
Micrel
General Description
The MIC2808 integrates a high performance 600mA DC/DC step down regulator 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 MIC2808 improves efficiency in the handset without compromising quality.
FEATUREs
• 2.7V to 5.5V input voltage range
• Stable with ceramic output capacitors
• Tiny 16-pin 2.0mm x 2.5mm TMLF® Package
• Thermal shutdown protection
• Current limit protection
RF PA Power Supply DC/DC Regulator
• Adjustable output power supply – DAC controlled
– VOUT = VDAC x 3
• Bypass mode operation
– Internal 95mΩ switch between PVIN and OUT pins
– VDAC > 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 – 32µVrms
• LDO1 – 200mA output current capability
• LDO2 – 30mA output current capability
APPLICATIONs
• CDMA2000 mobile phones
• UMTS/WCDMA mobile phones
• WiMAX/Wibro modules
• WiFi modules
• Power amplifier modules (PAMs) with linear PAs