Toshiba offers photocouplers suitable for IGBT/MOSFET gate drive. Our photocoupler portfolio includes an extensive lineup, ranging from photocouplers with overcurrent protection to those with an output current as high as 6.0 A. Thus, you can select the photocouplers that best fit your needs according to the gate capacitances of the driven IGBTs and MOSFETs.
Toshiba’s photocouplers guarantee a common-mode rejection (CMR) of up to 40 kV/µs, making them ideal for industrial applications such as inverters and servos, which will be installed in electrically noisy environments.
Photocouplers with low input current
Photocouplers with a maximum operating temperature of 125°C
|Clearance D Creepage Distance||8 mm||8 mm||5 mm||7 or 8 mm*||7 or 8 mm*||4 mm|
tpHL / tpLH
|6.0 A||500 ns||TLP358H|
|4.0 A||150 ns||TLP5214
|2.5 A||500 ns||TLP700H||TLP350H|
|1.0 A||150 ns||TLP5751
|0.6 A||700 ns||TLP701H||TLP351H|
* DIP8 and SDIP6 packages with clearance and creepage distances of 8 mm are available.
To order photocouplers in a package with guaranteed clearance and creepage distances of 8 mm, suffix the part number with the letter F. Example: TLP350HF
1. Combines high output current with low power consumption
Toshiba offers the TLP5214 smart gate-drive photocoupler that incorporates VCE(sat) and active Miller clamping capabilities that are designed to protect the IGBT from overcurrent conditions. The VCE(sat) detection circuit monitors the VCE(sat) voltage of the IGBT and performs a soft shutdown of the IGBT in the event of an overcurrent condition. It also delivers a FAULT signal to the controller. The Miller clamping circuit suppresses an increase in the gate voltage and thus a malfunction of the IGBT by bypassing the Miller current to ground via the photocoupler. Additionally, the TLP5214 provides rail-to-rail output, undervoltage lockout (UVLO) and other features, reducing the number of external components compared with that previously required. This helps reduce bill-of-material (BOM) costs and board size.
2. Common-mode transient immunity
Generally, the high-level output voltage of an IGBT-drive photocoupler is a few volts lower than the power supply voltage. In contrast, RRO photocouplers provide a full-swing output from ground to almost the supply voltage. The rail-to-rail output helps reduce the power loss of both the photocoupler and the IGBT during switching.
The TLP5751,TLP5752,TLP5754,TLP5214 marked in the above table are RRO photocouplers.
An inverter circuit might not work properly if voltage with a steep dv/dt is applied across the input and output of a photocoupler. The CMR of a photocoupler can be improved by adding a shield across its input and output and bypassing displacement current to ground. To provide a CMR sufficient for direct IGBT/MOSFET gate drive, many of Toshiba's IGBT gate-drive photocouplers have a shield for the photodetector chip. The TLP250H in particular guarantees a high CMR of 40 kV/µs.
3. Undervoltage lockout (UVLO)
Many of Toshiba's IGBT/MOSFET gate-drive photocouplers incorporate a UVLO circuit to prevent a failure in the low-voltage region. The UVLO circuit holds the output Low until the supply voltage, VCC, exceeds the rising UVLO threshold in order to prevent a false output from the photocoupler and thus a malfunction of the driven IGBT/MOSFET.