Skip to content


Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time


Design files for Quad Linear Amplifier (QLA) board

  • QLA.PrjPCB: Altium Designer project file
  • Snn.SchDoc: schematics (Altium Designer format)
  • Snn.Harness: signal harnesses (Altium Designer format)
  • AMP.PcbDoc: PCB layout (Altium Designer format)
  • QLA-Schematics.pdf: PDF of schematics
  • QLA-BOM.xls: Bill of Materials (Microsoft Excel format)
  • QLA-HeatSink.pdf: PDF of heat sink drawing
  • PCB fabrication (Gerber) files
  • PCB assembly files (e.g., paste masks, pick-and-place)

Release Notes

  • Rev 1.1: Build #0 (5 board pilot run)
  • Rev 1.2: Build #1 (44 boards)
    • Deleted trace from Q15A (MOSFET) to U39B (OPA549) to avoid glitches at power-up (on all 4 channels)
    • Added J11 to enable connection to remote LED panel
  • Rev 1.3 (PCB silkscreen is Rev 1.2): Build #2 (68 boards), Build #3 (72 boards), Build #4 (80 boards)
    • Changed relay (U31) from +12V to +5V to avoid rework needed to bring external +12V to board
    • Fixed silkscreen for Pot2 and Pot3 test points (they were swapped)
    • Changed R52 to 0 Ohms (Rev 1.1 and 1.2 boards were reworked accordingly)
    • Added screwlocks (Female, 4-40, 0.185") to DB9 connector
    • Design files indicate Rev 1.3, but manufactured boards show Rev 1.2; boards can be distinguished by looking at relay (U31)
  • Rev 1.4: Build #5 (92 boards)
    • Changed digital outputs from open-drain MOSFETs to bi-directional bus transceivers (74LVC2T45) with 5V output; direction controlled by FPGA IO1-5 and IO1-6. Proper operation requires FPGA Firmware Rev 5+
    • Added feedback of motor voltage fault (from LT4356) on FPGA IO1-7
    • Grounded heatsink on PCB
    • Added plated slots for soldering 68-pin connector tabs
    • Moved Q13, Q14 and updated PCB pads to facilitate assembly
  • Rev 1.4a: Build #6 (75 boards)
    • Increased acceptable range of motor supply voltage from 11.2V-50.2V to 10.5V-52.7V (values are approximate)
      • Changed R33, R34 to raise LT4356 maximum voltage from ~51.25V to ~52.7V
      • Changed R27, R28 to set MV_GOOD window comparator thresholds to 10.5V and 52.8V
    • Added transorb SMAJ64CA on back side of connector J5, between pins 2 and 3, to limit flyback voltages on motor power supply (especially with 48V supply)
  • Rev 1.4b: Build #7 (120 boards), Build #8 (80 boards)
    • Changed pot filter cutoff frequency from 60 Hz to 5 kHz
      • Changed R1-8 from 39.2K to 464 Ohm
      • Allows faster reading of multiplexed signals (SUJ pots)
    • Fixed description of Q9-11,15 (30V instead of 20V)
  • Rev 1.5: Build #9 (2 prototypes)
    • Added (open loop) motor voltage control as a software-selectable alternative to the existing (analog closed loop) motor current control
    • Added 10 digital I/O via an I/O expander (U41, Max7317):
      • 4 digital outputs to select between motor voltage control (0) or motor current control (1) for each axis
      • 4 digital outputs to enable the follower OPA549 op amps that previously were always enabled
      • 1 digital input that indicates whether voltage is present on safety line
      • 1 digital input that can be used to measure the motor supply voltage
    • Increased analog filter cutoff frequency from 60 Hz to 42 kHz for motor current feedback to ADC
    • Added pads for transorb (D12) on back side of board (previously, was either not present or was soldered between connector pins)
    • Changes due to component availability issues:
      • Support use of 1 LTC2604 quad DAC instead of 4 LTC2601 single DACs; populate pulldown resistor R75 to indicate use of LTC2604
      • Support AD7694 as an alternative to LTC1864 ADC; this required the addition of voltage level translators (U44, U45)
      • Changed part number for 2.5V linear regulator (U32), which included a pinout change
      • Changed footprint for safety relay (U31)
      • Changed footprint for D7 (Schottky diode)
      • Several other part number changes that did not change pinout or package type
  • Rev 1.6: Build #9 (98 boards)
    • Added tristate buffer (U46) to Max7317 output
    • Use OPA549 feedback cap (C74) for voltage control, in addition to current control, to prevent oscillation; increased C74 voltage rating from 16V to 100V and changed package from 0603 to 1206
    • Disconnected J2, pin 44, from GND (consistent with change to FPGA V3.1)


Design files for Quad Linear Amplifier (QLA) board






No packages published