MB3778 Datasheet, PDF (3/29 Pages) Fujitsu Component Limited. – Switching Regulator Controller

MB3778
s PIN DESCRIPTION
No.
Pin
Function
1
CT Oscillator timing capacitor terminal (150 pF to 15,000 pF) .
2
RT
Oscillator timing resistor terminal (5.1 kΩ to 100 kΩ) .
VREF × 1/2 voltage is also available at this pin for error amplifier reference input.
3
+IN1 Error amplifier 1 non-inverted input terminal.
4
−IN1 Error amplifier 1 inverted input terminal.
Error amplifier 1 output terminal.
5
FB1 A resistor and a capacitor are connected between this terminal and the −IN1 terminal to ad-
just gain and frequency.
OUT1 dead-time control terminal.
6
DTC1 Dead-time control is adjusted by an external resistive divider connected to the VREF pin.
A capacitor connected between this terminal and GND enables soft-start operation.
Open collector output terminal.
7
OUT1 Output transistor has common ground independent of signal ground.
This output can source or sink up to 50 mA.
8 E/GND Ground terminal.
9
VCC Power supply terminal (3.6 to 18 V)
Open collector output terminal.
10 OUT2 Output transistor has common ground independent of signal ground.
This output can source or sink up to 50 mA.
11
DTC2
Sets the dead-time of OUT2.
The use of this terminal is the same as that of DTC1.
Error amplifier 2 output terminal.
Sets the gain and adjusts the frequency when a resistor and a capacitor are connected be-
12
FB2 tween this terminal and the −IN2 terminal.
Voltage of VREF × 1/2 voltage is internally connected to the non-inverted input of error amplifier
2. Uses error amplifier 2 for positive voltage output.
13
−IN2 Error amplifier 2 inverted input terminal.
Power control terminal.
14
CTL
The IC is set in the stand-by state when this terminal is set “Low.”
Current consumption is 10 µA or lower in the stand-by state.
The input can be driven by TTL or CMOS.
The time constant setting capacitor connection terminal of the timer latch short-circuit protec-
15
SCP
tion circuit.
Connects a capacitor between this pin and GND.
For details, see “How to set time constant for timer latch short-circuit protection circuit”.
16
VREF
2.46 V reference voltage output terminal which can be obtained up to 1 mA.
This pin is used to set the reference input and idle period of the error amplifiers.
3