HE920 Hardware User Guide
1vv0301014 Rev.9 – 2014-01-23
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights
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Page 49 of 84
7.
Logic Level Specifications
Where not specifically stated, all the interface circuits work at 1.8V CMOS logic levels.
The following table shows the logic level specifications used in the Telit HE920 interface
circuits:
NOTE:
Do not connect HE920’s digital logic signal directly to OEM’s digital logic signal of with
level higher than 2.7V for 1.8V CMOS signals.
For 1,8V CMOS signals:
Absolute Maximum Ratings -Not Functional
Parameter
HE920
Min
Max
Input level on any
digital pin when on
-0.3V
+2.7V
Input voltage on
analog pins when on
-0.3V
+2.7 V
Operating Range - Interface levels (1.8V CMOS)
Level
HE920
Min
Max
Input high level
1.5V
2.1V
Input low level
-0.3V
0.5V
Output high level
1.35V
1.8V
Output low level
0V
0.45V
