What is the gate-driver that facilitates the overcurrent protection design of inverter applications?

Protective function assurance and operation timing design simplification of IGBT/MOSFET drive circuits using pre-drivers

The pre-driver TLP5231 is suitable for industrial inverters and photovoltaic power conditioning systems as a medium to high current IGBT/MOSFET driver, with a built-in overcurrent detecting function and a soft turn-off function. The TLP5231 also provides over-current protection with DESAT short-circuit detection that monitors the collector voltage of an IGBT or the drain voltage of a MOSFET. This function detects overcurrent and softly turns off the IGBT/MOSFET gate-voltage. This soft turn-off feature prevents fatal overcurrent caused by short-circuiting through the power devices for both high-side and low-side.

In addition, the conventional IGBT/MOSFET drive photocoupler only stops operation when UVLO [Note 1] is working, but the TLP5231 outputs a fault signal to the primary side when UVLO is working, supporting the design as a pre-driver more than a conventional IGBT/MOSFET.

Since the TLP5231 drives medium to high current MOSFET and IGBT gates via the p-channel and n-channel complementary buffer MOSFETs, the current flows to charge or discharge the buffer MOSFET, resulting in low power consumption. It is possible to create the required gate current for various IGBTs / MOSFETs simply by changing the external complementary buffer MOSFET size. By using a platform that combines TLP5231 with buffer MOSFETs and IGBT/MOSFET it is possible to cover a wide line-up system power sizes and contribute to reducing design workload.

[Note 1] UVLO: Under voltage lockout


  • Industrial inverters and Uninterruptible Power Supplies (UPS)
  • Photovoltaic power conditioning system


  1. Reduce the workload of dead-time design

2. Improve the design flexibility for the soft turn-off

3. Fault signal auto-reset

1. Reduce the workload of dead-time design

Reduce the workload of dead-time design

TLP5231 has two output lines to control buffer MOSFET Q1 / Q2 and provides a time difference (non-overlap time) between the ON / OFF signals of Q1 / Q2 to ensure dead-time when turning off both Q1 and Q2. This dual-output eliminates the need for dead-time design, which was difficult due to the buffer configuration with bipolar transistors, and prevents switching loss due to simultaneous ON-state generation.

2. Improve the design flexibility of soft turn-off

Improve the design flexibility of soft turn-off

TLP5231 requires an additional MOSFET for soft turn-off in the event of an anomaly. Since this soft turn-off MOSFET doesn’t share wires (lines) with buffer MOSFET Q2, flexible design is possible without worrying about trade-off with normal OFF-operation.

3. Fault signal auto-reset

The gate circuit of a power device controlling high voltages is very noisy, and DESAT monitoring is often falsely detected. To separate overcurrent detection due to anomaly from false detection of noise, as an example, there is a method to stop the system when fault signals are detected multiple times. In this case, if recovery from an abnormal stop is auto-reset type, the MCU doesn’t need to issue a reset signal for each fault signal. And the operation is simplified because the system can stop the machine after counting the specific number of fault signals. As a result, the designer can improve the stability of system operation.

Application Information

Application Information

Ext-PMOS: p-channel MOSFET (for current-buffer)
Ext-NMOS: n-channel MOSFET (for current-buffer)
GMOS: n-channel MOSFET (for soft turn-off control)

NOTE: This application circuit example is for reference only, and the designer should thoroughly evaluate it for mass production. In addition, it does not permit the use of Industrial Property Rights.

Internal Circuit

Internal Circuit

Main specifications of the new product

(@Ta =-40 to 110 °C unless otherwise specified)

Product Number


Absolute maximum rating

Peak high level output current IOPH (A)


Peak low level output current IOPL (A)


Electrical Characteristics

VOUTP high level output current IOUTPH max (A)


VOUTP low level output current IOUTPL min (A)


VOUTN high level output current IOUTNH max (A)


VOUTN low level output current IOUTNL min (A)


High level supply current (VCC2) ICC2H max (mA)


Low level supply current (VCC2) ICC2L max (mA)


High level supply current (VEE) IEEH min (mA)


Low level supply current (VEE) IEEL min (mA)


Threshold input current (H/L) IFHL max (mA)


Recommended operating conditions

Total output supply voltage (VCC2-VEE) (V)

21.5 to 30

Negative output supply voltage (VE-VEE) (V)

-15 to -6.5

Positive output supply voltage (VCC2-VE) (V)

15 to 23.5

Switching characteristic

Propagation delay time (L/H) tpLH (ns)

100 to 300

Propagation delay time (H/L) tpHL (ns)

100 to 300

Propagation delay skew tpsk (ns)

-200 to 200

High-level common-mode transient tolerance CMH min (kV/μs)


Low-level common-mode transient tolerance CML min (kV/μs)




Feedback (FAULT): Operates when a VCE(sat) is detected or a UVLO is detected (open collector output).

Isolation Characteristics

(@Ta=25 °C)

Isolation voltage BVS min (Vrms)


Structural parameter

Clearance distance min (mm)


Creepage distance min (mm)


Insulation thickness min (mm)


[Note] VE standard

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