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, Output
current 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 9
mΩ
power MOSFETs
Input or Output Average Current Limiting with
stable CC loop
5V/55mA low I
q
LDO to power system MCU
Available in QFN6x6-48 Package
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 9
mΩ
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.
Fig. 1 Application Schematic