VI
Vin
Cin 0.1 µF
LM317
Figure 2. Load Regulation and ∆IAdj/Load Test Circuit
Vout
LM317
IL
Adjust
IAdj
R1
240
1%
+
CO 1.0 µF
RL
(max Load)
*
RL
(min Load)
VO (min Load)
VO (max Load)
* Pulse testing required.
R2
* 1% Duty Cycle is suggested.
1%
Load Regulation (mV) = VO (min Load) – VO (max Load)
VO (min Load) – VO (max Load)
Load Regulation (% VO) =
VO (min Load)
x 100
Figure 3. Standard Test Circuit
Vin
Vout
LM317
IL
VI
Cin 0.1 µF
Adjust
IAdj
ISET
R2
1%
R1
240
1%
Vref
RL
+
CO 1.0 µF
VO
* Pulse testing required.
* 1% Duty Cycle is suggested.
To Calculate R2: Vout = ISET R2 + 1.250 V
To Calculate R2: Assume ISET = 5.25 mA
24 V
14 V
f = 120 Hz
Figure 4. Ripple Rejection Test Circuit
Vin
Vout
LM317
Cin 0.1 µF
Adjust
R2
1.65 k
1%
R1
240
1%
D1*
1N4002
RL
+
CO 1.0 µF
Vout = 10 V
VO
+
CAdj 10 µF
* D1 Discharges CAdj if output is shorted to Ground.
4
MOTOROLA ANALOG IC DEVICE DATA