MC780XXE Datasheet, PDF (20/26 Pages) Fairchild Semiconductor – 3-Terminal 1A Positive Voltage Regulator

MC78XXE/LM78XXE/MC78XXAE
Input
1
3
MC78XXE/LM78XXE
0.33uF
2
IQ
0.1uF R1 VXX
CO
Output
IO
IO =
VXX
R1
+ IQ
RL
Figure 9. Constant Current Regulator
Notes:
(1) To specify an output voltage. substitute voltage value for "XX." A common ground is required between the input and the
Output voltage. The input voltage must remain typically 2.0V above the output voltage even during the low point on the input
ripple voltage.
(2) CI is required if regulator is located an appreciable distance from power Supply filter.
(3) CO improves stability and transient response.
Input
1
3
MC78XXE/LM78XXE
Cl
0.33uF
2
IQ
0.1uF
Co
Output
VXX
R1
IRI ≥ 5IQ
R2
VO = VXX(1+R2/R1)+IQR2
Figure 10. Circuit for Increasing Output Voltage
Input
1
MC7805E
3
LM7805E
2
Cl
0.33uF
6
_2
LM741 ₃
4
+
Output
10kΩ
0.1uF
Co
IRI ≥ 5IQ
VO = VXX(1+R2/R1)+IQR2
Figure 11. Adjustable Output Regulator (7 to 30V)
20