Texas Instruments SN6505A

Description

The SN6505 is a low-noise, low-EMI push-pulltransformer driver, specifically designed for smallform factor, isolated power supplies. It drives lowprofile,center-tapped transformers from a 2.25 V to5 V DC power supply. Ultra-low noise and EMI areachieved by slew rate control of the output switchvoltage and through Spread Spectrum Clocking(SSC). The SN6505 consists of an oscillator followedby a gate drive circuit that provides thecomplementary output signals to drive groundreferencedN-channel power switches. The deviceincludes two 1-A Power-MOSFET switches to ensurestart-up under heavy loads. The switching clock canalso be provided externally for accurate placement ofswitcher harmonics, or when operating with multipletransformer drivers. The internal protection featuresinclude a 1.7A current limiting, under-voltage lockout,thermal shutdown, and break-before-make circuitry.SN6505 includes a soft-start feature that preventshigh inrush current during power up with large loadcapacitors. The SN6505 is available in a small 6-pinSOT23/DBV package. The device operation ischaracterized for a temperature range from –55°C to125°C.

Features

Push-Pull Driver for transformers

• Wide Input Voltage Range: 2.25 V to 5.5 V
• High Output Drive: 1 A at 5 V Supply
• Low RON 0.25 Ω Max at 4.5 V Supply
• Ultra-Low EMI
• Spread Spectrum Clocking
• Precision Internal Oscillator Options: 160 kHz(SN6505A) and 420 kHz (SN6505B)
• Synchronization of Multiple Devices with ExternalClock Input
• Slew-Rate Control
• 1.7 A Current-Limit
• Low Shutdown Current: <1 μA
• Thermal Shutdown
• Wide Temperature Range: –55°C to 125°C
• Small 6-Pin SOT23/DBV Package
• Soft Start to reduce In-rush current

Typical applications

• Radio Supplies
• Medical Instruments
• Isolated Power Supply for CAN, RS-485, RS-422, RS-232, SPI, I2C, Low-Power LAN
• Telecom Supplies
• Distributed Supplies
• Low-Noise Filament Supplies
• Process Control
• Low-Noise Isolated USB Supplies
• Precision Instruments

More information

• Datasheet
• IC product information