STCC05-B

2/13

FUNCTIONAL DESCRIPTION

The STCC05 is a control circuit embedding most of the analog & power circuitry of an air conditioner or

refrigirator control module. It interfaces the micro-controller MCU with the AC power and cooling process

sections.

The 5V voltage regulator supplies the micro-controller MCU. Its input voltage ranges from 7V to 18V; and

its average DC output current up to 50mA. With an output filtering capacitor of 100µF, its output voltage

The regulator includes also an over current limiter and a thermal shutdown. The over current limiter pro-

tects the regulator against output short circuits and inrush currents during the power up. The current limiter

is made of a serial shunt resistance as current sensor and a circuit that regulates the input current. More-

over, the thermal shutdown protects the whole circuit against overload operations. It is made of a thermal

sensing junction and a hysteresis comparator that is able to switch off the passing element.

Figure 2. Block diagram

Figure 3. Pin-out connections

RST\

ZVS

COM

SYN

20A RELAY

DRIVER

RELAY DRIVER

RELAY DRIVER

RELAY DRIVER

5V REGULATOR

BUZZER

DRIVER

30µs FILTER

EMI FILTER

ZERO VOLTS SYNC.

RESET

LEVEL SHIFTER

SYN

/RST

COM

ZVS

1

2

3

4

5

6

7

8

9

10

13

12

11

16

15

14

17

18

19

20

1.25 V

Reference

R

1

R

2

Over current

Limiter

R

SENSE

Thermal

Shutdown

V

V

/RST

V

DD

C

100nF

RESET

V

DD

3k

Ω

6k

Ω

V

DD

R

MCU