Datasheet

AD581
Rev. C | Page 8 of 12
PRECISION HIGH CURRENT SUPPLY CONNECTION FOR REDUCED PRIMARY SUPPLY
The AD581 can be easily connected with power pnp or power
Darlington pnp devices to provide much greater output current
capability. The circuit shown in Figure 10 delivers a precision
10 V output with up to 4 A supplied to the load. The 0.1 F
capacitor is required only if the load has a significant capacitive
component. If the load is purely resistive, improved high frequency
supply rejection results from removing the capacitor.
Whereas line regulation is specified down to 13 V, the typical
AD581 works as specified ≤12 V. The current sink capability
allows even lower supply voltage capability such as operation
from 12 V ±5% as shown in Figure 11. The 560  resistor reduces
the current supplied by the AD581 to a manageable level at a
full 5 mA load. Note that the other band gap references, without
current sink capability, may be damaged by use in this circuit
configuration.
AD581
V
IN
≥ 15
V
470Ω
0.1µF
+V
S
V
OUT
GND
2N6040
V
OUT
10V @ 4A
0
8014-010
AD581
GND
+V
S
V
OUT
12V ±5%
10V @ 0mA TO 5mA
560Ω 5%
08014-011
Figure 11. 12 V Supply Connection
Figure 10. High Current Precision Supply