mrfunkyjay
New Member
Hi, I had my schematics design for my final thesis work, in which I need to construct a variable current source, driven by an electronic switch.
On my way to completion, I found it useful to use CD4066B while four switches are sufficient to simply give the four different current source outputs I need.
Is 1 = 1mA
Is 2 = 5.7mA
Is 3 = 10.4mA
Is 4 = 15.2mA
The values above are obtained by simply divide the 1.25V by the amount of four resistors to give such output current. (Refer to LM317 data sheet, the Vref is equal to 1.25V and R1 is denoted as the current adjuster).
There is a schematics below, what my question is:
-The VDD and VSS of CD4066. What amount of voltage do I need to apply at the VSS pin? I don't get it working since I give 0V or GND connection to the VSS while VDD and VC are equal to +5V. Since I am controlling this circuit with microcontroller, so 5V voltage range is convenient to use. Please help, I am really confused. Should I give the VDD = +5V, VSS = -5V and VC equal to LOGIC 1(HIGH) = 5V and LOGIC 0(LOW) = 0V ???
Correct me if I'm wrong...
Best regards,
Kelvin
Indonesia
On my way to completion, I found it useful to use CD4066B while four switches are sufficient to simply give the four different current source outputs I need.
Is 1 = 1mA
Is 2 = 5.7mA
Is 3 = 10.4mA
Is 4 = 15.2mA
The values above are obtained by simply divide the 1.25V by the amount of four resistors to give such output current. (Refer to LM317 data sheet, the Vref is equal to 1.25V and R1 is denoted as the current adjuster).
There is a schematics below, what my question is:
-The VDD and VSS of CD4066. What amount of voltage do I need to apply at the VSS pin? I don't get it working since I give 0V or GND connection to the VSS while VDD and VC are equal to +5V. Since I am controlling this circuit with microcontroller, so 5V voltage range is convenient to use. Please help, I am really confused. Should I give the VDD = +5V, VSS = -5V and VC equal to LOGIC 1(HIGH) = 5V and LOGIC 0(LOW) = 0V ???
Correct me if I'm wrong...
Best regards,
Kelvin
Indonesia