MIC39501 Micrel Semiconductor, MIC39501 Datasheet - Page 8

• Manufacturer Part Number: MIC39501
• Description: Mic39500/mic39501 5a Low-voltage Low-dropout Regulator
• Manufacturer: Micrel Semiconductor

MIC39500/39501
with an input as low as 3.0V or 2.5V respectively. This gives
PNP-based regulators a distinct advantage over older, NPN-
based linear regulators.
A typical NPN regulator does not have the headroom to do
this conversion.
Minimum Load Current
The MIC39500/1 regulator is specifi ed between fi nite 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.
M9999-082605-B
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Error Flag
The MIC39501 version features an error fl ag circuit which
monitors the output voltage and signals an error condition
when the voltage 5% below the nominal output voltage. The
error fl ag 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 fl ag is inoperative during overtemperature
shutdown.
When the error fl ag is not used, it is best to leave it open.
The fl ag pin can be tied directly to pin 4, the output pin.
Enable Input
The MIC39501 version features an enable input for on/off
control of the device. Its shutdown state draws “zero” cur-
rent (only microamperes of leakage). The enable input is
TTL/CMOS compatible for simple logic interface, but can be
connected to up to 20V.
August 2005
Micrel