Texas Instruments SN6505 | Demoboard PMP23126

Description

The SN6505x is a low-noise, low-EMI push-pull transformer driver, specifically designed for small form factor, isolated power supplies. It drives low-profile, 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 SN6505x consists of an oscillator followed by a gate drive circuit that provides the complementary output signals to drive ground-referenced 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 1.7 A current limiting, under-voltage lockout, thermal shutdown, and break-before-make circuitry. SN6505x include s a soft-start feature that prevents high inrush current during power up with large load capacitors. SN6505A has a 160 kHz internal oscillator for applications that need to minimize emissions whereas SN6505B has a 420 kHz internal oscillators for applications that require higher efficiency and smaller transformer size. The SN6505x 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 transformersWide input voltage range: 2.25 V to 5.5 VHigh output drive: 1 A at 5 V supplyLow R ON 0.25 Ω max at 4.5 V supplyUltra-low EMISpread spectrum clockingPrecision internal oscillator options: 160 kHz ( SN6505A) and 420 kHz ( SN6505B)Synchronization of multiple devices with external clock inputSlew-rate control1.7 A Current-limitLow shutdown current: <1 µAThermal shutdownWide temperature range: –55°C to 125°CSmall 6-Pin SOT23 (DBV) packageSoft-start to reduce In-rush current

Typical applications

• Switch-mode power converters
• Merchant telecom rectifiers
• DC/DC converter
• On-board (OBC) and wireless charge
• Merchant network and server PSU

More information

• Datasheet