OPA2313： Low side bidirectional current sensing applications

user5768726

Part Number: OPA2313

TIDU675 The circuit diagram is shown in the figure.Does the bias voltage affect the current on the main road?How do you handle this bias voltage?

over 5 years ago

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi,

yes there's some influence, as the appnote mentions: "This topology is particularly useful when cost is a priority at the expense of accuracy and printed circuit board (PCB) space." But the influence is only very small and almost negligible. What exactly happens depends on the current source.

Kai

0 Paul Goedeke over 5 years ago in reply to kai klaas69

TI__Mastermind 30600 points

Hi User,

You can also look at this cookbook circuit:
www.ti.com/.../sboa223b.pdf

Because Rsense is typically small, there will not be very much voltage drop across it and the impact of the reference voltage on the top side of Rsense will be minimal and easily overwhelmed by the source current.

Best,
Paul

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OPA2313： Low side bidirectional current sensing applications