LM2687 LM2687 Low Noise Regulated Switched Capacitor Voltage Inverter Literature Number: SNVS060D LM2687
Low Noise Regulated Switched Capacitor Voltage
Inverter
General Description Features The LM2687 CMOS Negative Regulated Switched Capacitor
Voltage Inverter delivers a very low noise adjustable output
for an input voltage in the range of +2.7V to +5.5V. Four low
cost capacitors are used in this circuit to provide up to 10mA
of output current. The regulated output for the LM2687 is
adjustable between -1.5V and -5.2V. The LM2687 operates
at 100 kHz (typical) switching frequency to reduce output
resistance and voltage ripple. With an operating current of
only 500 ВµA (charge pump power efficiency greater than
90% with most loads) and 0.05 ВµA typical shutdown current,
the LM2687 provides ideal performance for cellular phone
power amplifier bias and other low current, low noise negative voltage needs. The device comes in a small 8-pin MSOP
or LLP package. n Inverts and regulates the input supply voltage
Small MSOP-8 or LLP-8 package
91% typical charge pump power efficiency at 10mA
Low output ripple (1mV typical)
Shutdown lowers Quiescent current to 0.05 ВµA (typical) Applications n Wireless Communication Systems
Cellular Phone Power Amplifier Biasing
Interface Power Supplies
Handheld Instrumentation …
