Toshiba Electronics Europe (TEE) has introduced a new family of flexible I/O expander ICs for use in mobile phone handsets and industrial and medical applications.
The TC35892/3/4 devices provide a low power solution to help overcome CPU limitations, adding connectivity and programmable functionality, including signal generation, keyboard support and PAL logic functions.
The TC35892/3/4 combines up to 24 general purpose and configurable input/output pins for signal control, with additional built-in functionality for managing a keyboard, PWM signal generation, a rotator wheel interface and offer a logic quasi PAL function. Connection to a host CPU is via a two-wire I2C serial interface, simplifying integration and minimising the possibility of EMI issues. Designers can effectively expand the I/O capabilities of an application processor while limiting the connections to just the serial interface and the clock signal. An additional interrupt signal may be used for real-time signal processing. Once triggered, the device can use its own internal or an external oscillator to work independently. The system is able to reduce power consumption by allowing the CPU to enter sleep mode while keeping all IO functions alive.
Toshiba's new IC family offers the flexibility to handle keyboard configurations with as many as 96 keys in a keyboard matrix. The device monitors for key presses and releases, can detect up to four simultaneous key depressions, and incorporates integral de-bouncing algorithms in hardware. PWM functionality is based on three versatile, cascadable timers that can be programmed to generate modulated PWM signals or well-defined one shot signals, without the need for interaction of an external processor. The rotator wheel state machine counts up or down the rotations of an external rotator wheel and can handle rotator devices with up to three dedicated click positions. The PAL function allows the programmable free logic combination of up to four input signals, generating another signal according to the programmed logic.
Operating from a low frequency 32 kHz (optional up to 20 MHz) clock source running on a supply voltage from 1.62 V to 3.6 V (and drawing less than 140 μA), TC35892/3/4 family is optimised for low power operation. Three different power modes ensure power consumption is kept low across a wide variety of operating conditions. The device can be powered down completely without affecting the connected system.
The devices can be supplied in a miniature 36-pin BGA package with a footprint of just 3.5 mm x 3.5 mm or 25-pin BGA (3.0 x 3.0 mm). QFN package variants are planned to be introduced to satisfy the needs of industrial applications.
Effective project quantities from 20,000pcs upwards can be supported by Toshiba.