Controller Operation

April 14, 2003
The IR2085S controller was optimized for the bus converter application as it is applied in distributed power architectures that use an intermediate voltage bus. This International Rectifier device combines a pulse-width-modulation (PWM) controller...

The IR2085S controller was optimized for the bus converter application as it is applied in distributed power architectures that use an intermediate voltage bus. This International Rectifier device combines a pulse-width-modulation (PWM) controller and a half-bridge driver (see the figure).

Each of these functions typically requires a separate eight-pin SOIC, but the IR2085S integrates the same functionality into just one of these packages. At the same time, the chip omits certain protection features that are normally external to the isolated converter in networking-related distributed power applications. Yet it includes enable and current-limiting functions.

The controller provides a gate-drive signal to a primary-side half-bridge driver, which has 1 A of gate-drive capability. The gate-drive circuit is optimized for the company's primary-side low-charge MOSFET, the IRF7493. This MOSFET specifies a maximum on-resistance of 15 mΩ at VGS = 10 V and a typical gate charge of 31 nC. The controller chip drives the primary-side MOSFETs directly, requiring no additional drivers or buffers.

An on-chip bias circuit generates the controller's 10- to 15-V supply. A soft-start feature gradually raises duty cycle from zero to 50% to limit inrush current at startup. The inrush current typically lasts for a period of 5 ms.

International Rectifier
www.irf.com

Sponsored Recommendations

Board-Mount DC/DC Converters in Medical Applications

March 27, 2024
AC/DC or board-mount DC/DC converters provide power for medical devices. This article explains why isolation might be needed and which safety standards apply.

Use Rugged Multiband Antennas to Solve the Mobile Connectivity Challenge

March 27, 2024
Selecting and using antennas for mobile applications requires attention to electrical, mechanical, and environmental characteristics: TE modules can help.

Out-of-the-box Cellular and Wi-Fi connectivity with AWS IoT ExpressLink

March 27, 2024
This demo shows how to enroll LTE-M and Wi-Fi evaluation boards with AWS IoT Core, set up a Connected Health Solution as well as AWS AT commands and AWS IoT ExpressLink security...

How to Quickly Leverage Bluetooth AoA and AoD for Indoor Logistics Tracking

March 27, 2024
Real-time asset tracking is an important aspect of Industry 4.0. Various technologies are available for deploying Real-Time Location.

Comments

To join the conversation, and become an exclusive member of Electronic Design, create an account today!