Onsemi MURB1660CT Ultrafast Rectifier: Datasheet, Pinout, and Application Circuits

The Onsemi MURB1660CT is a high-efficiency, ultrafast recovery rectifier designed for demanding high-frequency power conversion applications. Housed in a robust TO-220AB package, this rectifier is part of a series known for its ultrafast recovery time and soft recovery characteristics, which are critical for minimizing switching losses and reducing electromagnetic interference (EMI) in circuits.

This component is particularly well-suited for use in switch-mode power supplies (SMPS), inverters, and as freewheeling or clamp diodes in various power electronic systems.

Datasheet Overview: Key Specifications

The MURB1660CT is a common cathode dual rectifier, meaning two separate diodes are integrated within a single package with their cathodes connected to a common terminal. Its key electrical characteristics include:

Repetitive Peak Reverse Voltage (VRRM): 600 V

Average Forward Rectified Current (IO): 16 A per diode (Note: The specific current rating is contingent on the heatsink and thermal management; refer to the datasheet for detailed derating curves).

Peak Forward Surge Current (IFSM): 150 A

Maximum Forward Voltage Drop (VF): Typically 1.25 V at 8 A (per diode)

Typical Reverse Recovery Time (trr): 35 ns (Ultrafast)

Operating Junction Temperature (TJ): -65°C to +175°C

These specifications highlight the device's capability to handle high voltage and current stresses while maintaining efficiency through its fast switching performance. The ultrafast recovery time is a defining feature, as it directly reduces the reverse recovery current, leading to lower power losses in the switching transistor and improved overall system reliability.

Pinout and Package

The MURB1660CT is packaged in the industry-standard TO-220AB case, which is designed for easy mounting to a heatsink. The pinout configuration is as follows:

Pin 1 (Left Pin): Anode of Diode 1

Pin 2 (Center Pin): Common Cathode for both Diode 1 and Diode 2

Pin 3 (Right Pin): Anode of Diode 2

This common cathode configuration is ideal for use in full-wave center-tapped rectifier circuits, a common topology in power supply designs.

Application Circuits

The primary application for the MURB1660CT is in power rectification. Here are two common circuit examples:

1. Center-Tapped Full-Wave Rectifier:

This is the most straightforward application for this common-cathode device. It is perfectly designed for the secondary side of a center-tapped transformer. The AC input is applied between the transformer's center tap (which is connected to ground) and the two ends of the secondary winding (connected to the two anodes). The common cathode provides the pulsating DC output. This circuit is highly efficient and provides full utilization of both halves of the AC waveform.

2. Freewheeling/Clamp Diode in Switch-Mode Power Supplies (SMPS):

In inductive load circuits, such as those found in buck converters, forward converters, or motor drive circuits, the MURB1660CT can be used as a freewheeling diode. When the main power switch (e.g., a MOSFET) turns off, the current from the inductive load needs a path to circulate. The ultrafast rectifier provides this path, protecting the switch from voltage spikes and ensuring smooth current decay. Its soft recovery characteristic is vital here to suppress voltage transients and EMI.

ICGOOODFIND: The Onsemi MURB1660CT stands out as a highly reliable and efficient solution for high-frequency rectification. Its robust TO-220 package, high voltage and current ratings, and most importantly, its ultrafast and soft recovery performance, make it an excellent choice for designers aiming to optimize efficiency and reduce noise in power supplies, inverters, and other switching applications. Proper heatsinking is essential to leverage its full current-handling capability.

Keywords: Ultrafast Recovery, Common Cathode, Rectifier, Switching Losses, TO-220 Package.