IRS2548D LED Driver IC PFC and Half Bridge driver combo Peter Green – LED Group Mgr
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Transcript of IRS2548D LED Driver IC PFC and Half Bridge driver combo Peter Green – LED Group Mgr
COMPANY CONFIDENTIAL 11
IRS2548DLED Driver IC
PFC and Half Bridge driver comboPeter Green – LED Group Mgr
Energy Saving Products Business UnitApril 2011
COMPANY CONFIDENTIAL
LED Lighting Introduction
Small LEDs developed in 1960s for indication High Brightness / High Power LEDs now available Lumens per Watt better than Incandescent / Halogen
lamps Lumens per Watt equal or better than Fluorescent or
HID lamps HB/HP LEDs being adopted in general illumination Typical applications; bulb replacements, light fixtures,
Street lamps LEDs have longer operating life, typically 50000 hours LEDs offer better reliability / durability LEDs are easier to control and dim LEDs offer reduced Lumen depreciation
(less light output reduction over time) LEDs are normally DC driven LEDs are driven by constant current
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High Power LED Applications
LED Street Light Typically 120W per cobra head Example opposite uses 4 x 30W
LED panels One LED driver per cobra head Typically 1.4A output Single or multi channel output Optimize for efficiency (series LED
connection) or redundancy (4 channel output)
High Lumen output / directed light Controllable light output (PWM or linear dimming) Galvanically isolated low voltage outputs (safety) Open and short circuit protected Wide input voltage range 90 to 305VAC High power factor and low THD
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Power Factor Control is Power Quality
PFC regulations apply to:
China : China Compulsory Certificate (CCC)
Europe : IEC 1000-3-2
Japan : JIC C 61000-3-2
For products >75W (>26W for lighting applications)
“Power Factor”
Relationship between voltage and current waveforms
Measure of “power quality” that affects transmission network efficiency
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IRS2548D
Critical conduction mode (CrCM) PFC Control THD reduction by on time modulation Variable frequency oscillator (current controlled) Half bridge driver PWM dimming input (ENN) also disables PFC Over current protection (PFC and Half bridge) Fixed internal 1.6uS half bridge (HO and LO) dead time Internal bootstrap MOSFET Internal 15.6V zener clamp diode on VCC Micropower startup (250uA) Latch immunity and ESD protection Maximum half bridge offset voltage 600V Gate drive output current (PFC, HO, LO) +/-0.5A 14 lead SOIC package For LED driver and SMPS applications (typically >
50W) For wide AC input voltage range 90 to 305 VAC
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IRS2548D Target Applications
OFF LINE LEDLIGHT FIXTURES
IncandescentReplacement
HIDReplacement
Handheld LEDLamps
AUTOMOTIVE
LCD Back Light
HandheldDevices
Fluorescent Replacement
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L
N
E
EMI Filter & Rectifier
Output
IFB
Half-Bridge StagePFC Boost Converter
7
Two Stage LED Driver
IRS2548DIRS2548D
PFC + Half Bridge Driver ICPFC + Half Bridge Driver IC
Combo IC SolutionCombo IC Solution
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IRS2548D Typical Schematic
RVBUS1
RLO
+
RVBUS2
C1
L
N
RV1F1
CVS
DCP2
DCP1
CCOMP
COCROC
MPFC
CVBUS2
CVBUS1
RPFC
RZX
CVBUS
RVBUS
RFMIN
RVCC
CCS
RCS
RF1
RLM1RLM2
RHOMHS
MLS
CBS
CVCC1CVCC
+
+
BR1
C2
L1
CY
GND
DPFCLPFC
RFMAX
CRES
DOUT1
DOUT2
COUT
RPU
RCL
CVS
Reg+5V
LED+
LED-
RD1
RD2
RD3
RV1
RV2
CF1
CF2
2
ENN
1
2
3
VBUS
4
5
7
FMIN
6
7 8
13
12
11
10
9
14
OC
COMP
ZX
PFC
HO
VS
VB
VCC
COM
LO
CS
IRS
2548D
ROC
PFC MOSFET OPTO ISOLATOR(Feedback)
Half Bridge MOSFETs
RectifierDiodes/MOSFETs
Voltage and Current
Feedback
Frequency Control Input Bus Voltage Feedback
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IRS2548D Demo Board IRPLLED5
Features:High output current regulation90-305VAC universal inputDimmable with 1-10V DC inputNon-latched shutdown against output over-voltage Using IRS2548DS LED control IC
COMPANY CONFIDENTIAL
Test Results
Load: 2 x Eco Lumens EPAD connected in series
VACin(Vrms)
Pin(W)
PF THDi(%)
Fs(kHz)
Vout(Vdc)
Iout(Adc)
Pout(W)
Eff(%)
100 55.1 0.999 2.3 42.8 39.2 1.22 47.8 86.8
120 55.4 0.998 6.4 42.8 39.1 1.23 48.1 86.8
220 55.0 0.979 13.1 42.8 39.1 1.24 48.5 88.2
240 55.1 0.972 15.6 42.8 39.1 1.24 48.5 88.0
277 55.5 0.952 18.3 42.8 39.1 1.25 48.9 88.1
Driving32 x Samsung Sunnix6 HPLED packsTotal Power = 55W
COMPANY CONFIDENTIAL
Output V-I Characteristic
Green = LED VoltageBlue = LED Current
Open circuit voltage < 60VCurrent ripple ~15%Short circuit current = 1.5A
Voltage vs Current
0
10
20
30
40
50
60
00.
20.
40.
60.
8 11.
21.
41.
6
Current (A)
Vo
ltag
e (V
)
V-I
COMPANY CONFIDENTIAL
90 to 305VAC50/60Hz
2 Channel Driver
+48V
0V~ PFC IsolationVoltage Control
Power Converter
EMI filter/Rectification
2 Channel Driver
2 Channel Driver
700mA
700mA
Multi Channel LED Concept
One main power converter supplies 48V isolated DC bus
Wide input voltage range 90 to 305VAC High power factor and low THD Output modules provide 2 x 700mA
regulated current outputs
IRS2548D Based Power Stage
COMPANY CONFIDENTIAL
IRS2548D IC Summary
For LED driver and SMPS applications (typically > 50W) For wide AC input voltage range 90 to 305 VAC High Power Factor and Low THD Resonant Half Bridge Topology / Soft Switching Efficiency better than 85% above 50W Efficiency improves at higher power levels Suitable for isolated LED drivers > 50W Efficiency and flexibility surpasses Flyback solution above 50W Protected against short circuit in primary and secondary stages Enables regulated output current loop for LED driving Incorporates PWM dimming input, allows dimming to ~2% output