| Li-ion Battery Monitoring chip set (for PMOS-FET) MK5207 |
Provides the high accuracy and total cost-down of the battery protection circuit
Description
The MK5208 is a chip-set consisting of an analog front-end IC and a controller IC which supports 5 to 13 cells lithium-ion battery pack protection systems.
MK5208 measures the voltage more accurate than MK5207 and is improved so that NMOS-FET can be driven for the externally connected charge/discharge control. It can provide the more accuracy and the total cost-down of the battery protection circuit of multipe cells serial connection.
This chip set consists of the following two ICs.
- ML5208 Analog Front End IC for voltage measurement
- ML5227 Controller and embedded firmware

This chip set achieved the accuracy of ±10mV(Typ) overcharge/disovercharge voltage detection and measures the voltage of the battery cell with high accuracy.
Also, used with the current measurement, battery remainder measurement, and external thermistor, it measures the nearby battery and internal IC temperature and then detects the irregular operation of each battery cell and protects them.
Feature
- Compatible with multiple-cell series-connected (5 to 13 cells) Li-ion battery packs
- Highly accurate overcharge/overdischarge voltage detection for each cell: ±10mV(Typ.)
- Creates a bypass route for each battery cell connection pin, and realizes a cell-balancing function.
- The driving circuit of external NMOS-FET for charge/discharge control is built in.
- Nearby battery pack and internal IC temperature detection
- ML5208internal: 65°C to 90°C, threshold: 90°C
- Battery pack: 65°C to 85°C, threshold: 85°C
- Nearby battery pack and internal IC temperature detection
- System protection function when malfunctioned
- Short detection and protection:
- Short detection delay time can be set using an external capacitor.
- Irregular operation detection and protection:
- Automated protection by monitoring battery voltage with the ML5208 and by detecting communication clock from the ML5227
- Short detection and protection:
- Low current consumption
- Normal operation: 250µA (typ./chip set)
Power save mode: 105µA (typ./chip set)
Power down mode: 58µA (typ./chip set)
- Normal operation: 250µA (typ./chip set)
- Power-supply voltage
- +8V to +80V (Supplied to ML5208)
- Operation temperature range
- -40°C to +85°C
Applications

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Specification
| Chip Set Name | MK5208 | |
|---|---|---|
| IC part number | ML5208 / ML5227 | |
| The number of compatible cells | 5 to 13 cells | |
| FET driver for charge/discharge | NMOS-FET | |
| Overcharge/overdischarge voltage detection accuracy | ±10mV (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 | ML5208internal | 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 +80V | |
| Operating temperature range | -40 to +85°C | |
| Package | QFP44 / TQFP48 | |
Block Diagram of chip set

- ML5208 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, ML5208 supports N-MOS FET as the external FET for switching charge and discharge.
- ML5227 is the controller for ML5208 control. It can store the control program code and the parameter such as overcharge/overdischarge detection voltage into its internal Flash memory. It can be used according to the characteristics of li-ion battery cell without the nonvolatile memory.
