• Thorlabs GSL49A picosecond gain-switched laser
• Thorlabs PDA45 SiPM detector
• LabJack T7 Pro data acquisition device
• Custom FLIPR RF/analog processing board

• Accept one protected 24 VDC input from an external power brick.
• Generate a clean +15 V rail for the Thorlabs GSL49A laser.
• Generate clean +12 V and -12 V rails for the Thorlabs PDA45 SiPM detector.
• Generate a high-current clean +5 V rail for the LabJack T7 Pro and FLIPR analog board.
• Filter switching regulator noise before power reaches output connectors.
• Provide overcurrent and transient protection on the input and output rails.
• Provide a grounding strategy that minimizes switching-noise coupling into analog/RF circuitry.
• Support thermal dissipation for high-power regulators and LDOs.
• Provide mounting compatible with internal enclosure integration or optical-breadboard-style hardware.

• Single 24 VDC input with reverse-polarity, transient, inrush, and overcurrent protection.
• Four output rails:
  • +15 V at 1.5 A continuous
  • +12 V at 500 mA
  • -12 V at 500 mA
  • +5 V at 3.0 A to 4.0 A
• Buck pre-regulation followed by low-noise linear regulation where specified.
• LC pi filters and ferrite beads on LDO outputs.
• Bulk and high-frequency decoupling at output connectors.
• 4-layer PCB stackup with continuous ground plane.
• Thermal copper pours and heat-sink provisions for high-dissipation regulators.

Diagram

• Input connector J1: rugged locking connector.
• Candidate connector types:
  • 3-pin threaded circular DIN connector rated above 5 A
  • Locking 2.1 mm / 5.5 mm barrel jack rated above 5 A
• Reverse polarity protection:
  • Ideal diode controller, or
  • Series P-channel MOSFET implementation
• Input overvoltage / transient protection:
  • 26 V to 28 V TVS diode across the input
• Main inrush / overcurrent protection:
  • 5.0 A resettable PTC fuse
  • Soft-start capacitor network where required by regulator topology

• Load: Thorlabs GSL49A picosecond gain-switched laser, user-confirmed product page: https://www.thorlabs.com/item/GSL49A
• Confirmed load update from user-provided GSL49A documentation/image: +15 V Mini-XLR power connector, 800 mA load basis
• Design output: +15.0 VDC at 1.5 A continuous
• Topology:
  • 24 V to 16 V buck switching regulator
  • 15 V ultra-low-noise LDO rated above 1.5 A
• Output connector J2:
  • Female Mini-XLR socket intended to mate with the Thorlabs DS15 +15 V power supply cable / GSL-series laser power jack style
  • User-provided GSL49A documentation image confirms a male Mini-XLR connector for the +15 V power supply jack and an 800 mA load basis. Public sources also support DS15 / Mini-XLR power interface intent, but do not expose the official pin-by-pin DS15 Mini-XLR output pinout.
  • Do not assign final J2 pinout or manufacture a custom DS15-compatible cable until the DS15 Mini-XLR pin assignment is confirmed by Thorlabs or measured from a known-good DS15 supply.
• Output protection:
  • 1.5 A PTC resettable fuse
  • 16 V Zener or TVS clamp
• Output filtering:
  • LDO output pi filter
  • Series ferrite bead rated for rail current
  • Local bulk and ceramic decoupling at connector

• Load: Thorlabs PDA45 SiPM detector, user-confirmed product page: https://www.thorlabs.com/item/PDA45?aID=fbb99cf742815f28b9e295f906d7ebb8&aC=2
• Required load from pasted requirements: +/-12 VDC at 250 mA
• Design outputs:
  • +12.0 VDC at 500 mA
  • -12.0 VDC at 500 mA
• Topology options:
  • 24 V to +/-13.5 V dual-output DC-DC converter followed by matched LDOs, or
  • Separate buck and inverting buck-boost stages followed by positive and negative low-noise LDOs
• Suggested LDO class:
  • Positive rail: LT3045 or equivalent ultra-low-noise positive regulator
  • Negative rail: LT3094 or equivalent ultra-low-noise negative regulator
• Output connector J3:
  • Female 3-pin connector matching the Thorlabs LDS12B / PDA detector supply cable interface intent
  • Public Thorlabs-related documentation identifies LDS12B as a +/-12 VDC, 250 mA supply using a LUMBERG RSMV3 male 3-pin connector/cable for compatible PDA detectors.
  • Public PDA cable documentation lists the 3-pin mapping as Pin 1 / brown = +12 V, Pin 2 / black = GND, Pin 3 / blue = -12 V. Verify connector gender, board-side mating part, and numbering orientation against the exact cable before final footprint release.
• Output protection:
  • 500 mA resettable PTC fuse on +12 V
  • 500 mA resettable PTC fuse on -12 V
• Output filtering:
  • Pi filter and ferrite bead per rail
  • Bulk and ceramic decoupling at connector

• Loads:
  • LabJack T7 Pro
  • Custom FLIPR RF/analog board with high-frequency RF components such as low-noise amplifiers and mixers
• Design output: +5.0 VDC at 3.0 A to 4.0 A
• Topology:
  • 24 V to 6 V high-efficiency buck converter
  • 5.0 V high-current low-noise LDO
• Output connectors:
  • J4 to LabJack: rugged screw terminal block or internal USB Type-B / USB Type-C header used only for 5 V power delivery
  • J5 to FLIPR analog board: locking Molex KK or similar polarized 2-pin or 4-pin header
• Output protection:
  • 4.0 A resettable PTC fuse
• Output filtering:
  • Pi filter and ferrite bead
  • Bulk and ceramic decoupling at connector

• Insert LC pi filters on all LDO outputs before output connectors:
  • +15 V
  • +12 V
  • -12 V
  • +5 V
• Use ferrite beads in series with outgoing power lines.
• Select ferrites rated for each rail current and with impedance targeted around 100 MHz.
• Place decoupling close to output connectors:
  • Bulk capacitor, example 47 uF electrolytic or tantalum
  • 0.1 uF ceramic MLCC
  • 0.01 uF ceramic MLCC
• Keep switching nodes compact and away from analog output connector paths.
• Use layout practices that support a quiet analog/RF supply environment.

• 4-layer FR4 PCB.
• Proposed layer order:
  • Layer 1: Signal / components
  • Layer 2: continuous solid ground plane
  • Layer 3: power distribution
  • Layer 4: signal / secondary routing
• Maintain a continuous, unbroken ground plane on Layer 2.
• Use a star-grounding strategy that ties analog processing ground and high-power switching grounds together at a single controlled point.
• Avoid routing high di/dt switching currents through sensitive analog return paths.

• The +5 V high-current LDO and +15 V LDO are expected to dissipate significant heat.
• Provide large copper pours and thermal pads for linear regulators.
• Consider heat sinks or regulator packages with low thermal resistance.
• Perform thermal dissipation calculations before final component selection.

• External 24 VDC medical or industrial power brick.
• Brick should be sized for total downstream power plus regulator losses and margin.
• The design intent is to use an external brick to simplify safety compliance and avoid mains voltage on the PCB.

• The requested 5.0 A input PTC is directionally reasonable for a 24 V / 5 A brick, but final hold/trip current must account for PTC temperature derating and inrush.
• Any LDO dropping 16 V to 15 V at 1.5 A dissipates about 1.5 W, before tolerance and dropout margin.
• Any LDO dropping 6 V to 5 V at 4 A dissipates about 4 W, requiring careful package, copper, and thermal design.
• Final component ratings must be chosen only after a detailed power budget and thermal analysis.

Diagram

• PCB stackup: 4-layer FR4.
• Copper weight: 1 oz or 2 oz copper, to be selected based on thermal and current requirements.
• Power trace widths must support:
  • At least 3 A on the 5 V rail
  • At least 1.5 A on the 15 V rail
• Use sufficiently wide pours or planes for high-current paths.
• Include test points for all generated rails and key regulator enable/power-good signals where available.
• Assembly method is not yet specified.
• Component availability and preferred assembler are not yet specified.

• Power-good monitoring outputs
• Rail voltage/current telemetry
• Enable sequencing
• Fault indication LEDs
• LabJack-readable status lines

• Board is mounted internally inside the system enclosure.
• Cable routing should be convenient for LabJack, laser, SiPM, and analog-board connections.
• Mounting holes should support one of the following:
  • M4 or 8-32 hardware for Thorlabs optical breadboard compatibility
  • Standard M3 standoffs for generic enclosures
• Output connectors should be placed for accessible internal cable routing.
• High-power regulators should be placed to allow copper spreading and heat-sink access.
• Switching converter hot loops should be physically separated from sensitive analog/RF output routing.

• Use an external 24 VDC medical or industrial power brick instead of placing mains conversion on the PCB.
• Use buck pre-regulation followed by low-noise LDOs for sensitive rails.
• Use a continuous ground plane and controlled star-ground connection strategy.
• Use pi filters and ferrite beads on every LDO output before connectors.
• Treat the +5 V and +15 V LDOs as thermal-critical components.
• Prioritize low-noise power over maximum conversion efficiency where sensitive optical/RF performance requires it.

• The +5 V rail current target of 3 A to 4 A includes both LabJack and FLIPR analog-board loads.
• The external 24 V power brick can be selected with at least 5 A capacity.
• The listed Thorlabs connector styles need confirmation against the exact mating cable or device-side connector models before footprint selection.
• The board is not required to provide battery backup or power sequencing unless added later.
• The design target is an internal subsystem PCB, not a standalone externally accessible product.

• Exact Thorlabs GSL49A / DS15 Mini-XLR pinout and mating board-side connector part number. User-provided documentation confirms +15 V Mini-XLR and 800 mA load basis, but not pin-by-pin output assignment.
• Exact PDA45 / LDS12B board-side mating connector and numbering orientation. Public sources indicate LDS12B/PDA cable pinout as pin 1 brown +12 V, pin 2 black GND, pin 3 blue -12 V.
• Whether the +12 V and -12 V rails must be galvanically isolated from the 24 V input or only separately regulated and filtered.
• Actual LabJack T7 Pro 5 V current requirement in the intended mode.
• Estimated current draw of the custom FLIPR RF/analog board.
• Preferred assembler and component sourcing constraints.
• Required board size or enclosure mechanical envelope.
• Whether rail status LEDs, test points, or power-good/fault outputs are desired.

• All rails are present at specified voltages under nominal and worst-case expected load.
• Output ripple/noise is acceptable for the laser, SiPM detector, LabJack, and RF/analog board requirements.
• Regulators remain within safe thermal limits at full continuous load.
• Input protection withstands reverse polarity and expected transient conditions without downstream damage.
• Output protection limits fault current without nuisance tripping during normal operation.
• Grounding and layout minimize switching noise coupling into sensitive rails.
• Connectors mechanically mate with the target Thorlabs, LabJack, and FLIPR cabling.
• ERC/DRC checks pass before manufacturing export.

• Initial structured Project Specification created from the pasted FLIPR PDB requirements.
• Project renamed to FLIPR Power Distribution Board before this specification was created.
• Detailed component selection, exact footprints, thermal calculations, and final power budget are pending.
• Added user-confirmed GSL49A and PDA45 product links plus public connector findings: GSL49A uses DS15/Mini-XLR style +15 V interface with pinout still unconfirmed; PDA45/LDS12B-style interface uses +12 V/GND/-12 V mapping per public PDA cable documentation, pending exact board-side connector orientation verification.
• Updated GSL49A laser rail basis from prior public/source estimate to user-provided +15 V Mini-XLR, 800 mA load basis while retaining 1.5 A design margin in the PDB rail rating.