The ZXLB1600 DC/DC boost converter accepts an input voltage of between 1.6V and 5.5V and provides an adjustable output voltage of up to 28V for LCD backplane bias. The device contains the output switch and a second switch to isolate the coil from the input and provide true isolation in shutdown mode. The output can be adjusted by means of an externally applied dc voltage, or PWM control signal and can supply typically 10mA of output current at maximum output voltage. Higher current is available at lower output voltages. The input voltage range accepts a number of battery solutions, including dual dry cell and single Li-Ion cells and PFM operation mode allows the output to be regulated with high efficiency under light or no load conditions. The switching frequency range permits the use of miniature surface mount inductors. The voltage control range can be modified, if required, by external resistors. A low battery comparator is provided to indicate when the input voltage has fallen to within 2% of a preset threshold. FEATURES