Supply Current vs Logic Voltage

Part Number: TMUX6111
Other Parts Discussed in Thread: TMUX6112, TMUX6113,

TMUX6111, TMUX6112, TMUX6113

Dear Texas Support Team,

I am looking for a analog switch with low supply current.

  1. Could You provide a data curve like at the TMUX621x data sheet? (Figure 7-13. Supply Current vs Logic Voltage)
  2. Is the specification VDD supply current (TMUX611x data sheet tab. 7.5 Electrical Characteristics (Dual Supplies: ±15 V)) valid for digital input voltage at SEL1...SEL4? (not VA = analog switch voltage)
  3. Is there a input transition rise and fall rate for digital inputs? (Schmitt Trigger input)
  4. Is there a Power Dissipation Capacitance value or a data curve of supply current vs. digital frequency?

Thanks!

7.5 Electrical Characteristics (Dual Supplies: ±15 V)

The signal naming is confusing!

VA = analog switch voltage pin (Sx); VD = analog switch voltage pin (Dx); VSEL = Digital input pin (SEL1, SEL2, SEL3, SEL4) voltage

  • Hi Ralph,

    Thank you for your questions and sorry about the confusion! Please see below:

    1) Does not look like this datasheet has a curve like you mentioned, is there a specific set of conditions you are looking for in regards to the supply current?

    2) Yes, the VA voltage should be the VDIG voltage. Test condition should be noted at VDIG = 0V or 3.3V

    3) Please see the TON and TOFF values in the datasheet for approximate transition times when the digital input is changed. 

    4) We do not have such a curve available for this device. Can you provide what frequency you are anticipating to run the device at?

    Thanks!

    Bryan 

  • Hi Bryan,

    Thank you for your answers.

    1. What is the maximum (peak) supply current in voltage range of VDIG = 0V to 3.3V? (not 0V or 3.3V) The current IDD exceeds 23µA for VDIG higher than Logic voltage low and lower than Logic voltage high due to the CMOS-logic.
    2. o.k.
    3. What is the minimum slew-rate of digital input voltage?
    4. The frequency is 1MHz (e.g. Figure 30. A 2-output Sample and Hold Circuit Realized Using the TMUX611x Analog Switch).
  • Hi Ralph,

    See below for my responses:

    1) We do not spec all supply currents over the VDIG range, just the min and max. However, we can predict the supply current will be higher because as the logic voltage deviates from the supply and ground voltage (note that the logic circuits are normally biased at VDD/GND), there will be a larger potential difference inside the circuit, causing more current consumption from the device. Again, I unfortunately cannot provide what the maximum would be in this case as we do not collect that data.

    3) There is no such minimum required slew rate for the digital input voltages. Any voltage above VIH will be a logic high and any voltage below VIL will be a logic low and our devices have built in hysteresis to ensure there is no oscillating state changes occurring.

    4) Since 1MHz is well within the frequency range this device can support, the device should not exceed the maximum supply current as described in the datasheet, however, if you are not setting the logic voltage at VDD/GND, then you will mostly likely see some current consumption increase as I previously mentioned.

    Thanks!

    Bryan