MB39A104
■ SETTING THE OUTPUT VOLTAGE
• Output Voltage Setting Circuit
VO
R1
(−INE2)
−INE1
15
10
Error Amp
−
+
+
1.24
R2
VO (V) =
(R1 + R2)
R2
1.24 V
(CS2)
CS1
14
11
■ SETTING THE TRIANGULAR OSCILLATION FREQUENCY
The triangular oscillation frequency is determined by the timing capacitor (CT) connected to the CT terminal (pin
13), and the timing resistor (RT) connected to the RT terminal (pin 12).
Moreover, it shifts more greatly than the caluculated values according to the constant of timing resistor (RT) when
the triangular wave oscillation frequency exceeds 1 MHz. Therefore, set it referring to “Triangular Wave Oscillation
Frequency vs. Timing Resistor” and “Triangular Wave Oscillation Frequency vs. Timing Capacitor” in “■TYPICAL
CHARACTERISTICS”.
Triangular oscillation frequency : fOSC
1200000
fOSC (kHz) =:
CT (pF) •RT (kΩ)
13
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