The MAX17094 includes a high-performance step-up
regulator, a 250mA low-dropout (LDO) linear regulator, a
high-speed operational amplifier, a digitally adjustable
VCOM calibration device with nonvolatile memory and
I²C interface, and seven integrated high-voltage level
shifters. The device is optimized for thin-film transistor
(TFT) liquid-crystal display (LCD) applications.
The step-up DC-DC converter is a current-mode regulator
that provides the regulated supply voltage for
panel source driver ICs. The current-mode architecture
provides fast-transient responses to pulsed loads typical
of source driver loads. The high switching frequency,
which is programmable to any frequency between
450kHz to 1.2MHz with a single resistor, allows the use
of ultra-small inductors and ceramic capacitors. The
step-up regulator’s soft-start time is controlled by an
internal 10ms digital timer that requires no external
components; or if desired, the soft-start time can be
adjusted by adding a single external capacitor.
The low-voltage LDO linear regulator can provide at
least 250mA. The output voltage is accurate within ±2%.
The high-voltage, level-shifting scan driver is designed
to work with panels that incorporate row drivers on the
panel glass. Its seven outputs swing from +30V to -10V
and can swiftly drive capacitive loads.
The high-performance op amp is designed to drive the
LCD backplane and features 20MHz bandwidth, 45V/µs
slew rate, and 150mA output currents.
The programmable VCOM calibrator is externally
attached to the VCOM amplifier’s resistive voltage-divider
and sinks a programmable current to adjust the
VCOM voltage level. An internal 7-bit digital-to-analog
converter (DAC) controls the sink current. The DAC is
ratiometric relative to AVDD and is guaranteed monotonic
over all operating conditions. The calibrator
includes a nonvolatile memory device (IVR) to store the
desired VCOM voltage level. The 2-wire I²C interface
simplifies production equipment.
The MAX17094 is available in a 48-pin, 6mm x 6mm
TQFN package with a maximum thickness of 0.8mm for
thin LCD panels.
Applications
- Notebook Computer Displays
