Datasheet

ADR430/ADR431/ADR433/ADR434/ADR435/ADR439
Rev. J | Page 21 of 24
V–
V+
+
–
V
IN
N1
V
IN
V
OUT
TRIM
GND
5V
U2
2N7002
AD8601
U1
ADR431
V
O
R
L
25Ω
2
6
5
4
04500-014
PRECISION BOOSTED OUTPUT REGULATOR
A precision voltage output with boosted current capability can
be realized with the circuit shown in Figure 43. In this circuit,
U2 forces V
O
to be equal to V
REF
by regulating the turn-on of
N1. Therefore, the load current is furnished by V
IN
. In this
configuration, a 50 mA load is achievable at a V
IN
of 5 V. Moderate
heat is generated on the MOSFET, and higher current can be
achieved with a replacement of the larger device. In addition,
for a heavy capacitive load with step input, a buffer can be
added at the output to enhance the transient response.
Figure 43. Precision Boosted Output Regulator