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 μF

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 Ω 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

470

Ω

0.1µF

GND

2N6040

10V @ 4A

AD581

GND

12V ±5%

10V @ 0mA TO 5mA

560

Ω 5%

Figure 11. 12 V Supply Connection

Figure 10. High Current Precision Supply