Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsData collecting ICsData acquisition IC - DA converter (DAC) PDIP 8

General Description

The MAX544/MAX545 are serial-input, voltage-output,

14-bit digital-to-analog converters (DACs) that operate

from a single +5V supply. They provide 14-bit perfor-

mance (±0.5LSB INL and ±0.9LSB DNL) over tempera-

ture without any adjustments. The DAC output is

unbuffered, resulting in a low supply current of 0.3mA

and a low offset error of 0.6mV.

The DAC output range is 0V to V

REF.

For bipolar opera-

tion, matched scaling resistors are provided in the

MAX545 for use with an external precision op amp

(such as the MAX400), generating a ±V

REF

output

swing. The MAX545 also includes Kelvin-sense con-

nections for the reference and analog ground pins to

reduce layout sensitivity.

A 16-bit serial word is used to load data into the DAC

latch. The 10MHz, 3-wire serial interface is compatible

with SPI™/QSPI™/MICROWIRE™, and it also interfaces

directly with optocouplers for applications requiring isola-

tion. A power-on reset circuit clears the DAC output to 0V

(unipolar mode) when power is initially applied.

The MAX544 is available in 8-pin plastic DIP and SO

packages. The MAX545 is available in 14-pin plastic

DIP and SO packages.

Applications

Digital Offset and Gain Adjustment

Instrumentation

Industrial Process Control

Automated Test Equipment

Data-Acquisition Systems

Features

♦ Full 14-Bit Performance Without Adjustments

♦ +5V Single-Supply Operation

♦ Low Power: 1.5mW

♦ 1µs Settling Time

♦ Unbuffered Voltage Output Directly Drives 60kΩ

Loads

♦ SPI/QSPI/MICROWIRE-Compatible Serial Interface

♦ Power-On Reset Circuit Clears DAC Output to 0V

(unipolar mode)

♦ Schmitt-Trigger Inputs for Direct Optocoupler

Interface

♦ Pin-Compatible 16-Bit Upgrades

(MAX541/MAX542)

MAX544/MAX545

+5V, Serial-Input, Voltage-Output, 14-Bit DACs

________________________________________________________________ Maxim Integrated Products 1

INV

DGND

LDAC

AGNDS

AGNDF

OUT

RFB

TOP VIEW

MAX545

DIN

N.C.

SCLK

REFF

REFS

DIP/SO

DIN

REF

SCLK

DGND

AGND

OUT

MAX544

DIP/SO

Pin Configurations

14-BIT DAC

DATA LATCH

SERIAL INPUT REGISTER

CONTROL

LOGIC

MAX545

REFF

REFS

DIN

SCLK

AGNDS

AGNDF

OUT

INV

RFB

DGND

LDAC

INV

Functional Diagrams

19-1088; Rev 3; 12/99

PART

MAX544ACPA

MAX544BCPA

MAX544ACSA 0°C to +70°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

8 Plastic DIP

8 SO

Ordering Information

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.

For small orders, phone 1-800-835-8769.

SPI and QSPI are trademarks of Motorola, Inc.

MICROWIRE is a trademark of National Semiconductor Corp.

MAX544BCSA 0°C to +70°C 8 SO

INL

(LSB)

±1/2

±1

±1/2

±1

Ordering Information continued at end of data sheet.

Functional Diagrams continued at end of data sheet.

Summary of content (12 pages)

PAGE 1
9-1088; Rev 3; 12/99 +5V, Serial-Input, Voltage-Output, 14-Bit DACs Features ♦ Full 14-Bit Performance Without Adjustments ♦ +5V Single-Supply Operation ♦ Low Power: 1.5mW ♦ 1µs Settling Time ♦ Unbuffered Voltage Output Directly Drives 60kΩ Loads ♦ SPI/QSPI/MICROWIRE-Compatible Serial Interface ♦ Power-On Reset Circuit Clears DAC Output to 0V (unipolar mode) ♦ Schmitt-Trigger Inputs for Direct Optocoupler Interface ♦ Pin-Compatible 16-Bit Upgrades (MAX541/MAX542) Ordering Information PART TEMP.
PAGE 2
MAX544/MAX545 +5V, Serial-Input, Voltage-Output, 14-Bit DACs ABSOLUTE MAXIMUM RATINGS VDD to DGND ...........................................................-0.3V to +6V CS, SCLK, DIN, LDAC to DGND ..............................-0.3V to +6V REF, REFF, REFS to AGND ........................-0.3V to (VDD + 0.3V) AGND, AGNDF, AGNDS to DGND .......................-0.3V to +0.3V OUT, INV to AGND DGND .......................................-0.3V to VDD RFB to AGND DGND.............................................
PAGE 3
+5V, Serial-Input, Voltage-Output, 14-Bit DACs MAX544/MAX545 ELECTRICAL CHARACTERISTICS (continued) (VDD = +5V ± 5%, VREF = +2.5V, AGND = DGND = 0, TA = TMIN to TMAX, unless otherwise noted.
PAGE 4
Typical Operating Characteristics (VDD = 5V, VREF = +2.5V, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. REFERENCE VOLTAGE 0.40 0.35 0.30 0.33 0.32 0.31 0.30 0.29 0.28 0.27 0.25 0.20 0.15 0.26 0.25 0.20 -20 0 20 40 60 80 0.05 0 -0.05 -0.10 -0.15 -0.20 0 100 0.10 1 2 3 4 5 6 -60 -20 REFERENCE VOLTAGE (V) TEMPERATURE (°C) DIFFERENTIAL NONLINEARITY vs. TEMPERATURE INTEGRAL NONLINEARITY vs. TEMPERATURE 0.20 0.20 60 100 140 100 140 16k 20k GAIN ERROR vs.
PAGE 5
+5V, Serial-Input, Voltage-Output, 14-Bit DACs MAX544-10 CL = 10pF RL = ∞ CL = 10pF RL = ∞ OUT 500mV/div OUT 500mV/div 2µs/div 1µs/div 2µs/div 400ns/div MAJOR-CARRY OUTPUT GLITCH DIGITAL FEEDTHROUGH 2µs/div MAX544-10A FULL-SCALE STEP RESPONSE (fSCLK = 20MHz) FULL-SCALE STEP RESPONSE (fSCLK = 10MHz) CS (5V/div) SCLK 5V/div OUT (AC-COUPLED, 100mV/div) OUT (AC-COUPLED, 50mV/div) MAX544/MAX545-11 CODE = 0000 hex MAX544/MAX545-12 2µs/div Pin Descriptions MAX544 PIN NAME 1 OUT 2 AGND 3
PAGE 6
MAX544/MAX545 +5V, Serial-Input, Voltage-Output, 14-Bit DACs Pin Descriptions (continued) MAX545 PIN NAME FUNCTION 1 RFB Feedback Resistor. Connect to external op amp’s output in bipolar mode. 2 OUT DAC Output Voltage 3 AGNDF Analog Ground (force) 4 AGNDS Analog Ground (sense) 5 REFS Voltage Reference Input (sense). Connect REFS to external +2.5V reference. 6 REFF Voltage Reference Input (force). Connect REFF to external +2.5V reference. 7 CS 8 SCLK Serial-Clock Input.
PAGE 7
+5V, Serial-Input, Voltage-Output, 14-Bit DACs +2.5V MAX544/MAX545 +5V 10µF 0.1µF 0.1µF MC68XXXX VDD PCS0 CS MOSI DIN SCLK SCLK (REFS) UNIPOLAR OUT MAX495 OUT MAX544/MAX545 (LDAC) (GND) REF (REFF) DGND EXTERNAL OP AMP AGND_ ( ) ARE FOR MAX545 ONLY Figure 2a. Typical Operating Circuit—Unipolar Output +5V +2.5V 10µF 0.1µF 0.
PAGE 8
MAX544/MAX545 +5V, Serial-Input, Voltage-Output, 14-Bit DACs Digital Interface External Reference The MAX544/MAX545’s digital interface is a standard 3-wire connection compatible with SPI/QSPI/ MICROWIRE interfaces. The chip-select input (CS) frames the serial data loading at the data-input pin (DIN). Immediately following CS’s high-to-low transition, the data is shifted synchronously and latched into the input register on the rising edge of the serial clock input (SCLK).
PAGE 9
+5V, Serial-Input, Voltage-Output, 14-Bit DACs Reference and Analog Ground Inputs The MAX544/MAX545 operate with external voltage references from 2V to 3V, and maintain 14-bit performance if certain guidelines are followed when selecting and applying the reference. Ideally, the reference’s temperature coefficient should be less than 1.5ppm/°C to maintain 14-bit accuracy to within 1LSB over the 0°C to +70°C commercial temperature range.
PAGE 10
MAX544/MAX545 +5V, Serial-Input, Voltage-Output, 14-Bit DACs amplifier’s input resistance forms a resistive divider with the DAC output resistance, which results in a gain error. To contribute less than 1/2LSB of gain error, the input resistance typically must be greater than: 1 1  6.25kΩ ÷   = 205MΩ 2  214  The settling time is affected by the buffer input capacitance, the DAC’s output capacitance, and PC board capacitance. The typical DAC output voltage settling time is 1µs for a full-scale step.
PAGE 11
+5V, Serial-Input, Voltage-Output, 14-Bit DACs Functional Diagrams (continued) INL (LSB) PART TEMP.
PAGE 12
SOICN.EPS ________________________________________________________Package Information PDIPN.EPS MAX544/MAX545 +5V, Serial-Input, Voltage-Output, 14-Bit DACs Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.