U2102B Datasheet, PDF (7/19 Pages) TEMIC Semiconductors – Multifunction Timer

Figure 3-3. Power Supply as Static Zero-voltage Switch for AC Loads
U2102B
Sync
16
Voltage
limitation
+V_S
15
Push
pull
14
Temp.
monit.
GND
13
R₁ = R_sync
Load
V_mains
C₁
IGBT
R_G
R_sh
4. Voltage Monitoring
The internal voltage monitoring circuit surpresses uncontrolled conditions or output pulses of
insufficient amplitude which may occur while the operating voltage is being built up or reduced.
All latches in the circuit, the divider and the control logic are reset. When the supply voltage is
applied, the enable threshold (clamp voltage) of approximately 16 V must be reached so that the
circuit is enabled. The circuit is reset at approximately 11 V if the supply voltage breaks down. A
further threshold is activated in reverse phase control mode. If the supply voltage breaks down
in this mode, after the circuit has been enabled, the output stage is switched off at approximately
12.5 V, while the other parts of the circuit are not affected. The output stage can then be
switched on again in the following half-wave. As a result, the residual phase angle remains just
large enough, (e.g., in two-wire systems), so that the circuit can still be properly supplied with
power. In all operating modes, a single operating cycle is started after the supply voltage is
applied, independently of the trigger inputs, in order to immediately demonstrate the overall
function.
5. Chip Temperature Monitoring
The U2102B includes a chip temperature monitoring circuit which disables the output stage
when a temperature of approximately 140°C is reached. The circuit will only be enabled again
after cooling down and when the operating voltage has been additionally switched off and on.
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4767B–INDCO–10/05