Spark Logic

GStek GS72V3 synchronous buck controller pinout

The GS72V3 runs a single 300 kHz step-down channel with two external N-channel MOSFETs. Check the supply, bootstrap, gate drive and feedback on an existing converter.

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.

PSOP-8 (SP) pinout

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

1 · BOOT

Floating driver supply · Power

Connect the bootstrap capacitor between BOOT and PHASE. Measure the voltage across those two pins.

GStek GS72V3, rev. 0.4, pp. 2–3

Electrical limits · Link to this pin

Check supply and startup

  • 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

Connection guide

All 9 pins

PinSignalDirectionFunction
1BOOT Floating driver supplyFloating driver supply Connect the bootstrap capacitor between BOOT and PHASE. Measure the voltage across those two pins.
2UGATE Gate driveGate drive Drives the external high-side N-channel MOSFET. Its source and gate-drive return are at PHASE.
3GND ReturnReturn Signal and power return. Connect to system ground together with the exposed pad.
4LGATE Gate driveGate drive Drives the external low-side N-channel MOSFET. Measure relative to the low-side source at ground.
5VCC SupplySupply Control and gate-drive supply. Decouple to ground close to the IC. The power-stage input feeds the high-side MOSFET drain.
6FB FeedbackFeedback Sense the output through a divider after the inductor. The regulated feedback voltage is 0.6 V nominal.
7COMP/EN Compensation output and shutdownCompensation output and shutdown The error-amplifier output shares this pin with shutdown. Pull low to disable and release it to let the compensation network operate.
8PHASE Switch nodeSwitch node Connect to the high-side MOSFET source, low-side drain and inductor input. Also serves as the bootstrap return and low-side current-sense point.
9GND Exposed padExposed pad Solder the underside pad to the board ground and connect it to pin 3.

Signal assignments

Electrical limits

ParameterLimitConditions and source
VCC supply4.5–13.2 V4.5–13.2 V Recommended range for the control and gate-drive supply at pin 5. GStek GS72V3, rev. 0.4, p. 5
Power-stage VIN3–13.2 V3–13.2 V External MOSFET drain supply. If tied to VCC, use their common 4.5–13.2 V range. GStek GS72V3, rev. 0.4, p. 5
VCC power-on threshold4.2 V typical4.2 V typical 4.0–4.4 V rising. Typical hysteresis is 0.5 V. GStek GS72V3, rev. 0.4, pp. 5, 9
PWM oscillator270–330 kHz270–330 kHz 300 kHz typical while switching. GStek GS72V3, rev. 0.4, p. 5
FB regulation point0.594–0.606 V0.594–0.606 V 0.6 V nominal in internal reference mode. GStek GS72V3, rev. 0.4, p. 5
Soft-start interval2.4 ms typical2.4 ms typical Internal reference mode. GStek GS72V3, rev. 0.4, p. 6
Low-side current sense−300 mV nominal at PHASE−300 mV nominal at PHASE Rev. 0.4 senses the voltage across the conducting low-side MOSFET. Its on-resistance, temperature and inductor ripple affect the trip current. GStek GS72V3, rev. 0.4, pp. 6, 9–10

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.