Typical Applications (Continued)
Low Drift Current Source
5 Volt Current Limiter
00854610
*Minimum input-output voltage ranges from 40mV to 400mV, depending on
load current. Current limit is typically 160mA.
00854608
Regulator with Early Warning and Auxiliary Output
Latch Off When Error Flag Occurs
00854612
00854611
j
j
j
j
Early warning flag on low input voltage
Main output latches off at lower input voltages
Battery backup on auxiliary output
Operation: Reg. #1’s V is programmed one diode drop above 5V. Its
out
error flag becomes active when V ≤ 5.7V. When V drops below 5.3V, the
in
in
error flag of Reg. #2 becomes active and via Q1 latches the main output off.
When V again exceeds 5.7V Reg. #1 is back in regulation and the early
in
warning signal rises, unlatching Reg. #2 via D3.
17
www.national.com
NSC [ National Semiconductor ]
