THV6520 Datasheet, PDF (9/11 Pages) THine Electronics, Inc. – THV6520 is a controller IC power supply system with

THV6520_Rev.1.00_E
up to ±75mA of output current. In transients, it can
deliver up to 150mA at which point the over current
protection circuit limits the output current. Excessive
current draw over a period of time may cause the chip
temperature to rise and set off the over temperature
protection circuit.
LDO
The THV6520 has a integrated LDO which can supply
up to 350mA current while the input voltage is 3.3V. It is
suitable for the supply voltage to timing controller and
source IC.
Protection circuits
Under voltage lock out protection (UVLO)
The UVLO function is carried in order to prevent
malfunction in the state where input voltage is low. A
boost converter is suspended to the power supply voltage
which can carry out operational stability. UVLO is
released by more than 1.8V input voltage. And a boost
converter carries out, after starting soft start operation.
During steady-state operation, if the output of the boost
converter is under 85% of the nominal value, the
THL6520 activates an internal fault timer. If any
condition indicates a continuous fault for the fault timer
duration (160ms typ), the IC sets the fault latch to shut
down all its output. Once the fault condition is removed,
cycle the VIN (below the UVLO falling threshold) to
clear the fault latch and reactivate the device. The
fault-detection circuit is disabled during the soft-start
ramp.
Soft start (SS)
The boost converter carries the soft start function in
order to prevent the rush current at a start-up. This
function is to raise output voltage slowly. It is because
overshooting and rush current occur when input voltage
is inputted. When power is turned on, an internal 4μA
current source charges an external capacitor connected as
SS. When power is turned off, the external capacitor will
be discharged for the next soft start cycle.
Over voltage protection (OVP)
Over voltage protection is built in. If VLS is
disconnecting, the output voltage of a boost converter is
stopped and destruction of IC is prevented.
Over current protection (OCP)
In order to restrict the over-current by the abnormalities
of load, etc., the over-current protection circuit is built in.
Over-current detection of pulse-by-pulse system is
adopted. An output transistor is turned off if the current
which flows into an output transistor reaches boost
converter limit current (Ilim). An over-current protection
circuit detects the peak current of an inductor.
Input-and-output voltage and ripple current is taken into
consideration.
Thermal shut down (TSD)
In order to prevent destruction by heat, the thermal
shutdown circuit is built in. If the junction temperature
Tj is 150^oC or more, the thermal shutdown circuit will
operate and it will stop switching operation. Moreover,
the hysteresis of a thermal shutdown circuit is 15^oC. If Tj
falls, output voltage will return.
Copyright© 2013 THine Electronics, Inc. All rights reserved.
THine Electronics, Inc.
9/12