SN75ALS174: Output Capability and Functionality

Part Number: SN75ALS174
Other Parts Discussed in Thread: , AM26C32, AM26C31

I have seen this E2E post talking about there being differences between SN75ALS174 and SN75ALS174A.

[Question 1]
I can't find a DS for the SN75ALS174, only the SN75ALS174A.
Are the differences described in that E2E post accurate? (functionality is the same, but internals are mapped to different pins for the "A" version?

[Question 2]
The DS specifies |Vod1| (voltage differential between outputs with no loading) to be 1.5V to 6V.
How do you know what |Vod| actually is?
This 1.5V to 6V seems like a range based on some VCC supply condition, and not the diff. output voltage changing with temp/process...

[Question 4]
The below image shows an example, where the receiver (AM26C32) side has an XOR gate on the lines, and this is used to detect if a device is connected or not.
Basically, the receiver side has a 560Ω pullup to 5V, so with nothing connected / driving the lines, both wires are 5V. This is seen as logic "High" at both inputs to the XOR gate, and it outputs low.

If the XOR threshold is VIH > 2.4V and VIL < 0.8V, will the SN75ALS174(A) drive capability (Vod) be able to trigger 

My understanding from my customer is the AM26C31 driver works for this application, and this device has minimum Vod of 2V when RL = 100Ω.
The CM output is also MAX 3V, like the SN75ALS174(A). They want to know if the SN75ALS174(A) will also work...

  • Darren,

    The information from that e2e post is accurate.

    I guess the |Vod1| range with Io=0 would be less confusing if it's presented as from 1.5V to Vcc.

    SN75ALS174A should have similar driving strength as AM26C31 (min 2V Vod with 100Ohm load).