ADG1636 Suitability

I am looking for analog switches.

The first is SPDT two channel. It must be capable of switching between a 0 to 14v square wave signal and a -5 to +14v zero crossing square wave  signal. Current less then 10mA

The second is SPDT two channel. It must be capable of switching high and low. The high voltage is 14 volts. Low is 0 volts. Current 100 mA.or more.

I have found the ADG1636.  Is this suitable for both. If not, what do  recommend.

Ray.

  • 0
    •  Analog Employees 
    on Nov 5, 2017 5:20 PM

    Hi Ray,

    I'm looking into this. In the meantime, can you share a little more information for your application circuit: 

    • What is the application intended for?
    • What is the voltage supplies?
    • What is the load?
    • How fast is the switching frequency at the logic inputs?
    • What are the levels for the logic inputs?
    • How fast is the switching time of the SPDT switch for your application?
    • What is the required bandwidth?
    • What is your preferred package size?
    • If possible, can you share the schematic?

    Thanks and Best Regards,

    May

  • 0
    •  Analog Employees 
    on Nov 6, 2017 12:16 AM

    Hi Ray,

    I'm confused with your first statement and the previous reply. Please confirm which one is correct:

    -5 to +14B zero crossing square wave  signal or  zero crossing -5 to 18V? Also, am I correct to assume that these are the levels of nodes RELUCTOR1 to RELUCTOR6?

     

    Thanks,

    May

  • Hello May,

    The project is a engine simulator. This is used to test engine management ECU. I have been making them for years using mechanical SPDT toggle switches. I now want to make the simulator be fully controlled by PC software, so need some switch that can be controlled by an embedded micro.
     
    I have attached part of the schematic in two pdf files. Both are using the ADG436BRZ which I have doubts will do the job.

    Digital_Hi_Lo_Sw.pdf
    Has high low switches that go the the engine management ECU's digital inputs. The ECU will typically have a 2k2 pull up or pull down resistors. Pullup voltage would be 14 volts.
     

    TriggerGenerate.pdf
    This generates square wave signals. There are two types. 0 to 5 volt and zero crossing -5 to 18 volts. These connect to the engine management ECU trigger inputs. If the ECU expects Hall effect square wave signal from 0 to 5 then it will have around a 2k2 pull up. If it expects a zero crossing signal then there is very little load.

    The switching time can be very slow. 50 mSec would not be too slow. These switches are set, then you run the engine simulator. Switching them while the simulator is running does happen,  but has to be no faster then if using a mechanical toggle switch.

    While the load from the pull up and down resistors is not much I would feel happier if it could drive up to 100 mA.

    Ray.

    attachments.zip
  • May,

    Sorry to confuse you.

    The high and low  voltages of the RELUCTOR1 to 6 can be adjusted. The maximum range is -5 to 18 volts. The minimum is -1 to 3 volts.

    So at the maximum setting the high edge of the square wave signal is 18 volts and the low edge is -5v.

    At the minimum setting  the high edge of the square wave signal is 3 volts and the low edge is -1v.

    Ray.

  • 0
    •  Analog Employees 
    on Nov 6, 2017 6:23 PM

    Hi Ray,

    By high and low  voltages of the RELUCTOR1 to 6 adjusted, do you mean you don't know when will they provide +18V high edge? OR you can control the nodes to always have +14V at high edge? I'm concerned with the high edge level because this will determine the voltage supply we'll be operating the switch with.

    I'm looking into the dual supply SPDT switches which is more suitable for your application:

    1. If the analog input goes as high as 18V, then I would recommend the ADG5436 which is a High Voltage Latch-Up Proof Dual SPDT Switches. It can operate at Vdd/Vss dual supplies = +/-20V and will cater the +18V high edge at RELUCTOR1 to 6.  However, on resistance is 10 ohms so you might want to consider this in your design. It also has a current carrying capability of 130mA to 229mA at 25C operation at +/-20V supply, depending on the package.
    2. The ADG1636 could be an option but is only operational up to +/-8V voltage supplies, thus will not cater the  +18V high edge.
    3. Another option that I would recommend is the ADG1436 which has a low on resistance of 1.5ohms great for precision. However, the ADG1436 is operational up to +/-16.5V sual supply only and will not cater the +18V high edge. It also has a current carrying capability of 260mA to 400mA at 25C operation at +/-15V supply, depending on the package.

    Let me know your thoughts.

    Best Regards,

    May