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Contents

README

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JW1551QFNAH#TRPBF

JoulWatt Tech · AC-DC Controllers and Regulators · QFN-20(4x4)

JW1551QFNAH#TRPBF from JoulWatt Tech, in a QFN-20(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 COMP output Compensation pin for the feedback loop. Internally pulled up to ~3V through ~11.5kΩ; drives burst mode thresholds (~345mV/390mV) and over-load set point (~3V).
2 NC unconnected No connect.
3 NC unconnected No connect.
4 HV power_in High voltage startup pin. Draws current from the bulk rail to charge VCC at startup and drives the X-cap discharge function. Absolute max -0.3 to 600V; recommended 0V to 500V.
5 NC unconnected No connect.
6 NC unconnected No connect.
7 GND power_in Power ground return for the controller.
8 RFM input Maximum switching frequency set pin. External resistor programs fMAX per fMAX = 25 + 5×10^4 / RFM(kΩ) kHz (e.g. 475kHz typical at RFM=105kΩ).
9 RT input Resonant time set pin. External resistor programs the resonant/dead-time interval for the active clamp switching.
10 OTP input Over-temperature protection pin. Connects to an external NTC; internal ~105µA pull-up, shutdown when V<~1V, recovery at ~2.25V.
11 CS input Current sense input from the source of the primary switch. Used for peak current control, SCP, and CS UVP (~245mV threshold). Max current set point ~600mV, short-circuit protection at ~1V.
12 GON output Gate/enable output for the main primary switch (driven high ~5.25V, low ~30mV). Delay from EN high to GON high ~39.5µs.
13 GAC output Gate/enable output for the active clamp switch (driven high ~5.25V, low ~30mV). Fires ~80ns after GON goes low.
14 EN input Enable pin used to disable the IC. Absolute max -0.3 to 5.5V.
15 VDD power_out Internal 13V LDO regulator output. Bypass with a decoupling capacitor to GND.
16 VS input Voltage sense input pin. Monitors auxiliary/secondary winding voltage for SW/ZVS detection, brown-in/out (~467µA/~400µA), and VS OVP/UVP (~800µA/~66.6µA).
17 VCC power_in Controller supply pin. Turn-on ~14.8V, turn-off ~10.6V; absolute max -0.3 to 45V. Powered by internal HV startup and by auxiliary winding/boost in run.
18 BST output Boost switching node for the internal boost converter that supplies VCC. Boost frequency ~1.6MHz. Absolute max -0.3 to 45V.
19 GND power_in Power ground return for the controller.
20 VIN power_in Power supply input for the internal boost converter. Range 2.5V to 38V; UVP ~2V, OVP ~40.5V.
EP GND power_in Exposed thermal pad on the bottom of the QFN. Connect to GND plane for electrical ground return and thermal dissipation.

Key specifications

Parameter Value
Manufacturer JoulWatt Tech
Package QFN-20(4x4)
Category PMIC
Pins 21

Ordering variants

Same part, different packaging or reel option.

  • JW1551QFNAH#TRPBF

CAD (KiCad official)

  • Symbol: JW1551QFNAH#TRPBF
  • Footprint: Package_DFN_QFN:QFN-20-1EP_4x4mm_P0.5mm_EP2.5x2.5mm
  • 3D model: QFN-20(4x4) (KiCad packages3D, STEP)
  • 3D model files: jw1551qfnah-trpbf-etched.step / jw1551qfnah-trpbf-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); jw1551qfnah-trpbf.step / jw1551qfnah-trpbf.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: JoulWatt Tech datasheet (13 pp, sha256 6762b812efd5cb58, retrieved 2026-08-17, tier: lcsc)
  • Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF