Tachometer Input Specifications - Data Translation DT9837A User Manual

Tachometer Input Specifications

Table 25 lists the specifications for the tachometer input on the DT9837, DT9837A, and
DT9837B modules. The tachometer is not supported by the DT9837C module.
Feature
Number of channels
Resolution
Input voltage range
Threshold voltage
Maximum input frequency
Minimum pulse width high/low
(minimum amount of time it takes a
C/T to recognize an input pulse)
Clock frequency for tachometer
counter 0 measurements
Clock frequency for tachometer
counter 1 measurements
Table 25: Tachometer Input Specifications
DT9837
Specifications
1
31 bits per channel
±30 V
+2 V with 0.5 V
hysteresis
380 kHz
1.3 μs
12 MHz
(83 ns resolution)
–
DT9837A
Specifications
1 1
31 bits per channel 31 bits per channel
±30 V ±30 V
+2 V with 0.5 V +2 V with 0.5 V
hysteresis hysteresis
1 MHz 1 MHz
0.4 μs 0.4 μs
12 MHz 12 MHz
(83 ns resolution) (83 ns resolution)
48 MHz 48 MHz
(21 ns resolution) (21 ns resolution)
Specifications
DT9837B
Specifications
123