HA17384SPS Datasheet, PDF (19/29 Pages) Hitachi Semiconductor – High Speed Current Mode PWM Control IC for Switching Power Supply

HA17384SPS/SRP, HA17384HPS/HRP, HA17385HPS/HRP
100
Ta = 25°C
75
V_IN = 15V
50
25
0
500 1k 2k
5k 10k 20k
50k 100k 200k
Timing Resistance R_T (Ω)
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.
Figure 9 PWM Pulse ON Duty vs. Timing Resistance
Rev.3.00 Jun 15, 2005 page 19 of 28