Dear colleagues,
We are amplifying a LVTTL signal to TTL signal to communicate with the serial ports of the CR1000, but sometimes the voltage
range of the converted signal stands bellow the limits accepted by the datalogger.
We want to elevate the voltage range of the converted signal up to 7-8V, just to garantee that the logic levels would switch from low to high. Which high voltage limits the datalogger's logic ports can handle?
Regards,
Francisco.
The digital I/O ports (C1-C8) on the CR1000 have input states of high 3.8 to 16 V; low -8.0 to 1.2 V. Therefore, they should be able to handle your converted signal of 7-8V.
Strictly speaking 5V is the normal maximum but the CR1000 has a series of resistors and zener diodes to protect the inputs from excess voltages. If you put 7-8V into the control ports it should do not harm especially if the amplifier has limited current capability, i.e. similar to the drive capability of a CMOS driver chip.
Thank you very much for your answer. It cleared lots of doubts.
Regards,
Francisco.