T-reg revised – MOSFET-based high-voltage regulators for tube amps. Jan Didden In 2009 I designed a high-voltage regulator for tube equipment 1, 2. Originally based on a series tube, I also gave circuit details for use with an enhancement mode MOSFET. However, the readily available enhancement mode MOSFETs like the DN2540 have limited short. In this case the 'off' voltage (the lowest voltage of the wavaveform) at the MOSFET gate needs to be lifted up to at least as high as the supply voltage. For example if a logic level MOSFET is used, the minimum gate voltage would be equal to the supply voltage (5V) and the peak gate voltage would need to be 5V higher than the supply voltage Vcc. MDF3N50TH, High Voltage (HV) MOSFET High Voltage, N-Channel MOSFET, with low on-state resistance and high switching performance., Maximum Operating Temperature +150 °C, Number of Elements per Chip.

1. Mosfet High Voltage
2. High Power Mosfet
3. Mosfet High Voltage Input

The cause of this failure is a very high voltage, very fast transient spike (positive or negative). If such a spike gets onto the drain of a MOSFET, it gets coupled through the MOSFETs.

Using a MOSFET as a switch is generally pretty simple. Make the gate voltage sufficient with respect to the source and current flows through the channel. However, if you are switching higher voltages, you may need some additional circuitry to protect the device’s gate and possibly the microcontroller driving the whole thing, too. [Lewis] discusses high voltage switching in the latest in his series of videos dealing with MOSFETs. You can see the video below.

You’ll see in the video a breadboard setup driving a 50 V load and also a higher-voltage H-bridge. There are three major topics covered: Using an optoisolator, using a gate bleeder resistor, and using a zener diode to limit gate voltage.

Of course, an optoisolator isn’t necessary with or without the high voltage, as long as everything works well. It can, however, prevent high-frequency noise from conducting from the FET channel through the gate acting as a capacitor. It can also be useful for saving the controller if there is a failure that shorts the channel to the gate.

The bleeder resistor isn’t specific to high voltages, either. Because the gate is practically an open circuit at DC, it is a good idea to add a resistor like this so that when the gate drive is off, you don’t have to wait for the charge on the gate to dissipate. In addition, the resistor offers some protection against electrostatic discharge (ESD) damage, since the ESD will tend to flow through the resistor instead of punching through the gate oxide on the device. Mac os must have apps.

Mosfet High Voltage

The zener sees service in two ways. At first, the circuit uses it to derive 12 V from the 50 V supply. However, in a later incarnation, the design uses it as a clamp to keep a P-channel’s gate at 12 V. These are both important because the maximum rating of the gates is 20 V.

Although the devices in the video are IRF630s and IRF9630s, the principles apply to lots of different kind of FETs. Just remember what you kind you have and understand the datasheet before you finalize your design.

If you want something more basic, there are plenty of tutorials. We’ve even looked at high-side switches in detail.

Opto MOSFET relay for High Voltage Applications

Bright TOWARD achieves a higher level of power handling capability using LED triggered D-MOSFET technology. Compared to traditional mechanical relays, Opto MOSFET relays provide great benefits, including reducing real-estate of PCB – small form factor, longer life as semiconductor, and high-speed switching -quick response and performance. Opto MOSFET relay for high voltage applications in Industrial, Robotics, Security, and a broad range of applications. The Control line is optically isolated from the high voltage signal line. Therefore, these products give design flexibility in high power applications and ensure great dielectric strength between input and output signals.

The much higher voltage required? Macintosh 2016. Bright TOWARD Industrial Co., Ltd., released Silicon Carbide (SiC) products for high current and high voltage applications. Please visit out SiC page for more detail.

38 Series / 38-2 Series Opto MOSFET relay

Features

• 60 to 80mA / 600V Load (38 Series)
• 1500Vrms I/O Breakdown Voltage (38 Series)
• 120mA / 650V Load (38-2 Series)
• 3750Vrms I/O Breakdown Voltage (38-2 Series)
• for industrial control, robotics, security, transportation equipment, instrumentation, meters, and aerospace/defense applications

38-2 Series Data Sheet

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39 Series Opto MOSFET relay

Features

• 50mA /1000V Load
• 3750Vrms I/O Breakdown Voltage
• for industrial control, robotics, security, transportation equipment, instrumentation, meters, and aerospace/defense applications

39 Series Data Sheet

Software download for android. Please contact us for 39 Series Data Sheet

40 Series Opto MOSFET relay

High Power Mosfet

Features

• 45mA / 1500V Load
• 3750Vrms I/O Breakdown Voltage
• for industrial control, robotics, security, transportation equipment, instrumentation, meters, and aerospace/defense applications

Mosfet High Voltage Input