■DESCRIPTION
The MB39A119 is the N-ch MOS drive of the synchronousrectification type DC/DC converter IC using pulse width modulation (PWM) type that can charge Li-ion batteryfrom 1 cell to 4 cells and suitable for down-conversion. This IC integrates built-in comparator for the voltage detection of the AC adapter and switches the power supply to the AC adapter or battery automatically, enabling supply it to system. In addition, the constant voltage control state detection function is built in, which prevents mis-detecting the full charge. The MB39A119 provides a wide range of power supply voltage and low standby current, high efficiency, making it ideal for use as a built-in charge device in products such as notebook PC.

■FEATURES
• High efficiency : 97 % (Max)
• High-frequency operation : 1 MHz (Max)
• Built-in off time control function
• Built-in voltage detection function ofAC adapter (ACOK, XACOK terminal)
• Preventing mis-detection for the full charge by the constant voltage control state detection function (CVM terminal)
• Built-in two constant current control circuits
• Analog control of constant current value is possible ( +INE1, +INE2 terminal)
• Built-in output stage for N-ch MOS FET synchronous rectification
• Built-in charge stop function at low input voltage
• Output voltage setting accuracy : 4.2 V ±0.74 % (Ta= −10 °C to +85 °C)
• Built-in high accuracy charge current detection amplifier : ±4 %
(At input voltage difference 100 mV with Voltage gain 24.5 (V/V)
• Built-in high accuracy input current detection amplifier : ±3 %
(At input voltage difference 100 mV with Voltage gain 25 (V/V)
• Arbitrary output voltage can be set by external resistor
• In IC standby mode, output voltage setting resistor is made to be open to prevent inefficient current loss
• Quiescent current : 1.9 mA (Typ)
• Standby current : 0 µA (Typ)
• Package : QFN28