MB3875 Fujitsu Media Devices, MB3875 Datasheet - Page 17

• Manufacturer Part Number: MB3875
• Description: DC/DC Converter IC for Charging
• Manufacturer: Fujitsu Media Devices

Error Amp.3
Error Amp.1
Error Amp.2
AC ADAPTER VOLTAGE DETECTION
mode to reduce the charge current to keep AC adapter power constant when the partial potential point A of the
AC adapter voltage (Vcc) becomes lower than the voltage at the -INE1 terminal.
AC adapter detected voltage setting Vth
Vth (V) = (R1 + R2) / R2
OPERATION TIMING DIAGRAM
With an external resistor connected to the +INE1 terminal, the IC enters the dynamically-controlled charging
OUT
INE1 setting voltage range : 1.176 V to 4.2 V (equivalent to 7 V to 25 V for Vcc)
controlled charging
AC adapter dynamically-
FB2
FB3
FB1
V
CC
R1
R2
Constant voltage
control
INE1
A
INE1
INE1
11
8
Constant current control
<Error Amp.1>
MB3875/MB3877
AC adapter dynamically-
controlled charging
2.5 V
1.5 V
17