MIC2807 Datasheet, PDF (1/17 Pages) Micrel Semiconductor – RF PA Power Management IC 2MHz, 600mA DC/DC w/DAC Input and Bypass Switch, Dual Low Noise 200mA/30mA LDO Regulators

MIC2807
RF PA Power Management IC
2MHz, 600mA DC/DC w/DAC Input and
Bypass Switch, Dual Low Noise
200mA/30mA LDO Regulators
General Description
The MIC2807 integrates a high performance 600mA
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
(V_OUT) is variable from 0.3V to the input voltage (V_IN),
adjustable from 0.3V to 3.6V through a DAC input when
V_IN > V_OUT. 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 and it
is available in the tiny 2.5mm x 2.8mm MLF^® package.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• 2.7V to 5.5V input voltage range
• Stable with ceramic output capacitors
• Tiny 17-pin 2.5mm x 2.8mm MLF^® Package
• Thermal shutdown protection
• Current limit protection
RF PA Power Supply DC/DC Converter
• Adjustable output power supply – DAC controlled
– V_OUT = V_DAC 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 – 32µVrms
• LDO1 – 200mA output current capability
• LDO2 – 30mA output current capability
Applications
• CDMA2000 mobile phones
• UMTS/WCDMA mobile phones
• Wibro modules
• WiFi modules
• Power amplifier modules (PAMs) with linear PAs
Typical Application
CDMA2000/WCDMA RF Power Supply Circuit
DC/DC Output Voltage
vs. DAC Voltage
4.5
VIN = 4.2V
4.0 I_OUT = 100mA
3.5
3.0
x3
2.5
2.0
= ^{V DAC}
1.5
V ^OUT
1.0
0.5
0
0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5
DAC VOLTAGE (V)
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
January 2007
1
M9999-013007-A