LTC1400

1

1400fa

Complete SO-8, 12-Bit,

400ksps ADC with

Shutdown

which draws only 75mW from 5V or ±5V supplies. This

easy-to-use device comes complete with a 200ns sample-

and-hold and a precision reference. Unipolar and bipolar

conversion modes add to the flexibility of the ADC. The

LTC1400 has two power saving modes: Nap and Sleep.

In Nap mode, it consumes only 6mW of power and can

wake up and convert immediately. In the Sleep mode, it

consumes 30μW of power typically. Upon power-up from

Sleepmode,areferenceready(REFRDY)signalisavailable

in the serial data word to indicate that the reference has

settled and the chip is ready to convert.

The LTC1400 converts 0V to 4.096V unipolar inputs from

a single 5V supply and ±2.048V bipolar inputs from ±5V

supplies. Maximum DC specs include ±1LSB INL, ±1LSB

DNL and 45ppm/°C drift over temperature. Guaranteed AC

performance includes 70dB S/(N + D) and –76dB THD at

an input frequency of 100kHz, over temperature.

The 3-wire serial port allows compact and efficient data

transfer to a wide range of microprocessors, microcon-

trollers and DSPs.

■

High Speed Data Acquisition

■

Digital Signal Processing

■

Multiplexed Data Acquisition Systems

■

Audio and Telecom Processing

■

Digital Radio

■

Spectrum Analysis

■

Low Power and Battery-Operated Systems

■

Handheld or Portable Instruments

■

Complete 12-Bit ADC in SO-8

■

Single Supply 5V or ±5V Operation

■

Sample Rate: 400ksps

■

Power Dissipation: 75mW (Typ)

■

72dB S/(N + D) and –80dB THD at Nyquist

■

No Missing Codes over Temperature

■

Nap Mode with Instant Wake-Up: 6mW

■

Sleep Mode: 30μW

■

High Impedance Analog Input

■

Input Range (1mV/LSB): 0V to 4.096V or ±2.048V

■

Internal Reference Can Be Overdriven Externally

■

3-Wire Interface to DSPs and Processors (SPI and

Single 5V Supply, 400kHz, 12-Bit Sampling A/D Converter

APPLICATIO S

FEATURES

DESCRIPTIO

TYPICAL APPLICATIO

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

GND

CONV

CLK

MPU

P1.4

P1.3

P1.2

LTC1400

+

0.1

µF

10

µF

+

0.1

µF

10

µF

ANALOG INPUT

(0V TO 4.096V)

SERIAL

DATA LINK

5V

1400 TA01

SAMPLE RATE (Hz)

0.01

100

10

1

0.1

0.01

0.001

10

1k

1M

1400 TA02

0.1

1

100

10k 100k

NORMAL CONVERSION

NAP MODE

BETWEEN CONVERSION

SLEEP AND NAP MODE

BETWEEN CONVERSION

SLEEP MODE BETWEEN

CONVERSION

6.4MHz CLOCK

Power Consumption vs Sample Rate