Efficient Negative Voltage Regulation


Posted on Jun 1, 2012

Many applications require highly efficient negative-voltage post regulators with low dropout voltage


Efficient Negative Voltage Regulation
Click here to download the full size of the above Circuit.

in switch-mode supplies. A way to provide good negative-voltage regulation is with a low-dropout positive-voltage regulator operating from a well-isolated secondary winding of the switch-mode transformer. The technique works with any positive-voltage regulator, although highest efficiency occurs with low-dropout types. In the circuit, two programming resistors, Rl and R2, set the output voltage to 12 V, and the LT1086s servo the voltage between the output and its adjusting (ADJ) terminals to 1.25 V. Capacitor CI improves ripple rejection, and protection diode Dl eliminates common-load problems. Because a secondary winding is galvanically isolated, a regulator"s 12-V output can be referenced to ground. Therefore, in the case of a negative-voltage output, the positive-voltage terminal of the regulator connects to ground, and the -12-V output comes off the anode of Dl. The V-m terminal floats at 1.5 V or more above ground. This arrangement is the equivalent of connecting the positive terminal of a battery to ground and taking the output from the negative terminal.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Sola Sound ToneBender
4-Way Logic Probe
Car Parking Sensor Circuit Schematic Free With Explanation
12 volt switching power supply using ltc3810 5
Fun and easy to build buzzer circuit
water sensor alarm circuit using ic
logic tutor circuit
Schematic Diagram DCF77 Preamplifier circuit and explanation
ADUC841 20MIPS 8052 Flash MCU + 8-Ch 12-Bit ADC + Dual 12-Bit DAC
CoSaTrak drive satellite tracking circuit
Circuit of RIIA phono pre-amplifier op-27
Dual 25W stereo audio power amplifier circuit
Changes inductive boost LED Driver
Radio circuit



Top