Decapped BMS Chips

I've been slowly accruing a collection of battery monitoring system (BMS) chips, each designed to monitor a stack of battery cells in a multi-cell battery pack. Other than the die area and what's in their publicly-available datasheets, I don't say much about them. I designed the secondary bandgap reference on the MAX17823.

A yellow tape measure with black millimeter marks was used to estimate die size in the following photos. The estimates are probably within about 10%. Click on any photo for a higher resolution image.
ST L9963E

Die area: 4.34mm x 4.79mm = 20.8mm2

Channel count: 14


The orange color and what looks like a puddle... I sort of wonder whether this chip was coated in die coat, which relieves package stress and thus can improve accuracy, and whether the puddle is an artifact of the decapping chemicals interacting with the die coat.

NXP MC33771C

Die area: 4.90mm x 4.53mm = 22.2mm2

Channel count: 14



Die area: 4.36mm x 4.24mm = 18.5mm2

Channel count: 6

The bq79606 went into production summer 2019.


Die area: 3.61mm x 3.73mm = 13.4mm2 for the larger die

Channel count: 18



Die area: 3.07mm x 2.79mm = 8.6mm2
and 2.51mm x 1.01mm = 2.5mm2

Channel count: 12



Die area: 4.36mm x 4.15mm = 18.1mm2

Channel count: 12



Die area: 4.31mm x 3.85mm = 16.6mm2

Channel count: 6

Not AEC-Q100

As the Internet will tell you (ex. Jarrod on in comment dated 02/15/2017) this chip was used in the Tesla Model S.


Die area: 1.92mm x 2.29mm = 4.4mm2 per die, 13.2mm2 for all three


Die area: 2.32mm x 4.62mm = 10.7mm2
and 1.78mm x 2.58mm = 4.6mm2

The AD7280 is a fairly old chip, of an older generation.


Die area: 3.90mm x 4.43mm = 17.2mm2

I got the ISL78600 from some sketchy Chinese web site, if I recall well.


Die area: 4.36mm x 3.80mm = 16.6mm2

Last updated 9 August 2022
© Anna Mitros
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