mm1433 Mitsumi Electronics, Corp., mm1433 Datasheet - Page 10

• Manufacturer Part Number: mm1433
• Description: Lithium-ion Battery Charge Control
• Manufacturer: Mitsumi Electronics, Corp.

MITSUMI
2 Other Protective Functions
3. Checking Charging Operation
1.5 Recharging Operation
2.1 Forced Charge Disabling Function
2.2 Temperature Monitoring Function
2.3 Hysteresis and Delay Times
· During pre-charging and full charge operations, the open collector NPN transistor inside Pin 22 (LED R) is
· During 1mA charging operation, the open collector NPN transistor inside Pin 22 (LED R) repeats ON/OFF.
· If charging is prohibited during charging due to the timer reaching time up, the open collector NPN
· Pre-charging timer operation can be verified by Pin 3 (TP1) high/low switching.
constantly ON. Pre-charging and full charge can be verified by connecting Pin 22 (LED R) via a resistor
(pull-up connection) to a red LED, which will be constantly lit.
When operation switches from 1mA charging to pre-charging, the open collector NPN transistor inside Pin
22 (LED R) stays ON constantly. Switching from 1mA charging to pre-charging can be verified by
connecting Pin 22 (LED R) via a resistor (pull-up connection) to a red LED, which will be constantly lit.
transistor inside Pin 22 (LED R) will repeat ON/OFF. This can be verified by connecting Pin 22 (LED R) via
a resistor (pull-up connection) to an LED, which will blink.
The TP1 pin signal inverts at the 10th stage of the pre-charge timer binary counter (total 19 stages) and
· On detection of a full charge and after the end of charging, the battery voltage starts to drop.
· By setting pin 1 (CHGSW) or pin 2 (RESET) level HIGH (0.6V - 1.2V), charging is disabled. Normally,
· Pin 1 (CHGSW): Charging ON/OFF only; timer continues to work. Used to temporarily prohibit
· Pin 2 (RESET): Resets timer simultaneously with charging ON/OFF.
· Disablement using pin 2 takes precedence over pin 1.
· Pin 1 and Pin 2 are connected to Pin 5 (reference power supply output: VREF) via an internal resistor.
· A potential created by splitting the voltage at pin 5 (VREF) using external resistor and thermistor is
· If a thermistor is not used, a resistor can be connected for charging operation, but temperature
· Pin 5 (VREF) is approximately 1.207V ± 2% and output source current is approximately 180mA.
· Confirmation of charging prohibited status
· To protect the circuit from malfunction due to noise, etc., hysteresis characteristics are applied to the
· Also, a constant delay time is applied to full-charge detection, over-voltage detection, and recharge
· The respective delay times are set by the internal timers. See the "OSC CR Settings" on the data sheet
Recharging starts when the voltage has dropped to the recharge detection voltage (There is no re-
charging detection function for rank B.).
ground these pins.
charging.
This reference power supply does not have sync capability, so high level should not exceed Pin 5
voltage (VREF).
monitored at pin 12 (TDET). Charging is disabled if, at the start of charging, the temperature is not
within the range of 3°C to 43°C, or between 3°C and 50°C during charging.
protection will not operate. Note: Battery OPEN detection assumes that the battery pack thermistor is
removable. If the thermistor is not used, a battery OPEN detection circuit is required.
If charging is prohibited during charging due to the timers reaching time up, the open collector NPN
transistor inside Pin 22 (LED R) will repeat ON/OFF. This can be verified by connecting Pin 22 (LED R)
via a resistor (pull-up connection) to an LED, which will blink.
ADP detection voltage, low-voltage detection voltage, and preparatory charge detection voltage.
detection operations.
for the timer settings.
Lithium-Ion Battery Charge Control (1 to 2 cells) MM1433