© 2002 Microchip Technology Inc.

DS21414B-page 1

TC3405

Features

• 16-bit Resolution at Eight Conversions Per

Second, Adjustable Down to 10-bit Resolution at

512 Conversions Per Second

• 1.8V – 5.5V Operation, Low Power Operating

250

µA; Sleep: 35µA

• microPort™ Serial Bus Requires only two

Interface Lines

• Uses Internal or External Reference

• Automatically Enters Sleep Mode when not in use

• One Differential and Three Single-ended Inputs

with Built-In Multiplexer

Shutdown Mode

Applications

• Consumer Electronics, Thermostats, CO

Monitors, Humidity Meters, Security Sensors

• Embedded Systems, Data Loggers,

Portable Equipment

• Medical Instruments

Device Selection Table

Package Type

General Description

The TC3405 is a low cost, low power analog-to-digital

converter based on Microchip’s Sigma-Delta technol-

ogy. It will perform 16-bit conversions (15-bit plus sign)

at up to eight per second. The TC3405 is optimized for

use as a microcontroller peripheral in low cost, battery

operated systems. A voltage reference is included, or

a reset generator provides Power-on Reset and Brown-

out protection while an extra threshold detector is suit-

able for use as an early warning power fail detector, or

as a Wake-up Timer.

The TC3405’s 2-wire microPort™ digital interface is

used for starting conversions and for reading out the

data. Driving the SCLK line low starts a conversion.

After the conversion starts, each additional falling edge

the A/D resolution by one bit and cuts conversion time

in half. After a conversion is completed, clocking the

SCLK line puts the MSB through LSB of the resulting

data word onto the SDAT line, much like a shift register.

The part automatically sleeps when not performing a

data conversion.

TheTC3405isavailableina16-PinPDIPanda16-Pin

QSOP package.

Part

Number

Package

Temperature

Range

TC3405VPE

16-Pin PDIP (Narrow)

0

°Cto +85°C

TC3405VQR

16-Pin QSOP Narrow)

0

°Cto +85°C

16-Pin PDIP

16-Pin QSOP

1

16

215

314

413

512

611

710

IN4

89

IN1-

IN2

REFIN

GND

A0

VDD

SDAT

REFOUT

TC3405

SCLK

A1

RESET

VTH

IN3

ENABLE

IN1+

16-Bit, Low Cost, Low Power Sigma-Delta A/D Converter