■DESCRIPTION
MB39A125/126 is a DC/DC converter IC for charging Li-ion battery, which is suitable for down-conversion, and
uses pulse width modulation (PWM) for controlling the output voltage and current independently. This IC integrates the build-in comparator for the voltage detection of the ACadapter, and selects the AC adapter or battery auto matically for power supply to the system.

■FEATURES
• High efficiency : 97%(MAX)
• Built-in two constant current control circuits
• Analog control of the charging current value (+INE1, +INE2 terminal)
• Built-in AC adapter voltage detection function (ACOK, XACOK terminal)
• External output voltage setting resistor : MB39A125
• Built-in output voltage setting resistor : MB39A126
• Built-in charge stop function at low VCC
• Output voltage setting accuracy : ±0.74%(Ta = −10 °C to +85 °C) : MB39A125
                                             : 12.6 V/16.8 V ±0.8%(Ta = −10 °C to +85 °C) : MB39A126
• Built-in high accuracy current detection amplifier (±5%) (At input voltage difference 100 mV) , 
                                                                   (±15%) (At input voltage difference 20 mV)
• In IC standby mode (Icc =0 µA Typ) , make output voltage setting resistor open to prevent inefficient current loss
• Built-in soft-start circuit
• Standby current : 0 µA (Typ)
• Totem-pole type output for Pch MOS FET