Linux Cyberdeck Design

flux

There’s still a moderate amount left before this is a full manufacturable board. The first-pass schematic is started, but we are not ready for PCB layout/manufacturing yet.
Main things still left to figure out
  1. Display connection
    • Exact Waveshare 6.25" DSI LCD-B connector pinout
    • DSI lane count
    • Backlight power/current
    • Touch interface, if any
    • Correct FPC connector part
  2. Battery and power
    • Exact 10,000 mAh battery pack
    • Battery connector/current rating
    • Battery protection/NTC details
    • Confirm charger settings for that pack
    • Validate 5 V boost converter can handle CM5 + LTE + display + USB-A peaks
  3. Protection parts
    • USB-C ESD protection
    • USB-A USB 3.0 ESD protection
    • HDMI ESD protection
    • SIM card ESD protection
    • Possibly battery/input fuse or protection
  4. Regulator final values
    • Final inductor part numbers
    • Capacitor voltage/package choices
    • TPS61288 compensation check
    • Thermal/current margin check
    • Layout-sensitive switching-node constraints
  5. CM5 details
    • Decide whether to add RTC backup for CM5 VBAT
    • Decide whether to expose nRPIBOOT/service pads
    • Confirm GPIO assignments for LTE, audio, IMU, keyboard wake
  6. LTE/SIM7600 details
    • Confirm exact SIM7600G-H-M.2 hardware guide handling for VDD_AUX and VDD_1V8
    • Confirm LTE/GNSS antenna connector placement strategy
    • Add SIM ESD
    • Add RF/layout keepout rules
  7. Keyboard board
    • Main-board FPC is planned, but keyboard PCB itself still needs to be designed
    • Need switch/keycap sourcing
    • Need keyboard RP2040 schematic/firmware pin map finalized
  8. Mechanical basics
    • Rough board size
    • Port locations
    • Battery location
    • Screen/keyboard placement constraints
    • Mounting holes
    • Antenna placement/keepouts
  9. PCB layout setup
    • Stackup choice, likely 6-layer because of USB 3.0, HDMI, MIPI DSI, RF, and power density
    • Controlled-impedance rules
    • Differential-pair rules
    • Power trace/current rules
    • Thermal copper areas
  10. Bring-up and manufacturing prep
  • Test pads
  • Debug headers
  • Board bring-up checklist
  • BOM cleanup
  • Footprint review
  • DRC
  • Gerbers/BOM/pick-and-place
My estimate
Schematic is roughly 55–65% figured out.
Full board readiness is more like 30–40% complete, because layout, power validation, protection, display details, and mechanical constraints are still significant.
The biggest blockers are:
  1. Exact display connector/pinout
  2. Exact battery pack
  3. Power validation for the 5 V rail
  4. ESD/protection parts
  5. Mechanical board size/port placement
  6. Keyboard PCB design
Once those are decided, the remaining work becomes much more straightforward.
Power, display, protection
Find display pinout
Validate power rail
Add protection parts
Add test pads
Review battery connector

Waiting for input

Sign up to send

Files

Schematic

Layout

3D View

Preliminary Power Budget — Linux Cyberdeck
Status
Updated from the user's confirmed decisions. Architecture-level power decisions are closed; final regulator validation still requires datasheet checks during schematic design.
Confirmed Battery Pack

Table

ParameterSelection
Configuration1S2P, two pouch cells in parallel
Cells2x BatterySpace PL-5467100-2C
Cell rating4250 mAh, 3.7 V, 8.5 A / 2C max discharge each
ProtectionTenergy PCM P/N 32190
PCM rating6 A working, 11 ± 2 A cutoff, 10K NTC B3435
Pack capacity8500 mAh / ~31.5 Wh nominal
Usable energy~26–27 Wh after conversion
Runtime estimate~3.3 h at 8 W, ~2.2 h at 12 W
Nominal stack101.5 x 67.5 x 11.6 mm
Battery bayDesign for ~14–15 mm including tolerance/swell headroom
ConnectorMolex Micro-Fit 3.0, 3-pos: B+, B-, NTC
Leads>=20 AWG
Confirmed Power Architecture
Diagram



  
    
  
  
    
  


































USB-C PD Sink Input
TPS25730D PD Sink
1S2P Battery Pack
Tenergy 32190 PCM
BQ25792 Charger / Power Path
Battery/System Rail
TPS61288 node_5V Boost
TPS63020 3.9V LTE Rail
TLV62569 3.3V Rail
Raspberry Pi CM5
Waveshare DSI LCD
TPS2553 USB-A VBUS Switch
MAX98357A Speaker Amp
USB2514B Hub
Keyboard RP2040
IMU / Logic
SIM7600G-H-M.2
Preliminary Load Assumptions

Table

SubsystemRailTypical EstimatePeak EstimateNotes
Raspberry Pi CM5 SC1598 / CM51080005 VTBD by workloadup to 2.5 A module peak target8 GB Lite wireless CM5
Waveshare 6.25inch DSI LCD (B)5 V400 mA typicalbudget 1 AMax published as TBD; 400 mA required for startup
SIM7600G-H-M.2 LTE/GNSS3.9 V0.1–0.8 A~2 A burstDedicated TPS63020 rail and local bulk capacitance required
RP2040-LoRa board3.3 V / USB50–150 mA300 mAHF 850–930 MHz variant
Keyboard RP2040 + QMK3.3 V / USB20–100 mA200 mANo backlight in rev 1; optional LED stuffing footprints
USB-A downstream VBUS5 V0–900 mA900 mATPS2553 current-limited switch
USB2514B hub + logic3.3 V / 5 V50–200 mA300 mAInternal USB 2.0 hub
Speaker amplifier5 V100–500 mA1 A+MAX98357A, mono 8 ohm speaker
LEDs, IMU, RTC, debug3.3 V / VBAT20–100 mA200 mAMiscellaneous allowance
Preliminary System Power Ranges

Table

Operating StateEstimated Power
Idle Linux, radios mostly idle, display low brightness6–8 W
Typical interactive use8–12 W
Heavy use with LTE bursts, bright display, USB-A load, speaker15–22 W transient
Confirmed IC Selections
  • PD sink: TPS25730D.
  • Charger: BQ25792.
  • 5 V boost: TPS61288.
  • LTE rail: TPS63020 at 3.9 V.
  • 3.3 V rail: TLV62569.
  • USB hub: USB2514B.
  • Fuel gauge: MAX17048.
  • Battery protection: XB8886A pending OCP check, fallback BQ29700 + FET pair.
  • USB-A VBUS: TPS2553.
  • ESD candidates: TPD4E05U06 / USBLC6-2SC6 / TPD4E02B04.
Critical Checks During Schematic Review
  • Confirm BQ25792 1S charging configuration, thermal limits, and 3–4 A charge-current feasibility.
  • Confirm TPS61288 5 V boost thermal and inductor sizing at CM5/display/USB peak load.
  • Confirm TPS63020 supports SIM7600 burst current at 3.9 V with adequate bulk capacitance.
  • Confirm battery PCM and board-side eFuse/PTC coordination.
  • Confirm USB-C PD sink current negotiation and no backfeed into VBUS.
  • Confirm all battery temperature/NTC and fuel-gauge connections.

  • Status

  • Confirmed Battery Pack

  • Confirmed Power Architecture

  • Preliminary Load Assumptions

  • Preliminary System Power Ranges

  • Confirmed IC Selections

  • Critical Checks During Schematic Review