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10-Bit and 12-Bit, 1MSPS SAR ADCs

ISL267440, ISL267450A

The ISL267440 and ISL267450A are 10-bit and 12-bit, 1MSPS

sampling SAR-type ADCs featuring excellent linearity over supply

and temperature variations, which are drop-in compatible with

the AD7440 and AD7450A. The robust, fully-differential input

offers high impedance to minimize errors due to leakage

currents, and the specified measurement accuracy is maintained

with input signals up to the supply rails.

The reference accepts inputs from 0.1V to 2.2V for 3V operation

and 0.1V to 3.5V for 5V operation, which provides design

flexibility in a wide variety of applications. The ISL267440,

ISL267450A also feature up to 8kV Human Body Model ESD

survivability.

The serial digital interface is SPI compatible and is easily

interfaced to all popular FPGAs and microcontrollers. Power

dissipation is 8.5mW at a sampling rate of 1MSPS, and just 5µW

between conversions utilizing Auto Power-Down mode (with a 5V

supply), making the ISL267440, ISL267450A excellent solutions

for remote industrial sensors and battery-powered instruments.

The ISL267440, ISL267450A are available in an 8 lead MSOP

package, and are specified for operation over the Industrial

temperature range (–40°C to +85°C).

Features

• Drop-in Compatible with AD7440, AD7450A

• Differential Input

• Simple SPI-compatible Serial Digital Interface

• Guaranteed No Missing Codes

• 1MHz Sampling Rate

• 3V or 5V Operation

•Low Operating Current

- 1.25mA at 1MSPS with 3V Supplies

- 1.70mA at 1MSPS with 5V Supplies

• Power-down Current between Conversions: 1µA

• Excellent Differential Non-Linearity

• Low THD: -83dB (typ)

• Pb-Free (RoHS Compliant)

• Available in MSOP Package

Applications

• Remote Data Acquisition

• Battery Operated Systems

• Industrial Process Control

• Energy Measurement

• Data Acquisition Systems

• Pressure Sensors

• Flow Controllers

FIGURE 1. BLOCK DIAGRAM

FIGURE 2. DIFFERENTIAL LINEARITY ERROR vs CODE

SERIAL

INTERFACE

VDD

VREF

GND

VIN+

VIN

–

SCLK

SDATA

CS

SAR

LOGIC

VREF

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

0

1024

2048

3072

4096

CODE

December 5, 2011

FN7708.0

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.

All other trademarks mentioned are the property of their respective owners.