BQ78350-R1A: Connection between microcontroller and high-side FET driver

Julián Cid

Part Number: BQ78350-R1A
Other Parts Discussed in Thread: BQ76200, BQ78350, BQ76930, BQ76920, BQ76940

Hello,

In figure 9-4 of the datasheet of the high-side FET driver (bq76200), the microcontroller symbol has 4 pins labeled as GPIO although the microcontroller datasheet only has 2 GPIO pins (GPIO A and GPIO B). Could the connection between controller and driver be done this way?:

GPIO A --> CP_EN
GPIO B --> PMON_EN
\PRECHG --> PCHG_EN
ALERT --> ALERT

Thanks in advance,

Julián.

over 1 year ago

0 Dominik Hartl11 over 1 year ago

TI__Guru 61266 points

The bq78350 can't control the bq76200 - you'd have to use a dedicated uC as shown in the picture in the bq76200 datasheet.

0 Julián Cid over 1 year ago in reply to Dominik Hartl11

Prodigy 30 points

Hi Dominik,

I'm trying to build the whole system based on the BQ76930 AFE Battery monitor. If you take a look on the BQ769x0 datasheet, on the figure 9-4, it is mentioned that the microcontroller shown in the picture is a BQ78350.

Regards,

Julián.

0 Dominik Hartl11 over 1 year ago in reply to Julián Cid

TI__Guru 61266 points

The bq78350 won't control the bq76200 directly. You'd have to use a uC to control the bq78350 GPIO pins, which will control the bq76200 in the schematics that you referenced. See 14.2 in https://www.ti.com/lit/ug/sluubd3e/sluubd3e.pdf.

0 Julián Cid over 1 year ago in reply to Dominik Hartl11

Prodigy 30 points

In the datasheet of the bq78350 uC there is a schematic in which it is said that the bq78350 uC can control the bq76920 AFE (BQ78350-R1A datasheet). Is this because the bq78350 uC can ONLY control the bq76920 AFE as a standalone and the bq76930 AFE and bq76940 AFE need an aditional external uC to control the bq78350 uC?

As for my understanding, the bq76930 AFE is a direct replacement of th bq76920 AFE in terms of functionality, with the only difference being the number of cells it supports.

Could the bq78350 uC be programmed with an external uc and be left as a standalone unit?

Regards,

Julián.

0 Dominik Hartl11 over 1 year ago in reply to Julián Cid

TI__Guru 61266 points

The bq78350's GPIOs are just pass-through from what an external uC writes to the bq78350. The bq78350 won't do anything by itself if you hook it up to the bq76200. That's what I meant with that it can't control the bq76200. You need an uC that either controls the bq76200 directly or if you want, you can choose to use the bq78350's GPIOs controlled by the uC.

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BQ78350-R1A: Connection between microcontroller and high-side FET driver