MB39A113 Datasheet, PDF (21/51 Pages) Fujitsu Component Limited. – ASSP for Power Supply Applications (Secondary Battery)

MB39A113
s SETTING THE DYNAMICALLY-CONTROLLED CHARGING
With an external resistor connected to + INE1(pin 9), the IC enters the dynamically-controlled charging mode
to reduce the charge current to keep AC adapter power constant when the partial potential point A of the AC
adapter voltage (VCC) become lower the − INE2 terminal voltage.
Dynamically-controlled charging setting voltage : Vth
Vth (V) = (R1 + R2) /R2 × −INE1
VCC
−INE1
8
A
9
R1
+INE1
R2
<Error Amp1>
−
+
s ABOUT CONSTANT-VOLTAGE CONTROL STATE DETECTION/OVERVOLTAGE
DETECTION TIMING CHART
In the constant-voltage control state, the CVM terminal (pin 5) of the constant-voltage control state detection
block (CV Comp.) outputs “L” level, when the voltage at the FB3 terminal (pin 15) of the error amplifier (ErrorAmp
3) becomes 2.6 V (Typ) or less.
When the DC/DC converter output voltage enters the state of the over-voltage higher than a setting voltage, the
voltage at FB3 terminal (pin 15) of the error amplifier (Error Amp3) becomes 1.3 V (Typ) or less. As a result, the
OVP terminal (pin 18) of the overvoltage detection block (OV Comp.) outputs “H” level.
Both the CVM terminal and the OVP terminal are open-drain output forms :
Error Amp3 FB3
2.6 V CV Comp. VTHL
2.5 V
Error Amp2
Error Amp1 FB12
CV Comp. CVM
OV Comp. OVP
OUT
1.5 V
1.3 V OV Comp. VTHL
Constant
Constant voltage control Overvoltage
current control
state
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