1、Features

• Bidirectional single Inductor Buck-Boost Controller for Step-Up/Step-Down DC/DC Conversion and battery charge management

• Bidirectional buck-boost operation to support battery charging and discharging using OTG signal

• Dynamical programming of input current, Outputcurrent and Output voltage using PWM signal or

  analog signal

• 1 Cell to 6 Cells battery charge management

• 2V to 32 V wide output range

• Comprehensive protection features including Output Short Protection (OSP), Cycle-by-Cycle input and output Peak Current Limit, thermal regulation, thermal shutdown, input UVLO, input OVP, output OVP etc.

• Adjustable Switching Frequency using resistor

• Frequency dithering for good EMI performance

• Integrated 2-A MOSFET Gate Drivers

• Integrated two 9mΩ power MOSFETs

• Input or Output Average Current Limiting withstable CC loop

• Available in QFN6x6-48 Package

2、Applications

• Automotive Start-Stop Systems

• Backup Battery and Super capacitor Charging

• Industrial PC Power Supplies

• USB Power Delivery

• Power bank ,HUB

3、Description

PL9405 is a synchronous 4-switch bidirectional Buck-Boost converter capable of regulating the output voltage at above or below the input voltage.  PL9405 operates over a wide input voltage range of 3.6 V to 32 V (36 V maximum) to support a variety of applications. Integrated two 9mΩ power MOSFETs.  PL9405 can operate at charger mode for 1, 2, 3, 4, 5 and 6 cells battery charge. 

PL9405 employs Constant ON time control in buck, boost and buck-boost operation modes for superior load and line regulation. The switching frequency could be set to 150kHz, 300kHz, 600kHz or 1200kHz based on different resistor value between FREQ pin and GND pin. The device also features a programmable soft-start function and offers all kinds of protection features including cycle-by-cycle current limiting, input under voltage lockout (UVLO), output over voltage protection (OVP), input Over Voltage Protection, thermal shutdown and output short protection etc. 

 VADJ, IADJ pins are used to program output VBUS voltage and output current limit at battery discharging mode when OTG is high, which makes PL9405 an excellent option for USB Power Delivery (PD) application. PL9405 provides voltage control loop, constant current loop, thermal regulation loop, battery temperature sensing, which makes it a perfect solution for batter charge management.