1

dc2507af

DEMO MANUAL DC2507A

Description

LTC2986 and LTC2986-1

Input Protected Universal Temperature

Measurement System on a Chip

Demonstration circuit DC2507A is a resistive protection

networkdesignedtointerfacetheLTC®2986demonstration

boards (DC2508 for LTC2986 or DC2618 for LTC2986-1).

The LTC2986 is a pin and software compatible 10-chan-

nel version of the 20-channel LTC2983. The LTC2986

includes several new modes enabling external protection/

filtering resistors for 2-/3-/4-wire RTDs, thermistors, and

thermocouples. The DC2507A includes a universal input

4-input terminal block, front end protection/filtering resis-

tors,andainterfaceforconnectingtotheDC2508/DC2618

demonstration circuit.

The 4-input terminal block (J1) can directly interface to a

single2-/3-/4-wireRTD,orathermistor,orathermocouple

(with 4 options for cold junction compensation). A single

hardware design is shared between all sensor types.

Switching between sensors simply requires a change in

software(channelassignmentprogramming).AllLTC2986

L

, LT, LTC, LTM, Linear Technology, the Linear logo and Linduino are registered trademarks

and QuikEval is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners.

input channels are isolated from the terminal block by a

2.4kΩ, 1W protection resistor, while the complementing

DC2508 contains 100pF filtering capacitors. As a refer-

ence, the DC2507A includes a top level hookup diagram

for each sensor type, see Figure 1.

The DC2507A requires a DC2531 or DC2608 kit. These kits

contain the LTC2986 motherboard (DC2508 or DC2618)

Additionally, QuikEval™ software is used to program

the LTC2986 channel assignment data and display the

temperature results.

Design files for this circuit board are available at

http://www.linear.com/demo/DC2507A

Figure 1. DC2507A Demonstration Board

TO DC2508 OR DC2618

AND DC2026

• 2-WIRE RTD

• 3-WIRE RTD

• 4-WIRE RTD

• THERMISTOR

• THERMOCOUPLE

UNIVERSAL

SENSOR INPUT

DC2507A F01