Examples of current sense amplifiers and a live circuit with a LT6105 …
↓↓↓ Complete description, time index and links below ↓↓↓
In the first part (link below) I covered the drawbacks of using general purpose OpAmps as current sense amplifiers. This part starts with five examples of dedicated current sense amplifier and how they perform compared to OpAmps.
Afterwards I design and build a current measurement circuit based on a LT6105 current sense amplifier. To my surprise the LT6105 worked as floating device, which it shouldn’t – if you have an idea, please leave a comment!
Intro …
00:00 Intro – let’s get physical
Examples …
01:32 TI INA181 – 50 cent for four 0.1% resistors in a chip
05:45 Maxim MAX9918 – amplification set through resistors
08:27 TI INA28x – 120dB CMRR with black magic
11:40 ST TSC103 – digitally selectable amplification
16:24 AD LT6105 – variable amplification and current output
Design with a LT6105 …
18:57 Design parameters – what’s going in, what should get out
20:52 Output voltage – minimizing the error at zero
24:25 Output current – everything is current driven
27:23 Output resistance – just Ohm’s law
29:24 Resistor tolerances – values tweaked and pot added
Live circuit with a LT6105 …
34:21 On breadboard – with soldered Kelvin connections
35:21 0mA – no low swing output error
36:05 100mA – spot on without tweaking the pot
37:38 400mA – full scale without a noticeable error
39:03 It was floating – and shouldn’t have worked, but it did
41:15 Common mode voltage – slight differences in the output
Wrap-Up …
44:57 Wrap-Up – that’s all folks
Current Sense Amplifiers (1/2): Why not to use an OpAmp (CMRR etc.): https://youtu.be/ot0njl-8M1M
My Third Attempt at SMD Soldering (Perfection with Hot Plate): https://youtu.be/IVyo3CzccOw
Small Project: Constant Resistance 24V/100W AC/DC Electronic (*) Load – Part 1: https://youtu.be/sFYHVK4ngXE
Small Project: Constant Resistance 24V/100W AC/DC Electronic (*) Load – Part 2: https://youtu.be/Xl1ccdrZ2GE
Tutorials: https://www.youtube.com/playlist?list=PLwq-2MnM58FKn3920rc1V0qoTsQDheTIw