User's Manual

Note d‘étude / Technical document :
URD1– OTL 5696.1– 003 / 72361 Edition 02
HILO 3G Application Note
17 January 2011 - Page 29 / 38
5. ESD & EMC Recommendation
Using human body model from JEDEC JESD 22-A114 standard, HiLo3G can hold 2KV on each of the 40 pins and contact
areas such as antenna pads and connector.
5.1 Handling HiLo3G
HiLo3G are packaged in boxes.
HiLo3G contains electronic circuits sensitive to human hand's electrostatic electricity.
Handling without ESD protection could result in permanent damages or even destruction of the module.
5.2 ESD Recommendations
ESD current can penetrate into the device via the typical following components:
• SIM connector
• Microphone
• Speaker
• Battery / data connector
• All pieces with conductive paint.
 In order to avoid ESD issues, efforts shall be done to decrease the level of ESD current on electronic components
located inside of the device (customer‘s board, input of the HiLo3G, etc…)
5.2.1 Avoid ESD
 Ensure good ground connections of the HiLo3G to the customer‘s board.
 Flex (if any) shall be shielded and FPC connectors shall be correctly grounded at each extremity.
 Put capacitor 100nF on battery, or better put varistor or ESD diode in parallel on battery and charger wires (if any) and
on all power wires connected to the module.
 Uncouple microphone and speaker by putting capacitor or varistor in parallel of each wire of these devices.
Here are the pin number to be protected over 2KV and references of varistors.
Pin1/2/39/40: VBAT
Pin5/6/7: USB
Pin10: VGPIO
Pin15/16/24/25: USIM
Pin19/20: Microphone
Pin21/22: SPK
Part
Vendor
Part number
Varistor
LITTLEFUSE
V0402MHS12NR
Varistor (for USB line)
COOPER
0402ESDA-MLP1
5.3 EMC recommendations
In case of EMC issue due to a headset audio device, the solution may consist in inserting a filter on the wires of the
microphone and of the speaker.