EM6420 Datasheet, PDF (1/1 Pages) EM Microelectronic - MARIN SA – Ultra Low Power Capacitive Touch Sensor Interface IC

EM MICROELECTRONIC - MARIN SA
EM6420
Ultra Low Power Capacitive Touch Sensor Interface IC
Description
The EM6420 is an ultra low power Touch Sensor Interface IC
able to scan sequentially up to 16 capacitive sensors. No
software development is required. The device parameters
(number of used sensors, sensors scan frequency, sensors
sensitivity level, IRQ condition) are configurable either from a
host microcontroller through a communication port or through
configuration inputs.
Recognised touch inputs will be signaled with an active edge
at the IRQ pad and data are ready to be read through the
communicaion port by the host MCU. Conditions for the IRQ
to get active are configurable : at the end of every scan, at
the end of a scan if at least one sensor is active or at the end
of a scan if the sensors state has changed.
The EM6420 can also detect the most active sensor in
applications where sensors are tightly spaced. It compares
relative levels among sensors and selects the sensor with the
largest signal strength.
To increase the number of sensors >16, use several EM6420
in parallel.
Depending on the selected supply voltage range, 3 or 4
decoupling capacitors are required for the entire functionality
of the EM6420 from -40 to + 85°C.
Features
ƒ Up to 16 analogue sensor inputs
ƒ User selectable communication interfaces : 4-wire SPI,
I²C, 4-bit parallel interface and 8-bit direct output
ƒ User-selectable active edge IRQ output signal
ƒ Active high enable input
ƒ No software development and tuning required
ƒ Development tools and documentations available
ƒ Complete solution/module available: IC + sensors
design on any subtract
Electrical Characteristics
ƒ Supply voltage
1.2 V to 2.0 V
or
2.2 V to 3.6 V
ƒ Power consumption active
ƒ Power consumption standby
ƒ Power consumption sleep
ƒ Nominal sensor capacitance
ƒ Sensors scan frequency
8.5 µA @ 3.0 V
5.5 µA @ 3.0 V
0.6 µA @ 3.0 V
3 to 31 pF
1 Hz to 128 Hz *
* frequency depending on number of sensors
ƒ COM clock frequency
up to 400 kHz
Availability
ƒ Naked die
ƒ SMT package MLF40
Design Considerations
The EM6420 is well suited for battery and mains powered
applications where the following features are important :
ƒ Tamper proof applications
ƒ Nice and clean designs
ƒ Touch function to avoid buttons and keys
ƒ Slider functions
ƒ Hygienic issues, cleaning aspects
ƒ Waterproof designs
Applications
ƒ Mobile phones, cordless phones
ƒ PDA, keyboards
ƒ White & brown goods
ƒ Toys
ƒ Lighting - Sliders for dimming
Copyright © 2008, EM Microelectronic-Marin SA
Subject to change without notice
Rev. B, 10/08
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