MIC37252 Datasheet, PDF (7/8 Pages) Micrel Semiconductor – 2.5A, Low Voltage UCap LDO Regulator

MIC37252
Minimum Load Current
The MIC37252 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 operation.
Enable Input
The MIC37252 also 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 V_IN. When enabled, it draws approximately 15µA.
Adjustable Regulator Design
V_IN
ENABLE
SHUTDOWN
MIC37252
IN OUT
R1
EN ADJ
GND
R2
V_OUT
C_OUT
Micrel
The MIC37252 allows programming of the output voltage
anywhere between 1.24V and the 5.5V maximum operating
rating of the family. Two resistors are used. Resistors values
are recommended to be less than 10kΩ in value to improve
stability. The resistor values can be sized to draw the mini-
mum load current for this device. The resistor values are
calculated by:
R1 =
R2


V_OUT
1.240
−
1^{}
Where V_OUT is the desired output voltage. Figure 2 shows
component definition. Applications with widely varying load
currents may scale the resistors to draw the minimum load
current required for proper operation (see above).
V_OUT = 1.240V ^{}1+ _RR21^{}
Figure 2. Adjustable Regulator with Resistors
January 2003
7
MIC37252