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# XTR110 1-5V i/p

Other Parts Discussed in Thread: XTR110

Hello TI,

I intend to use xtr110 for i/p = 1-5 V  and o/p = 4-20mA and I have developed a prototype for the same.

The connections are as shown in fig. (as per datasheet)

pin 5 is used as i/p while pin 3 & 4 are shorted to common.

While testing with this configuration I got 22V at pin 14 which as per my knowledge is not desirable.

Voltage at pin 11 is 0V which suggests that xtr110 is not turned on.

After that I disconnected pin12 and 15 from pin 3 and left shorted 12 and 15 open, but no luck.

I have checked all the connections and they are properly done.

I tried this with 4 xtr110 ic's but it gives same result.

I'm bit confused as I couldn't find exact configuration of pin 15 and 12, please guide me where I'm making mistake.

Regards

Shrikant L

• Shrikant,

What power supply voltage are you using for the XTR110? The voltage at pin 14 will be whatever is required to drive the necessary output current. For example, for a power supply voltage of 24V, the output at pin 14 will be at least 2 Vbe drops below the power supply, or 24 - (2 * 0.6V) = 22.8V. Have you attached a load resistor to the output and measured the output current for different input voltages?

• Hi John,

There is a =24V regulated power supply. I have attached a 250E 0.1% resistor and I get  approx 22V accross it (Approx. 83mA current).

I have checked it for differrent voltages and the voltage drop accross 250E resistor changes according to the change in the supply voltage.

Can you plz explain where I should connect pin 12 and pin 15.(I have kept pin 11 open)

Regards

Shrikant L

• Shrikant,

Pin 15 is the 10V reference output, and pin 12 is the 10V reference feedback. You should NOT short these to ground as is shown on your previous schematic. Since you are not using the 10V reference you should leave pin 12 connected to pin 15, but do not connect those two to anything else.

• Here is a basic Tina simulation created by my colleague Collin Wells which should demonstrate the basic functionality.

XTR110.TSC