MAX8795A High-Performance Boost Converter

The MAX8795A includes a high-performance step-up converter, two linear regulator controllers, and five high-current operational amplifiers for active-matrix thin-film transistor (TFT) liquid crystal displays (LCDs). It also includes a logic-controlled high-voltage switch with programmable delays.

The step-up DC-DC converter provides a regulated supply voltage for the panel source driver IC. The converter is a high frequency (1.2MHz) current mode regulator with an integrated 20V n-channel MOSFET, allowing the use of ultra-small inductors and ceramic capacitors. The device provides fast transient response for pulsed loads and offers over 85% efficiency.

The gate-on and gate-off linear regulator controllers use an external charge pump connected to the switch node to provide a stable TFT gate-on and gate-off supply. The MAX8795A contains five high-performance operational amplifiers. These amplifiers are used to drive the LCD backplane (VCOM) or gamma correction divider. The device provides high output current (±130mA), high slew rate (45V/?s), wide bandwidth (20MHz), and full-scale input and output.

The MAX8795A is available in a lead-free, 32-pin, thin QFN package with a maximum thickness of only 0.8mm, suitable for ultra-thin LCD panel designs. It is also available in a 32-pin LQFP package with a 0.8mm pin pitch.

Key Features

● 2.5V to 5.5V supply voltage range

● 1.2MHz current mode boost regulator

Provides fast transient response to pulse loads

High accuracy output voltage (1%)

On-chip 20V, 3A, 0.16Ω n-channel MOSFET

High efficiency (85%)

● Linear regulator controller for VGON and VGOFF

● High performance operational amplifier

±130mA output short-circuit current

45V/us slew rate

20MHz -3dB bandwidth

Full scale input/output

● Logic-controlled, delay-adjustable high-voltage switch

● Timer delayed fault lockout of all regulator outputs

● Overheat and overload protection

● 0.6mA quiescent current

The simplest working circuit

application

● Automotive display

● LCD monitor panel table

● Laptop monitor