OB2112 is a highly integrated and cost effective controller for Li-Ion Battery Power Bank application. It integrates one synchronous step-down DC-DC Buck converter (5V input, 2A output), one synchronous step-up DC/DC Boost converter (5V/2.4A) and one power bridge (5V/2.4A). An 8-bit 8051 based MCU is also integrated for flexible parameter setting.


When only external power supply is present, OB2112 enters the Buck operation mode to charge the Li-Ion battery. Constant current (programmable trickling current or large current of up to 2A) operation mode or constant voltage operation mode is provided to charge the Li-Ion battery depending on the status of the battery. Fully protection functions including input Over Voltage Protection (OVP), battery OVP, battery Over Temperature Protection (OTP), Over Current Protection (OCP) are provided.


When only external loading is presented, OB2112 enters the Boost operation mode to discharge the Li-Ion battery. Constant voltage operation mode (5V/2.4A) is provided to charge up the loading. Fully protection functions including output Over Voltage Protection (OVP), battery Under Voltage Protection (UVP), battery OTP, Over Current Protection (OCP) and output Short Circuit Protection (SCP) are provided.


When both external power supply and external loading are presented, OB2112 enters path-through operation mode. The internal power bridge is turned on to directly connect the external power supply with the external loading. OB2112 distributes the maximum allowed external power supply power to satisfy the need of the external loading first and then distributes the rest to charge up the Li-Ion battery through the Buck operation. In addition to the full set of protection features in Buck operation, output SCP is also provided under this mode.


When neither the external power supply nor the external loading is connected to OB2112, OB2112 enters idle mode, where no switching is operated and the power bridge is shut off. OB2112 enters sleep mode after staying in idle mode for more than 10s (this is programmable). Very low power consumption (typical 25uA at 3.7V battery voltage) is obtained in sleep mode. Either the plug-in of external power supply or external loading or pushing-button will wake up OB2112.  


OB2112 is offered with TSSOP20/PP,   TSSOP24/PP and TSSOP28/PP package.




n   Integrated MCU, Buck, Boost and power bridge in one SOC

n   Path-through feature

n   Very low sleep mode power consumption (typical 25uA, 3.7V battery voltage)

n   5V input, 2A output synchronous mode Buck with programmable frequency (300kHz,)

n   Up to 5V/2.4A synchronous mode Boost with programmable frequency (300kHz)

n   Up to 5V/2.4A power bridge

n   Drive capacitive load

n   Provide trickle currenttypical 30mA when battery is over discharged

n   Programmable battery voltage

n   Programmable gain of Buck mode current sense

n   Programmable constant current level in Buck mode

n   Programmable output voltage in Boost mode

n   Programmable battery UVP threshold in Boost mode

n   Programmable gain of Boost mode current sense

n   Programmable and flexible LED indicator pattern

n   Programmable thermal fold-back at too high battery or IC temperature

n   Comprehensive protections: input OVP, output OVP, output SCP, battery OVP, battery UVP, battery OTP, OCP.




n  Li-Ion battery power bank

n  Single Li-Ion battery portable device






Figure1 OB2112UP Typical Application Diagram


Figure2 OB2112VP Typical Application Diagram

Figure4 OB2112YP Typical Application Diagram