The MIC2807 integrates a high performance DC/DC converter intended for powering a power amplifier (PA) in a mobile phone with dual low noise low dropout (LDO) regulators for the rest of the RF section. Optimized for low noise performance, the MIC2807 improves efficiency in the handset without compromising quality.The MIC2807 has a 2MHz, constant frequency pulse width modulated (PWM) DC/DC converter designed for low noise operation and high efficiency. The output voltage (VOUT) is variable from 0.3V to the input voltage (VIN), adjustable from 0.3V to 3.6V through a DAC input when VIN > VOUT. The converter will work in a 100% duty cycle mode to offer maximum power and efficiency in the application. In addition to 100% duty cycle, the DC/DC converter has a bypass mode of operation where the input voltage node (PVIN pin) is shorted to the output voltage node (OUT pin) through a 95mΩ switch.The integrated dual low noise low dropout regulators are optimized for high PSRR capability and fast turn-on times. The constant frequency DC/DC converter along with dual low noise LDO regulators enables a very quiet and efficient solution for mobile applications.The MIC2807 is a µCap design, operating with small ceramic output capacitors and inductors for stability, reducing required board space and component cost..

• 2.7V to 5.5V input voltage range
• Stable with ceramic output capacitors
• Thermal shutdown protection
• Current limit protection
RF PA Power Supply DC/DC Converter
• Adjustable output power supply - DAC controlled
  • VOUT = VDAC x 3
• Bypass mode operation
  • Internal 95mΩ switch between PVIN and OUT pins
  • V DAC >1.2V
• Up to 600mA output current in PWM mode
• 100% duty cycle operation for maximum efficiency
• Tiny 4.7µH, 1µF output inductor and capacitor
• Low-noise 2MHz PWM operation
• >90% efficiency
Dual Low Noise Low Dropout Regulators
• High accuracy: ±2% over temperature
• High PSRR: greater than 70dB
• Very low output noise: 32 µVrms
• LDO1: 200mA output current capability
• LDO2: 30mA output current capability