March 2000

9

MIC39300/39301

MIC39300/39301

Micrel

Minimum Load Current

The MIC39300/1 regulator is specified between finite loads.

If the output current is too small, leakage currents dominate

and the output voltage rises. A 10mA minimum load current

is necessary for proper regulation.

Error Flag

The MIC39301 version features an error flag circuit which

monitors the output voltage and signals an error condition

when the voltage drops 5% below the nominal output voltage.

The error flag is an open-collector output that can sink 10mA

during a fault condition.

Low output voltage can be caused by a number of problems,

including an overcurrent fault (device in current limit) or low

input voltage. The flag is inoperative during overtemperature

shutdown.

Enable Input

The MIC39301 version features an enable input for on/off

control of the device. Its shutdown state draws “zero” current

(only microamperes of leakage). The enable input is TTL/

CMOS compatible for simple logic interface, but can be

connected to up to 20V. When enabled, it draws approxi-

mately 15

µA.