preliminary EUP2619 ds2619 ver0.1 nov. 2011 1 tft lcd dc-dc converter with integrated charge pumps and op-amp description the EUP2619 generates power supply rails for thin-f ilm transistor (tft) liquid-crystal display (lcd) panel s in tablet pcs and notebooks operated from 2.5v to 5.5v input supply. the device integrates a step-up converter, positive and negative charge pumps, and a high speed v com buffer. the external compensated step-up converter, providi ng the regulated supply voltage for the panel source drive r ics, features an internal power mosfet and high frequenc y operation allowing to use small inductors and capac itors. the step up converter uses fixed-frequency peak cur rent mode control architecture which provides fast load-transient response and easy compensation. a 2. 8a peak current limit for the internal switch protects power supply fault condition. the regulated positive and negative charge pump reg ulators generate the positive and negative supply rails for the tft lcd gate resistive voltage-divider ics. the high speed v com buffer features 500ma short circuit current, 20mhz bandwidth, fast slew rate 45v/s, an d rail-to-rail inputs and outputs. the EUP2619 includes internal power-up sequencing, over/under voltage protections of the boost convert er, and over temperature protection to ensure in safe opera ting. the EUP2619 are available in a 16-pin 3mm 3mm tqfn packages. features 2.5v to 5.5v input supply range 1.2mhz current-mode step-up converter - built-in 20v/2.8a, 0.16 n-channel mosfet - high efficiency up to 90% - 1% accurate output voltage - fast transient response to pulse load - over-current protection - output under-voltage protection 600khz negative charge pump driver for vgl 600khz positive charge pump driver for vgh high speed high current 18v v com buffer - 500ma output short-circuit current - 45v/ s slew rate - 20mhz, -3db bandwidth - rail-to-rail input and output power-on sequence control thermal-overload protection 3mm 3mm tqfn-16 package rohs compliant and 100% lead (pb)-free halogen-free applications tablet pcs notebook displays typical application circuit figure 1.
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