MIC2194

Micrel

MIC2194

2

October 2002

Pin Configuration

1

COMP

FB

EN/UVLO

CS

8

VIN

OUTP

GND

VDD

7

6

5

2

3

4

8 Lead SOIC (M)

Ordering Information

Part Number

Output Voltage

Frequency

Junction Temp. Range

Package

MIC2194BM

Adjustable

400KHz

–40

°C to +125°C

8-lead SOP

Pin Description

Pin Number

Pin Name

Pin Function

1

COMP

Compensation (Output): Internal error amplifier output. Connect to a

capacitor or series RC network to compensate the regulator’s control loop.

2

FB

Feedback (Input): The circuit regulates this pin to 1.245V.

3

EN/UVLO

Enable/Undervoltage Lockout (Input): A low level on this pin will power down

the device, reducing the quiescent current to under 0.5

µA. This pin has two

separate thresholds, below 1.5V the output switching is disabled, and below

0.9V the device is forced into a complete micropower shutdown. The 1.5V

threshold functions as an accurate undervoltage lockout (UVLO) with

hysteresis.

4

CS

The (–) input to the current limit comparator. A built-in offset of 110mV

between VIN and CSL in conjunction with the current sense resistor sets the

current limit threshold level. This is also the (–) input to the current amplifier.

5

VDD

3V internal linear-regulator output. VDD is also the supply voltage bus for the

chip. Bypass to GND with 1

µF.

6

GND

Ground.

7

OUTP

High current drive for the synchronous N-channel MOSFET. Voltage swing

is from ground to VIN. On-resistance is typically 3

Ω @ 5V

8

VIN

Input voltage to the circuit. Also the high side input to the current sense

amplifier supplies power to the gate drive circuit.