AT42QT1040-MMH Atmel, AT42QT1040-MMH Datasheet - Page 19

• Manufacturer Part Number: AT42QT1040-MMH
• Description: IC TOUCH SENSOR 4KEY 20-VQFN
• Manufacturer: Atmel
• Series: QTouch™r
• Type: Resistiver

Specifications of AT42QT1040-MMH

• Touch Panel Interface: 4, 2-Wire
• Number Of Inputs/keys: 4 Key
• Data Interface: I²C, Serial
• Data Rate/sampling Rate (sps, Bps): 200k
• Voltage Reference: Internal
• Voltage - Supply: 1.8 V ~ 5.5 V
• Current - Supply: 10mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-VQFN Exposed Pad, 20-HVQFN, 20-SQFN, 20-DHVQFN
• Output Type: Logic
• Input Type: Logic
• Supply Voltage: 1.8 V to 5.5 V
• Dimensions: 3 mm L x 3 mm W x 0.8 mm H
• Output Voltage: 0.7 V to 0.8 V
• Temperature Range: - 40 C to + 85 C
• Termination Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: AT42QT1040-MMH; AT42QT1040-MMHTR

General Advice
Figure 2-5.
Effect of ESD Creepage On a Flex Tail
ESD Strike Here
Gap Beside
Panel
Panel
Zap!
Flex Tail
Sensor
(1)
Under extreme circumstances
, where extra ESD protection must be added, consider placing very low
capacitance (1 pF or less) varistors or transient suppressor devices near to the control chip.
If the creepage path is "broken" before the ESD meets the sensor, then this will block the creepage; for
example, if there is adhesive on the surface around and overlapping the electrode. Generally, creepage
occurs only on insulating uniform non-dissapative surfaces. This is a complex field of study that should
be considered but probably not over-analyzed; simple precautions usually suffice.
1. These include direct contact sensors or situations where such gaps are unavoidable.
Touch Sensors Design Guide
2-9
10620D–AT42–04/09