SBAA549 April   2022 AMC23C11 , AMC23C12 , AMC23C14

 

  1.   Trademarks
  2. 1Background
  3. 2Overcurrent Protection on DC+
  4. 3DC+ Power Supply Solution
    1. 3.1 Selection of Charge Pump Capacitor
    2. 3.2 Simulation in PSpice for TI
    3. 3.3 Hardware Test
    4. 3.4 Low-Cost Power Supply Solution
  5. 4Power-On Short-Circuit Risk and Solution
  6. 5Reference

3.3 Hardware Test

The actual circuit is built according to the circuit diagram in Figure 3-1, where the capacitor C2 = C7 = 1 μF, R4 = 10 Ω, R6 = 5 Ω, the low-side driver supply is 15 V, and the DC bus voltage is 10 V. The supply voltage and ripple are tested at different duty cycles for 1 kHz and 20 kHz.

Table 3-1 1-kHz Switching Frequency
Duty Cycle V_MAX Ripple
20% 11.4 V 3.44 V
50% 11.9 V 2.96 V
80% 12.2 V 2.16 V
Table 3-2 20-kHz Switching Frequency
Duty Cycle V_MAX Ripple
20% 12.9 V 352 mV
80% 12.9 V 104 mV

Table 3-1 and Table 3-2 show that lower switch frequency and lower duty cycle bring lower supply voltage (V_MAX) and larger ripple. A similar result is obtained for the 150-V DC bus voltage.