The MAX1233/MAX1234 are complete PDA controllers in
5mm × 5mm, 28-pin QFN and TQFN packages. They feature
a 12-bit analog-to-digital converter (ADC), low onresistance
switches for driving resistive touch screens, an
internal +1.0V/+2.5V or external reference, ±2°C accurate,
on-chip temperature sensor, direct +6V battery monitor,
keypad controller, 8-bit digital-to-analog converter
(DAC), and a synchronous serial interface. Each of the
keypad controllers’ eight row and column inputs can be
reconfigured as general-purpose parallel I/O pins (GPIO).
All analog inputs are fully ESD protected, eliminating the
need for external TransZorb? devices.
The MAX1233/MAX1234 offer programmable resolution
and sampling rates. Interrupts from the devices alert the
host processor when data is ready, when the screen is
touched, or a key press is detected. Softwareconfigurable
scan control and internal timers give the user
flexibility without burdening the host processor. These
devices consume only 260μA at the maximum sampling
rate of 50ksps. Supply current falls to below 50μA for
sampling rates of 10ksps. The MAX1233/MAX1234 are
guaranteed over the -40°C to +85°C temperature range.
Applications
Personal Digital Assistants
Pagers
Touch-Screen Monitors
Cellular Phones
MP3 Players
Portable Instruments
Point-of-Sale Terminals