STCC05-B Datasheet, PDF (2/13 Pages) STMicroelectronics – HOME APPLIANCE CONTROL CIRCUIT

STCC05-B
Figure 2. Block diagram
VPS
RL4
VPS
RL3
VPS
RL2
VPS
RL1
BZ2
BZ1
20A RELAY
DRIVER
RELAY DRIVER
RELAY DRIVER
RELAY DRIVER
VPS
BUZZER
DRIVER
VPS
VPS
5V REGULATOR
IN4
IN3
IN2
IN1
ENBZ
INBZ
VDD
COM
SYN
INS
RESET
ZERO VOLTS SYNC.
30µs FILTER
LEVEL SHIFTER
EMI FILTER
RST\
ZVS
OUTS
Figure 3. Pin-out connections
VPS
1
SYN
2
INS
3
RL1
4
RL2
5
RL3
6
RL4
7
BZ1
8
BZ2
9
ENBZ
10
20
VDD
19
/RST
18
ZVS
17
OUTS
16
IN1
15
IN2
14
IN3
13
IN4
12
INBZ
11
COM
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 voltage supply
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
accuracy is better than +/- 5% in the whole operating range of the ambient temperature T_AMB, the load
current I_DD and the input voltage V_PS , contributing directly to the ADC accuracy.
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.
VPS
R_SENSE
Thermal
Shutdown
Over current
Limiter
1.25 V
Reference
R₁
R₂
VDD
V_DD
VDD
VH
VL
V_H = 3.75 V
V_L = 3.40 V
V_DD
6kΩ
/RST
3kΩ
MCU
V_DD
R_UP > 100kΩ
RESET
C_UP =
100nF
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