lv5781 Sanyo Semiconductor Corporation, lv5781 Datasheet - Page 5

• Manufacturer Part Number: lv5781
• Description: 3a, Point-of-load, Chopper-type Step-down Converter
• Manufacturer: Sanyo Semiconductor Corporation

Pin Functions
Input Equivalent Circuits
Heat sink fin
5, 8, 10
Pin No.
Pin No.
5, 8, 10
13
14
6, 9
1
4
11
12
13
14
1
2
3
4
7
Pin Name
FB_GND
GND
FB1
FB2
FB0
V IN
OERRAMP
Pin name
FB_GND
ENABLE
CBOOT
PGND
GND
FB1
FB2
FB0
V IN
SW
SS
FB_GND
GND of output voltage setting pins FB0 and FB2. It is connected to GND for use when pin FB2 is used.
Output ON/OFF with an active-high polarity. When set to L, the current consumption is reduced to 10µA or
less.
Soft start time constant setting. The charge current is set to approx. 6.5µA and when a capacitor of 0.1µF is
connected between this pin and GND, the output rises in approx. 12ms.
Test pin for verifying the internal reference voltage. It must be set to open for actual use.
Power input. It is used with voltages ranging from 4.5V to 6V.
Inductor drive output
Power GND pin. This is the output GND. It is connected so that where at all possible, no impedance is
shared with other GND pins (GND, FB_GND).
For generating the gate voltage of the internal high-side n-channel MOS transistor. A capacitor with a
capacitance of at least 0.1µF (max. 2.2µF) is connected between this pin and the SW pin for use.
Transconductance-type Error_Amp output. An integration constant is provided between this pin and GND to
implement phase compensation.
Used to feed back the output voltage to this pin when the output voltage is to be set to 3.3V. In such a case,
FB_GND is connected to GND. Refer to application circuit 1.
When the output voltage is to be set to a desired value, connect resistors between FB0 and GND and
between FB0 and V OUT to feed back the output voltage to this pin. In such a case, leave FB_GND and
FB2 open. Refer to application circuit 2.
Analog GND (connected to GND).
GND
V IN
FB0
FB2
FB1
LV5781
GND
V IN
Equivalent Circuit
Description
116kΩ
118kΩ
50kΩ
54.5kΩ
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