Preliminary Datasheet 380kHz, 2A Asynchronous DC-DC Buck Converter AP3202 General Description Features The AP3202 is a 380kHz fixed frequency, current Input Voltage Range: 4.75V to 18V mode, PWM buck (step-down) DC-DC converter, Fixed 380kHz Frequency capable of driving a 2A load with high efficiency, High Efficiency: up to 93% excellent line and load regulation. The device Output Current: 2A integrates N-channel power MOSFET switch with Current Mode Control low on-resistance. Current mode control provides fast Built-in Over Current Protection transient response and cycle-by-cycle current limit. Built-in Thermal Shutdown Function Built-in UVLO Function A standard series of inductors are available from Built-in Over Voltage Protection several different manufacturers optimized for use Built-in Soft-start with the AP3202. This feature greatly simplifies the design of switch-mode power supplies. Applications This IC is available in SOIC-8 package. LCD TV Set Top Box Portable DVD Digital Photo Frame SOIC-8 Figure 1. Package Type of AP3202 Mar. 2011 Rev. 1. 2 BCD Semiconductor Manufacturing Limited 1 Preliminary Datasheet 380kHz, 2A Asynchronous DC-DC Buck Converter AP3202 Pin Configuration M Package (SOIC-8) Figure 2. Pin Configuration of AP3202 (Top View) Pin Description Pin Number Pin Name Function Bootstrap pin. A bootstrap capacitor is connected between the BS pin 1 BS and SW pin. The voltage across the bootstrap capacitor drives the internal high-side power MOSFET Supply input pin. A capacitor should be connected between the IN pin 2 IN and GND pin to keep the input voltage constant Power switch output pin. This pin is connected to the inductor and 3 SW bootstrap capacitor 4 GND Ground pin Feedback pin. This pin is connected to an external resistor divider to program the system output voltage. When the FB pin voltage exceeds 5 FB 20% of the nominal regulation value of 1.222V, the over voltage protection is triggered. When the FB pin voltage is below 0.6V, the oscillator frequency is lowered to realize short circuit protection Compensation pin. This pin is the output of the transconductance error amplifier and the input to the current comparator. It is used to 6 COMP compensate the control loop. Connect a series RC network from this pin to GND. In some cases, an additional capacitor from this pin to GND pin is required Control input pin. Forcing this pin above 1.5V or set this pin floating enables the IC. Forcing this pin below 0.5V shuts down the IC. When 7 EN the IC is in shutdown mode, all functions are disabled to decrease the supply current below 1 A 8 NC No Connection Mar. 2011 Rev. 1. 2 BCD Semiconductor Manufacturing Limited 2