TL497A Datasheet, PDF (5/9 Pages) Texas Instruments – SWITCHING VOLTAGE REGULATORS

TL497A
SWITCHING VOLTAGE REGULATORS
RCL
VI
14 13
L
10
8
TL497A
1 23 4 567
CT
APPLICATION INFORMATION
SLVS009D – JUNE 1976 – REVISED JULY 1999
R1
R2 = 1.2 kΩ
VO
CO
+ ƪ ƫ ^{DESIGN EQUATIONS}
I(PK)
2 IO max
VO
VI
+ L (mH)
m ^VI
I(PK)
ton
(
s)
Choose L (50 to 500 µH), calculate
ton (25 to 150 µs)
BASIC CONFIGURATION
(Peak Switching Current = I(PK) < 500 mA)
RCL
L
VI
VO
14 13
10
8
TL497A
R1
CO
[ m CT(pF) 12 ton ( s)
+ W R1 (VO – 1.2 V) k
+ RCL
0.5 V
I(PK)
[ ^{ƪ ) ƫ} CO (mF) ton(ms)
VI
VO
I(PK)
IO
Vripple (PK)
1 2 3 45
CT
R2 = 1.2 kΩ
EXTENDED POWER CONFIGURATION
(using external transistor)
Figure 1. Positive Regulator, Step-Up Configurations
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