Datasheet NCP1729 (ON Semiconductor) - 10

NCP1729
1 6 OSC −Vout Vin 2 5 + + + + + + + 3 4 Capacitors = 3.3 F
Figure 24. Negative Output Voltage Tripler
A single device can be used to construct a negative voltage tripler. The output voltage is approximately equal to −3.0 Vin minus the forward voltage drop of each external diode. The performance characteristics for the above converter are shown below. Note that curves A and C show the circuit performance with economical 1N4148 diodes, while curves B and D are with lower loss MBRA120E Schottky diodes. 0 −2.0 A −4.0 AGE T C B −6.0
Curve Vin (V) All Diodes Rout ( )
−8.0 A 3.0 1N4148 247 −10.0 D B 3.0 MBRA120E 228 , OUTPUT VOL out −12.0 V C 5.0 1N4148 198 −14.0 TA = 25°C D 5.0 MBRA120E 188 −16.0 0 10 20 30 40 50 Iout, OUTPUT CURRENT
Figure 25. Tripler Load Regulation, Output Voltage vs. Output Current http://onsemi.com 10