MICROCHIP TC1303B-DF0EMFTR

The TC1303/TC1304 combines a 500 mA synchronous buck regulator and 300 mA Low-Dropout Regulator (LDO) with a power-good monitor to provide a highly integrated solution for devices that require multiple supply voltages. The unique combination of an integrated buck switching regulator and low-dropout linear regulator provides the lowest system cost for dual-output voltage applications that require one lower processor core voltage and one higher bias voltage.

The 500 mA synchronous buck regulator switches at a fixed frequency of 2.0 MHz when the load is heavy, providing a low noise, small-size solution. When the load on the buck output is reduced to light levels, it changes operation to a Pulse Frequency Modulation (PFM) mode to minimize quiescent current draw from the battery. No intervention is necessary for smooth transition from one mode to another.

The LDO provides a 300 mA auxiliary output that requires a single 1 μF ceramic output capacitor, minimizing board area and cost. The typical dropout voltage for the LDO output is 137 mV for a 200 mA load.

For the TC1303/TC1304, the power-good output is based on the regulation of the buck regulator output, the LDO output or the combination of both. The TC1304 features start-up and shutdown output sequencing.

The TC1303/TC1304 is available in either the 10-pin DFN or MSOP package.

Additional protection features include: UVLO, overtemperature and overcurrent protection on both outputs.

• Dual-Output Regulator (500 mA Buck Regulator and 300 mA Low-Dropout Regulator)
• Power-Good Output with 300 ms Delay
• Total Device Quiescent Current = 65 μA, Typical
• Independent Shutdown for Buck and LDO Outputs (TC1303)
• Both Outputs Internally Compensated
• Synchronous Buck Regulator:
  • Over 90% Typical Efficiency
  • 2.0 MHz Fixed-Frequency PWM (Heavy Load)
  • Low Output Noise
  • Automatic PWM to PFM mode transition
  • Adjustable (0.8V to 4.5V) and Standard Fixed-Output Voltages (0.8V, 1.2V, 1.5V, 1.8V, 2.5V, 3.3V)
• Low-Dropout Regulator:
  • Low-Dropout Voltage = 137 mV Typical @ 200 mA
  • Standard Fixed-Output Voltages (1.5V, 1.8V, 2.5V, 3.3V)
• Power-Good Function:
  • Monitors Buck Output Function (TC1303A)
  • Monitors LDO Output Function (TC1303B)
  • Monitors Both Buck and LDO Output Functions (TC1303C and TC1304)
  • 300 ms Delay Used for Processor Reset
• Sequenced Startup and Shutdown (TC1304)
• Small 10-pin 3x3 DFN or MSOP Package Options
• Operating Junction Temperature Range: -40°C to +125°C
• Undervoltage Lockout (UVLO)
• Output Short Circuit Protection
• Overtemperature Protection

• Cellular Phones
• Portable Computers
• USB-Powered Devices
• Handheld Medical Instruments
• Organizers and PDAs