PIN CONFIGURATION
TO-252-2L
TO-220-3L
TO-263-2L
TO-263-3L
1
2
3
1
2
3
1
2
3
1
2
3
PIN DESCRIPTION
Functions
Pin No.
Pin name
I/O
--/O
O
1
2
3
Ground/ADJ
Output voltage
Input supply voltage
GND/ADJ
V
OUT
V
IN
I
FUNCTION DESCRIPTION
The AMS1085 is a LDO regulator, its pass transistor is made up of a single NPN transistor being driven by a PNP.
The dropout voltage is defined as: VDROP = VBE+ VSAT.
The AMS1085 has two versions: the fixed output version and the adjustable output version. Output voltages can be
1.5V, 1.8V, 2.5V, 3.3V, and 5.0V.On-chip thermal shut-down circuit provides protection against overload
and overheating that would create excessive junction temperature.
The adjustable output version requires a 22 μF or bigger tantalum capacitor at output for AMS1085 stability. The
capacitor for fixed output version can be smaller and should be determined base on actual application. Generally,
the stability of linear regulator stability decreases with output currents increase.
6
Advanced Monolithic Systems http://www.ams-semitech.com