Transformer Driver for Isolated Power Supplies

1FEATURES
• Push-Pull Driver for Small Transformers
• Single 3.3 V or 5 V Supply
• High Primary-side Current Drive:
– 5 V Supply: 350 mA (max)
– 3.3 V Supply: 150 mA (max)
• Low Ripple on Rectified Output Permits Small Output Capacitors
• Small 5-pin SOT23 Package

APPLICATIONS
• Isolated Interface Power Supply for CAN, RS-485, RS-422, RS-232, SPI, I2C, Low-Power LAN
• Industrial Automation
• Process Control
• Medical Equipment

DESCRIPTION
The SN6501 is a monolithic oscillator/power-driver, specifically designed for small form factor, isolated power
supplies in isolated interface applications. It drives a low-profile, center-tapped transformer primary from a 3.3 V
or 5 V DC power supply. The secondary can be wound to provide any isolated voltage based on transformer
turns ratio.
The SN6501 consists of an oscillator followed by a gate drive circuit that provides the complementary output
signals to drive the ground referenced N-channel power switches. The internal logic ensures break-before-make
action between the two switches.
The SN6501 is available in a small SOT23-5 package, and is specified for operation at temperatures from –40°C
to 125°C.