Measurement Computing USB-CTR04 - Manual (Page 20)

USB-CTR04 User's Guide Specifications
Timers
Table 2. Timer specifications
Parameter Specification
Terminal names TMR0, TMR1, TMR2, TMR3
Timer type PWM output with count, period, delay, and pulse width registers
Output value Default state is idle low with pulses high, software-selectable output invert
Internal clock frequency 96 MHz
Effective frequency range 0.022 Hz to 48 MHz
Register widths 32-bit
High pulse width 10.42 ns min
Low pulse width 10.42 ns min
Output high voltage 4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –24 mA)
Output low voltage 0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 24 mA)
Output current 24 mA max per pin, constrained to 240 mA across all output pins (counter outputs,
timer outputs, digital outputs, pacer clock output, and +VO)
Digital input/output
Table 3. Digital input/output specifications
Parameter Specification
Digital type TTL
Number of I/O 8
Configuration Bit-configurable as input (power on default) or output
Pull-up configuration The port has a 47 kΩ resistor configurable as a pull-up or pull-down (default) with
an internal jumper.
Digital I/O transfer rate
(system-paced, asynchronous)
33 to 8000 port reads/writes or single bit reads/writes per second typical, system
dependent.
Digital input pacing Onboard clock, external input scan clock (CLKI)
Digital input trigger source External single channel digital trigger (TRIG)
Input high voltage 2.0 V min
5.0 V absolute max
Input low voltage 0.8 V max
0 V recommended min
Output high voltage 4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –24 mA)
Output low voltage 0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 24 mA)
Output current 24 mA max per pin, constrained to 240 mA across all output pins (counter
outputs, timer outputs, digital outputs, pacer clock output, and +VO)
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