THV3056 Datasheet, PDF (22/32 Pages) THine Electronics, Inc. – 3ch Buck/Boost 2ch CP 1ch HVLDO 1ch LVLDO Controller

THV3056_Rev.2.00_E
VGH/VGL
85%
85%
SCP
Latch Voltage=1.2V
SCP Latch Time >> VGH/VGL Startup Time
Figure 11. Charge Pump SCP Operation Waveform
● Over Voltage Protection(OVP)
OVP circuit stops the output, if the output voltage on ch-1/2/3 exceed the predetermined voltage. The internal OVP
comparator (with reference voltage of 1.5V for ch-1 and ch-3, 1.06V for ch-3) monitors the voltage on INV pins. The
output of OVP comparator is connected to OUT pin. When the voltage on INV pin exceeds 1.5V for ch-1 and ch-3,
1.06V for ch-2, OUT pin turns external MOS transistor Off and stops switching operation to prevent the output voltage
excessing the predetermined voltage.(See Figure 12.) Also, OVP comparator of ch-2 and ch-3 report the abnormal
operation to SCP circuit.
Vout
Rh
FB
Error AMP
PWM COMP
-
INV
+
100uA
VREF
OUT
OVP COMP
-
+
ch1, ch-3=1.5V
ch-2=1.06V
Figure 12. OVP Circuit
Note) Operation at FB - INV short circuit
　 When FB pin and INV pin are short circuited, the internal constant current circuit (100uA) affects the output voltage.
An approximate output voltage is given by the following formula.
　 The output voltage at FB-INV short circuited(Vout) = the normal output voltage x 1.25 + Rh x 100uA
Also, OVP comparator has Delay circuit of 0.5us to prevent the malfunction, so the actual output voltage will be higher
than the result of calculation.
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THine Electronics, Inc.