LM317L
Figure 19. Adjustable Current Limiter
Vout
R1
1.25k
Vin
Adjust
* To provide current limiting of IO
to the system ground, the source of
the current limiting diode must be tied to
a negative voltage below – 7.25 V.
V
R2
≥
ref
IDSS
Vref
R1 =
IOmax + IDSS
VO < POV + 1.25 V + VSS
ILmin – IP < IO < 100 mA – IP
As shown O < IO < 95 mA
R2
500
D1
1N914
D2
1N914
LM317L
+
120
Adjust
MPS2222
720
1N5314
1.0k
TTL
Control
1.0µF
VO
IO
Figure 20. 5 V Electronic Shutdown Regulator
D1
1N4002
Vout
+25V
Vin
LM317L
VSS*
Minimum Vout = 1.25 V
D1 protects the device during an input short circuit.
Figure 21. Slow Turn–On Regulator
Figure 22. Current Regulator
Iout
Vin
LM317L
Vout
240
Adjust
R2
MPS2907
50k
+
10µF
1N4002
Vin
LM317L
R1
Vout
Adjust
IAdj
R2
Ioutmax =
Vref
R1
Vref
R1 + R2
+ IAdj
^
1.251 V
R
V
^
R1.25R2
1+
Ioutmax =
+ IAdj
5.0 mA < Iout < 100 mA
8
MOTOROLA ANALOG IC DEVICE DATA
ONSEMI [ ON SEMICONDUCTOR ]
