NCP1342 Quasi-Resonant Flyback Controller

Texas Instruments Power_Management — specifications, applications, sourcing support and RFQ.

NCP1342 Quasi-Resonant Flyback Controller

RFQ Available Sourcing Support Alternative Matching RoHS
Part Number
NCP1342
Manufacturer
Texas Instruments
Package
SOIC-8 NB (Case 751), SOIC-9 NB (Case 751BP), Pb-Free
Category
Power Management
Product Type
LDO Regulator

Quick Sourcing Note

NCP1342 from Texas Instruments is a Power_Management quasi-resonant flyback controller offered in SOIC-8 NB (Case 751) and SOIC-9 NB (Case 751BP), Pb-Free packages. Datasheet parameters include a high-voltage startup circuit rated from -0.3 to 700 V, VCC supply input rating from -0.3 to 30 V, and operating junction temperature from -40 to 125 °C. Key controller values include a 17.0 V typical startup threshold, 9.0 V typical minimum operating voltage, 28 V typical VCC overvoltage protection threshold, 0.800 V typical current limit threshold, and 4 ms soft-start timer. The device supports flyback power conversion designs using startup, gate-drive, feedback, ZCD, brownout, and X2 capacitor discharge functions.

Specifications

TypeDescription
Part NumberNCP1342
ManufacturerTexas Instruments
Product TypeLDO Regulator
CategoryPower Management
Package / CaseSOIC-8 NB (Case 751), SOIC-9 NB (Case 751BP), Pb-Free
Integrated High-Voltage Startup Circuit Input Voltage-0.3 to 700 V; maximum rating; source page 6
High-Voltage Startup Circuit Input Current20 mA; maximum rating; source page 6
Supply Input Voltage-0.3 to 30 V; maximum rating; source page 6
Supply Input Current30 mA; maximum rating; source page 6
Operating Junction Temperature-40 to 125 °C; maximum rating; source page 6
Maximum Junction Temperature150 °C; maximum rating; source page 6
Storage Temperature Range-60 to 150 °C; maximum rating; source page 6
Startup Threshold16.0 min, 17.0 typ, 18.0 max V; VCC increasing, dV/dt=0.1 V/ms; source page 7
Minimum Operating Voltage8.5 min, 9.0 typ, 9.5 max V; VCC decreasing; source page 7
Operating Hysteresis7.5 min V; VCC(on) - VCC(off); source page 7
Internal Latch / Logic Reset Level4.5 min, 6.5 typ, 7.5 max V; VCC decreasing; source page 7
Startup Delay500 max µs; delay from VCC(on) to DRV enable; source page 7
Startup Current Sourced From VCC Pin, 105 °C Range2.4 min, 3.75 typ, 5.0 max mA; VCC=VCC(on)-0.5 V, -40 °C to 105 °C; source page 7
Startup Current Sourced From VCC Pin, 125 °C Range2.0 min, 3.75 typ, 5.0 max mA; VCC=VCC(on)-0.5 V, -40 °C to 125 °C; source page 7
Operating Current1.0 typ, 1.5 max mA; fsw=50 kHz, CDRV=open; source page 7
Skip Mode Supply Current0.230 typ, 0.400 max mA; VFB=0 V, excluding FB current; source page 7
Fault or Latch Supply Current0.115 typ, 0.250 max mA; VCC=VCC(on)-0.5 V; source page 7
VCC Overvoltage Protection Threshold27 min, 28 typ, 29 max V; VCC OVP; source page 7
VCC Overvoltage Protection Delay25 min, 32 typ, 40 max µs; VCC OVP event; source page 7
Line Voltage Removal Detection Timer65 min, 100 typ, 135 max ms; X2 capacitor discharge, all versions except xxxxxA/D/E/F/G; source page 7
Discharge Timer Duration21 min, 32 typ, 43 max ms; X2 capacitor discharge, all versions except xxxxxA/D/E/F/G; source page 7
VCC Discharge Current13 min, 18 typ, 23 max mA; VCC=20 V, X2 capacitor discharge; source page 7
System Brownout Startup Threshold, Other Versions107 min, 112 typ, 116 max V; VHV increasing, other versions except xxxxxE; source page 7
System Brownout Startup Threshold, xxxxxA/D/H89 min, 94 typ, 99 max V; VHV increasing, versions xxxxxA, xxxxxD, xxxxxH; source page 7
Brownout Threshold, Other Versions93 min, 98 typ, 102 max V; VHV decreasing, other versions except xxxxxE; source page 7
Brownout Threshold, xxxxxA/D/H79 min, 84 typ, 89 max V; VHV decreasing, versions xxxxxA, xxxxxD, xxxxxH; source page 7
Gate Drive Rise Time20 typ, 40 max ns; VDRV from 10% to 90%; source page 7
Gate Drive Fall Time5 typ, 30 max ns; VDRV from 90% to 10%; source page 7
Gate Drive Source Current Capability500 typ mA; gate drive output; source page 8
Gate Drive Sink Current Capability800 typ mA; gate drive output; source page 8
Feedback Open Pin Voltage4.8 min, 5.0 typ, 5.1 max V; FB pin open; source page 8
FB to Internal Current Setpoint Division Ratio3.7 min, 4.0 typ, 4.3 max; feedback control; source page 8
Internal Feedback Pull-Up Resistor17 min, 20 typ, 23 max kΩ; VFB=0.4 V; source page 8
Maximum Frequency Clamp, VFMAX=0.5 V440 min, 500 typ, 560 max kHz; 9-pin versions only, VFMAX=0.5 V; source page 8
Maximum Frequency Clamp, VFMAX=3.5 V61 min, 70 typ, 79 max kHz; 9-pin versions only, VFMAX=3.5 V; source page 8
FMAX Disable Threshold3.85 min, 4.00 typ, 4.15 max V; 9-pin versions only; source page 8
Maximum On Time28 min, 32 typ, 40 max µs; controller on-time limit; source page 8
ZCD Threshold Voltage35 min, 60 typ, 90 max mV; VZCD decreasing; source page 8
Demagnetization Propagation Delay80 typ, 250 max ns; VZCD step from 4.0 V to -0.3 V; source page 8
Current Limit Threshold Voltage0.760 min, 0.800 typ, 0.840 max V; VCS increasing; source page 8
Leading Edge Blanking Duration220 min, 265 typ, 330 max ns; DRV minimum width minus tdelay(ILIM1); source page 8
Soft-Start Timer4 ms; feature list; source page 1
No-Load Power ConsumptionBelow 30 mW; with integrated active X2 capacitor discharge feature; source page 1
Datasheet Statusrequest_only

Product Overview

Electrical limits include a high-voltage startup circuit input voltage rating of -0.3 to 700 V and VCC supply input voltage rating of -0.3 to 30 V. Thermal ratings include -40 to 125 °C operating junction temperature, 150 °C maximum junction temperature, and -60 to 150 °C storage temperature range.

Key Features

  • Quasi-resonant flyback controller for Power_Management designs
  • Integrated high-voltage startup input rated to 700 V
  • 17.0 V typical startup threshold on increasing VCC
  • 9.0 V typical minimum operating voltage on decreasing VCC
  • 28 V typical VCC overvoltage protection threshold
  • Gate drive supports 500 mA source current capability
  • Gate drive supports 800 mA sink current capability
  • 0.800 V typical current limit threshold voltage
  • 4 ms soft-start timer from feature list
  • Below 30 mW no-load power with active X2 discharge

Typical Applications

  • Quasi-resonant flyback power supplies
  • Power_Management controller assemblies
  • X2 capacitor discharge circuits
  • Brownout-monitored AC input designs
  • SOIC-8 or SOIC-9 controller boards
  • Low no-load power supply designs

Procurement Notes

When requesting a quote for NCP1342, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.

If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.

For power IC and power device sourcing, voltage rating, current rating, power dissipation, package thermal performance, protection features, qualification grade and application conditions should be reviewed before approval.

FAQ

What type of controller is the NCP1342?

The extracted datasheet facts identify NCP1342 as a quasi-resonant flyback controller in the Power_Management category. The listed package options are SOIC-8 NB (Case 751) and SOIC-9 NB (Case 751BP), Pb-Free.

What are the main voltage ratings for NCP1342?

The high-voltage startup circuit input voltage is rated from -0.3 to 700 V as a maximum rating. The supply input voltage is rated from -0.3 to 30 V, and the VCC overvoltage protection threshold is 27 V minimum, 28 V typical, and 29 V maximum.

What startup and operating thresholds are specified?

With VCC increasing at dV/dt=0.1 V/ms, the startup threshold is 16.0 V minimum, 17.0 V typical, and 18.0 V maximum. With VCC decreasing, the minimum operating voltage is 8.5 V minimum, 9.0 V typical, and 9.5 V maximum.

What gate-drive capability does the NCP1342 provide?

The gate drive output has a 500 mA typical source current capability and an 800 mA typical sink current capability. Gate drive timing facts list a 20 ns typical rise time and a 5 ns typical fall time under the stated VDRV transition conditions.

Technical Review & Sourcing Note

Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: July 26, 2026.

This page is based on manufacturer datasheet information and LDeepAI sourcing review. Specifications should be verified against the official manufacturer datasheet before final procurement or design approval. Final electrical, optical and reliability approval should be confirmed by the buyer's engineering team.

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