Renesas推出半导体IC器件M61041FP

The M61041FP is an semiconductor IC device developed for smart battery packs. It is ideal for smart battery system (SBS) battery packs that consist of four lithium ion batteries connected in series. A high-voltage device, it is suitable for use with a wide variety of charger systems.

It incorporates all the analog circuitry required by smart batteries in a single chip. When used in conjunction with a microprocessor, it allows the implementation of a variety of functions, such as battery capacity detection, through the addition of minimal peripheral devices. The functions of the M61041FP are described below.

1. Battery Voltage Detect Circuit
The M61041FP can output the voltage levels of the batteries connected in series via the Analog_out pin. An onchip buffer amplifier monitors the pin voltages of the batteries. Offset voltage correction using adjustment by the microprocessor is also supported. The M61041FP is configured to detect the battery voltage using a microprocessor driven using a power supply voltage of 5.2 V.

2. Charge/Discharge Current Detect Circuit
SBS requires a function for monitoring the battery capacity. The M61041FP uses an on-chip amplifier to monitor battery capacity based on a drop in the voltage of an external sensor resistor. In this way, the charge/discharge current is converted into a voltage.

The voltage amplification ratio can be adjusted from the microprocessor. In addition, the current output shift voltage can be adjusted from the microprocessor, widening the allowable dynamic range of the A/D converter.

3. Overcurrent Detect Circuit

The M61041FP has an on-chip overcurrent detect circuit. If an excessive current flows from the lithium ion batteries, the discharge control FET is shut off after a set delay time, halting discharge. This makes the battery pack safer. The delay time can be set using an external capacitor. It is possible to determine the overcurrent detect status by monitoring the CIN pin. The overcurrent detect circuit provides protection regardless of the processing speed of the microprocessor.

4. Series Regulator

The M61041FP has an on-chip low-dropout series regulator. It can be used as the power supply for the microprocessor, thereby simplifying power supply block design