Micrel, Inc.

MIC20XX Family

January 2009

9

M9999-012109-A

Descriptions

These pin and signal descriptions aid in the differentiation of a pin from electrical signals and components connected to

VOUT pin.

Pin Descriptions

Pin Name

Type

Description

VIN

Input

Supply input. This pin provides power to both the output switch and the switch’s

internal control circuitry.

GND

─

Ground.

ENABLE

Input

Switch Enable (Input):

FAULT/

Output

Fault status. A logic LOW on this pin indicates the switch is in current limiting, or has

been shut down by the thermal protection circuit. This is an open-drain output

allowing logical OR’ing of multiple switches.

CSLEW

Input

Slew rate control. Adding a small value capacitor between this pin and VIN slows

turn-ON of the power FET.

VOUT

Output

Switch output. The load being driven by the switch is connected to this pin.

VUVLO

Input

Variable Under Voltage Lockout (VUVLO): Monitors the input voltage through a

resistor divider between VIN and GND. Shuts the switch off if voltage falls below the

threshold set by the resistor divider. Previously called VUVLO.

ILIMIT

Input

Set current limit threshold via a resistor connected from ILIMIT to GND.

Signal Descriptions

Signal Name

Type

Description

Input

Electrical signal input voltage present at the VIN pin.

GND

─

Ground.

Input

Electrical signal input voltage present at the ENABLE pin.

Output

Electrical signal output voltage present at the FAULT/ pin.

Component

Capacitance value connected to the CSLEW pin.

Output

Electrical signal output voltage present at the VOUT pin.

Internal

VUVLO internal reference threshold voltage. This voltage is compared to the

VUVLO pin input voltage to determine if the switch should be disabled. Reference

threshold voltage has a typical value of 250mV.

Component

Capacitance value connected in parallel with the load. Load capacitance.

Output

Electrical signal output current present at the VOUT pin.

Internal

Switch’s current limit. Fixed at factory or user adjustable.