MAX8795A

The MAX8795A includes a high-performance step-up regulator, two linear-regulator controllers, and five highcurrent operational amplifiers for active-matrix, thin-film transistor (TFT), liquid-crystal displays (LCDs). Also included is a logic-controlled, high-voltage switch with adjustable delay.

Features of the MAX8795A are:(1)2.5V to 5.5V input supply range; (2)fast transient response to pulsed load; (3)high-accuracy output voltage (1%); (4)built-in 20V, 3A, 0.16 n-channel MOSFET; (5)high efficiency (85%); (6)linear-regulator controllers for VGON and VGOFF; (7)High-performance operational amplifiers; (8)logic-controlled, high-voltage switch with; (9)adjustable delay; (10)timer-delay fault latch for all regulator outputs; (11)thermal-overload protection; (12)0.6mA Quiescent current.The step-up DC-DC converter provides the regulated supply voltage for the panel source driver ICs. The converter is a high-frequency (1.2MHz) current-mode regulator with an integrated 20V n-channel MOSFET that allows the use of ultra-small inductors and ceramic capacitors. It provides fast transient response to pulsed loads while achieving efficiencies over 85%.

The absolute maximum ratings of the MAX8795A can be summarized as:(1)operating temp:-40 to 85;(2)storage temperature range:-65 to +150;(3)junction temperature range:150;(4)SUP to AGND:-0.3V to +20V;(5)DRN to GON:-30V to +30V;(6)POS_ to NEG_ RMS current:5mA.Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied.Exposure to absolute maximum rating conditions for extended periods may affect device reliability.The IC employs soft-start for each regulator to minimize inrush current and voltage overshoot and to ensure a well-defined startup behavior. Each output uses a 7-bit soft-start DAC. For the step-up and the gate-on linear regulator, the DAC output is stepped in 128 steps from zero up to the reference voltage. For the gate-off linear regulator, the DAC output of MAX8795A steps from the reference down to 250mV in 128 steps. The soft-start duration is 14ms (typ) for all three regulators.