LV58761MX

No.A1964-4/7

Pin Function

Pin No.

Pin name

Function

Equivalent circuit

1

BOOT

Upper MOS transistor boot strap capacitance connection pin.

Connect the boot capacitance of about 0.022uF between SW

pins. To protect the SW pin’s absolute maximum rating , to ensure

stable

operation, and to eliminate noise , the boot capacitance serial

resistance (about 100Ω) Rb

proves effective.

VIN

BOOT

SW

Short protection

circuit

Output MOS

2

VIN

Input Voltage Pin. Connect substantially large (10uF more)

capacitance between this pin and GND.

3

SW

Power Switch pin.

Connect the output LC filter.

Connect the above capacitance between this pin and BOOT pin.

4

GND

Ground pin.

5

FB

Feedback pin.

Set the output voltage by means of split resistor in the section of

the output voltage

VOUT-FB-GND. VOUT setting is made as calculated below.

VOUT = Vref × { 1 +

(R1 + R10)

R3

}

Vref = 0.8V

Example: 3.3V output voltage

(See, Block Diagram and Application example)

VOUT = 0.8 × { 1 +

(27k + 4.3k)

10k

}

=3.304V

SS

VREF

0.8V

VIN

FB

Internal Regulation line

8

SS

Soft start pin.

Sets the soft start time by means of the built-in 5

μA source

voltage and external soft start capacity. The soft start capacity

CSS can be set as follows:

CSS = 5μA ×

Tss

Vref

Where, Tss is the soft start time and Vref is the reference

voltage.

Example:2.4ms soft start time achieved

CSS = 5μA ×

2.4ms

0.8V = 0.015μF

6

COMP

Phase compensation pin.

Connects with the phase compensation external capacitance and

resistance of DC/DC converter close loop.

COMP

VIN

Short

protection

circuit

Internal Reguretion line

7

EN

Enable pin.

Converter enabled when set to the HIGH voltage and disabled

when GND or OPEN state.

EN

VIN