Datasheet

ManualsBrandsANALOG DEVICES ManualsData collecting ICsData acquisition IC - DA converter (DAC) TSSOP 16

Dual, Current-Output,

Serial-Input, 16-/14-Bit DACs

Data Sheet

AD5545/AD5555

Rev. G Document Feedback

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FEATURES

16-bit resolution AD5545

14-bit resolution AD5555

±1 LSB DNL monotonic

±1 LSB INL

2 mA full-scale current ±20%, with V

REF

= 10 V

0.5 µs settling time

2Q multiplying reference-input 6.9 MHz BW

Zero or midscale power-up preset

Zero or midscale dynamic reset

3-wire interface

Compact 16-lead TSSOP package

APPLICATIONS

Automatic test equipment

Instrumentation

Digitally controlled calibration

Industrial control PLCs

Programmable attenuator

PRODUCT OVERVIEW

The AD5545/AD5555 are 16-bit/14-bit, current-output, digital-

to-analog converters designed to operate from a 4.5 V to 5.5 V

supply range.

An external reference is needed to establish the full-scale

output-current. An internal feedback resistor (R

) enhances

the resistance and temperature tracking when combined

with an external op amp to complete the I-to-V conversion.

A serial data interface offers high speed, 3-wire microcontroller

compatible inputs using serial data in (SDI), clock (CLK), and

chip select (

). Additional

LDAC

function allows

simultaneous update operation. The internal reset logic allows

power-on preset and dynamic reset at either zero or midscale,

depending on the state of the MSB pin.

The AD5545/AD5555 are packaged in the compact TSSOP-16

package and can be operated from −40°C to +85°C.

FUNCTIONAL BLOCK DIAGRAM

AD5545/

AD5555

REF

OUT

GND

SDI

CLK

DGND MSB

LDAC

DAC A

D0..DX

16 OR 14

ADDR

DECODE

INPUT

POWER-

RESET

INPUT

DAC A

DAC B

OUT

GND

DAC B

02918- 0-001

Figure 1.

Summary of content (24 pages)

PAGE 1
Dual, Current-Output, Serial-Input, 16-/14-Bit DACs AD5545/AD5555 Data Sheet FEATURES FUNCTIONAL BLOCK DIAGRAM 16-bit resolution AD5545 14-bit resolution AD5555 ±1 LSB DNL monotonic ±1 LSB INL 2 mA full-scale current ±20%, with VREF = 10 V 0.5 µs settling time 2Q multiplying reference-input 6.9 MHz BW Zero or midscale power-up preset Zero or midscale dynamic reset 3-wire interface Compact 16-lead TSSOP package VREFA VREFB 16 OR 14 VDD RFBA D0..
PAGE 2
AD5545/AD5555 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Grounding ................................................................................... 11 Applications ....................................................................................... 1 Applications Information .............................................................. 12 Product Overview..................................................
PAGE 3
Data Sheet AD5545/AD5555 SPECIFICATIONS ELECTRICAL CHARACTERISTICS VDD = 5 V ± 10%, IOUT = virtual GND, GND = 0 V, VREF = 10 V, TA = full operating temperature range, unless otherwise noted. Table 1.
PAGE 4
AD5545/AD5555 Data Sheet Parameter AC CHARACTERISTICS Output Voltage Setting Time Symbol Conditions Min tS Reference Multiplying BW DAC Glitch Impulse Feedthrough Error BW Q VOUT/VREF Digital Feedthrough Total Harmonic Distortion Analog Crosstalk Q THD CTA Output Spot Noise Voltage eN To ±0.1% full scale, data = zero scale to full scale to zero scale VREF = 100 mV rms, data = full scale, C1 = 5.
PAGE 5
Data Sheet AD5545/AD5555 ABSOLUTE MAXIMUM RATINGS Table 2. Parameter VDD to GND VREF to GND Logic Inputs to GND V(IOUT) to GND Input Current to Any Pin except Supplies Package Power Dissipation Thermal Resistance θJA 16-Lead TSSOP Maximum Junction Temperature (TJ max) Operating Temperature Range Storage Temperature Range Lead Temperature RU-16 (Vapor Phase, 60 sec) RU-16 (Infrared, 15 sec) Rating –0.3 V to +8 V –18 V to +18 V –0.3 V to +8 V –0.3 V to VDD + 0.
PAGE 6
AD5545/AD5555 Data Sheet PIN CONFIGURATION AND FUNCTION DESCRIPTIONS RFBA 1 16 CLK VREFA 2 15 LDAC IOUTA 3 AGNDA 4 AGNDB 5 14 MSB AD5545/ AD5555 TOP VIEW (Not to Scale) 13 VDD 12 DGND IOUTB 6 11 CS VREFB 7 10 RS RFBB 8 9 SDI 02918- 0- 002 Figure 4. 16-Lead TSSOP Table 3. Pin Function Descriptions Pin No.
PAGE 7
Data Sheet AD5545/AD5555 1.0 1.0 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 DNL (LSB) INL (LSB) TYPICAL PERFORMANCE CHARACTERISTICS 0 –0.2 0 –0.2 –0.4 –0.4 –0.6 –0.6 –0.8 –0.8 –1.0 0 8192 –1.0 16384 24576 32768 40960 49152 57344 65536 CODE (Decimal) 0 0248 4096 6144 8192 10240 12288 14336 16384 CODE (Decimal) 02918- 0- 009 02918- 0- 012 Figure 5. AD5545 Integral Nonlinearity Error Figure 8. AD5555 Differential Nonlinearity Error 1.0 1.5 VREF = 2.5V TA = 25°C 0.8 1.
PAGE 8
AD5545/AD5555 Data Sheet 2 3.0 0 –2 2.0 –4 0x5555 GAIN (dB) SUPPLY CURRENT (mA) 2.5 1.5 0x8000 –6 –8 1.0 0xFFFF 0x0000 0.5 –10 –12 0 10k 100k 10M 1M CLOCK FREQUENCY (Hz) –14 10k 100M 100k 1M 10M 100M FREQUENCY (Hz) 02918-0-117 02918- 0- 015 Figure 14. Reference Multiplying Bandwidth Figure 11. Supply Current vs.
PAGE 9
Data Sheet AD5545/AD5555 THEORY OF OPERATION The AD5545/AD5555 contain a 16-/14-bit, current-output, digital-to-analog converter, a serial-input register, and a DAC register. Both parts require a minimum of a 3-wire serial data interface with an additional LDAC for dual channel simultaneous update. DIGITAL-TO-ANALOG CONVERTER The DAC architecture uses a current-steering R-2R ladder design. Figure 17 shows the typical equivalent DAC.
PAGE 10
AD5545/AD5555 Data Sheet SERIAL DATA INTERFACE to the DAC A register. At this time, the output is not updated. To load DAC B data, pull CS low for an 18-bit duration and program DAC B with the proper address and data, then pull CS high to latch data to the DAC B register. Finally, pull LDAC low and then high to update both the DAC A and DAC B outputs simultaneously. The AD5545/AD5555 use a minimum 3-wire (CS, SDI, CLK) serial data interface for single channel update operation.
PAGE 11
Data Sheet AD5545/AD5555 Table 7.
PAGE 12
AD5545/AD5555 Data Sheet APPLICATIONS INFORMATION STABILITY BIPOLAR OUTPUT The AD5545/AD5555 is inherently a 2-quadrant multiplying DAC. It can easily be set up for unipolar output operation. The full-scale output polarity is the inverse of the reference input voltage. VDD U1 RFB VDD IOUT VREF VREF C1 VO AD8628 GND AD5545/AD5555 U2 02918- 0- 020 Figure 21.
PAGE 13
Data Sheet AD5545/AD5555 PROGRAMMABLE CURRENT SOURCE Figure 24 shows a versatile V-to-I conversion circuit using improved Howland Current Pump. In addition to the precision current conversion it provides, this circuit enables a bidirectional current flow and high voltage compliance. This circuit can be used in a 4 mA to 20 mA current transmitter with up to a 500 Ω of load.
PAGE 14
AD5545/AD5555 Data Sheet By putting Equations 7 through 10 together, the following results: DAC WITH PROGRAMMABLE INPUT REFERENCE RANGE  DC  1    128  D  C  VREF AB  VREF  DC D 1  NA  128  DC 2 Because high voltage references can be costly, users may consider using one of the DACs, a digital potentiometer, and a low voltage reference to form a single-channel DAC with a programmable input reference range.
PAGE 15
Data Sheet AD5545/AD5555 REFERENCE SELECTION When selecting a reference for use with the AD55xx series of current output DACs, pay attention to the output voltage, temperature coefficient specification of the reference. Choosing a precision reference with a low output temperature coefficient minimizes error sources. Table 10 lists some of the references available from Analog Devices, Inc., that are suitable for use with this range of current output DACs.
PAGE 16
AD5545/AD5555 Data Sheet Table 11. Suitable Analog Devices Precision Op Amps Part No. OP97 OP1177 AD8675 AD8671 ADA4004-1 AD8603 AD8607 AD8605 AD8615 AD8616 Supply Voltage (V) ±2 to ±20 ±2.5 to ±15 ±5 to ±18 ±5 to ±15 ±5 to ±15 1.8 to 5 1.8 to 5 2.7 to 5 2.7 to 5 2.7 to 5 VOS Maximum (μV) 25 60 75 75 125 50 50 65 65 65 IB Maximum (nA) 0.1 2 2 12 90 0.001 0.001 0.001 0.001 0.001 0.1 Hz to 10 Hz Noise (μV p-p) 0.5 0.4 0.1 0.077 0.1 2.3 2.3 2.3 2.4 2.
PAGE 17
Data Sheet AD5545/AD5555 EVALUATION BOARD FOR THE AD5545 The EVAL-AD5545SDZ is used in conjunction with an SDP1Z system demonstration platform board available from Analog Devices, which is purchased separately from the evaluation board. The USB-to-SPI communication to the AD5545 is completed using this Blackfin®-based demonstration board. SYSTEM DEMONSTRATION PLATFORM The system demonstration platform (SDP) is a hardware and software evaluation tool for use in conjunction with product evaluation boards.
PAGE 18
AD5545/AD5555 Data Sheet EVALUATION BOARD SCHEMATICS 02918-0-028 Figure 28. EVAL-AD5545SDZ Schematic Part A Rev.
PAGE 19
Data Sheet AD5545/AD5555 02918-0-029 Figure 29. EVAL-AD5545SDZ Schematic Part B Rev.
PAGE 20
AD5545/AD5555 Data Sheet 02918-0-030 Figure 30. EVAL-AD5545SDZ Schematic Part B Rev.
PAGE 21
Data Sheet AD5545/AD5555 02918-0-031 EVALUATION BOARD LAYOUT 02918-0-032 Figure 31. Silkscreen Figure 32. Component Side Rev.
PAGE 22
Data Sheet 02918-0-033 AD5545/AD5555 Figure 33. Solder Side Rev.
PAGE 23
Data Sheet AD5545/AD5555 OUTLINE DIMENSIONS 5.10 5.00 4.90 16 9 4.50 4.40 4.30 6.40 BSC 1 8 PIN 1 1.20 MAX 0.15 0.05 0.20 0.09 0.65 BSC 0.30 0.19 COPLANARITY 0.10 SEATING PLANE 0.75 0.60 0.45 8° 0° COMPLIANT TO JEDEC STANDARDS MO-153-AB Figure 34.