Datasheet

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

__________________General Description

The MAX5302 combines a low-power, voltage-output,

12-bit digital-to-analog converter (DAC) and a precision

output amplifier in an 8-pin µMAX package. It operates

from a single +5V supply, drawing less than 280µA of

supply current.

The output amplifier’s inverting input is available to the

user, allowing specific gain configurations, remote sens-

ing, and high output current capability. This makes the

MAX5302 ideal for a wide range of applications, includ-

ing industrial process control. Other features include a

software shutdown and power-on reset.

The serial interface is SPI™/QSPI™/MICROWIRE™ com-

patible. The DAC has a double-buffered input, organized

as an input register followed by a DAC register. A 16-bit

serial word loads data into the input register. The DAC

with the input register. All logic inputs are TTL/CMOS-

logic compatible and buffered with Schmitt triggers to

allow direct interfacing to optocouplers.

Applications

Industrial Process Control

Automatic Test Equipment

Digital Offset and Gain Adjustment

Motion Control

Remote Industrial Control

Microprocessor-Controlled Systems

Features

♦ 12-Bit DAC with Configurable Output Amplifier

♦ +5V Single-Supply Operation

♦ Low Supply Current: 0.28mA Normal Operation

2µA Shutdown Mode

♦ Available in 8-Pin µMAX

♦ Power-On Reset Clears DAC Output to Zero

♦ SPI/QSPI/MICROWIRE Compatible

♦ Schmitt-Trigger Digital Inputs for Direct

Optocoupler Interface

MAX5302

Low-Power, 12-Bit Voltage-Output DAC

with Serial Interface

________________________________________________________________ Maxim Integrated Products 1

MAX5302

OUT

DIN

SCLK

DAC

REF

DAC

INPUT

CONTROL

GND

16-BIT

SHIFT

Functional Diagram Pin Configuration

19-1559; Rev 0; 10/99

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.

8 µMAX

PIN-PACKAGETEMP. RANGE

0°C to +70°C

-40°C to +85°CMAX5302EUA

MAX5302CUA

PART

REF

DIN

SCLK

GND

OUT

MAX5302

µMAX

TOP VIEW

Summary of content (12 pages)

PAGE 1
9-1559; Rev 0; 10/99 Low-Power, 12-Bit Voltage-Output DAC with Serial Interface The MAX5302 combines a low-power, voltage-output, 12-bit digital-to-analog converter (DAC) and a precision output amplifier in an 8-pin µMAX package. It operates from a single +5V supply, drawing less than 280µA of supply current. The output amplifier’s inverting input is available to the user, allowing specific gain configurations, remote sensing, and high output current capability.
PAGE 2
MAX5302 Low-Power, 12-Bit Voltage-Output DAC with Serial Interface ABSOLUTE MAXIMUM RATINGS VDD to GND ..............................................................-0.3V to +6V REF, OUT, FB to GND ................................-0.3V to (VDD + 0.3V) Digital Inputs to GND ...............................................-0.3V to +6V Continuous Current into Any Pin.......................................±20mA Continuous Power Dissipation (TA = +70°C) 8-Pin µMAX (derate 4.10mW/°C above +70°C) .........
PAGE 3
Low-Power, 12-Bit Voltage-Output DAC with Serial Interface (Circuit of Figure 8, VDD = +5V ±10%, VREF = +2.5V, RL = 5kΩ, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C. Output buffer connected in unity-gain configuration.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DIGITAL INPUTS DYNAMIC PERFORMANCE Voltage Output Slew Rate SR Output Settling Time To ±1/2LSB, VSTEP = 2.5V Output Voltage Swing Rail-to-rail (Note 2) 0.
PAGE 4
__________________________________________Typical Operating Characteristics (VDD = +5V, RL = 5kΩ, CL = 100pF, TA = +25°C, unless otherwise noted.) -4 RELATIVE OUTPUT (dB) 0.1 -0.1 -0.2 -0.3 -8 -12 360 -16 320 300 280 260 220 -20 0.4 1.2 2.0 2.8 3.6 REFERENCE VOLTAGE (V) 4.4 0 2M 2.5M 4 3 300 250 200 150 100 1 50 60 100 OUTPUT FFT PLOT -60 -80 5.6 1.6 2.7 3.8 FREQUENCY (kHz) 4.9 6.0 100 10 FREQUENCY (kHz) FULL-SCALE OUTPUT vs.
PAGE 5
Low-Power, 12-Bit Voltage-Output DAC with Serial Interface DIGITAL FEEDTHROUGH (fSCLK = 100kHz) MAX5302 toc11 MAX5302 toc10 MAJOR-CARRY TRANSITION CS 5V/div SCLK 2V/div OUT AC-COUPLED 100mV/div OUT AC-COUPLED 10mV/div CODE = 2048 10µs/div 2µs/div CS = 5V MAX5302 toc12 DYNAMIC RESPONSE OUT 1V/div GND 10µs/div GAIN = 2, SWITCHING FROM CODE 0 TO 4020 _______________________________________________________________________________________ 5 MAX5302 Typical Operating Characteristics (continued) (
PAGE 6
MAX5302 Low-Power, 12-Bit Voltage-Output DAC with Serial Interface _____________________Pin Description PIN NAME 1 OUT 2 CS Chip-Select Input. Active low.
PAGE 7
Low-Power, 12-Bit Voltage-Output DAC with Serial Interface SCLK MAX5302 SK Serial-Interface Configurations DIN SO CS I/O The MAX5302’s 3-wire serial interface is compatible with both MICROWIRE (Figure 2) and SPI/QSPI (Figure 3). The serial-input word consists of 3 control bits followed by 12+1 data bits (MSB first), as shown in Figure 4. The 3-bit control code determines the MAX5302’s response outlined in Table 1. MICROWIRE PORT The MAX5302’s digital inputs are double buffered.
PAGE 8
MAX5302 Low-Power, 12-Bit Voltage-Output DAC with Serial Interface CS COMMAND EXECUTED SCLK 1 DIN 8 C1 C2 C0 D11 D10 D9 D8 9 D7 D6 16 D5 D4 D3 D2 D1 D0 S0 Figure 5. Serial-Interface Timing Diagram tCSW CS tCSO tCSS tCL tCP tCH tCSH tCS1 SCLK tDS tDH DIN Figure 6. Detailed Serial-Interface Timing Diagram DIN SCLK CS1 CS2 TO OTHER SERIAL DEVICES CS3 CS CS MAX5302 CS MAX5302 MAX5302 SCLK SCLK SCLK DIN DIN DIN Figure 7.
PAGE 9
Low-Power, 12-Bit Voltage-Output DAC with Serial Interface Applications Information Unipolar Output For a unipolar output, the output voltage and the reference input have the same polarity. Figure 8 shows the MAX5302 unipolar output circuit, which is also the typical operating circuit. Table 2 lists the unipolar output codes. Figure 9 illustrates a Rail-to-Rail® output.
PAGE 10
MAX5302 Low-Power, 12-Bit Voltage-Output DAC with Serial Interface R1 R2 REF +5V +5V REF VDD VDD 10k FB V+ FB MAX5302 10k DAC OUT VOUT DAC OUT V- GND MAX5302 GND R1 = R2 = 10kΩ ±0.1% Figure 9. Unipolar Rail-to-Rail Output Circuit Digitally Programmable Current Source The circuit of Figure 12 places an NPN transistor (2N3904 or similar) within the op amp feedback loop to implement a digitally programmable, unidirectional current source.
PAGE 11
Low-Power, 12-Bit Voltage-Output DAC with Serial Interface MAX5302 +5V AC REFERENCE INPUT +5V 26k +5V MAX495 REF VDD VL MAX5302 500mVp-p IOUT DAC 10k VDD REF OUT 2N3904 FB DAC OUT GND R MAX5302 GND Figure 11. AC Reference Input Circuit Figure 12.
PAGE 12
Low-Power, 12-Bit Voltage-Output DAC with Serial Interface 8LUMAXD.EPS MAX5302 Package Information 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.