Pin functions

N

Function

Description

1

COMP

This pin is the Error Amplifier output and is made for loop compensation.

2

This is the inverting input of the Error Amplifier. It is normall y connected to the switching power supply

output through a resistor divider.

3

A voltage proportional to inductor current is connected to this input. The PWM uses this information to

terminate the output switch conduction.

4

5

GROUND

This pin is the combined control circuitry and power ground.

6

OUTPUT

This output directly drives the gate of a power MOSFET. Peak currents up to 1A are sourced and sink by

this pin.

7

This pin is the positive supply of the integrated circuit.

8

Application information

2.5V

1mA

V

FB

2

COMP

1

Figure 1. Error Amp Configuration

7

ON/OFF COMMAND TO S/R OF IC

MIK3842 MIK3843

MIK3844 MIK3845

13mA

16V

10V

8.4V

7.6V

0.2mA

During UVLO, the Output is low

Figure 2. Undervoltage Lockout

R

COMP

CURRENT

SENSE

+

2

_

1

3

ERROR

AMP

2R

R

1V

CURRENT

SENSE

COMPARATOR

C

GND

5

Peak current is determined by

1.0V

Figure 3. Current Sense Circuit

3

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