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UCC28782ADRTWR

Texas Instruments · AC-DC Controllers And Regulators · WQFN-24(4x4)

UCC28782ADRTWR from Texas Instruments, in a WQFN-24(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 FLT input The controller enters the fault state if FLT is pulled above 4.5 V or below 0.5 V, with a 50-µA source for an external NTC to AGND and a 750-µs line-OVP delay when used for bulk-voltage sensing.
2 RTZ input A resistor from RTZ to AGND programs the adaptive delay from the PWMH turn-off edge to the PWML turn-on edge, with 20 kΩ < RRTZ < 1.1 MΩ recommended and parasitic capacitance minimized.
3 RDM input A resistor from RDM to AGND programs the synthesized demagnetization time that sets the PWMH on-time for ZVS tuning, with 2 kΩ < RRDM < 500 kΩ recommended.
4 IPC input The intelligent power control pin sources 50 µA into a resistor to AGND or CS to raise the peak-current threshold at very light load, with VIPC used to set the SBP2 current level.
5 BUR input A resistor divider from REF to AGND sets the burst-mode threshold voltage VBUR, which must be between 0.7 V and 2.4 V to be effective.
6 FB input The feedback current signal from the optocoupler is sensed at this pin, which presents a 4.25-V node with 0 µA to 75 µA pulled out of the pin, and a 220-pF filter to REF is recommended.
7 REF power_out The 5-V reference output requires a 0.22-µF ceramic bypass to AGND, can supply limited external load current, and pulling it low shuts down PWM and forces a VDD restart.
8 AGND power_in Analog ground that is the return for all analog control signals and for the PWMH and RUN drivers, and must be kept separate from noisy ground paths.
9 CS input The current-sense input sets the peak primary current through a line-compensation resistor, and the controller enters over-current fault when CS exceeds 1.2 V.
10 RUN output The RUN output is high in the run state to enable switching and can source up to about 44 mA peak to bias an external isolator or gate driver, and it is low during start-up, wait, and fault states.
11 PGND power_in Low-side ground return of the PWML driver, which may be Kelvin-connected to the current-sense resistor and tolerates 5-V positive and -1-V negative transients relative to AGND.
12 PWML output Low-side gate driver output with 0.5-A peak source and 1.9-A peak sink capability, clamped to the P13 voltage.
13 S13 output The switched 13-V rail is coupled to P13 through an internal 2.8-Ω switch controlled by RUN, and PWML switching begins only after S13 exceeds the 10-V power-good threshold.
14 P13 power_out The regulated 13-V output derived from VDD requires a 1-µF ceramic bypass to AGND, and a 20-V Zener to AGND is recommended for protection.
15 PWMH output The PWM output drives the high-side clamp switch through an external high-voltage gate driver and is clamped to the 5-V REF level.
16 SWS input The switch-node sensing input for ZVS auto-tuning must be coupled through a current-limiting resistor above 500 Ω, and only signals below 15 V are monitored.
17 XCD input The X-capacitor discharge input detects AC-line zero crossings at a 6.5-V threshold and supports up to 2-mA maximum discharge current, and it must be tied to AGND if the function is not used.
18 XCD input This redundant X-capacitor discharge input works in parallel with pin 17 so the discharge function continues if one XCD pin is in a fail-open condition.
19 VDD power_in The controller bias input and integrated boost converter output requires a hold-up capacitor to BGND, with a 10-µF to 15-µF ceramic and a minimum 25-V rating recommended for wide-output designs.
20 BGND power_in Boost converter return connected to the source of the internal 30-V boost switch, kept separate to minimize the high di/dt switching loop.
21 BSW input The boost converter switch node connected to the drain of the internal 30-V boost switch has an absolute maximum rating of -0.3 V to 30 V.
22 BIN input The boost converter input from the rectified auxiliary winding has an absolute maximum rating of -0.3 V to 30 V, and a 24-V TVS to AGND is recommended for protection.
23 VS power_in The voltage-sense input from the auxiliary winding monitors input and output voltages and zero-current detection, with an absolute maximum range of -0.75 V to 7 V.
24 SET input The SET pin selects GaN or Si primary-FET optimization of ZVS, dead-time and protection settings, tied to AGND for GaN (VSET = 0 V) or to REF for Si (VSET = 5 V).
25 EP power_in The exposed thermal pad must be connected to AGND.

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package WQFN-24(4x4)
Category Power Management (PMIC)
Pins 25

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
Input voltage, VDD VDD 38 V 9
Input voltage, VDD-SWS -20 38 V 9
Input voltage, SWS SWS -6 38 V 9
Input voltage, CS CS -0.3 3.6 V 9
Input voltage, VS VS -0.75 7 V 9
Input voltage, PGND PGND -1 4 V 9
Input voltage, RTZ, BUR, SET, RDM, IPC, FLT, FB -0.3 7 V 9
Input voltage, XCD, BIN, BSW -0.3 30 V 9
Output voltage, REF, PWMH, RUN -0.3 7 V 9
Output voltage, P13, S13, PWML -0.3 20 V 9
Operating junction temperature TJ -40 150 °C 9
Storage temperature Tstg -65 150 °C 9
Bias supply operating voltage VVDD 14 34 V 10
VDD capacitor CVDD 10 µF 10
P13 bypass capacitor CP13 1 µF 10
REF bypass capacitor CREF 0.22 µF 10
Operating junction temperature TJ -40 140 °C 10
Junction-to-ambient thermal resistance RθJA 43.1 °C/W 10
Junction-to-case (top) thermal resistance RθJC(top) 31.6 °C/W 10
Junction-to-board thermal resistance RθJB 20.3 °C/W 10
Junction-to-top characterization parameter ΨJT 0.5 °C/W 10
Junction-to-board characterization parameter ΨJB 20.3 °C/W 10
Junction-to-case (bottom) thermal resistance RθJC(bot) 5.7 °C/W 10
Supply current, run state (no switching) IRUN(STOP) 0.88 2.2 2.66 mA No switching 10
Supply current, run state (switching) IRUN(SW) 2.66 3 3.55 mA Switching, IVSL = 0 µA 10
Supply current, wait state IWAIT 452 580 695 µA IFB = -85 µA, VBIN = VBSW = VVDD = 20 V, sum of IBIN, IBSW, and IVDD 10
Supply current, start state ISTART 150 235 301 µA VVDD = VVDD(ON) - 100 mV, VVS = 0 V 10
VDD startup current limit during startup IVDD(LIMIT) 1.2 2 2.53 mA VVDD increasing, VSWS - VVDD = 1 V, VVDD = 16.5 V 10
VDD turnon threshold VVDD(ON) 16.31 17 17.91 V VVDD increasing 10
VDD turnoff threshold VVDD(OFF) 9.94 10.6 11.17 V VVDD decreasing 10
VDD regulation level in boost mode VVDD(BOOST) 17.6 18.5 19.4 V IVDD = 0 mA to 30 mA, VBIN = 9 V 11
UVLO on voltage of VBIN in boost mode VBIN(ON) 2.03 2.2 2.42 V VBIN increasing 11
Highest VBIN to enable boost mode VBIN(EN) 14.44 14.9 15.47 V VBIN decreasing 11
Peak current threshold in CPC control IBSW(MAX) 0.27 0.335 0.38 A 11
Maximum switching frequency in CPC control (UCC28782AD, UCC28782BDL, UCC28782CD) fBSW 389 420 499 kHz VBIN = 9 V 11
Minimum off time in COT control tBOFF(MIN) 198 255 353 ns IFB = -85 µA 11
P13 voltage level including load regulation VP13 12 12.8 13.6 V 0 mA to 60 mA out of P13, run state, VVDD = 20 V 11
REF voltage level VREF 4.9 5 5.13 V IREF = 0 A 11
Current sourcing limit of REF pin IREF(MAX) 14.3 17 20.3 mA REF shorted to AGND, VVDD = 20 V 11
S13_OK threshold to enable switching VS13_OK 9.63 10.2 10.7 V VRUN = 5 V 11
Regulated FB voltage level VFB(REG) 4.02 4.25 4.53 V 15
Maximum control FB current IFB(SBP) 64.2 75 87.1 µA IFB increasing 15
VS line-sense run current IVSL(RUN) 313 365 408.6 µA Current out of VS pin increasing 14
Shut-down voltage of VVDD for boost output OVP VBOVPTH 21.5 25 28.2 V 14
Brown-out detection delay time tBO 28.8 55 85.2 ms IVSL < IVSL(STOP) 14
OPP fault timer (UCC28782AD, UCC28782BDL, UCC28782CD) tOPP 130 164 201.1 ms IFB = 0 A 14
Fault reset delay timer (UCC28782AD, UCC28782BDL, UCC28782CD) tFDR 1.2 1.5 2.25 s OCP, OPP, OVP, SCP or CS pin fault 14
Maximum PWML on-time for detecting CS pin fault (VSET = 5 V) tCSF1 1.6 2.05 2.5 µs VSET = 5 V 14
Maximum PWML on-time for detecting CS pin fault (VSET = 0 V) tCSF0 0.85 1.05 1.27 µs RRDM < RRDM(TH) for VSET = 0 V 14
RRDM threshold for CS pin fault RRDM(TH) 35 55 70 kΩ 14
Shut-down voltage of input OVP VIOVPTH 4.3 4.5 4.67 V FLT voltage increasing 14
NTC shut-down voltage VNTCTH 0.47 0.5 0.52 V FLT voltage decreasing 14
SWS zero voltage threshold (VSET = 0 V) VTH(SWS) 3.7 4.04 4.4 V VSET = 0 V 14
SWS zero voltage threshold (VSET = 5 V) VTH(SWS) 8.1 8.5 9.1 V VSET = 5 V 14
Maximum programmable dead time from PWMH low to PWML high tZ(MAX) 397.8 478 592.8 ns RRTZ = 280 kΩ, IVSL = -1 mA, VSET = 5 V 14
Maximum PWMH width with maximum tuning (UCC28782AD, UCC28782BDL, UCC28782CD) tDM(MAX) 6 6.95 7.53 µs VSWS = 12 V 15
Minimum PWMH width with minimum tuning (UCC28782AD, UCC28782BDL, UCC28782CD) tDM(MIN) 3 3.43 3.77 µs VSWS = 0 V 15
Clamping voltage for XCD OVP VXCD(OVP) 23 26 30 V IXCD = 20 mA 15
Maximum XCD discharge current IXCD(MAX) 1.65 2 2.5 mA VXCD = 15 V 15
Dwell time for each XCD sense step (UCC28782AD, UCC28782BDL, UCC28782CD) tXCD(STEP) 9 12 14 ms 15

Materials and finish

As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).

Part Material Colour / plating Datasheet says Page
contacts copper to minimize the regulator output switching loop area. Rather than with the BGND pin, the low-noise ground terminal of CVDD should be used to connect the BGND net to the AGND pin with a low im 36

CAD (KiCad official)

  • Symbol: UCC28782ADRTWR
  • Footprint: Package_DFN_QFN:QFN-24-1EP_4x4mm_P0.5mm_EP2.6x2.6mm
  • 3D model: WQFN-24(4x4) (KiCad packages3D, STEP)
  • 3D model files: ucc28782adrtwr-etched.step / ucc28782adrtwr-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); ucc28782adrtwr.step / ucc28782adrtwr.glb are the bare package body.

Provenance

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

  • Datasheet: Texas Instruments datasheet (100 pp, sha256 8ad1796404544817, retrieved 2026-10-21, tier: lcsc)
  • Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF