SRP Hitachi Semiconductor, SRP Datasheet - Page 20

• Manufacturer Part Number: SRP
• Description: High Speed Current Mode PWM Control IC for Switching Power Supply
• Manufacturer: Hitachi Semiconductor

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
20
Note: In the oscillation system of this IC, a constant discharging current of 8.4mA
flows the timing capacitor during triangular wave fall. Therefore, note that a
small maximum ON duty (large dead band) leads to a large supply current.
Refer to the equations of oscillation frequency and supply current for details.
100
75
50
25
0
500
Figure 9 PWM Pulse ON Duty vs. Timing Resistance
1k
2k
Timing Resistance R
5k
10k
20k
T
( )
Ta = 25 C
V
IN
50k
= 15V
100k 200k