LM5177 Part Audit

cherepanyadima

cherepanyadima

Check this schematic component against the datasheet for [MPN] and assign the correct pin orientation, section, and terminal order without changing, replacing, renumbering, or remapping any pins. Remove the Pin Group property from all pins if it exists. Place Power pins first and Ground pins last. Within each section, distribute the pins as evenly as possible between the left and right sides; for example, split 10 pins as 5/5 and 11 pins as 5/6 or 6/5. If a section contains only one pin, leave it on the most appropriate side. Keep the symbol compact, balanced, and visually symmetrical. If a pin function is unclear, assign Unclear / Check datasheet, then apply all changes directly to the schematic component.

flux

I’ll map all 39 terminals to datasheet-backed functional sections, assign balanced left/right orientations and terminal order, remove Pin Group everywhere, then verify the resulting symbol metadata.

flux

The TI pin table is available; I’m now deriving a compact functional-section layout without altering any pin identity or mapping.

flux

Updated all 39 LM5177DCPR terminals:
  • Assigned seven datasheet-based sections, with Power and Bias first and Ground last.
  • Balanced each section across left/right sides.
  • Assigned unique terminal order values 1–39.
  • Removed Pin Group from every terminal.
  • Preserved all pin names, numbers, mappings, and footprint associations unchanged.
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Files

Pins

Symbol

Layout

Preview

NC
Pin Number
28
ISNSP
Pin Number
23
FB
Pin Number
19
PGND
Pin Number
30
NC
Pin Number
33
EPAD
Pin Number
EPAD
HO2_LL
Pin Number
9
DTRK
Pin Number
10
NC
Pin Number
24
LO2
Pin Number
29
SLOPE
Pin Number
14
LO1
Pin Number
32
CFG
Pin Number
13
COMP
Pin Number
18
IMONOUT
Pin Number
6
SW2
Pin Number
25
SW1
Pin Number
36
SS/ATRK
Pin Number
16
CSB
Pin Number
38
SYNC
Pin Number
11
ISNSN
Pin Number
22
NFLT
Pin Number
7
NC
Pin Number
2
HO1
Pin Number
34
NC
Pin Number
5
BIAS
Pin Number
1
HB1
Pin Number
35
HO1_LL
Pin Number
8
VOUT
Pin Number
20
AGND
Pin Number
17
EN/UVLO
Pin Number
4
VIN
Pin Number
3
HB2
Pin Number
26
MODE
Pin Number
12
VCC
Pin Number
31
NC
Pin Number
21
CSA
Pin Number
37
RT
Pin Number
15
HO2
Pin Number
27
Part Audit Report
Scope
Audit of the LM5177DCPR part project against the official Texas Instruments LM5177 datasheet (Rev. F): https://www.ti.com/lit/ds/symlink/lm5177.pdf
Datasheet facts below were extracted from the official TI PDF. The datasheet query returned OCR text without immutable inline citation URIs, so page-level provenance could not be embedded in this report.
Current Part Information

Table

FieldCurrent / observed stateAssessment
MPNLM5177DCPRCorrect
ManufacturerTexas InstrumentsCorrect after metadata update
DescriptionBuck-boost regulator / controller descriptionFunctionally appropriate after metadata update
Part typeIntegrated circuit / power managementAppropriate
PackageDCP, 38-pin HTSSOP PowerPADFootprint corresponds to DCP0038A
Terminal count39Correct: 38 perimeter leads plus exposed PowerPAD
Designator prefixUCorrect
Datasheet propertyExisting indexed uploaded URL is inaccessible; official TI URL identifiedNot successfully replaced due to part-metadata mutation failure
Key Specifications
  • Four-switch synchronous bidirectional buck-boost controller.
  • Recommended VIN range: 2.9 V to 60 V; headline operating range is 3.5 V to 60 V, with operation down to 2.8 V when BIAS is above 3.5 V.
  • Regulated output range: 3.3 V to 60 V.
  • Absolute maximum VIN, VOUT, SW1, and SW2 high-side voltage: 85 V.
  • Switching frequency: 100 kHz to 600 kHz; external synchronization supported.
  • Typical operating quiescent current: 60 µA; shutdown current: 3 µA.
  • Peak gate-driver capability: 2 A.
  • Operating junction range: -40 °C to 125 °C recommended; 150 °C absolute maximum.
  • DCP package nominal body: 9.7 mm × 4.4 mm, 0.5 mm pitch, 1.2 mm maximum height.
  • DCP-38 thermal resistance RθJA: 33.6 °C/W under TI's specified test conditions.
Symbol and Pin Cross-Check
Pin numbering and names
All 38 numbered signal pins match the TI pin diagram:
1 BIAS, 2 NC, 3 VIN, 4 EN/UVLO, 5 NC, 6 IMONOUT, 7 nFLT, 8 HO1_LL, 9 HO2_LL, 10 DTRK, 11 SYNC, 12 MODE, 13 CFG, 14 SLOPE, 15 RT, 16 SS/ATRK, 17 AGND, 18 COMP, 19 FB, 20 VOUT, 21 NC, 22 ISNSN, 23 ISNSP, 24 NC, 25 SW2, 26 HB2, 27 HO2, 28 NC, 29 LO2, 30 PGND, 31 VCC, 32 LO1, 33 NC, 34 HO1, 35 HB1, 36 SW1, 37 CSA, 38 CSB.
The exposed pad is present as EPAD, giving 39 terminals total.
Mismatches / quality issues
  1. All terminal Pin Type properties are Unspecified. The datasheet defines Input, Output, I/O, Ground, Power, and No Connect types. This weakens ERC behavior.
  2. Pin Description properties are absent for every terminal. The datasheet provides detailed descriptions and required unused-pin states.
  3. Exposed-pad numbering differs. The schematic terminal uses Pin Number EPAD; TI's land-pattern drawing identifies the exposed pad as pad 39, while the pin-function table calls it PAD/PowerPAD. Using numeric pin 39 would better match manufacturing convention.
  4. Minor naming style difference: schematic NFLT versus datasheet nFLT. Electrically unambiguous, but the active-low notation is clearer in the datasheet form.
  5. Potential datasheet text anomaly to avoid copying: the extracted ISNSP description repeats “connect ISNSN to ground” when the monitor is disabled. Confirm the original PDF visually before authoring unused-pin instructions.
Footprint Cross-Check
Matches
  • 38 perimeter pads plus one exposed thermal pad.
  • 0.5 mm lead pitch.
  • Row center spacing and package outline correspond to the TI DCP0038A PowerPAD TSSOP package.
  • Exposed pad is approximately 2.896 mm × 4.699 mm, matching TI's 2.9 mm × 4.7 mm land pattern.
  • Pin-1 marker and DCP0038A 3D model are present.
Dimensional difference
  • Current perimeter copper pads are approximately 1.4097 mm × 0.2794 mm.
  • TI's example board layout calls for 1.5 mm × 0.3 mm pads.
  • The current pads are therefore about 0.0903 mm shorter and 0.0206 mm narrower than TI's example land pattern. This appears to be an imperial-rounded footprint rather than an exact copy of the TI recommendation. It may still be manufacturable, but the TI land pattern is the safer default unless assembly-house rules dictate otherwise.
Thermal-pad implementation note
TI recommends connecting PowerPAD to analog ground and using thermal vias to a ground plane. The footprint includes the exposed copper pad, but no thermal-via array is embedded in the footprint. Vias can be added at board level according to assembly requirements; filled, plugged, or tented vias are preferred when placed under paste.
  1. Replace the inaccessible Datasheet property with https://www.ti.com/lit/ds/symlink/lm5177.pdf when the part-metadata editor is available.
  2. Populate every terminal's Pin Type and Pin Description from TI Table 4-1.
  3. Change exposed-pad pin number from EPAD to 39, retaining the visible name EPAD or PowerPAD.
  4. Rename NFLT to nFLT or ~FLT if the symbol naming system supports active-low notation.
  5. Consider resizing the 38 perimeter pads to TI's 1.5 mm × 0.3 mm recommendation after confirming the intended assembly process.
  6. Add a board-level thermal-via pattern beneath the exposed pad in actual designs.
Overall Assessment
The part has the correct MPN, pin count, package family, pin numbering, pin names, and broadly correct DCP38 footprint geometry. The main deficiencies are missing pin descriptions/types, the exposed-pad numbering convention, an inaccessible datasheet property, and slightly undersized perimeter pads compared with TI's recommended land pattern.

  • Scope

  • Current Part Information

  • Key Specifications

  • Symbol and Pin Cross-Check

  • Pin numbering and names

  • Mismatches / quality issues

  • Footprint Cross-Check

  • Matches

  • Dimensional difference

  • Thermal-pad implementation note

  • Recommended Corrections

  • Overall Assessment