I/O Expander can easily expand the functions such as GPIOs,
Keypads, LED controls and timers to the existing systems.
The IO Expander addresses some of the mechanical and
electrical challenges that arise during the design of a modern high-end
clam-shell or advanced feature phone. By conception,
typical Baseband or application LSI packages are kept at a minimum pin
count. Very often the pin multiplexers have to be incorporated into
those LSI to compromise functionality or flexibility with respect to the
cost.
Moreover signals of the main processors must often be transported over a
mechanical hinge to remote areas of the mobile phone. The number of wires
being routed over these hinges should be minimised due to the mechanical
properties of the hinge. Flexible IO Expander+ allows to overcome those limits. Its
flexible expansion capabilities makes it particularly useful for entire
platform roadmaps with different functional extensions for each member of
the platform family.
Read
more (pdf 679KB).
I/O Expander Concept
The
I/O Expander allows extended I/O functions controlled via a
simple and easy to integrate I2C interface linked to your host
CPU. It allows an easy realization of additional digital
inputs and outputs, also for time critical input signals that
can generate interrupts to the host. It features
intelligent control of keypads and of normal switches, it
incorporates a variety of timer and PWM functions for LED or
other digitally controlled peripherals. All this enables
manufacturers to quickly launch spin-off models and other
variations of their hardware, if their host CPU cannot support
those function anymore.
Application/Benefits:
- Reduction of mechanical stress on hinges in clamp shell phones
Flexible IO Expander+ reduces dramatically the number of wires over movable parts.
- Full support of low power operation from a 32kHz signal clock
Flexible IO Expander+ requires only a 32kHz clock signal for the full operation
which can be generated internally or externally. The current consumption of this LSI is highly optimized for the use in
mobile phones.
- I/O Expansion of baseband processors
Baseband or application chip packages are often limited in the amount of
balls for basic periphery. Due to this limitation, required IO
functionality might be missing. Flexible IO Expander+ provides up to 24 general
purpose Input/Output pins at the location, where needed.
- Expand your mobile phone with up to 96 keys
Flexible IO Expander+ provides the full flexibility to handle various keyboard
configuration from 2x2 to 8x12. Also single keys are supported. The Keyboard module detects up to four
simultaneous key presses and de-bouncing is done in hardware. The LSI is
able to detect key presses and releases.
- PWM signal generation for LED and vibrator control
Three independent versatile timers can be programmed to generate
modulated PWM signals without interaction of the host processor during
runtime.
- Rotator wheel interface in TC35892XBG
The rotator wheel state machine counts up or down rotations of an
external rotator wheel. The interface is able to handle rotator devices
with three dedicated click positions.
- Additional glue logic to the phone in TC35892XBG
The additional configurable on chip glue logic allows to combine up to
four input signals.
- EMI reduction on wires through hinge.
Flexible IO Expander+ can operate only from a 32kHz clock. No high speed clock is
required for stand-by or operation mode.
Features
- Low-power operation
- I2C interface; Max. 8×12 key matrix; PWM timer;
general-purpose I/O pins (GPIO)
- Up to 24 general-purpose I/O pins
-
Read more... (211KB pdf)
General Specifications
General specifications table of TC35890XBG, TC35892BG,
TC35893XBG,TC35894XBG, TC35895WBG
Further Information
MPD (Mobile Peripheral Devices)
For more information please
contact us.
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