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Part Review: LM65645SRZTRQ1
Review status
Updated after requested fixes on 2026-06-29.
Sources reviewed
  • Current Flux part project: silicon-yard/lm65645srztrq1
  • Official TI stable datasheet URL now set in project properties: https://www.ti.com/lit/ds/snvsch2a/snvsch2a.pdf
  • TI stable landing URL also verified: https://www.ti.com/lit/gpn/lm65645-q1
  • Datasheet: LM656x5-Q1 High-Performance, 3V to 65V, Pin Compatible, 2.5A/3.5A/4.5A Automotive Low EMI Synchronous Buck Converters, Rev. A, SNVSCH2A.
Current part metadata
  • Project / part name: LM65645SRZTRQ1
  • Manufacturer Part Number: LM65645SRZTRQ1
  • Manufacturer Name: Texas Instruments
  • Designator Prefix: U
  • Part Type: Power Management
  • Package or Case Code: 20-WFQFN Exposed Pad
  • Published part UID: 09539ad5-1a72-4448-b6ea-c7fa986c3197
  • Schematic terminals: 21, including exposed pad/DAP
  • Project context pad count: 21
Key datasheet specifications
  • Device family: LM656x5-Q1 automotive synchronous buck converters
  • Specific device: LM65645-Q1, 4.5 A version
  • Input voltage: 3 V to 65 V DC; 70 V transient for <100 ms
  • Output current: 0 A to 4.5 A
  • Switching frequency: 300 kHz to 2.2 MHz
  • Feedback: 0.8 V adjustable threshold; fixed 3.3 V by FB to GND; fixed 5 V by FB to VCC
  • Package: RZT0020A, WQFN-FCRLF, 20 pins plus exposed thermal pad
  • Package nominal size: 2.60 mm x 3.60 mm; outline range 2.5-2.7 mm x 3.5-3.7 mm
  • Pitch: 0.5 mm
  • Operating junction temperature: -40°C to +150°C
  • Automotive: AEC-Q100 Grade 1, -40°C to +125°C ambient
Fixes applied
  • Replaced Datasheet URL with official TI direct PDF URL: https://www.ti.com/lit/ds/snvsch2a/snvsch2a.pdf
  • Renamed pin 2 from PGOOD to datasheet name PG
  • Renamed pin 5 from MODE_SYNC_TEMP to MODE_SYNC
  • Renamed pin 7 from EN to EN_UVLO
  • Updated ground pins PGND1, PGND2, and DAP to Ground
  • Updated no-connect pins to Not Connected and added no-connect descriptions
  • Added datasheet-derived pin descriptions to functional pins
  • Used Flux-standard pin type values after replacing non-standard No Connect and Open Drain entries with Not Connected and Open Collector
Datasheet pinout cross-check after fixes

Table

Datasheet pinDatasheet nameFlux symbol terminalPin typeStatus
1NCNC1Not ConnectedMatch
2PGPGOpen CollectorMatch; open collector is Flux equivalent for open-drain behavior
3FBFBInputMatch
4VCCVCCPower OutMatch
5MODE/SYNCMODE_SYNCInputMatch as slash-safe alias
6RTRTInputMatch
7EN/UVLOEN_UVLOInputMatch as slash-safe alias
8NCNC2Not ConnectedMatch
9PGND1PGND1GroundMatch
10NCNCNot ConnectedMatch
11VIN1VIN1Power InMatch
12NCNCNot ConnectedMatch
13SW1SW1Power OutMatch
14SW2SW2Power OutMatch
15BOOTBOOTPower InMatch
16NCNCNot ConnectedMatch
17VIN2VIN2Power InMatch
18NCNCNot ConnectedMatch
19PGND2PGND2GroundMatch
20BIASBIASPower InMatch
DAPExposed padDAP, Pin Number 21GroundMatch as Flux representation
Footprint review after fixes
  • Electrical pad naming now follows the updated symbol aliases: PG, MODE_SYNC, and EN_UVLO are reflected in the PCB pad list.
  • The footprint includes the expected 21 primary pads: 20 package terminals plus DAP/exposed pad.
  • The visible footprint outline is consistent with the RZT0020A package body range of 2.5-2.7 mm x 3.5-3.7 mm.
  • Pin-1 marker is present.
  • The layout tree still shows additional Mounts pad nodes, including unnamed pads and designators 22-27. These appear separate from the 21 primary electrical pads and may represent mechanical/wettable-flank/thermal construction features; they should be left only if intentionally non-electrical and not exported as unintended component pins.
Automated review result
The component review check query returned no matching populated review items for the selected part-review checks, so the re-review was performed by direct schematic/layout inspection plus datasheet comparison.
Remaining items / recommendations
  1. No symbol pinout mismatches remain for pins 1-20 plus DAP.
  2. No pin type issues remain among the reviewed functional terminals using Flux-standard pin type values.
  3. Confirm the extra footprint Mounts pad nodes are intentional non-electrical package construction features; otherwise remove or mark them non-electrical according to footprint authoring conventions.

  • Review status

  • Sources reviewed

  • Current part metadata

  • Key datasheet specifications

  • Fixes applied

  • Datasheet pinout cross-check after fixes

  • Footprint review after fixes

  • Automated review result

  • Remaining items / recommendations