BQ40Z50-R2 datasheet(32/51 Pages) TI1

32 / 51 page

C13

2.2 F

PBI

VC4

VC3

VC2

VC1

SRN

SRP

PTCEN

PTC

LEDCNTLC

LEDCNTLB

LEDCNTLA

SMBC

SMBD

DISP

bq40z50-R2

SLUSCS4 – JUNE 2017

www.ti.com

Product Folder Links: bq40z50-R2

Submit Documentation Feedback

Figure 26. Differential Filter

9.2.2.2.2

Power Supply Decoupling and PBI

The bq40z50-R2 device has an internal LDO that is internally compensated and does not require an external

decoupling capacitor.

The PBI pin is used as a power supply backup input pin providing power during brief transient power outages. A

standard 2.2-µF ceramic capacitor is connected from the PBI pin to ground, as shown in Figure 27.

Figure 27. Power Supply Decoupling

9.2.2.2.3

System Present

The System Present signal informs the gas gauge whether the pack is installed into or removed from the system.

In the host system, this pin is grounded. The PRES pin of the bq40z50-R2 device is occasionally sampled to test

for system present. To save power, an internal pullup is provided by the gas gauge during a brief 4-μs sampling

pulse once per second. A resistor can be used to pull the signal low and the resistance must be 20 kΩ or lower

to ensure that the test pulse is lower than the VIL limit. The pullup current source is typically 10 µA to 20 µA.

BQ40Z50-R2 Datasheet(PDF) 32 Page - Texas Instruments