LM2711 Datasheet | National Semiconductor

Description The LM2711 is a pact bias solution for TFT displays. It has a current mode PWM step-up DC/DC converter with a 1.4A, 0.17Ω internal switch. Capable of generating 8V at 300m A from a Lithium Ion battery, the LM2711 is ideal for generating bias voltages for large screen LCD panels. The LM2711 can be operated at switching frequencies of 600k Hz or 1.25MHz, allowing for easy filtering and low noise. An external pensation pin gives the user flexibility in setting frequency pensation, which makes possible the use of small, low ESR ceramic capacitors at the output. The LM2711 uses a patented internal circuitry to limit startup inrush current of the boost switching regulator without the use of an external softstart capacitor. An external softstart pin enables the user to tailor the softstart to a specific application. The LM2711 contains 4 Gamma buffers capable of supplying 50m A source and sink. The TSSOP-20 package ensures a low profile overall solution. Features n 1.4A, 0.17Ω, internal power switch n VIN operating range: 2.2V to 7.5V n 600k Hz/1.25MHz selectable frequency step-up DC/DC converter n 20 pin TSSOP package n Inrush current limiting circuitry n External softstart override n 4 Gamma buffers Applications n LCD Bias Supplies Typical Application Circuit © 2003 National Semiconductor Corporation DS200468 .national. Connection Diagram Top View TJMAX TSSOP 20 package = 125˚C, θJA = 120˚C/W (Note 1) Pin Description Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Name VSW VIN SHDN FSLCT Vs+ GMA1-in GMA2-in GMA3-in GMA4-in NC NC GMA4-out GMA3-out GMA2-out GMA1-out SS VC FB AGND GND Power switch input. Switching Regulator Power input. Shutdown pin, active low. Frequency Select pin. FSLCT = VIN for 1.25 MHz, FSLCT = AGND or floating for 600k Hz. Gamma Buffer input supply. Gamma Buffer input. Gamma Buffer input. Gamma Buffer input. Gamma Buffer input. No Connection, leave open. No Connection, leave open. Gamma Buffer...