Project Description
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Project description
It has adjustable voltage limit but not adjustable current limit.
Some design notes:
Vin = 10-13.2V
Iin = 2.6A max
Vout (fixed) = 5.0V when R3 = 2.1k, R4 = 5k
When R4 wiper goes to GND side of R4, output goes to 0V.
When R4 wiper goes to high side of R4, output goes to VREF (~ 7.15V).
Vout (max, short circuit) = 2.6A
With R1||R2 = ~0.25 ohm, short circuit current limit is 0.65V/0.25ohm = 2.6A.
At Isc, R1 and R2 share ~1.7W, so 2W components provide 50% derating
At Isc, Q1 drops all of the input voltage except the 0.65V across the sense resistors, so worst case 13.2-0.65 = 32.6W, which is 60% of MJB44H11G's rated power.
Variable current limit control can be added by separately controlling ISENSE based on a variable gain on the output current sense voltage. Need multiple MJB44H11G's in parallel to achieve higher output current. Need current amplifier on U1 VOUT output to accommodate this.
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Component (15)
Qty
Description
Resistor
R15
1
Generic Resistor (1k)
LM723CN/NOPB
U1
1
Standard
MJB44H11T4G
Q1
1
Standard
Capacitor
C3
1
Generic Capacitor (1 uF)