8.2.1.1.1 External Components

The procedure for calculating the external components is illustrated with the following design example. Only the values for the 3.3 V output are calculated because the procedure is the same for the 1.8-V output. The circuit shown in Figure 14 is configured for the following specifications:

• CH1 output voltage, V_OUT1 = 3.3 V
• CH2 output voltage, V_OUT2 = 1.8 V
• CH1 maximum load current, I_OUT1 = 8 A
• CH2 maximum load current, I_OUT2 = 8 A
• Minimum input voltage, V_IN(min) = 6 V
• Maximum input voltage, V_IN(max) = 36 V
• Switching frequency, f_SW = 230 kHz

Some component values were chosen as a compromise between the 3.3-V and 1.8-V outputs to allow identical components to be used on both outputs. This design can be reconfigured in a dual-channel interleaved configuration with a single 3.3-V output which requires identical power channels.