AS1367
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
The AS1367 is low-dropout, low-quiescent-current linear regulator intended for LDO regulator applications where
output current load requirements range from no load to 150mA. All devices come standard with adjustable output
voltages of 1.2V to 5.0V and fixed output voltages
The AS1367 also features a Power-OK output to indicate when the output is within 6% of final value, and also an
Enable pin. Shutdown current for the whole regulator is typically 10nA. The device features integrated short-circuit and
over current protection. Under-Voltage lockout prevents erratic operation when the input voltage is slowly decaying
(e.g. in a battery powered application). Thermal Protection shuts down the device when die temperature reaches
160°C. This is a useful protection when the device is under sustained short circuit conditions.
As illustrated in
the devices comprise a reference, error amplifier, P-channel MOSFET pass transistor,
Power-OK detect logic, internal voltage divider, current limiter, reverse-battery protection, thermal sensor and
shutdown logic.
The bandgap reference is connected to the inverting input of the error amplifier. The error amplifier compares this
reference with the feedback voltage and amplifies the difference. If the feedback voltage is lower than the reference
voltage, the P-channel MOSFET gate is pulled lower, allowing more current to pass to the output, and increases the
output voltage. If the feedback voltage is too high, the pass-transistor gate is pulled up, allowing less current to pass to
the output. The output voltage feeds back through an internal resistor voltage divider connected to pin OUT.
Figure 16. AS1367 - Block Diagram
IN
EN
Reverse-
Battery
Protection
Shutdown/
Power-On
Control Logic
-
Error
Amplifier
+
AS1367
Thermal
Overload
Protection
OUT
Bandgap Voltage
&
Current Reference
Trimmable
Reference
Voltage
POK
Power-OK
Compare
Logic
NMOS
GND
Output Voltages
Standard products are factory-set with output voltages from 1.2V to 5.0V. A two-digit suffix of the part number identifies
the nominal output
Non-standard devices are available. For more information
contact:
www.austriamicrosystems.com
Revision 1.02
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AMSCO [ AUSTRIAMICROSYSTEMS AG ]
