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reference designNCP1945LA | Demoboard NCP1945

Onsemi NCP1945LA | Demoboard NCP1945

Power Factor Controllers | NCP1945

Overview

TopologyFlyback Converter
Input voltage90-305 V
Output 156 V

Description

This reference design covers the specification, design,and operation of the NCP1945 LED Driver demonstrationboard. This board features a 75 W Critical ConductionMode (CRM) boost PFC with a quasi-resonant (QR)flyback. The secondary side is controlled by the NCL38046constant current/ constant voltage controller. Thissecondary side controller allows for constant powerlimiting, which can prevent damage to an LED. This boardtakes advantage of several of the key features of theNCP1945 to demonstrate a LED driver that is capable ofdelivering less than 8% THD at 115 Vac − 277 Vac, whiledeep dimming down below 5% without any visibleflickering on the LED.This board is designed to be highly adjustable such that theuser can explore a setup that will most closely match theirapplication. In addition to the AC-input, the user can set theTHD adjustment voltage, the output current setpoint, theconstant power coefficient, constant power shape, and thedimming. The dimming on this board can be implementedin two separate ways. More details are provided about eachof these features in their corresponding sections in thisdesign note.

Features

− Integrated High-voltage Startup Circuit with BrownoutDetection− Integrated Input Filter Capacitor Discharge Capability− Dual Range VCC, with 150 V VCCH Pin for Connectionto High Voltage Aux Winding− PFC Valley Synchronized Frequency Foldback− Dynamic Response Enhancer− THD Enhancer

Typical applications

  • LED drivers

More information

Parts approved by Onsemi

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Order Code
Data­sheet
Simu­lation
Downloads
Status
Product series
C
Tol. C
Size
Qmin.
DF(%)
RISO
Ceramic Type
Fl(mm)
Packaging
Operating Temperature
Q
Endurance(h)
IRIPPLE(mA)
ILeak(µA)
Pitch(mm)
Ø D(mm)
Pins
Type
G(mm)
Working Voltage(V (AC))
IR(A)
L(mH)
RDC max.(mΩ)
VR(V (DC))
VT(V (AC))
Material
L(mm)
W(mm)
H(mm)
Mount
SamplesAvailability & Sample
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885342208016
SPECWCAP-CSMH Mid and High Voltage, 150 pF, ±10%
Simu­lation
Availability
–
Downloads8 files

RF & Microwave simulation models

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product seriesWCAP-CSMH Mid and High Voltage
Capacitance150 pF
Capacitance±10% 
Size1206 
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Dissipation Factor2.5 %
Insulation Resistance10 GΩ
Ceramic TypeX7R Class II 
Pad Dimension0.6 mm
Packaging7" Tape & Reel 
Operating Temperature -55 °C up to +125 °C
Q-Factor600 
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Rated Voltage1000 V (DC)
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Length3.2 mm
Width1.6 mm
Height1.25 mm
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–Check availability
885012206072
SPECWCAP-CSGP MLCCs 25 V(DC), 150 nF, ±10%
Simu­lation
Availability
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Downloads9 files

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product seriesWCAP-CSGP MLCCs 25 V(DC)
Capacitance150 nF
Capacitance±10% 
Size0603 
Q-Factor [1]600 
Dissipation Factor3.5 %
Insulation Resistance3.3 GΩ
Ceramic TypeX7R Class II 
Pad Dimension0.4 mm
Packaging7" Tape & Reel 
Operating Temperature -55 °C up to +125 °C
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Rated Voltage25 V (DC)
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Length1.6 mm
Width0.8 mm
Height0.8 mm
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–Check availability
860020778021
SPECWCAP-ATG5 Aluminum Electrolytic Capacitors, 470 µF, ±20%
Simu­lation
Availability
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Downloads8 files

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product seriesWCAP-ATG5 Aluminum Electrolytic Capacitors
Capacitance470 µF
Capacitance±20% 
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Dissipation Factor9 %
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PackagingAmmopack 
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Endurance 2000
Ripple Current690 mA
Leakage Current296.1 µA
Pitch5 mm
Diameter13 mm
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Rated Voltage63 V (DC)
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Length20 mm
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–Check availability
7448011305
SPECWE-CMBNC Common Mode Power Line Choke Nanocrystalline, –, –
Simu­lation
Availability
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Downloads11 files

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product seriesWE-CMBNC Common Mode Power Line Choke Nanocrystalline
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SizeXS 
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Operating Temperature -55 °C up to +125 °C
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Pins4 
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Pin length3 mm
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Rated Current1.3 A
Inductance5 mH
DC Resistance200 mΩ
Rated Voltage300 V (DC)
Insulation Test Voltage2100 V (AC)
MaterialNanocrystalline 
Length14 mm
Width7.5 mm
Height16 mm
MountTHT 
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7447028
SPECWE-FI Leaded Toroidal Line Choke, –, –
Simu­lation–
Availability
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Downloads8 files

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product seriesWE-FI Leaded Toroidal Line Choke
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Operating Temperature -40 °C up to +105 °C
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Pin length20 mm
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Rated Current1.9 A
Inductance0.15 mH
DC Resistance130 mΩ
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Length16 mm
Width9.1 mm
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MountTHT 
–Check availability
7447040
SPECWE-FI Leaded Toroidal Line Choke, –, –
Simu­lation–
Availability
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Downloads8 files

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product seriesWE-FI Leaded Toroidal Line Choke
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Operating Temperature -40 °C up to +105 °C
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Pin length15 mm
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Rated Current1 A
Inductance0.24 mH
DC Resistance380 mΩ
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Length11.5 mm
Width6.9 mm
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MountTHT 
–Check availability
750313048
SPECInductor, –, –
Simu­lation–
Availability
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Downloads5 files

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product series Inductor
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SizeRM10 
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PackagingTray 
Operating Temperature -40 °C up to +125 °C
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Pin length2.54 mm
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Inductance0.39 mH
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Insulation Test Voltage1500 V (AC)
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Length26.16 mm
Width26.16 mm
Height19.05 mm
MountTHT 
–Check availability
61300211121
SPECWR-PHD Pin Header - Single, –, –
Simu­lation–
Availability
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Downloads7 files

Status
ActiveProduction is active. Expected lifetime: >10 years.
iProduction is active. Expected lifetime: >10 years.
Product seriesWR-PHD Pin Header - Single
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Insulation Resistance1000 MΩ
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PackagingBag 
Operating Temperature -40 °C up to +105 °C
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Pitch2.54 mm
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Pins2 
TypeStraight 
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Working Voltage250 V (AC)
Rated Current3 A
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Length5.08 mm
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MountTHT 
–Check availability