MIC5202_13 Datasheet, PDF (8/10 Pages) Micrel Semiconductor – Dual, 100mA Low-Dropout Regulator

Micrel, Inc.
Application Information
The MIC5202 is a dual linear voltage regulator with low
dropout voltage and low ground current features. Ideal for
battery operated applications, the MIC5202 offers 1%
output voltage accuracy, two independent enable pins,
reversed battery protection, short circuit current limit and
overtemperature protection. When the MIC5202 is
disabled, the ground pin current drops to sub-micro amp
and prolongs the battery life.
Input Supply Voltage
VIN1 and VIN2 provide power to each internal circuit and
may be tied together.
Ground
Both ground pins (pin 2 and 4) must be tied to the same
ground potential when using a single power supply.
Input Capacitor
A 1µF tantalum or aluminum electrolytic capacitor should
be placed close to each V_IN pin if there is more than 10
inches of copper between the input and the capacitor, or
if a battery is used as the supply.
Output Capacitor
The MIC5202 requires an output capacitor of 1µF or
greater to maintain stability. Increasing the output
capacitor leads to an improved transient response;
however, the size and cost also increase. Most tantalum
and aluminum electrolytic capacitors are adequate; film
capacitors will work as well, but at a higher cost. Many
aluminum electrolytics have electrolytes that freeze at –
MIC5202
30°C, so tantalum capacitors are recommended for
operations below –25°C. An equivalent series resistance
(ESR) of 5Ω or less with a resonance frequency above
500 kHz is recommended. The output capacitor value
may be increased without limit.
At lower output loads, a smaller output capacitor value is
required for output stability. The capacitor can be
reduced to 0.47µF for current below 10mA or 0.33µF for
current below 1mA.
No-Load Stability
Unlike many other voltage regulators, the MIC5202
remains stable and in regulation with no load. This is
especially important in CMOS RAM keep-alive
applications.
Enable Input
The MIC5202 features dual active-high enable pins that
allow each regulator to be enabled and disabled
independently. Forcing the enable pin low disables the
regulator and sends it to a “zero” off-mode-current state.
In this state, current consumed by the regulator goes
nearly to zero. Forcing the enable pin high enables the
output voltage. The active-high enable pin typically
consumes 8µA of current and cannot be left floating; a
floating enable pin may cause an indeterminate state on
the output.
Thermal Shutdown
When the internal die temperature of MIC5202 reaches
the limit, the internal driver is disabled until the die
temperature falls.
May 10, 2013
8
Revision 2.0