Spark Logic

GStek GS72V3 synchronous buck controller connection guide

GStek GS72V3 synchronous buck controller (PSOP-8 (SP)) connection guide. Check supply and startup. Trace the bootstrap and MOSFET stage.

PSOP-8 (SP)

9 contacts Current package

Green Solution Technology (GStek) · Eight leads with an exposed ground pad. The documented order code is GS72V3SP-R.

Check supply and startup

Required

On an unpowered board, identify the controller supply at pin 5 and the separate VIN connection at the high-side MOSFET drain. Some boards use the same rail for both. Keep the existing VCC bypass capacitor and COMP/EN compensation network in circuit.

  • Controller supply
    • VCC bypass capacitor positive
    • Controller supply rail
  • Power-stage input
    • Power-stage VIN rail
    • High-side MOSFET drain
    • VIN bulk capacitor positive
  • Ground
    • VCC bypass capacitor return
    • Power-stage input capacitor return
    • Bench supply return
  • Shutdown and compensation
    • Existing compensation network
    • Open-drain shutdown control when fitted

Bench checks

  • With power off, verify pin 3 and EP9 connect to board ground and check both supply rails for shorts. Use a current-limited supply at the board’s rated input voltage.
  • Check for 4.5–13.2 V from pin 5 to GND and verify the MOSFET drain supply separately. VCC above the power-on threshold does not prove that VIN has reached the power stage.
  • Check whether an external transistor holds COMP/EN below 0.3 V. Release the pull-down to allow startup. Applying a logic-high drive here interferes with the error amplifier.

GStek GS72V3, rev. 0.4, pp. 3, 5–6, 9

Connection scenarios

PSOP-8 (SP) wiring map

External wiring example · Check supply and startup

Highlighted contacts are used in the required step or selected circuit. Select a contact to highlight its wiring nets.

PSOP-8 (SP) · Top view, rotated from the datasheet figure so pin 1 is at upper left. The ground pad is on the underside.
Dashed outline shows the underside pad schematically. See the package drawing for the footprint.
Selected pin details

9 · GND

Exposed pad · Ground

Solder the underside pad to the board ground and connect it to pin 3.

GStek GS72V3, rev. 0.4, pp. 2–3

Connected nets

Electrical limits · Pin in the reference

Dashed lines show external connections in this wiring example.

  • Ground
    • VCC bypass capacitor return
    • Power-stage input capacitor return
    • Bench supply return

Models and documents

The pin map and measurements use the full rev. 0.4 datasheet for GS72V3SP-R. The rev. 1.0 product brief shows a different overcurrent setting network. Check the board and document revision before interpreting current limit or replacing its parts.

GS72V3SP-R
PSOP-8 (SP) in tape and reel.