MAX4173 Current Sense Amplifier VOUT to VCC Rail Voltage?

[hal9001]

Does the VOUT voltage go up to VCC voltage on current sense amplifiers like MAX4173? What do you find in the data sheet to verify this ?

OUT to GND = VCC+0.3V but "Out High Voltage (VCC-VOH)" =1.2V max. Can some one please clarify what this means?

Cheers!

[SiliconWizard]

(VCC-VOH) =1.2V max => means that, as you guessed, the output voltage will saturate at VCC-1.2V (worst case) under normal conditions. So your parameters (Rsense, expected current range) should accomodate that.

* For instance, if VCC= 3.3V, Rsense = 20 mOhm and a T version (+20V/V gain), the usable current range will be up to 5.25 A:

Vout = Gain * Rsense * Iload
Vout <= Vcc - 1.2 (worst case)
=> Iload <= (Vcc - 1.2) / (Gain * Rsense)

Also note that the output will never get down to ground. There's a minimum output voltage (VOL). Consequence is that the minimum measurable current depends on this:

Iload(min) = Vout(min) / (Gain * Rsense)

If we take VOL = 5 mV (note that it can get better or worse depending on conditions), with the above example, we get:
Iload(min) = 12.5 mA
This will be the minimum measurable current. So choose your parameters carefully.

[hal9001]

Thanks this helps a lot!