National Semi Intros LM2702 Power Management ICs

National Semiconductor Corp. (Santa Clara, CA) introduced three boost converters with integrated buffers that are suitable for generating bias supplies for large-format, thin-film-transistor, liquid-crystal displays (TFT LCDs). Based on National's LM2622 boost converter, the LM2702, LM2710 and LM2711 include the VCOM buffer, Gamma buffers and other circuitry that support soft-start, power supply sequencing and other features.

The current-mode, pulse-width modulated boost converter is the core of all three of the new devices. The LM2702 features two integrated buffers, one VCOM buffer and one Gamma buffer. The LM2702 operates from an input-supply voltage in the 2.2V to 12V range and is available in a TSS0P-16 package. The LM2710 features five integrated buffers, one VCOM buffer and four Gamma buffers, or, alternately, five Gamma buffers. The LM2711 features four integrated buffers, one VCOM buffer and three Gamma buffers, or, alternately, four Gamma buffers. Both devices operate from an input-supply voltage in the 2.2V to 7.5V range and are available in a TSS0P-20 package.

All three devices feature integrated, patented, soft-start circuitry that limits the startup inrush current of the boost converter without the need for external components. The soft-start circuitry supports tailoring of startup timing via a soft-start pin.

In quantities of 1,000 pieces, the LM2702 is $1.40 each, the LM2710 is $2.00 each and the LM2711 is $1.80 each.