High Voltage DC Converter

MAX5025 High Voltage DC Converter Circuit

As we know that the Micro Electronic Mechanical Systems (MEMS) are a system that combines mechanical and electrical components and are made using semiconductor fabrication techniques. Devices of the system such as pressure and acceleration sensors that combine sensors and amplification or conditioning circuits often require high DC-bias voltages 40V to 100V at low current below 1mA, but the available supply voltage below 12V May be. Alternatively, needs of high voltage DC converter encountered in other applications include switches, valves, and waveguides.

High Voltage DC Converter Circuit

Here is a DC-DC converter that combines capacitive and inductive step-up converter (buck converter) circuitry without the need for expensive transformers to achieve high voltage. A high voltage DC  converter  MAX5025 (U1) to convert the typical 5V input to 36V, and 2-stage charge pump to increase the voltage more than 100V.

High Voltage DC Converter Circuit

U1 is the step-up DC-DC converter capable of +36 V output voltage, and charge-pump converter 2 stages (D2-D5 and C1-C4) are almost three times the output of U1. Divider R1/R2 provides feedback to adjust the output voltage of the circuit.

High Voltage DC Converter Equations

For lower the output voltage of 70V, remove D4, D5, C3, and C4 to produce a charge-pump stage. Similarly, you can add another stage to generate voltages higher than 100V. An optional post filter (R3 and C5) reduces output ripple to below 10mVP-P. Use the equation to calculate the values ​​of resistors R1 and R2, please visit Maxim Application Note 1751 for high voltage DC converter info.