ETRX357 Telegesis Ltd, ETRX357 Datasheet - Page 23

• Manufacturer Part Number: ETRX357
• Description: MODULE ZIGBEE EM357 W/CHIP ANT
• Manufacturer: Telegesis Ltd

Specifications of ETRX357

• Frequency: 2.4GHz
• Data Rate - Maximum: 250kbps
• Modulation Or Protocol: 802.15.4 Zigbee
• Applications: ISM
• Power - Output: 3dBm
• Sensitivity: -100dBm
• Voltage - Supply: 2.1 V ~ 3.6 V
• Current - Receiving: 27mA
• Current - Transmitting: 31mA
• Data Interface: PCB, Surface Mount
• Memory Size: 192kB Flash, 12kB RAM
• Antenna Connector: On-Board, Chip
• Operating Temperature: -40°C ~ 85°C
• Package / Case: Module
• Rohs Compliant: YES
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 920-1006-2

ETRX351 AND ETRX357
15 Recommended Footprint
In order to surface mount a ETRX3 series module, we recommend that you use pads which are
1mm wide and 1.2mm high. You must retain the “keep-out” zone shown in section 12, and ensure
that this area is free of copper tracks and/or copper planes/layers.
You must also ensure that there is no exposed copper on your layout which may contact with the
backside of the ETRX3 series module.
For best RF performance it is required to provide good ground connections to the ground pads of
the module. It is recommended to use multiple vias between each ground pad and a solid ground
plane to minimize inductivity in the ground path.
Figure 12. Recommended Footprint
The land pattern dimensions above serve as a guideline.
We recommend that you use the same pad dimensions for the solder paste screen as you have for
the copper pads. However these sizes and shapes may need to be varied depending on your
soldering processes and your individual production standards. We recommend a paste screen
thickness of 120µm to 150µm.
Although the undersides of the ETRX3 series modules are fully coated, no exposed copper, such
as through-hole vias, planes or tracks on your board component layer, should be located below the
ETRX3 series module in order to avoid ‘shorts’. In cases where a exposed track or through hole
via has to be located under the module it must be kept away from ETRX3 series module’s via
holes. All ETRX3 series modules use a multilayer PCB containing an inner RF shielding ground
plane, therefore there is no need to have an additional copper plane directly under the ETRX3
series module.
©2009 Telegesis (UK) Ltd
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ETRX35x Preliminary Product Manual