DS56

3 of 6

102299

OVERVIEW

A block diagram of the DS56 is shown in Figure 1. The DS56 consists of three major components:

1. Precision bandgap voltage reference

2. Temperature sensor

3. Thermostat comparators

The DS56 incorporates an internal temperature sensor with a typical transfer function of (in mV with T

expressed in °C):

impedance of 1.5 k

Ω.

The DS56 has two independent temperature comparators, each with its own input (or trip point) and

output.

Additionally, the hysteresis for both comparators is typically 5°C (31.0 mV).

The DS56 bandgap voltage reference is available on pin 1 to allow for a designer to set the trip point(s)

by resistively dividing the reference voltage. One possible scenario is illustrated in Figure 1. For optimum

performance, the VREF pin should be connected to a 50 µA load.

The comparator outputs are taken off-chip via open-drain FETs, thus requiring external pullups. The

thermostat transfer function is illustrated in Figure 2.

The supply range of the DS56 is 2.7V to 5.5V, allowing for applications ranging from industrial control

to battery-powered portable equipment.

THERMOSTAT OUTPUT TRANSFER FUNCTION Figure 2