Datasheet

LM2578A, LM3578A
www.ti.com SNVS767E –AUGUST 2000–REVISED APRIL 2013
9V ≤ V
in
≤ 15V R5 = 270
V
o
= 12V C1 = 1820 pF
I
o
= 100 mA C2 = 220 μF
V
ripple
= 50 mV C3 = 20 pF
f
osc
= 50 kHz C4 = 0.0022 μF
R1 = 110k L1 = 220 μH
R2 = 10k D1, D2 = 1N5819
R3 = 0.15 Q1 = D44
R4 = 220k
Figure 35. Buck-Boost Regulator
V
in
= 5V R4 = 0.15Ω
V
o
±12V C1 = 820 pF
I
o
= ±40 mA C2 = 10 pF
f
osc
= 80 kHz C3 = 220 μF
R1 = 10 kΩ D1, D2, D3 = 1N5819
R2 = 240 kΩ T1 = PE-64287
R3 = 240 kΩ
Figure 36. RS-232 Line Driver Power Supply
Capacitor C1 sets the oscillator frequency and is selected from Figure 14.
Capacitor C2 serves as a compensation capacitor for synchronous operation and a value of 10 to 50 pF should
be sufficient for most applications.
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