Datasheet

MT-X1S Manual

temperature is limited to the maximum PCB temperature. It has an accuracy of +/- 2C (max.) and it

outputs 19.5mV/C. It consumes only 6uA (typ.). For more information on this IC, please consult the

datasheet.

8-channel Lowside / Relay Driver

The 8-channel lowside / relay driver is the MAX4820 from Maxim. The outputs are open-drain.

Each channel can drive low at 70mA each. Channels can be connected together to increase the

current capability. All channels have kickback protection diodes, allowing them to driver relays. Note

that solder jumper J2 must be connected for kickback protection to be available. All eight outputs,

along with 3.3V (regulated Vcc) and ~5V (external voltage), are routed to a 10-pin header. Thus,

devices that use either 3.3V or 5V (ie: 5V relay, 5V LCD backlight) are supported. Voltages greater

than 5.5V on the external power input header require J2 to be disconnected, which will disable the relay

driver kickback protection. The IC is connected to SPI F and can be disconnected using the solder

jumpers. Note that MISO is not connected, so the XMEGA cannot read from the IC. Also note that the

SPI F SS line is not used as the chip select, but instead, Q2 is used. Thus, it is necessary to configure

the SS pin as an output, or enable the pullup and leave it as an input so that SPI will operate as a

master. The maximum operating speed is 2MHz. The protocol is very simple; essentially just a shift

consult the datasheet.

LEDs

There are four LEDs connected to pins D0-D3, and can be disconnected by using the solder

jumpers. The LEDs are on when the outputs are high. The LEDs are connected to ground through 249

ohm series resistors.

External 1MB low-power SRAM (optional)

An external 1 MB low-power SRAM module is available separately.

* 8-Mbit (1024 x 8) static RAM

* Cypress CY62158EV30 IC

* 45ns

* 2.2V-3.6V

* 18mA (25mA max) @ max speed

* 2uA (8uA max) when not selected

* -40C to +85C

* 2 latches for address lines (20-bit)

* dedicated 8-bit data lines

* Measures 34.6mm x 25.0mm (1.36" x 0.98")

* Fits EBI header on MT-X1 development board

January 29, 2015 14 http://www.mattairtech.com/