The LM3212 is a DC-DC converter optimized for powering GSM RF power amplifiers (PAs) from a single Lithium-Ion cell; however, it may also be used in other applications. The LM3212 steps down an input voltage from 2.7V to 5.5V to a dynamically adjustable output voltage of 0.5V to 3.4V. The output voltage is set through a VCON analog input that adjusts the output voltage to ensure efficient operation at all power levels of the RF PA.
The LM3212 has a unique Active Current Bypass (ACB) feature that speeds up output voltage transition times, provides extra drive and a low-resistance analog bypass. The LM3212 has an AUTO_BY pin to force the LM3212 into bypass mode during low input-voltage operation thus overriding the automatic analog bypass feature. Forced bypass can also be achieved by setting VCON > VIN/2.5.
In addition the LM3212 offers a fixed-frequency PWM mode to minimize RF interference and a shutdown mode to turn the device off and reduce battery consumption to 0.02 µA (typ.)
The LM3212 is available in a 16-bump lead-free DSBGA package. A 1.6 MHz switching frequency allows use of tiny surface-mount components for the required inductor and two ceramic capacitors.
1.6 MHz (typ.) PWM Switching Frequency
ACB Reduces Inductor Requirements and Size
Operates From a Single Li-Ion Cell (2.7V to 5.5V)
Dynamically Adjustable Output Voltage (0.5V to 3.4V)
