Vout = 5V Iout = 1A Following the design procedure from the LM2596 datasheet the input/output capacitor, diode and inductor values are computed. Inductor Selection (L1): the inductor value is equal to 68µH using the 1 amp load current and the 12 volt input voltage. The L30 from this figure corresponds to a number of possible inductors, both through hold and surface mount types, from various suppliers. The Coilcraft surface mount inductor, part number DO5022P-683, is chosen with a 2.3 amp RMS current. Figure 51 - Inductor Selection Graph 1 Output Capacitor (Cout): The National Semiconductor datasheet for the LM2596 uses as a quick design component selection table and the details guidelines below for selecting the output capacitor consisting of: Capacitor voltage rating > 1.5*Vout Capacitor values no larger than 820µF Low ESR capacitors Table 25- Output Capacitor Selection Table 1 This suggests that a 220µF output capacitor with a 10V rating is appropriate from AVX TPS series. This surface mount tantalum capacitor is rated at 20% tolerance with a temperature range from -55°C t0 125°C. The DC voltage rating is 10V which is twice the value of the output voltage and abides by restriction number 1. Furthermore the ESR is equal to 0.1 Ohm and is in concordance with restriction number 3. This part can be ordered from Digi-Key, part number for $2.21. Catch Diode Selection (D1): The datasheet further details the guidelines for selecting the catch diode as follows: Current rating >1.3*Maximum Load Current Reverse Voltage Rating > 1.25*Maximum Input Voltage Short Reverse Recovery Time Using these given restrictions the Schottky diode from Diodes Inc. is selected; part number 1N5820DITR-ND. The forward current rating is equal to 3 amps to fulfill restriction number 1 where the maximum load current is 1 amp. Furthermore the reverse voltage rating is 20V, more than 1.25 times the input
Vout = 5V Iout = 1A Following the design procedure from the LM2596 datasheet the input/output capacitor, diode and inductor values are computed. Inductor Selection (L1): the inductor value is equal to 68µH using the 1 amp load current and the 12 volt input voltage. The L30 from this figure corresponds to a number of possible inductors, both through hold and surface mount types, from various suppliers. The Coilcraft surface mount inductor, part number DO5022P-683, is chosen with a 2.3 amp RMS current. Figure 51 - Inductor Selection Graph 1 Output Capacitor (Cout): The National Semiconductor datasheet for the LM2596 uses as a quick design component selection table and the details guidelines below for selecting the output capacitor consisting of: Capacitor voltage rating > 1.5*Vout Capacitor values no larger than 820µF Low ESR capacitors Table 25- Output Capacitor Selection Table 1 This suggests that a 220µF output capacitor with a 10V rating is appropriate from AVX TPS series. This surface mount tantalum capacitor is rated at 20% tolerance with a temperature range from -55°C t0 125°C. The DC voltage rating is 10V which is twice the value of the output voltage and abides by restriction number 1. Furthermore the ESR is equal to 0.1 Ohm and is in concordance with restriction number 3. This part can be ordered from Digi-Key, part number for $2.21. Catch Diode Selection (D1): The datasheet further details the guidelines for selecting the catch diode as follows: Current rating >1.3*Maximum Load Current Reverse Voltage Rating > 1.25*Maximum Input Voltage Short Reverse Recovery Time Using these given restrictions the Schottky diode from Diodes Inc. is selected; part number 1N5820DITR-ND. The forward current rating is equal to 3 amps to fulfill restriction number 1 where the maximum load current is 1 amp. Furthermore the reverse voltage rating is 20V, more than 1.25 times the input
Electric%20Car%20Conversion%20Group%203%20SD1%20P2a.docx