MIC49300
Adjustable Regulator Design
The MIC49300 adjustable version allows programming the
output voltage anywhere between 0.9Vand 5V. Two resistors
are used. The resistor value between V
OUT
and the adjust pin
should not exceed 1kΩ. Larger values can cause instability.
The resistor values are calculated by:
V
R1 = R2 ×
OUT
−1
0
.
9
Where V
OUT
is the desired output voltage.
Enable
The fixed output voltage versions of the MIC49300 feature an
active high enable input (EN) that allows on-off control of the
regulator. Current drain reduces to “zero” when the device is
sn}tñ◊wn, with only microamperes of leakage current. The
EN input has TTL/CMOS compatible thresholds for simple
logic interfacing. EN may be directly tied to V
IN
and pulled
up to the maximum supply voltage
Micrel, Inc.
August 2005
7
M9999-082605-B
MICREL [ MICREL SEMICONDUCTOR ]
