Super amplifier, filter and analog interface knowledge points

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/µs), 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/µs slew rate

　　20MHz -3dB bandwidth

　　Full range input/output

　　Logic-controlled, delay-adjustable high-voltage switch

　　Timer-delayed fault latches all regulator outputs

　　Overheat and overload protection

　　0.6mA quiescent current