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LD7792SGS

Leadtrend Tech · AC-DC Controllers and Regulators · SOP-16

LD7792SGS from Leadtrend Tech, in a SOP-16. 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 VCC power_in Supply voltage pin. Recommended operating range 10 V to 29 V; UVLO(on)=18 V typ, UVLO(off)=8 V typ, VCC OVP=31.5 V typ, PDR=7 V typ. Bypass with a 22-100 uF capacitor.
2 GND power_in Ground return for the controller. All small-signal returns and current-sense resistors reference to this pin.
3 FBCOMP input Voltage feedback pin for the Flyback stage. Connect a photo-coupler to close the secondary-side regulation loop. Also used for OLP (VOLP=4.2 V typ), burst mode (start 0.8 V / stop 0.4 V), PFC on/off threshold and heavy-load trigger (2.9 V). Internally divided 1/5.5 into the PWM comparator; open-loop clamp 5.4 V typ.
4 FBAUX input Zero-current detection and over-voltage protection for the Flyback unit. Sensed via a resistor from the transformer auxiliary winding; ZCD trip 50 mV, OVP trigger current 300 uA (4-cycle debounce), upper clamp 2 V, lower clamp 0 V.
5 OTP input External over-temperature protection pin. Sources 80 uA typ through an external NTC to ground; turn-off trip 1.0 V typ (with 400-600 us debounce), turn-on 1.35 V typ. Auto-recovery when temperature falls.
6 PFCCOMP output Output of the PFC voltage-loop transconductance error amplifier (GM=80 umho typ). Connect a 0.1-2.2 uF compensation capacitor to GND. Upper clamp 5.2 V typ, minimum clamp 0.9 V; PFC burst mode stop threshold 1.0 V typ.
7 PFCONOFF input Threshold-voltage setting pin for PFC ON/OFF loading control (compared against FBCOMP). Sources 24.5 uA typ for the PFC-OFF threshold and 25.75 uA typ for the PFC-ON threshold; set the threshold with an external resistor to GND.
8 PFCAUX input Zero-current detection input for the PFC boost stage. Connect through a 10-51 kohm resistor to the PFC auxiliary winding (recommended current ~1 mA, max 1.5 mA). ZCD trip 0.2 V, upper clamp 4 V, ZCD time-out 50 us typ.
9 VOSENSE input PFC output voltage sense input. Regulation reference is 2.5 V; PFC OVP trip 2.63 V (0.13 V hysteresis). Sources 8 uA at low line (VHV<=210 V) for line-compensation, 0 uA at high line (>=230 V). Enable/disable thresholds 1.1/0.9 V; internal pull-down 6 Mohm typ. Recommended capacitor <=10 nF.
10 FBSENSE input Flyback current-sense input. Connect to the Flyback MOSFET source sense resistor to implement cycle-by-cycle peak-current limit at VOCQR=0.65 V typ (350 ns LEB, 80 ns delay). OCP high-line compensation adds 200 uA through an external ROCP (100-1k ohm) when FBCOMP>2.9 V.
11 PFCSENSE input PFC current-sense input. Connect to the PFC MOSFET source sense resistor for cycle-by-cycle current limit; trip threshold 0.52 V at low line, 0.40 V at high line (>=230 V) with 250 ns LEB. Sense resistor value also selects PWM vs QRM frequency reduction mode (<=220 ohm PWM, >=820 ohm QRM).
12 PFCDRIVER output Gate-drive output for the external PFC boost MOSFET. CMOS totem-pole with 500/-1000 mA drive; output clamped at 13 V typ (VCC=17 V), rise time 130 ns / fall time 45 ns into 3 nF. Absolute max -0.3 V to 20 V.
13 FBDRIVER output Gate-drive output for the external Flyback MOSFET. CMOS totem-pole with 500/-1000 mA drive; output clamped at 13 V typ (VCC=17 V), rise time 130 ns / fall time 45 ns into 3 nF. Absolute max -0.3 V to 20 V.
14 CT passive External timing capacitor pin. Sets OLP debounce time, PFC turn-off debounce time and Flyback soft-start period; e.g. CT=47 nF gives FB soft-start 10 ms, OLP debounce 64 ms, PFC turn-off debounce 1 s.
15 NC unconnected No internal connection. Leave floating or tie to GND per PCB practice.
16 HV power_in High-voltage startup and line-sensing pin. Connect to AC line/neutral (input side of bridge diode preferred) through a 10-50 kohm resistor to source the VCC start-up current (1.5 mA below PDR, 3 mA between PDR and UVLO(on)); shut off after UVLO(on) to eliminate startup loss. Also senses AC peak for brown-in (105 V typ) / brown-out (85 V typ), high/low line detection (230 V / 210 V typ) and X-cap discharge (3 mA). Absolute max 650 V; add a 10 kohm series resistor to limit negative-spike current.

Key specifications

Parameter Value
Manufacturer Leadtrend Tech
Package SOP-16
Category PMIC
Pins 16

Ordering variants

  • LD7792SGS

CAD (KiCad official)

  • Symbol: LD7792SGS
  • Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
  • 3D model: SOP-16 (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: Leadtrend Tech datasheet (None pp, sha256 8872b49f05b5a019, 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

Symbol & Footprint

Schematic Symbol

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PCB Footprint

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