Silicon-controlled Rectifier (SCR) Specifications- Explained

There are many different specifications which you'll find on a datsheet for silicon-controlled rectifiers (SCRs).

There is gate trigger voltage, gate trigger current, holding current, on-state voltage, peak gate power dissipation...

What do all of these terms mean? How do they apply to the SCR? Why are they important? What significance do they hold when choosing an SCR for a circuit?

We hope to explain these terms so that you can understand the specifications of an SCR.

SCR Datasheet Specifications

Gate Trigger Current
Gate Trigger Voltage
Holding Current
On-state Voltage
Peak Gate Power Dissipation

Gate Trigger Current

Gate Trigger Current is the minimum gate current needed to switch the SCR on.

Just like a BJT, an SCR needs sufficient current applied to its gate terminal in order to turn on.

Gate Trigger Voltage

Gate Trigger Voltage is the minimum gate voltage required to trigger the gate terminal, which then turns on the SCR.

Holding Current

Holding Current is the minimum current through the anode-to-cathode terminal required to maintain the SCR's on state.

While the gate trigger current is the current needed to switch the SCR to the on state, the holding current is the current required to maintain this on state.

On-state Voltage

On State-Voltage is the anode-to-cathode voltage present when the SCR is on.

Peak Gate Power Dissipation

The Peak Gate Power Dissipation is the maximum power that may be dissipated between the gate and the cathode region in a silicon-controlled rectifier (SCR).

Related Resources

How to Build a Very Basic SCR Circuit