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 on-resistance 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. Software-configurable 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. Features: ♦ ESD-Protected Analog Inputs ±15kV IEC 1000-4-2 Air-Gap Discharge ±8kV IEC 1000-4-2 Contact Discharge ♦ Single-Supply Operation +2.7V t
The MAX1233 and MAX1234 are complete PDA‑style touch‑screen controller ICs offered in 5 mm × 5 mm 28‑pin QFN and TQFN packages. They integrate a 12‑bit ADC, 8‑bit DAC, keypad controller, GPIO pins and a synchronous serial interface, supporting low‑power operation and ESD‑protected analog inputs.
The devices operate from single‑supply voltages (+2.7 V to +3.6 V for MAX1233, +4.75 V to +5.25 V for MAX1234), provide programmable resolution and sampling rates up to 50 ksps, and function over a temperature range of –40 °C to +85 °C. Detailed electrical characteristics, timing diagrams and layout recommendations are included for designers.
| Package | 28‑Pin 5 mm × 5 mm QFN and TQFN |
|---|---|
| Supply Voltage (MAX1233) | +2.7 V to +3.6 V |
| Supply Voltage (MAX1234) | +4.75 V to +5.25 V |
| ADC Resolution | 12‑bit |
| Maximum Sampling Rate | 50 ksps |
| Current Consumption at 50 ksps | 260 µA |
| Current Consumption at 10 ksps | < 50 µA |
| Operating Temperature Range | -40 °C to +85 °C |
| ESD Protection Rating | ±15 kV |
| DAC Resolution | 8‑bit |
| GPIO Pins | Up to 8 |
| Reference Options | Internal +1.0 V/+2.5 V or external |
MAX1233 operates from +2.7 V to +3.6 V, while MAX1234 operates from +4.75 V to +5.25 V.
Both devices are rated for ±15 kV ESD protection per IEC 1000‑4‑2.
They are guaranteed to operate from –40 °C to +85 °C.