Datasheet

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

General Description

The MAX5822 is a dual, 12-bit, voltage-output, digital-to-

analog converter (DAC) with an I

C-compatible, 2-wire

interface that operates at clock rates up to 400kHz. The

device operates from a single 2.7V to 5.5V supply and

draws only 115µA at V

= 3.6V. A power-down mode

decreases current consumption to less than 1µA. The

MAX5822 features three software-selectable power-

down output impedances: 100kΩ, 1kΩ, and high imped-

ance. Other features include internal precision rail-to-rail

output buffers and a power-on reset (POR) circuit that

powers up the DAC in the 100kΩ power-down mode.

The MAX5822 features a double-buffered I

C-compatible

serial interface that allows multiple devices to share a

single bus. All logic inputs are CMOS-logic compatible

and buffered with Schmitt triggers, allowing direct inter-

facing to optocoupled and transformer-isolated inter-

faces. The MAX5822 minimizes digital noise feedthrough

by disconnecting the clock (SCL) signal from the rest of

the device when an address mismatch is detected.

The MAX5822 is specified over the extended tempera-

ture range of -40°C to +85°C and is available in a minia-

ture 8-pin µMAX

package. Refer to the MAX5821 data

sheet for the 10-bit version and the MAX5820 data sheet

for the 8-bit version.

Applications

Digital Gain and Offset Adjustments

Programmable Voltage and Current Sources

Programmable Attenuation

VCO/Varactor Diode Control

Low-Cost Instrumentation

Battery-Powered Instrumentation

Features

♦ Ultra-Low Supply Current

115µA at V

= 3.6V

135µA at V

= 5.5V

♦ 300nA Low-Power Power-Down Mode

♦ Single 2.7V to 5.5V Supply Voltage

♦ Fast 400kHz I

C-Compatible 2-Wire Serial

Interface

♦ Schmitt-Trigger Inputs for Direct Interfacing to

Optocouplers

♦ Rail-to-Rail Output Buffer Amplifiers

♦ Three Software-Selectable Power-Down Output

Impedances

100kΩ, 1kΩ, and High Impedance

♦ Read-Back Mode for Bus and Data Checking

♦ Power-On Reset to Zero

♦ 8-Pin µMAX Package

MAX5822

Dual, 12-Bit, Low-Power, 2-Wire, Serial

Voltage-Output DAC

________________________________________________________________ Maxim Integrated Products 1

REF

SDASCL

OUTB

OUTAGND

ADD

μMAX

TOP VIEW

MAX5822

Pin Configuration

Ordering Information

μC

SDA

SCL

SDA

REF

SCL

OUTA

OUTB

OUTA

OUTB

MAX5822

Typical Operating Circuit

19-2315; Rev 1; 3/05

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP

RANGE

PIN-

PACKAGE

ADDRESS

MAX5822LEUA

-40

C to +85

8 µMAX

0111 00X

MAX5822MEUA

-40

C to +85

8 µMAX

1011 00X

µMAX is a registered trademark of Maxim Integrated Products, Inc.

Summary of content (13 pages)

PAGE 1
9-2315; Rev 1; 3/05 Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC The MAX5822 is a dual, 12-bit, voltage-output, digital-toanalog converter (DAC) with an I2C-compatible, 2-wire interface that operates at clock rates up to 400kHz. The device operates from a single 2.7V to 5.5V supply and draws only 115µA at VDD = 3.6V. A power-down mode decreases current consumption to less than 1µA. The MAX5822 features three software-selectable powerdown output impedances: 100kΩ, 1kΩ, and high impedance.
PAGE 2
MAX5822 Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC ABSOLUTE MAXIMUM RATINGS VDD, SCL, SDA to GND ............................................-0.3V to +6V OUT_, REF, ADD to GND..............................-0.3V to VDD + 0.3V Maximum Current into Any Pin............................................50mA Continuous Power Dissipation (TA = +70°C) 8-Pin µMAX (derate 4.5mW above +70°C) ..................362mW Operating Temperature Range ...........................
PAGE 3
Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC (VDD = +2.7V to +5.5V, GND = 0, VREF = VDD, RL = 5kΩ, CL = 200pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = +5V, TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX 0.05 x VDD Input Hysteresis Input Leakage Current V ±0.1 Digital inputs = 0 or VDD Input Capacitance UNITS ±1 6 µA pF DIGITAL OUTPUT (SDA) Output Logic Low Voltage Three-State Leakage Current VOL IL ISINK = 3mA ±0.
PAGE 4
ELECTRICAL CHARACTERISTICS (continued) (VDD = +2.7V to +5.5V, GND = 0, VREF = VDD, RL = 5kΩ, CL = 200pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VDD = +5V, TA = +25°C.) (Note 1) PARAMETER SYMBOL STOP Condition Setup Time CONDITIONS MIN tSU,STO Bus Capacitance Cb Maximum Duration of Suppressed Pulse Widths tSP TYP MAX UNITS 400 pF 50 ns 0.6 µs (Note 5) 0 All devices are 100% production tested at TA = +25°C and are guaranteed by design at TA = TMIN to TMAX.
PAGE 5
Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC ZERO-CODE ERROR vs. SUPPLY VOLTAGE ZERO-CODE ERROR vs. TEMPERATURE 4 2 6 4 2 3.4 4.1 4.8 5.5 -15 10 35 60 85 MAX5822 toc09 3.4 2.7 4.1 4.8 SUPPLY VOLTAGE (V) GAIN ERROR vs. TEMPERATURE DAC OUTPUT VOLTAGE vs. OUTPUT SOURCE CURRENT (NOTE 6) DAC OUTPUT VOLTAGE vs. OUTPUT SINK CURRENT (NOTE 6) -1.2 -0.8 -0.4 4 3 2 1 -15 10 35 60 1.5 CODE = 400 hex 1.0 0.5 CODE = FFF hex NO LOAD 0 MAX5822 toc12 2.
PAGE 6
Typical Operating Characteristics (continued) (VDD = +5V, RL = 5kΩ, TA = +25°C.) POWER-DOWN SUPPLY CURRENT vs. SUPPLY VOLTAGE POWER-UP GLITCH EXITING SHUTDOWN MAX5822 toc17 MAX5822 toc16 500 ZOUT = HIGH IMPEDANCE NO LOAD POWER-DOWN SUPPLY CURRENT (nA) MAX5822 Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC 400 300 MAX5822 toc18 5V VDD TA = -40°C TA = +25°C 0 500mV/div OUT_ 200 10mV/div OUT_ 100 TA = +85°C CLOAD = 200pF CODE = 800 hex 0 2.7 3.4 4.1 4.
PAGE 7
Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC PIN NAME 1 VDD Power Supply FUNCTION 2 GND Ground 3 ADD Address Select. A logic high sets the address LSB to 1; a logic low sets the address LSB to 0. 4 SCL Serial Clock Input 5 SDA Bidirectional Serial Data Interface 6 REF Reference Input 7 OUTA DAC A Output 8 OUTB DAC B Output Detailed Description The MAX5822 is a dual, 12-bit, voltage-output DAC with an I 2 C/SMBus™-compatible 2-wire interface.
PAGE 8
MAX5822 Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC START and STOP Conditions When the serial interface is inactive, SDA and SCL idle high. A master device initiates communication by issuing a START condition. A START condition is a high-tolow transition on SDA with SCL high. A STOP condition is a low-to-high transition on SDA, while SCL is high (Figure 2). A START condition from the master signals the beginning of a transmission to the MAX5822.
PAGE 9
Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC Sr P SCL SDA Figure 2. START and STOP Conditions SCL waits for a START condition followed by its slave address. The serial interface compares each address value bit by bit, allowing the interface to power down immediately, if an incorrect address is detected. The LSB of the address word is the Read/Write (R/W) bit.
PAGE 10
MAX5822 Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC MSB S LSB A6 A5 A4 A3 A2 A1 A0 R/W MSB D7 MSB ACK C3 LSB C2 C1 C0 D11 D10 D9 D8 ACK LSB D6 D5 D4 D3 D2 D1 D0 ACK P EXAMPLE-WRITE DATA SEQUENCE MSB S LSB A6 A5 A4 A3 A2 A1 A0 R/W MSB X MSB ACK C3 LSB C2 C1 C0 D11 X X X D10 D9 D8 ACK LSB X X X B A PD1 PD0 ACK P EXAMPLE-WRITE TO POWER-DOWN REGISTER SEQUENCE Figure 6. Example Write-Command Sequences (Figure 7).
PAGE 11
Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC MAX5822 Table 3. Command Byte Definitions SERIAL DATA INPUT FUNCTION C3 C2 C1 C0 D11 D10 D9 D8 0 0 0 0 DAC DATA DAC DATA DAC DATA DAC DATA Load DAC A input and DAC registers with new data. Contents of DAC B input registers are transferred to the DAC register. Both outputs are updated. 0 0 0 1 DAC DATA DAC DATA DAC DATA DAC DATA Load DAC B input and DAC registers with new data.
PAGE 12
MAX5822 Dual, 12-Bit, Low-Power, 2-Wire, Serial Voltage-Output DAC S MSB LSB A6 R/W =0 A4 A5 A3 A2 A1 A0 MSB LSB C3 ACK C2 C1 C0 D11 D10 D9 D8 ACK DATA BYTES GENERATED BY MASTER DEVICE Sr MSB LSB A6 R/W =1 A4 A5 A3 A2 A1 A0 MSB ACK X DATA BYTES GENERATED BY MAX5822 MSB D7 LSB X PD1 PD0 D11 D10 D9 D8 ACK ACK GENERATED BY MASTER DEVICE LSB D6 D5 D4 D3 D2 D1 D0 ACK P Figure 8.
PAGE 13
Dual, 12-Bit, Low-Power, 2-Wire Serial Voltage Output DAC E Ø0.50±0.1 8 INCHES DIM A A1 A2 b H c D e E H 0.6±0.1 1 L 1 α 0.6±0.1 S BOTTOM VIEW D MIN 0.002 0.030 MAX 0.043 0.006 0.037 0.014 0.010 0.007 0.005 0.120 0.116 0.0256 BSC 0.120 0.116 0.198 0.188 0.026 0.016 6∞ 0∞ 0.0207 BSC 8LUMAXD.EPS 4X S 8 MILLIMETERS MAX MIN 0.05 0.75 1.10 0.15 0.95 0.25 0.36 0.13 0.18 2.95 3.05 0.65 BSC 2.95 3.05 4.78 5.03 0.41 0.66 0∞ 6∞ 0.