Part Review and Datasheet Verification


Completed the L9961TR part review and saved the detailed findings in l9961tr-part-review.
Key flags: the Datasheet URL was already set to ST’s official PDF, but the project properties show incorrect Part Type: Inductors and Package or Case Code: TO; official package is VFQFPN 5x5x1 32L P0.5. The main pinout mismatches are pin 13 and pin 27, which the ST-sourced pin table lists as GND while the symbol currently uses TM_ENTER and TM1.
Suggested next steps:
  • Correct the package and part-type properties.
  • Verify pins 13/27 directly in the PDF before editing the symbol.
  • Populate Pin Type and Pin Description properties from the datasheet.
  • Verify exact QFN exposed-pad and perimeter-pad geometry before fabrication.
Populate Pin Type and Pin Description properties from the datasheet.
I’ll update each terminal’s Pin Type and Pin Description from the ST L9961 datasheet pin table, then re-read the schematic to verify the properties landed correctly.
The first pass added the datasheet detail, but Flux warned that several Pin Type values were non-standard; I’m normalizing them to Flux’s supported Pin Type options while keeping the detailed electrical behavior in Pin Description.
Populated Pin Type and Pin Description for all 33 terminals and verified the updates in the schematic.
I normalized Pin Type values to Flux-supported options while preserving datasheet-specific details like analog input, open-drain, active level, and pull-down behavior in Pin Description. Pins 13 and 27 are now treated as GND terminals based on the ST pin table.
Fix properties and review
Fix part properties
Verify symbol pinout
Check footprint geometry
Run ERC DRC

Name
Pin #
Type
Part Type
Pin Description
Terminal Order
C0
1
Input
Terminal
Cell 1 negative terminal
ISENSEP
2
Input
Terminal
Current sense ADC positive input terminal
ISENSEM
3
Input
Terminal
Current sense ADC negative input terminal
GND
4
Ground
Terminal
Device ground
SCL
5
Input
Terminal
I2C clock line; active low
SDA
6
Bi-Directional
Terminal
I2C data line; digital input/open-drain, active low
RDY
7
Output
Terminal
Ready interrupt output
VREG
8
Power Out
Terminal
3.3 V LDO regulator output
NTC
9
Input
Terminal
NTC sensing input
OD
10
Open Collector
Terminal
Open-drain switch for NTC connection to GND; active low
FAULTN_SAFE
11
Open Collector
Terminal
Critical fault output; active low
FAULTN
12
Bi-Directional
Terminal
Fault output / external CHG/DCHG shutdown trigger; digital input/open-drain, active low
GND
13
Ground
Terminal
Device ground; connect to pin 4 GND
WAKEUP
14
Bi-Directional
Terminal
Wakeup from STANDBY input; internal pull-down, active high
NSHIP
15
Input
Terminal
Wakeup from SHIPMENT / DEEP SLEEP input; active high
FUSE
16
Bi-Directional
Terminal
Fuse pre-driver output / external fuse activation trigger; internal pull-down, active high
DCHG
17
Output
Terminal
Discharge switch gate
VSD
18
Output
Terminal
Discharge switch source
VSC
19
Output
Terminal
Charge switch source
CHG
20
Output
Terminal
Charge switch gate
VCP1M
21
Passive
Terminal
Charge pump flying capacitor input
VCP1P
22
Passive
Terminal
Charge pump flying capacitor input
VCP2M
23
Passive
Terminal
Charge pump flying capacitor input

L9961TR