Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsData collecting ICsData acquisition IC - AD converter (ADC) External , Internal uMAX 8

General Description

The MAX1272/MAX1273 multirange 12-bit data-acquisi-

tion systems (DAS) operate with a single 5V supply. The

software-programmable analog input accepts a variety

of voltage ranges: ±10V, ±5V, 0 to 10V, 0 to 5V for the

MAX1272; ±V

REF

, ±V

REF

/2, 0 to V

REF

, 0 to V

REF

/2 for the

MAX1273. The software-selectable extended analog

input range increases the effective dynamic range to 14

bits and provides the flexibility to interface 4–20mA pow-

ered sensors directly to a single 5V system. In addition,

the MAX1272 provides fault protection to ±12V. Other

features include a 5MHz track/hold (T/H) bandwidth,

87ksps throughput rate, and internal (4.096V) or external

(2.40V to 4.18V) reference.

The MAX1272/MAX1273 serial interfaces connect

directly to SPI/QSPI™/MICROWIRE

-compatible

devices without any external logic.

Four software-programmable power-down modes

(delayed standby, immediate standby, delayed full power-

down, and immediate full power-down) provide low-cur-

rent shutdown between conversions. In standby mode, the

internal reference buffer remains active, thus eliminating

startup delay.

The MAX1272/MAX1273 are available in an 8-pin

µMAX

package. Both devices are available in the

extended (-40°C to +85°C) temperature range.

Applications

Industrial Control Systems

Data-Acquisition Systems

Robotics

Automatic Testing

Battery-Powered Instruments

Medical Instruments

Features

o Four Software-Selectable Input Ranges

MAX1272: 0 to 10V, 0 to 5V, ±10V, ±5V

MAX1273: 0 to V

REF

, 0 to V

REF

/2, ±V

REF

±V

REF

o 12-Bit Resolution, No Missing Codes

o 5V Single-Supply Operation

o SPI/QSPI/MICROWIRE-Compatible 3-Wire

Interface

o 87ksps Sampling Rate

o ±12V Fault-Protected Analog Input (MAX1272)

o Internal (4.096V) or External (2.4V to 4.18V)

Reference

o Low Power

1.5mA at 87ksps

0.4mA at 10ksps

0.2mA at 1ksps

o Four Power-Down Modes

o 8-Pin µMAX Package

MAX1272/MAX1273

Fault-Protected, 12-Bit ADCs

with Software-Selectable Input Range

________________________________________________________________

Maxim Integrated Products

DOUT

REF

AINGND

VDD

DIN

SCLK

MAX1272

MAX1273

µMAX

TOP VIEW

Pin Configuration

Ordering Information

19-2921; Rev 3; 12/11

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP

RANGE

PIN-

PACKAGE

INL

(LSB)

MAX1272EUA+ -40°C to +85°C

8 µMAX ±1

MAX1273EUA+ -40°C to +85°C

8 µMAX ±1

QSPI is a trademark of Motorola, Inc.

MICROWIRE is a registered trademark of National Semiconductor Corp.

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

Denotes a lead(Pb)-free/RoHS-compliant package.

Typical Application Circuit appears at end of data sheet.

EVALUATION KIT

AVAILABLE

Summary of content (19 pages)

PAGE 1
9-2921; Rev 3; 12/11 KIT ATION EVALU LE B A IL A AV Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range The MAX1272/MAX1273 multirange 12-bit data-acquisition systems (DAS) operate with a single 5V supply. The software-programmable analog input accepts a variety of voltage ranges: ±10V, ±5V, 0 to 10V, 0 to 5V for the MAX1272; ±VREF, ±VREF/2, 0 to VREF, 0 to VREF/2 for the MAX1273.
PAGE 2
MAX1272/MAX1273 Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range ABSOLUTE MAXIMUM RATINGS VDD to GND ..............................................................-0.3V to +6V AIN to GND (MAX1272) ...................................................... ±12V AIN to GND (MAX1273) ........................................................ ±6V DOUT, CS, DIN, SCLK, REF to GND..........-0.3V to (VDD + 0.3V) Maximum Current into Any Pin............................................
PAGE 3
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range (VDD = 4.75V to 5.25V, unipolar/bipolar input range, external reference mode, VREF = 4.096V, CREF = 1.0μF, fSCLK = 1.4MHz, 50% duty cycle, CLOAD = 50pF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETERS Small-Signal Bandwidth SYMBOL BW-3dB CONDITIONS ±5V (MAX1272) or ±VREF/2 (MAX1273) range 2.5 0 to 10V (MAX1272) or 0 to VREF (MAX1273) range 2.
PAGE 4
MAX1272/MAX1273 Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range ELECTRICAL CHARACTERISTICS (continued) (VDD = 4.75V to 5.25V, unipolar/bipolar input range, external reference mode, VREF = 4.096V, CREF = 1.0μF, fSCLK = 1.4MHz, 50% duty cycle, CLOAD = 50pF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETERS SYMBOL Input Current CONDITIONS Converting VREF = 4.
PAGE 5
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range (VDD = 4.75V to 5.25V, unipolar/bipolar input range, external reference mode, VREF = 4.096V, CREF = 1.0μF, fSCLK = 1.4MHz, 50% duty cycle, CLOAD = 50pF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 6
Typical Operating Characteristics (continued) (Typical operating circuit, BIP = RNG = 1, VDD = 5V, external reference mode, VREF = 4.096V, CREF = 1.0μF, fSCLK = 1.4MHz, 50% duty cycle, 87ksps, TA = +25°C, unless otherwise noted.) 0.6 0.5 0.4 8 INTERNAL REFERENCE 0.3 0.2 7 6 5 4 3 INTERNAL/EXTERNAL REFERENCE 2 EXTERNAL REFERENCE 0.1 1 0 -15 10 35 85 60 4 3 INTERNAL/EXTERNAL REFERENCE 4.75 4.80 4.85 4.90 4.95 5.00 5.05 5.10 5.15 5.20 5.25 SUPPLY VOLTAGE (V) 0.9990 0.9985 0.9980 0.9975 0.
PAGE 7
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range SUPPLY CURRENT vs. CONVERSION RATE FFT PLOT -20 -60 -80 -100 -120 VAIN = 0 STANDBY POWER-DOWN MODE BETWEEN CONVERSIONS 2000 SUPPLY CURRENT (μA) AMPLITUDE (dB) -40 2500 MAX1272/73 toc12 fAIN = 10kHz MAX1272/73 toc11 0 1500 EXTERNAL REFERENCE 1000 INTERNAL REFERENCE 500 -140 -160 0 20 30 40 50 0.1 OFFSET ERROR vs. SUPPLY VOLTAGE OFFSET ERROR vs.
PAGE 8
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range MAX1272/MAX1273 Pin Description PIN NAME FUNCTION 1 SCLK 2 DIN Serial Data Input. Data clocks in on the rising edge of SCLK. 3 VDD 5V Supply. Bypass with a 0.1μF capacitor to GND. 4 GND Ground 5 AIN Analog Input 6 REF Reference Buffer Output/Reference Input. Bypass REF with a 1μF capacitor to GND. In internal reference mode, the reference buffer provides a 4.096V nominal output.
PAGE 9
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range CS SCLK SERIAL INTERFACE LOGIC VDD MAX1272 MAX1273 GND AIN DOUT MAX1272/MAX1273 DIN SIGNAL CONDITIONING OUT T/H IN 12-BIT SAR ADC CLK REF REF 4.096V REFERENCE Figure 2. Simplified Block Diagram Table 1.
PAGE 10
MAX1272/MAX1273 Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range Table 2. Input Range and Polarity Selection for MAX1272 NEGATIVE FULL SCALE ZERO SCALE FULL SCALE 0 — 0 VREF × 1.2207 1 -VREF × 1.2207 0 VREF × 1.2207 0 — 0 VREF × 2.4414 1 -VREF × 2.4414 0 VREF × 2.4414 ZERO SCALE FULL SCALE INPUT RANGE RNG BIP 0 to 5V 0 ±5V 0 0 to 10V 1 ±10V 1 Table 3.
PAGE 11
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range MAX1272/MAX1273 ••• CS tCSS tCH tCL tCSH tCSH SCLK ••• tDS tDH ••• DIN tDO tDV tTR ••• DOUT Figure 4. Detailed Serial Interface Timing ACQUISITION 4 SCLKs CONVERSION 12 SCLKs HI-Z 32 24 D1 D3 D2 D4 D5 16 D7 D6 D9 8 1 SCLK LSB D8 D11 MSB D10 HI-Z DOUT D0 RESERVED REF MODE0 PD MODE1 BIP START DIN RNG CS AUTO STANDBY Figure 5.
PAGE 12
MAX1272/MAX1273 Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range CS ACQUISITION 4 SCLKs MODE1 BIP PD START RNG D0 D2 D1 D3 D5 32 D4 D7 D9 D8 D11 24 D10 D0 D2 D1 D3 D4 D5 CONVERSION 12 SCLKs LSB RESULT 1 D6 RESERVED REF MODE1 MODE0 BIP PD RNG START ACQUISITION 4 SCLKs MSB 16 D7 D9 D8 8 1 DOUT LSB RESULT 0 D10 D11 MSB D6 RESERVED HI-Z SCLK CONTROL BYTE 2 CONTROL BYTE 1 REF MODE1 MODE0 BIP PD START DIN RNG CONTROL BYTE 0 CONVERS
PAGE 13
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range IN MAX6064 REF CREF MAX1272 MAX1273 1.0μF OUT REF MAX1272 MAX1273 1.0μF CREF GND Figure 7a. Internal Reference Configuration Figure 7b. External Reference Configuration External Reference To use an external reference, disable the internal buffer by setting the REF bit in the 8-bit control word to zero (see Table 1), and apply a reference voltage to REF. Use an external reference voltage ranging from 2.40V to 4.18V.
PAGE 14
MAX1272/MAX1273 Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range ACQUISITION 4 SCLKs REF RESERVED MODE0 PD MODE1 BIP RNG START D1 D2 D3 D4 24 32 D5 D6 D8 D7 HI-Z 16 SCLK 8 1 D11 DOUT LSB D9 MSB D10 HI-Z D0 RESERVED REF 0 0 MODE1 RNG DIN BIP START CS CONVERSION 12 SCLKs POWERED UP POWERED UP POWERED DOWN Figure 8.
PAGE 15
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range PIC16 with SSP Module and PIC17 Interface The MAX1272/MAX1273 are compatible with a PIC16/PIC17 controller (μC) using the synchronous serial-port (SSP) module.
PAGE 16
MAX1272/MAX1273 Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range Table 5. Detailed SSPCON Register Contents—PIC16/PIC17 CONTROL BIT SYNCHRONOUS SERIAL-PORT CONTROL REGISTER (SSPCON) WCOL BIT7 X Write Collision Detection Bit SSPOV BIT6 X Receive Overflow Detection Bit SSPEN BIT5 1 Synchronous Serial-Port Enable Bit: 0: Disables serial port and configures these pins as I/O port pins. 1: Enables serial port and configures SCK, SDO, and SCI pins as serial port pins.
PAGE 17
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range Definitions Integral Nonlinearity Integral nonlinearity (INL) is the deviation of the values on an actual transfer function from a straight line. This straight line can be either a best-straight-line fit or a line drawn between the endpoints of the transfer function, once offset and gain errors have been nullified. The static linearity parameters for the MAX1272/MAX1273 are measured using the endpoint method.
PAGE 18
MAX1272/MAX1273 Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range Typical Operating Circuit 5V SUPPLIES 0.1μF 5V VLOGIC = 5V GND VDD AIN R* = 5Ω CS 0.1μF VDD SCLK GND MAX1272 MAX1273 5V MAX1272 MAX1273 DGND DIGITAL CIRCUITRY REF 1.0μF I/O SCK μP DIN MOSI DOUT MISO GND *OPTIONAL Figure 14. Power-Supply Grounding Connections Package Information Chip Information PROCESS: BiCMOS 18 For the latest package outline information and land patterns (footprints), go to www.
PAGE 19
Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range REVISION NUMBER REVISION DATE 0 7/03 1 12/03 Update Table 1 2 5/04 Removed all references to μMAX packages. 3 12/11 Replaced PDIP packages with μMAX packages.