Digital DPST Toggle Switch

[rayhall]

Hello,

I have been using a mechanical DSPT toggle switches in my projects for a long time. These switches switch between two square wave signals. One signal is 0 to 5 volts and the other -2.5 to 2.5 volts. I have tried to use the ADG1436 digital switch in my latest project. The 0 to 5 volt signal comes out of the switch as it went in. The -2.5 to 2.5 volt does not. I get a 0 to 2.5 volt signal.

Is there some IC that works just like my old mechanical switches and does not mess with the signal.

Ray.

 

[Les Jones]

I think a CD4053 would do what you want but it would require a negative supply voltage of greater than - 2.5 volts.

Les.

 

[AnalogKid]

Without a schematic of your circuit, it is *impossible* to say for sure. But -

1. What are the power supply voltages going to the 1436?

2. What is the current that the signals have to supply to their downstream loads?

ak

 

[crutschow]

Most analog switches can only carry a signal peak voltage no greater than the supply rails, but here are some that can go to ±25Vpk signal with a single 5V supply.

 

[rayhall]

Most analog switches can only carry a signal peak voltage no greater than the supply rails, but here are some that can go to ±25Vpk signal with a single 5V supply.

Very helpful...I now know to search for "Above and Below Rails".

Thank you.

Without a schematic of your circuit, it is *impossible* to say for sure

You need a schematic for a SPDT toggle switch ?

 

[AnalogKid]

You need a schematic for a SPDT toggle switch ?

No. I requested a schematic for and additional information about the circuit you can't get to work:

I have tried to use the ADG1436 digital switch in my latest project. The 0 to 5 volt signal comes out of the switch as it went in. The -2.5 to 2.5 volt does not. I get a 0 to 2.5 volt signal.

1. What are the power supply voltages going to the ADG1436?
2. What is the current that the signals have to supply to their downstream loads?

AND, since you brought it up,,,

When you combine both the electrical combinations and the physical orientation (I want signal A when the handle is to the left), a schematic for a SPDT toggle switch has a 1-in-6 chance of being correct, and a 5-in-6 chance of being wrong.

ak

 

[rayhall]

No. I requested a schematic for and additional information about the circuit you can't get to work:

1. What are the power supply voltages going to the ADG1436?
2. What is the current that the signals have to supply to their downstream loads?

AND, since you brought it up,,,

When you combine both the electrical combinations and the physical orientation (I want signal A when the handle is to the left), a schematic for a SPDT toggle switch has a 1-in-6 chance of being correct, and a 5-in-6 chance of being wrong.

ak

Here is the schematic for the ADG1436. http://www.turbofast.com.au/tfbin/ADG1436_Circuit.png

HALL = 0 to 5 volt square wave signal
RELUCTOR = -2.5 to 2.5 volt square wave signal
TRIG = either of the above signals out.

Also the power supply to VVD = 3 to 7 volts not as in the schematic. I changed it.

 

[AnalogKid]

Vdd is not specified for anything less than +5.0 V. Also, it usually is a serious problem for any input to go outside the power rails, such as a +5 V control signal going to a +3.3 V device. If your part was operated in this manner, it might be permanently damaged.

Separate from that, there is nothing in the specs to indicate if asymmetrical supplies are allowed or not. Since the part is fully characterized for a single +12 V supply, my guess is that +7 / -5 V probably is ok.

ak

 

[rayhall]

Vdd is not specified for anything less than +5.0 V. Also, it usually is a serious problem for any input to go outside the power rails, such as a +5 V control signal going to a +3.3 V device. If your part was operated in this manner, it might be permanently damaged.

Separate from that, there is nothing in the specs to indicate if asymmetrical supplies are allowed or not. Since the part is fully characterized for a single +12 V supply, my guess is that +7 / -5 V probably is ok.

ak

Believing the switch was rail to rail is why the 3 to 7 volts on the VDD and -5 on the VSS. The device I am making allows the user to adjust the peak voltage on the RELUCTOR signal from 3 to 7 volts. The low negative is permanently set to -2.5 volts.