Typical applications:

description

® In LT 1943 a four-output adjustable switching regulator provided power for a large TFT LCD panel. The device, in a low-profile 28-pin thermally enhanced TSSOP package, can generate either 3.3V or 5V logic power for the triple-output power required for TFT LCD panels. The operating input voltage range is 4.5V to 22V, and the buck regulator provides a low-voltage output V logic up to 2A. High power boost converter, lowerpower boost converter and one negative output converter provide 3 independent output voltages AV, DD, V and V off LCD panel requirements. A high-side PNP provides a delayed on-signal V and can handle up to 30mA. Protect the circuit and ensure that Feng is disabled if the four output programming voltages are below 10% or more.

The 1.2MHz clock synchronization inside all switches allows the use of flat inductors and ceramic capacitors throughout. The current-mode architecture provides superior transient response. For optimal flexibility, all outputs are adjustable. Soft start, included in all four channels. A PTOO pin can drive an optional PMOS bypass device to provide output disconnect for AV DD output.