THV3543 Datasheet, PDF (12/19 Pages) THine Electronics, Inc. – 2 channel Buck/Boost 2 channel Charge Pump Controller

THV3543_Rev.1.00_E
Voltage Reference Circuit
Voltage reference circuit generates temperature-compensated voltage (1.2V) which is used as the internal reference
voltage. Also an external load current (up to 1mA, maximum) can be obtained from VREF pin. Please connect a
capacitor (0.01µF) between VREF pin and SGND for stability.
VREG5
VREG5 is Built-in 5V local regulator. Please connect an external capacitor (10µF) between VREG5 pin and SGND.
Oscillator Circuit
Oscillation frequency is internally fixed at 500kHz.
Thermal Shut Down (TSD)
Thermal Shut Down circuit is built in to prevent damages caused by excessive heat. When the junction temperature
reaches 175 °C, TSD circuit stops switching operation and the regulator VREG5 operation. The release temperature is
160°C.
DC/DC Converter CH-1, CH-2
CH-1 and CH-2 are PWM controllers. CH-1 is for Boost, CH-2 is fixed at 3.3V for Buck. Power MOSFET and Over
Current Detection Circuit are built in. Maximum Duty Cycle ratio of CH-1 LX1 pin is 8.3%, CH-2 LL2 pin is 88%.
Charge Pump Circuit VGH, VGL
VGH is positive charge pump, and VGL is negative. VGH and VGL also can operate in PFM mode. The duty cycle
ratio of VGH is fixed at 50%, VGL is fixed at 80%.
VO2_OK, VGH_OK
VO2_OK and VGH_OK are open drain output of the pull-down transistor. When the power supply is turned on, the
transistor is turned on pulling VO2_OK pin and VGH_OK pin to ground level. When each voltage on CH-2 and VGH
reaches 85% of normal output voltage, VO2_OK and VGH_OK are turned off respectively.
Load Switch Control
LSW_OUT1 pin controls the external P-CH MOSFET load switch after normal start-up of VGL. Soft start function is
built in.
LSW_OUT2 pin is open drain output. When PG_LOGIC pin is turned High level, pull-down transistor is turned off.
LSW_OUT2 pin can be used as the external N-CH MOSFET load switch controller or level shifter.
Operational Amplifier
Operational amplifier is used for Vcom or Half AVDD. Use an external bipolar transistor when large output current
is required.
LDO
LDO have built-in recovery type current limiting protection. The load current capacity is within 250mA. The output
voltage is set by external resistance (See “Output Voltage Setting (LDO)”).
Copyright© 2011 THine Electronics, Inc.
12/19
THine Electronics, Inc.