Power Module (Type-A / Rev.B)

If the load devices connected to the power supply circuit operate under maximum load conditions and the circuit cannot supply enough power, causing a shutdown, significant issues can arise depending on the application.

Therefore, to prevent such situations, it is necessary to design the power supply circuit with a margin of approximately 20% or more under worst-case conditions.

1. DC-DC Converter 1 (LTM8074IY#PBF)

A DC-DC converter circuit was designed to step down 24V to 12V using Linear’s “LTM8074IY#PBF” IC. When selecting the feedback resistor for the “LTM8074IY#PBF” to achieve a 12V output from a 24V input, the maximum output current is 1.5A.

The conversion efficiency is at its minimum value of 77% under no-load conditions.

Therefore, the maximum power that needs to be supplied to the “LTM8074IY#PBF” IC from the 24V power source is 23.3[W], which corresponds to a current of 24V / 0.97A.

2. DC-DC Converter 2 (LTM8023EV#PBF)

A DC-DC converter circuit was designed to step down 24V to 5V using Linear’s “LTM8023EV#PBF” IC. When selecting the feedback resistor for the “LTM8023EV#PBF” to achieve a 5V output from a 24V input, the maximum output current is 2A.

The conversion efficiency is at its minimum value of 68% under no-load conditions.

Therefore, the maximum power that needs to be supplied to the “LTM8023EV#PBF” IC from the 24V power source is 14.6[W], which corresponds to a current of 5V / 0.61A.

3. LDO (AMS1117-3.3)

An LDO circuit was designed to step down 5V to 3.3V using UMW’s “AMS1117-3.3” IC.

Schematic of Power Module (Type-A / Rev.B)

PCB Artwork of Power Module (Type-A / Rev.B)

Verification of Power Module (Type-A / Rev.B)

Please understand that the load test could not be conducted due to the absence of electronic load.

24V Output
(The reason why the output voltage is 23.5V instead of 24V is due to the Schottky diode.)

5V Output

12V Output

3.3V Output

Power Module (Type-A / Rev.B)Block Diagram of Power Module (Type-A / Rev.B)1. DC-DC Converter 1 (LTM8074IY#PBF)2. DC-DC Converter 2 (LTM8023EV#PBF)3. LDO (AMS1117-3.3)Schematic of Power Module (Type-A / Rev.B)PCB Artwork of Power Module (Type-A / Rev.B)Verification of Power Module (Type-A / Rev.B)