIN = 5 V for
specified performance.
16
23
DVCC
SELECT
This pin when connected to GND disables the internal supply and an external supply
must be connected to the DVCC pin. Leave this pin unconnected to enable the internal
supply. Refer to features section.
19
20
26
27
IOUT
Current output pin.
BOOST
Optional external transistor connection. Connecting an external transistor will reduce
the power dissipated in the AD5420. Refer to the features section.
N/A
N/A
24
2±
29
36
CAP1
CAP2
AVDD
Connection for optional output filtering capacitor. Refer to Features section.
Connection for optional output filtering capacitor. Refer to Features section.
Positive Analog Supply Pin. Voltage ranges from 10.±V to 40V/60V.
Rev. PrD | Page 10 of 29
Preliminary Technical Data
AD5420
TSSOP Pin No. LFCSP Pin No. Mnemonic
Description
Paddle
Paddle
AGND
Ground reference for analog circuitry.
Rev. PrD | Page 11 of 29
AD5420
Preliminary Technical Data
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 7. Integral Non Linearity vs. Code
Figure 8.Differential Non Linearity vs. Code
Figure 9. Total Unadjusted Error vs. Code
Figure 10. Integral Non Linearity vs. Temperature
Figure 11. Differential Non Linearity vs. Temperature
Figure 12. Integral Non Linearity vs. Supply
Rev. PrD | Page 12 of 29
Preliminary Technical Data
AD5420
Figure 13. Differential Non Linearity vs. Supply Voltage
Figure 14. Integral Non Linearity vs. Reference Voltage
Figure 15. Differential Non Linearity vs. Reference Voltage
Figure 16. Total Unadjusted Error vs. Reference Voltage
Figure 17. Total Unadjusted Error vs. Supply Voltage
Figure 18. Offset Error vs. Temperature
Rev. PrD | Page 13 of 29
AD5420
Preliminary Technical Data
Figure 19. Gain Error vs. Temperature
Figure 21. IOUT vs. Time on Power-up
Figure 20. Voltage Compliance vs. Temperature
Figure 22. IOUT vs. Time on Output Enabled
Figure 23. DICC vs.Logic Input Voltage
Figure 24. AIDD vs AVDD
Rev. PrD | Page 14 of 29
Preliminary Technical Data
AD5420
Figure 25. DVCC Output Voltage vs. DICC Load Current
Figure 28. Refout Output Noise (100kHz Bandwidth)
Figure 26. Refout Turn-on Transient
Figure 29. Refout Line Transient
Figure 27. Refout Output Noise (0.1Hz to 10Hz Bandwidth)
Figure 30. Refout Load Transient
Rev. PrD | Page 15 of 29
AD5420
Preliminary Technical Data
Figure 31. Refout Histogram of Thermal Hysteresis
Figure 32. Refout Voltage vs. Load Current
Rev. PrD | Page 16 of 29
Preliminary Technical Data
TERMINOLOGY
AD5420
Total Unadjusted Error
Relative Accuracy or Integral Nonlinearity (INL)
Total unadjusted error (TUE) is a measure of the output error
taking all the various errors into account, namely INL error,
offset error, gain error, and output drift over supplies,
temperature, and time. TUE is expressed in % FSR.
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 endpoints of the DAC transfer
function. A typical INL vs. code plot can be seen in Figure 7
Current Loop Voltage Compliance
The maximum voltage at the IOUT pin for which the output
currnet will be equal to the programmed value.
Differential Nonlinearity (DNL)
Differential nonlinearity (DNL) is the difference between the
measured change and the ideal 1 LSB change between any two
adjacent codes. A specified differential nonlinearity of 1 LSB
maximum ensures monotonicity. This DAC is guaranteed
monotonic by design. A typical DNL vs. code plot can be seen
in Figure 8.
Power Supply Rejection Ratio (PSRR)
PSRR indicates how the output of the DAC is affected by
changes in the power supply voltage.
Reference TC
Monotonicity
Reference TC is a measure of the change in the reference output
voltage with a change in temperature. It is expressed in ppm/°C.
A DAC is monotonic if the output either increases or remains
constant for increasing digital input code. The AD5724R/
AD5734R/AD5754R are monotonic over their full operating
temperature range.
Line Regulation
Line regulation is the change in reference output voltage due to
a specified change in supply voltage. It is expressed in ppm/V.
Full-Scale Error
Load Regulation
Full-Scale error is a measure of the output error when full-scale
code is loaded to the DAC register. Ideally, the output should be
full-scale − 1 LSB. Full-scale error is expressed in percent of
full-scale range (% FSR).
Load regulation is the change in reference output voltage due to
a specified change in load current. It is expressed in ppm/mA.
Thermal Hysteresis
Zero-Scale TC
Thermal hysteresis is the change of reference output voltage
after the device is cycled through temperatures from +25°C to
−40°C to +85°C and back to +25°C. This is a typical value from
a sample of parts put through such a cycle. See Table TBDfor a
histogram of thermal hysteresis.
This is a measure of the change in zero-scale error with a change in
temperature. Zero-scale error TC is expressed in ppm FSR/°C.
Gain Error
This is a measure of the span error of the DAC. It is the
deviation in slope of the DAC transfer characteristic from ideal
expressed in % FSR. A plot of gain error vs. temperature can be
seen in Table TBD
VO _ HYS = VO (25°C) −VO _TC
VO (25°C) −VO _TC
VO _ HYS (ppm) =
×106
Gain TC
VO (25°C)
This is a measure of the change in gain error with changes in
temperature. Gain Error TC is expressed in ppm FSR/°C.
where:
VO(25°C) = VO at 25°C
VO_TC = VO at 25°C after temperature cycle
Rev. PrD | Page 17 of 29
AD5420
Preliminary Technical Data
THEORY OF OPERATION
The AD5420 is a precision digital to current loop output
converter designed to meet the requirements of industrial
process control applications. It provides a high precision, fully
integrated, low cost single-chip solution for generating current
loop outputs. The current ranges available are; 0 to 20mA, 0 to
24mA and 4 to 20mA, The desired output configuration is user
selectable via the CONTROL register.
Reference Buffers
The AD5420 can operate with either an external or internal
reference. The reference input has an input range of 4 V to 5 V,
5 V for specified performance. This input voltage is then buffered
before it is applied to the DAC.
SERIAL INTERFACE
The AD5420 is controlled over a versatile 3-wire serial interface
that operates at clock rates up to 30 MHz. It is compatible with
SPI®, QSPI™, MICROWIRE™, and DSP standards.
ARCHITECTURE
The DAC core architecture of the AD5420 consists of two
matched DAC sections. A simplified circuit diagram is shown
in Figure 33. The 4 MSBs of the 16-bit data word are decoded to
drive 15 switches, E1 to E15. Each of these switches connects 1
of 15 matched resistors to either ground or the reference buffer
output. The remaining 12 bits of the data-word drive switches
S0 to S11 of a 12-bit voltage mode R-2R ladder network.
Input Shift Register
The input shift register is 24 bits wide. Data is loaded into the
device MSB first as a 24-bit word under the control of a serial
clock input, SCLK. Data is clocked in on the rising edge of
SCLK. The input register consists of 8 control bits and 16 data
bits as shown in Table 7. The 24 bit word is unconditionally
latched on the rising edge of LATCH. Data will continue to be
clocked in irrespective of the state of LATCH, on the rising edge
of LATCH the data that is present in the input register will be
latched, in other words the last 24 bits to be clocked in before
the rising edge of LATCH will be the data that is latched. The
timing diagram for this operation is shown in Figure 2.
R
R
V
OUT
2R
2R
S1
2R
S11
2R
E1
2R
E2
2R
2R
S0
E15
V
REF
12-BIT R-2R LADDER
FOUR MSBs DECODED INTO
15 EQUAL SEGMENTS
Figure 33. DAC Ladder Structure
The voltage output from the DAC core is converted to a current
(see diagram, Figure 34) which is then mirrored to the supply
rail so that the application simply sees a current source output
with respect to ground.
AVDD
R2
R3
T2
A2
16-BIT
DAC
T1
A1
I
OUT
R1
Figure 34. Voltage to Current conversion circuitry
Rev. PrD | Page 1± of 29
Preliminary Technical Data
AD5420
Table 7. Input Shift Register Format
MSB
LSB
D22 D21 D20 D19 D1± D17 D16 D15 D14 D13 D12 D11 D10 D9 D± D7 D6 D5 D4 D3 D2 D1 D0
ADDRESS WORD DATA WORD
D23
AD5420*
CONTROLLER
Table 8. Control Word Functions
Address
Word
Function
DATA OUT
SERIAL CLOCK
CONTROL OUT
SDIN
SCLK
00000000
00000001
00000010
No Operation (NOP)
DATA Register
Readback register value as per Read Address
(See Table 10)
LATCH
DATA IN
SDO
01010101
01010110
CONTROL Register
RESET Register
SDIN
AD5420*
Standalone Operation
The serial interface works with both a continuous and noncon-
tinuous serial clock. A continuous SCLK source can only be
used if LATCH is taken high after the correct number of data
bits have been clocked in. In gated clock mode, a burst clock
containing the exact number of clock cycles must be used, and
LATCH must be taken high after the final clock to latch the
data. The first rising edge of SCLK that clocks in the MSB of the
dataword marks the beginning ot the write cycle. Exactly 24
rising clock edges must be applied to SCLK before LATCH is
brought high. If LATCH is brought high before the 24th rising
SCLK edge, the data written will be invalid. If more than 24
rising SCLK edges are applied before LATCH is brought high,
the input data will also be invalid.
SCLK
LATCH
SDO
SDIN
AD5420*
SCLK
LATCH
SDO
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 35. Daisy Chaining the AD5420
Rev. PrD | Page 19 of 29
AD5420
Preliminary Technical Data
Daisy-Chain Operation
mode, a burst clock containing the exact number of clock cycles
must be used, and LATCH must be taken high after the final
clock to latch the data. See Figure 4 for a timing diagram.
For systems that contain several devices, the SDO pin can be
used to daisy chain several devices together as shown in Figure
35. This daisy-chain mode can be useful in system diagnostics
and in reducing the number of serial interface lines. Daisychain
mode is enabled by setting the DCEN bit of the CONTROL 1
register. The first rising edge of SCLK that clocks in the MSB of
the dataword marks the beginning of the write cycle. SCLK is
continuously applied to the input shift register. If more than 24
clock pulses are applied, the data ripples out of the shift register
and appears on the SDO line. This data is clocked out on the
falling edge of SCLK and is valid on the next rising edge. By
connecting the SDO of the first device to the SDIN input of the
next device in the chain, a multidevice interface is constructed.
Each device in the system requires 24 clock pulses. Therefore,
the total number of clock cycles must equal 24 × N, where N is
the total number of AD5420 devices in the chain. When the
serial transfer to all devices is complete, LATCH is taken high.
This latches the input data in each device in the daisy chain.
The serial clock can be a continuous or a gated clock.
Readback Operation
Readback mode is invoked by setting the control word and read
address as shown in Table 9 and Table 10 when writing to the
input register. The next write to the AD5420 should be a NOP
command which will clock out the data from the previously
addressed register as shown in Figure 3.
By default the SDO pin is disabled, after having addressed the
AD5420 for a read operation, a rising edge on LATCH will
enable the SDO pin in anticipation of data being clocked out,
after the data has been clocked out on SDO, a rising edge on
LATCH will disable (tri-state) the SDO pin once again.
To read back the data register for example, the following
sequence should be implemented:
1. Write 0x020001 to the AD5420 input register. This
configures the part for read mode with the data register
selected.
2. Follow this with a second write, a NOP condition, 0x000000
During this write, the data from the register is clocked out
on the SDO line.
A continuous SCLK source can only be used if LATCH is taken
high after the correct number of clock cycles. In gated clock
Table 9. Input Shift Register Contents for a read operation
MSB
LSB
D23
D22
D21
D20
D19
D18
D17
D16
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Read
Address
0
0
0
0
0
0
1
0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Table 10. Read Address Decoding
Read Address
Function
00
01
10
Read Status Register
Read Data Register
Read Control Register
Rev. PrD | Page 20 of 29
Preliminary Technical Data
AD5420
DEFAULT CONFIGURATION
On initial power-up of the AD5420, the power-on-reset circuit
ensures that all registers are loaded with zero-code, as such the
default output range is 4mA to 20mA. The current output until
a value is programmed is 0mA. An alternative current range
may be selected via the CONTROL register.
20mA
⎡
⎤
IOUT
=
=
× D
× D
2N
⎢
⎣
⎥
⎦
24mA
2N
⎡
⎤
IOUT
⎢
⎣
⎥
⎦
TRANSFER FUNCTION
16mA
2N
⎡
⎣
⎤
For the 0 to 20mA, 0 to 24mA and 4 to 20mA current output
ranges the output current expressions are respectively given by;
IOUT
=
× D + 4mA
⎢
⎥
⎦
where:
D is the decimal equivalent of the code loaded to the DAC.
N is the bit resolution of the DAC.
DATA REGISTER
The DATA register is addressed by setting the control word of the input shift register to 0x01. The data to be written to the DATA register
is entered in positions D15 to D0 as shown in Table 11,
Table 11. Programming the Data Register
MSB
LSB
D0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
DATA WORD
CONTROL REGISTER
The CONTROL register is addressed by setting the control word of the input shift register to 0x55. The data to be written to the
CONTROL register is entered in positions D15 to D0 as shown in Table 12. The CONTROL register functions are shown in Table 13.
Table 12. Programming the CONTROL Register
MSB
LSB
D0
R0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
0
0
REXT
OUTEN
SR CLOCK
SR STEP
SREN
DCEN
R2
R1
Table 13. Control Register Functions
Option
Description
Table 14. Output Range Options
REXT
Setting this bit selects the external current
setting resistor, Further details in Features
section
Output enable. This bit must be set to enable
the output.
R2
R1
R0
Output Range Selected
4 to 20 mA Current Range
0 to 20 mA Current Range
0 to 24 mA Current Range
1
0
1
1
1
0
OUTEN
1
1
1
SR CLOCK
SR STEP
SREN
See Features Section. Digital Slew Rate Control
See Features Section. Digital Slew Rate Control
Digital Slew Rate Control enable
Daisychain enable
DCEN
R2,R1,R0
Output range select. See Table 14
Rev. PrD | Page 21 of 29
AD5420
Preliminary Technical Data
RESET REGISTER
The RESET register is addressed by setting the control word of the input shift register to 0x56. The data to be written to the RESET
register is entered in positions D15 to D0 as shown in Table 15. The RESET register options are shown in Table 15 and Table 16.
Table 15. Programming the CONTROL 2 Register
MSB
LSB
D0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
RESET
Table 16. Control 2 register Functions
Option Description
RESET
Setting this bit performs a reset operation, restoring the AD5420 to its initial power on state
STATUS REGISTER
The STATUS register is a read only register. The STATUS register functionality is shown in Table 17 and Table 18.
Table 17. Decoding the STATUS Register
MSB
LSB
D15
D14
D13
D12
D11
D10
D9
D8 D7
D6 D5
D4
D3
D2
D1
D0
IOUT FAULT
SLEW ACTIVE
OVER TEMP
Table 18. STATUS Register Functions
Option
Description
IOUT FAULT
SLEW ACTIVE
OVER TEMP
This bit will be set if a fault is detected on the IOUT pin.
This bit will be set while the output value is slewing (slew rate control enabled)
This bit will be set if the AD5420 core temperature exceeds approx. 150°C.
Rev. PrD | Page 22 of 29
Preliminary Technical Data
AD5420
FEATURES
output current over temperature an external precision 15kΩ low
drift resistor can be connected to the RSET pin of the AD5420 to
be used instead of the internal resistor R1. The external resistor
is selected via the CONTROL 1 register. See Table 12.
FAULT ALERT
The AD5420 is equipped with a FAULT pin, this is an open-
drain output allowing several AD5420 devices to be connected
together to one pull-up resistor for global fault detection. The
FAULT pin is forced active by any one of the following fault
scenarios;
DIGITAL POWER SUPPLY
By default the DVCC pin accepts a power supply of 2.7V to 5.5V,
alternatively, via the DVCC SELECT pin an internal 4.5V power
supply may be output on the DVCC pin for use as a digital power
supply for other devices in the system or as a termination for
pull-up resistors. This facility offers the advantage of not having
to bring a digital supply across an isolation barrier. The internal
power supply is enabled by leaving the DVCC SELECT pin
unconnected. To disable the internal supply DVCC SELECT
should be tied to 0V.
1) The Voltage at IOUT attempts to rise above the
compliance range, due to an open-loop circuit or
insufficient power supply voltage. The IOUT current is
controlled by a PMOS transistor and internal
amplifier as shown in Figure 34. The internal circuitry
that develops the fault output avoids using a
comparator with “window limits” since this would
require an actual output error before the FAULT
output becomes active. Instead, the signal is generated
when the internal amplifier in the output stage has less
than approxiamately one volt of remaining drive
capability (when the gate of the output PMOS
transistor nearly reaches ground). Thus the FAULT
output activates slightly before the compliance limit is
reached. Since the comparison is made within the
feedback loop of the output amplifier, the output
accuracy is maintained by its open-loop gain and an
output error does not occur before the FAULT output
becomes active.
EXTERNAL BOOST FUNCTION
The addition of an external boost transistor as shown in Figure
36 will reduce the power dissipated in the AD5420 by reducing
the current flowing in the on-chip output transistor (dividing it
by the current gain of the external circuit). A discrete NPN
transistor with a breakdown voltage, BVCEO, greater than 60V
can be used.
The external boost capability has been developed for those
users who may wish to use the AD5420 at the extremes of the
supply voltage, load current and temperature range. The boost
transistor can also be used to reduce the amount of temperature
induced drift in the part. This will minimise the temperature
induced drift of the on-chip voltage reference, which improves
drift and linearity.
2) If the core temperature of the AD5420 exceeds approx.
150°C.
The OPEN CCT and OVER TEMP bits of the STATUS register
are used in conjunction with the FAULT pin to inform the user
which one of the fault conditions caused the FAULT pin to be
asserted. See Table 17 and Table 18.
MJD31C
OR
2N3053
BOOST
AD5420
ASYNCHRONOUS CLEAR (CLEAR)
I
OUT
CLEAR is an active high clear that clears the Current output to
the bottom of its programmed range. It is necessary to maintain
CLEAR high for a minimum amount of time (see Figure 2) to
complete the operation. When the CLEAR signal is returned
low, the output remains at the cleared value until a new value is
programmed.
1k
R
LOAD
0.022
F
Figure 36. External Boost Configuration
INTERNAL REFERENCE
The AD5420 contains an integrated +5V voltage reference with
initial accuracy of 2mV max and a temperature drift
coefficient of 10 ppm max. The reference voltage is buffered
and externally available for use elsewhere within the system. See
Figure 32 for a load regulation graph of the Integrated reference.
EXTERNAL CURRENT SETTING RESISTOR
Referring to Figure 34, R1 is an internal sense resistor as part of
the voltage to current conversion circuitry. The stability of the
output current over temperature is dependent on the stability of
the value of R1. As a method of improving the stability of the
Rev. PrD | Page 23 of 29
AD5420
Preliminary Technical Data
DIGITAL SLEW RATE CONTROL
Table 20. Slew Rate Step Size Options
The Slew Rate Control feature of the AD5420 allows the user to
control the rate at which the output current changes. With the
slew rate control feature disabled the output currrent will
change at a rate limited by the output drive circuitry and the
attached load. If the user wishes to reduce the slew rate this can
be achieved by enabling the slew rate control feature.With the
feature enabled via the SREN bit of the CONTROL register, (See
Table 12) the output, instead of slewing directly between two
values, will step digitally at a rate defined by two parameters
accessible via the CONTROL register as shown in Table 12. The
parameters are SR CLOCK and SR STEP. SR CLOCK defines
the rate at which the digital slew will be updated, e.g. if the
selected update rate is 1MHz the output will update every 1µs,
SR STEP defines by how much the output value will change at
each update. Together both parameters define the rate of change
of the output current.Table 19 and Table 20 outline the range of
values for both the SR CLOCK and SR STEP parameters.
SR STEP
Step Size (LSBs)
000
001
010
011
100
101
110
111
1
2
4
±
16
32
64
12±
The following equation describes the slew rate as a function of
the step size, the update clock frequency and the LSB size.
StepSize×UpdateClockFrequency× LSBSize
SlewRate =
1×106
Where:
Table 19. Slew Rate Update Clock Options
Slew Rate is expressed in A/µs
LSBSize = Fullscale Range / 65536
SR CLOCK
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Update Clock Frequency (Hz)
1000000
500000
333333
250000
200000
100000
50000
33333
25000
20000
12500
10000
±333
When the slew rate control feature is enabled, all output
changes will change at the programmed slew rate, i.e. if the
CLEAR pin is asserted the output will slew to the clear value at
the programmed slew rate. The output can be halted at its
current value with a write to the CONTROL register. To avoid
halting the output slew, the SLEW ACTIVE bit can be used to
check that the slew has completed before writing to the AD5420
registers. See Table 17.
IOUT FILTERING CAPACITORS
Two capacitors may be placed between the pins CAP1, CAP2
and AVDD as shown in Figure 37. The capacitors form a filter on
the current output circuitry reducing the bandwidth and the
rate of change of the output current.
6666
5000
3921
AVDD
C1
C2
AVDD
CAP1
AD5420 CAP2
I
OUT
GND
Figure 37. IOUT Filtering Capacitors
Rev. PrD | Page 24 of 29
Preliminary Technical Data
AD5420
APPLICATIONS INFORMATION
avoid radiating noise to other parts of the board and should
DRIVING INDUCTIVE LOADS
never be run near the reference inputs. A ground line routed
between the SDIN and SCLK lines helps reduce crosstalk
between them (not required on a multilayer board that has a
separate ground plane, but separating the lines helps). It is
essential to minimize noise on the REFIN line because it
couples through to the DAC output.
When driving inductive or poorly defined loads connect a
0.01µF capacitor between IOUT and GND. This will ensure
stability with loads beyond 50mH. There is no maximum
capacitance limit. The capacitive component of the load may
cause slower settling, though this may be masked by the settling
time of the AD5420.
Avoid crossover of digital and analog signals. Traces on
opposite sides of the board should run at right angles to each
other. This reduces the effects of feed 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.
TRANSIENT VOLTAGE PROTECTION
The AD5420 contains ESD protection diodes which prevent
damage from normal handling. The industrial control
environment can, however, subject I/O circuits to much higher
transients. In order to protect the AD5420 from excessively high
voltage transients , external power diodes and a surge current
limiting resistor may be required, as shown in Figure 38. The
constraint on the resistor value is that during normal operation
the output level at IOUT must remain within its voltage
compliance limit of AVDD – 2.5V and the two protection diodes
and resistor must have appropriate power ratings.
GALVANICALLY ISOLATED INTERFACE
In many process control applications, it is necessary to provide
an isolation barrier between the controller and the unit being
controlled to protect and isolate the controlling circuitry from
any hazardous common-mode voltages that might occur. The
iCoupler® family of products from Analog Devices provides
voltage isolation in excess of 2.5 kV. The serial loading structure
of the AD5420 make it ideal for isolated interfaces because the
number of interface lines is kept to a minimum. Figure 39 shows
a 4-channel isolated interface to the AD5420 using an
ADuM1400. For further information, visit
AV
DD
AV
DD
R
P
AD5420
I
OUT
GND
R
LOAD
http://www.analog.com/icouplers.
Figure 38. Output Transient Voltage Protection
Controller
LAYOUT GUIDELINES
ADuM1400 *
V
V
V
V
V
OA
IA
IB
IC
ID
To SCLK
Serial Clock Out
ENCODE
ENCODE
ENCODE
ENCODE
DECODE
DECODE
DECODE
DECODE
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
AD5420 is mounted should be designed so that the analog and
digital sections are separated and confined to certain areas of the
board. If the AD5420 is in a system where multiple devices
require an AGND-to-DGND connection, the connection
should be made at one point only. The star ground point should
be established as close as possible to the device.
V
V
OB
To SDIN
Serial Data Out
SYNC Out
OC
To LATCH
To CLEAR
V
OD
Control out
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 39. Isolated Interface
The AD5420 should have ample supply bypassing of 10 µF in
parallel with 0.1 µF on each 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 low
effective series inductance (ESI) such as the common ceramic
types, which provide a low impedance path to ground at high
frequencies to handle transient currents due to internal logic
switching.
MICROPROCESSOR INTERFACING
Microprocessor interfacing to the AD5420 is via a serial bus that
uses protocol compatible with microcontrollers and DSP
processors. The communications channel is a 3-wire
(minimum) interface consisting of a clock signal, a data signal,
and a latch signal. The AD5420 require a 24-bit data-word with
data valid on the rising edge of SCLK.
For all interfaces, the DAC output update is initiated on the
rising edge of LATCH. The contents of the registers can be read
using the readback function.
The power supply lines of the AD5420 should use as large a
trace as possible to provide low impedance paths and reduce the
effects of glitches on the power supply line. Fast switching
signals such as clocks should be shielded with digital ground to
Rev. PrD | Page 25 of 29
AD5420
Preliminary Technical Data
At maximum ambient temperature of 85°C the AD5420BREZ
(24-lead TSSOP) can dissipate 950mW and the AD5420BCPZ
(40-lead LFCSP) can dissipate 1.42W.
To ensure the junction temperature does not exceed 125°C
while driving the maximum current of 24mA directly into
ground (also adding an on-chip current of 3mA), AVDD should
be reduced from the maximum rating to ensure the package is
not required to dissipate more power than stated above. See
Table 21, Figure 40 and Figure 41.
THERMAL AND SUPPLY CONSIDERATIONS
The AD5420 is designed to operate at a maximum junction
temperature of 125°C. It is important that the device is not
operated under conditions that will cause the junction
temperature to exceed this value . Excessive junction
temperature can occur if the AD5420 is operated from the
maximum AVDD and driving the maximum current (24mA)
directly to ground. In this case the ambient temperature should
be controlled or AVDD should be reduced. The conditions will
depend on the device and package.
2.5
65
60
TSSOP
LFCSP
2
55
TSSOP
50
45
40
35
30
25
LFCSP
1.5
1
0.5
0
40
45
50
55
60
65
70
75
80
85
25
35
45
55
65
75
85
Ambient Temperature (°C)
Ambient Temperature (°C)
Figure 40. Maximum Power Dissipation Vs Ambient Temperature
Figure 41. Maximum Supply Voltage Vs Ambient Temperature
Table 21. Thermal and Supply considerations for each package
TSSOP
LFCSP
Maximum allowed power dissipation
when operating at an ambient
temperature of ±5°C
T
max− T
125 − 85
T
max− T
A
125 − 85
J
A
J
=
= 950mW
=
= 1.42W
Θ
42
Θ
28
JA
JA
Maximum allowed ambient
temperature when operating from a
supply of 40V/60V and driving 24mA
directly to ground.
T
max− P × Θ
= 125 −
40 × 0.027
)
× 42 = 79°C
T max− P × Θ = 125−
(
60× 0.027
)
× 28 = 79°C
J
D
JA
J
D
JA
Maximum allowed supply voltage
when operating at an ambient
temperature of ±5°C and driving 24mA
directly to ground.
T
max− T
125 − 85
T
max− T
A
125 − 85
J
A
J
=
= 35V
=
= 53V
AI
× Θ
0.027 × 42
AI
× Θ
JA
0.027 × 28
DD
JA
DD
Rev. PrD | Page 26 of 29
Preliminary Technical Data
OUTLINE DIMENSIONS
AD5420
5.02
5.00
4.95
7.90
7.80
7.70
24
13
12
4.50
4.40
4.30
3.25
3.20
3.15
EXPOSED
PAD
(Pins Up)
6.40 BSC
1
BOTTOM VIEW
TOP VIEW
1.20 MAX
1.05
1.00
0.80
8°
0°
0.20
0.09
0.15
0.05
0.30
0.19
0.65
BSC
0.75
0.60
0.45
SEATING
PLANE
0.10 COPLANARITY
COMPLIANT TO JEDEC STANDARDS MO-153-ADT
Figure 42. 24-Lead Thin Shrink Small Outline Package, Exposed Pad [TSSOP_EP]
(RE-24)
Dimensions shown in millimeters
6.00
BSC SQ
0.60 MAX
0.60 MAX
PIN 1
INDICATOR
31
40
1
30
PIN 1
INDICATOR
0.50
BSC
TOP
VIEW
4.25
4.10 SQ
3.95
5.75
BCS SQ
EXPOSED
PAD
(BOT TOM VIEW)
0.50
0.40
0.30
21
10
11
20
0.25 MIN
4.50
REF
12° MAX
0.80 MAX
0.65 TYP
0.05 MAX
0.02 NOM
1.00
0.85
0.80
0.30
0.23
0.18
COPLANARITY
0.08
0.20 REF
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-220-VJJD-2
Figure 43. 40-Lead Lead Frame Chip Scale Package
(CP-40)
Dimensions shown in millimeters
ORDERING GUIDE
Model
AD5420BREZ
AD5420BCPZ
AVDD max
Temperature Range
-40°C to ±5°C
-40°C to ±5°C
Package Description
24 Lead TSSOP_EP
40 Lead LFCSP
Package Option
40V
60V
RE-24
CP-40
Rev. PrD | Page 27 of 29
AD5420
NOTES
Preliminary Technical Data
Rev. PrD | Page 2± of 29
Preliminary Technical Data
NOTES
AD5420
©2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
PR06997-0-11/07(PrD)
Rev. PrD | Page 29 of 29
相关型号：
AD5420ACPZ-REEL7
SERIAL INPUT LOADING, 40 us SETTLING TIME, 16-BIT DAC, QCC40, 6 X 6 MM, ROHS COMPLIANT, MO-220VJJD-2, LFCSP-40
ROCHESTER
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