Texas Instruments SN6505A

Description

The SN6505 is a low-noise, low-EMI push-pull transformer driver, specifically designed for small form factor, isolated power supplies. It drives lowprofile, center-tapped transformers from a 2.25 V to 5 V DC power supply. Ultra-low noise and EMI are achieved by slew rate control of the output switch voltage and through Spread Spectrum Clocking (SSC). The SN6505 consists of an oscillator followed by a gate drive circuit that provides the complementary output signals to drive groundreferenced N-channel power switches. The device includes two 1-A Power-MOSFET switches to ensure start-up under heavy loads. The switching clock can also be provided externally for accurate placement of switcher harmonics, or when operating with multiple transformer drivers. The internal protection features include a 1.7A current limiting, under-voltage lockout, thermal shutdown, and break-before-make circuitry. SN6505 includes a soft-start feature that prevents high inrush current during power up with large load capacitors. The SN6505 is available in a small 6-pin SOT23/DBV package. The device operation is characterized for a temperature range from –55°C to 125°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 External Clock 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

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

More information

• Datasheet
• IC product information