EXT

EXT

B

B

I

G

OUT

EXT

Hall

V

IN

Hall

V

OUT,0A

V

B

* S

* A

I * G * S

* A

V

Hall

V

S

G * S

* A

NL

NL

FS

V

e

100% *

V

11

TMCS1101

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SBOS825 – SEPTEMBER 2019

Product Folder Links: TMCS1101

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Accuracy Parameters (continued)

(8)

8.1.4 External Magnetic Field Errors

The TMCS1101 does not have stray field-rejection capabilities, so external magnetic fields from adjacent high-

current traces or nearby magnets can impact the output measurement. The total sensitivity (S) of the device is

comprised of the initial transformation of input current to magnetic field quantified as the magnetic coupling factor

(G), as well as the sensitivity of the Hall element and the analog circuitry that is factory calibrated to provide a

final sensitivity. The output voltage is proportional to the input current by the device sensitivity, as defined in

Equation 9.

where

•

S is the TMCS1101 sensitivity in mV/A.

•

G is the magnetic coupling factor in mT/A.

•

•

(9)

leadframe current, and is added as an extra input term in the total output voltage function:

(10)

Observable from Equation 10 is that the impact of an external field is an additional equivalent input current

circuitry sensitivity, so all gain variants have equivalent input-referred current error due to external magnetic

fields.

(11)