Li-ion Battery Monitoring chip set (for PMOS-FET)
MK5207

MK5207 is a chip set that provides all functions for controlling, monitoring, and protecting systems using multiple-cell series-connected lithium-ion battery packs.
This chip set consists of the following two ICs.

  • ML5207 Analog front-end IC for protection
  • ML5227 Controller

It is a chip set of controlling, monitoring, and protecting for multiple-cell series-connected lithium-ion battery pack.


This chip set is applying PMOS-FET for charge/discharge control and achieves highly accurate overcharge/overdischarge voltage detection, ±15mV(Typ.), for each cell.
By using this chip set, it will become possible to construct a battery pack protection system with functions such as cell-balancing during charging, overcharge/overdischarge detection, and short circuit detection. It is possible to store parameters such as those for overcharge/overdischarge detection in the built-in Flash Memory, making it adaptable for various systems according to customer’s needs. Also, since the control program code for this chip set is stored in the built-in Flash Memory, no external memory is required.


Chip Set Name MK5207
IC part number ML5207 / ML5227
The number of compatible cells 5 to 13 cells
FET driver for charge/discharge PMOS-FET
Overcharge/overdischarge voltage detection accuracy ±15mV (Typ.)
The detection range*1 Overcharge detection 3.6V to 4.4V
Overcharge release 3.4V to 4.4V
Overdischarge detection 2.0V to 3.0V
Overdischarge release 2.0V to 3.0V
Temperature measurement function ML5207 internal 65 to 90°C
External (Max. 3 inputs) 65 to 85°C
System protection to deal with the irregular operation Short detection
Irregular SPI clock detection
Current consumption (typ) Under normal operation 250µA
Under power save mode 105µA
Under power-down mode 51µA
Power supply voltage*2 +8 to +57.2V
Operating temperature range -25 to +85℃
Package QFP44 / TQFP48




  • lectrically assisted bicycles, electric bicycles, electric bike
  • Electric tools
  • UPS(Uninterruptible power supply)
  • Lithium-ion battery storage device


Block Diagram of chip set

  • ML5207 is analog front-end IC for the li-ion battery pack protection system of 5 to 13 cells. The li-ion battery pack protection system is organized by using it with the controller. It is possible to detect an overcuurent by connencting the sensing resistance externally, besides the overcharge and overdischarge of each cell. Moreover, ML5207 supports P-MOS FET as the external FET for switching charge and discharge.