
42
Base Station Specifications
TB9300 Specifications Manual
© Tait International Limited August 2022
1.8.9
Tx Key Input
The Tx Key input is not the same as an E-wire input:
Large negative voltages (traditionally associated with E&M signaling)
can damage the reciter hardware if applied directly.
Tait offers an isolation adapter that provides E&M isolated signaling
(order number TBC101A).
Logic state:
Active low.
1.8.10
1PPS Timing Reference Input (BNC)
Electrical Characteristics
Parameter
Specification
Comments
Low voltage level
<= +0.8 V
Input active
High voltage level
>= +2 V
Input inactive
Input hysteresis
>= 0.4 V
Input resistance
>= 10 k
Ω
To +5 rail
Maximum external pull up voltage
<= 20 V
Input low threshold
V
IL
< 0.6 V
Input high threshold
V
IH
> 2.3 V
Input termination
470
Ω
+ 5% (AC terminated)
Transient input voltage
|V
IN
| < 15 V
Frequency
1 PPS
Polarity
rising edge represents a timing reference
Maximum jitter
±50 ns