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


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

COMPANY CONFIDENTIAL 4

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


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


IRS2548D Target Applications

OFF LINE LEDLIGHT FIXTURES

IncandescentReplacement

HIDReplacement

Handheld LEDLamps

AUTOMOTIVE

LCD Back Light

HandheldDevices

Fluorescent Replacement


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


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


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


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


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


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


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

irs2548d led driver ic pfc and half bridge driver combo peter green – led group mgr

Documents