COS6505B

The COS6505A/B/C Family are low-EMI push-pull transformer drivers, specifically designed for small form factor, isolated power supplies in isolated interface applications. The device drives a low-profile, center-tapped transformer primary from a 2.25-V to 5-V DC power supply. The secondary can be wound to provide any isolated voltage based on transformer turns ratio. The COS6505AB/C consist 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 internal protection features under-voltage lockout, thermal shutdown and output current limiting. Low noise and low-EMI are achieved by slew rate control of the output switch voltage and through Spread Spectrum Clocking (SSC).

Applications

• Isolated Interface Power Supply for CAN, RS-485, RS422, RS-232, SPI, I2C
• Low-Power LAN
• Isolated USB Supplies
• Industrial Automation
• Medical Equipment

Key features

• Push-pull driver for transformers
• Operates with 2.25-V to 5.5-V supply
• High output drive: 1A at 5V supply
• Low RON 0.25Ω at 4.5V
• Spread spectrum clocking (SSC)
• Ultra-low EMI
• Precision internal oscillator options: 160kHz (COS6505A), 420 kHz (COS6505B/C)
• Synchronization of multiple devices with external clock input
• Slew-rate control
• 1.7A Current-limit
• Low shutdown current: <1 μA
• Thermal shutdown protection
• Wide temperature range: -45°C to 125°C
• Small package: SOT23-6