Trouble using ADG436

[Jeanius]

I'm building a circuit that uses 4 ADG436 SPDT switch IC's (Analog Devices: ADG436: LC2MOS ±15 V Dual SPDT Switch :: Analog Switches :: Switches/Multiplexers), and am having trouble getting the switches to switch. I've got +5V, -5V, and ground correctly connected, an input voltage of +.8V at the D1 terminal, and a 0-5 V digital signal going into IN1. However, when I change the digital signal from 0V to 5V, the outputs (S1A and S1B) do not change.

Has anyone used this, or could someone provide some insight into using this IC?

[sauravgoswami]

Read the datasheets,there may be jumping problems..

[Jeanius]

I looked through the datasheet, and couldn't find anything I'd violated. I'm not an electrical engineer, so I could be overlooking something, but have troubleshooted the circuit so many times I'm baffled. What would cause jumping?

[sauravgoswami]

Buddy i think u shud give +/- 15V power suplly it will work

[Jeanius]

Unfortunately, I'm bound to +/- 5V due to the device I'm using (NI DAQ USB-6008), but I think I found out what was causing the problem.

I'm using a DC-DC voltage switching regulator (Data sheet: http://datasheets.maxim-ic.com/en/ds/MAX4391-MAX634.pdf) to obtain -5V. However, I had no connection at pins 1 and 2, which appear to be current drains and low battery detectors. Leaving this open allowed the -5V to discharge slowly to 0V (over the course of a few minutes) after disconnecting all power. After talking with Analog Devices tech support, I learned that providing a negative power supply with no positive power supply would certainly damage the ADG436. That's probably why it won't switch.

My new question, and perhaps I should start a new thread about this, is how I should go about setting up the LBD and LBR pins on the MAX634. My confusion arises from the value of Vlowbatt. I don't know what to set for Vlowbatt in the equation described on page 5 of the data sheet. If anyone could help figure that out, there is a large pile of kudos waiting for you!

[Jeanius]

I just got some advice saying that replacing the 1N914 diode specified in the wiring diagram on page 5 of the data sheet with a 1N4148 would provide some improvements, but I'm not sure if it'd solve my problem. Anyone have any ideas on whether or not this is a significant enough of a change?

[sauravgoswami]

Just do it and see for yourself,i can tell u only after i get through the datasheets!!