7

7-37

SSTS Series

DESCRIPTION

The standard SSTS functionality combines a highly

accurate temperature sensor and a switch in a low cost,

compact, rugged unit. Temperature is monitored using a

thermistor configured with precision matched thick film

resistors in a bridge configuration. The module also

contains the control and amplifier electronics necessary to

drive a relay, used to switch motors or valves to control

the temperature in a system. The external load is driven

by the SSTS output transistor. The circuit can be tailored

for different input voltages, such as 12 Vdc, ideally suited

for automotive HVAC applications. The module "trips" at a

desired set point, and resets at an upper trip point

established by the hysteresis parameter (+1.5°C typical).

The module is designed with a "nose" protrusion that

extends into the flow path of the medium being measured.

This is typically placed in the evaporator of an air

conditioning unit. The electrical interface consists of +Vin,

Ground, and Output. The modules are constructed using

hybrid technology on a ceramic substrate.

The SSTS is exclusively available for customer specific

applications. The following design parameters need to be

specified by the customer:

• Lower temperature trip point

• Upper temperature trip point

• Output drive requirement

• "Nose" configuration

• Attachment configuration

• Socket/connector interface configuration.

• Nominal and min./max. supply voltage

NEW PRODUCT

SSTS SERIES

Solid State

Temperature Switch

CUSTOM POWER MODULES

Parameter

Conditions

Min.

Typ.

Max.

Units

Input Voltage

9

12

16

Vdc

Quiescent Current

Vin = 12V

10

mA

Trip Point

Nom. -0.5

*

Nom. +0.5

°C

Hysteresis

**

°C

Output Saturation

Ic = 150mA

0.3

V

Operating Temperature

-40

+85

°C

ELECTRICAL

* Trip point available in 0.5°C increments.

** Custom Hysteresis settings are available (1.5°C typical).

Specifications subject to change without notice.

SSTS shown prior to encapsulation and as a finished assembly.