Rainbow Electronics MAX16841 User Manual

EVALUATION KIT AVAILABLE

19-6028; Rev 0; 10/11

MAX16841

Controller IC for Dimmable Offline LED Lamps

General Description

The MAX16841 is an LED driver for AC line (100V, 120V, 220V, and 230V AC) input lamps. It features proprietary control of the input current that allows lamps to dim smoothly from full to zero light intensity, while providing active power factor correction (PFC). It is a very flexible product that can be used in isolated (e.g., flyback) and nonisolated (e.g., buck) configurations. The conventional use of an optocoupler in isolated configurations can be avoided in MAX16841-based designs.

The constant frequency-control technique of the device allows maximization of the conversion efficiency at both low and high AC line by operating at the conduction mode that minimizes total conduction and switching losses.

The device can be configured for universal input (90V to 264V AC) dimmable applications, allowing the design of an LED lamp that can be operated and dimmed worldwide.

This device can be used without electrolytic capacitors, thus maximizing the lamp lifetime. In this case, the LED current is a rectified sinusoid with a frequency that is twice the AC line frequency.

The device also features thermal shutdown, current limit, open LED protection, and VCC undervoltage lockout. The MAX16841 is available in an 8-pin SO package and operates over the -40NC to +125NC temperature range.

Features

S Smooth Dimming with Leading-Edge (Triac) and

Trailing-Edge Dimmers

S Active Power Factor Correction

S Nonisolated (e.g., Buck) and Isolated

(e.g., Flyback) Topologies

S Universal 90V to 264V AC Input Range

S Constant Frequency-Control Scheme Maximizes

Efficiency at High and Low AC Line Voltage

S Constant Power Control with No Need for

Optocouplers

S Very-Low Quiescent Current

S Output Open and Short Protection

S Thermal Shutdown

S Available in an 8-Pin SO Package

Ordering Information appears at end of data sheet.

Typical Operating Circuits appear at end of data sheet.

For related parts and recommended products to use with this part, refer to www.maxim-ic.com/MAX16841.related.

Applications

Retrofit LED Lamps with Triac Dimming

Universal Input LED Retrofit Lamps

Industrial and Commercial Lighting

Residential LED Lighting

�� Maxim Integrated Products 1

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

MAX16841

Controller IC for Dimmable Offline LED Lamps

ABSOLUTE MAXIMUM RATINGS

IN to GND .............................................................. -0.3V to +26V

NDRV, DIMOUT to GND ........................... -0.3V to (VIN + 0.3V)

All Other Pins to GND .............................................-0.3V to +6V

NDRV Continuous Current .............................................. Q10mA

DIMOUT Continuous Current ............................................ Q2mA

Continuous Power Dissipation (TA = +70NC)

8 SO (derate 7mW/NC above +70NC) ..................588.2mW

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

PACKAGE THERMAL CHARACTERISTICS (Note 1)

8 SO

Junction-to-Ambient Thermal

Resistance (BJA) (based on S8+2) ...........................136NC/W

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-

layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.

ELECTRICAL CHARACTERISTICS

(VIN = 12V, TA = TJ = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

IN Operating Range V

IN Undervoltage Threshold UVLOR

IN Overvoltage Threshold OVLOR

IN Input Supply Current I

TH

TH Operating Range 0 4 V

TH Threshold Voltage V

TH Input Supply Current VTH = 0V 0.16 0.3

REFI

REFI Operating Range V

REFI Input Supply Current V

DIMOUT

DIMOUT On-Resistance

TH to DIMOUT Propagation Delay

INTERNAL OSCILLATOR

Oscillator Frequency

IN

TH

REFI

INVIN

rising, V

NDRV not switching, VTH = 0V 0.7 1.3 2.6

NDRV switching, 177.5kW/330pF on NDRV, VTH = 5V, V VCS = 0V, V

VIN = 8V 1.6

VTH rising, hysteresis = 150mV 1.17 1.215 1.26 V

= 2V 48.5 50 51.5

REFI

DIMOUT = IN DIMOUT = GND

VTH rising 40 80

VTH falling 40 80

RT = 47.5KI

RT = 177.5kI

RT = 297.5kI

Operating Temperature Range ........................ -40NC to +125NC

Junction Temperature .....................................................+150NC

Storage Temperature Range ............................ -65NC to +150NC

Lead Temperature (soldering, 10s) ................................+300NC

Soldering Temperature (reflow) ......................................+260NC

Junction-to-Case Thermal

Resistance (BJC) (based on S8+2) .............................38NC/W

11 20 V

= 1V 9.5 10 10.5 V

HYST

= 1.8V 21 22 23 V

HYST

1.7 2.7 4.2

0.5 3.25 V

20 40 20 40

50

160 180 200

270 300 330

REFI

COMP

= 2.35V

= 2V,

mA

FA

I

ns

kHz

�� Maxim Integrated Products 2

MAX16841

Controller IC for Dimmable Offline LED Lamps

ELECTRICAL CHARACTERISTICS (continued)

(VIN = 12V, TA = TJ = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

RT Resistance Range 47.5 297.5 Oscillator Decode Resolution 6 Bits Dither Frequency Range 45kHz to 330kHz 1.875 % Frequency Dither Ramping DAC 7 Bits Dither Frequency 1.5 kHz

CURRENT SENSE

CS Input Bias Current

CS Voltage at Current Limit V

CS Voltage at Current Limit Soft-Start

CS Voltage at Hiccup Current Limit

CS Hiccup Shutdown CS > hiccup 1.2 s Hiccup Detection Cycles 3 Times

CS Regulation Voltage

TRANSCONDUCTANCE AMPLIFIER

Transconductance G

COMP Sink Current I

COMP Source Current I

NDRV

NDRV Operating Range 0 V

NDRV On-Resistance

NDRV Dead Time Rising or falling 5 Ns

NDRV Rise Time NDRV = 1nF, 10% to 90% 15 ns

NDRV Fall Time NDRV = 1nF, 90% to 10% 15 ns

NDRV Reference Current Startup only 7.5 8 8.5

THERMAL SHUTDOWN

Thermal-Shutdown Threshold TJ rising 164

Thermal Hysteresis 20

Note 2: All parameters are tested at TA = +25NC only. Limits over temperature are guaranteed by design.

CS_LIMIT

m

SINK

SOURCE

VCS = 2V, V

V

= 2V, V

COMP

VCS = 0.45V

V

= 2.2V, V

COMP

VCS = 0.45V Q0.05V

V

= 2V, V

COMP

V

= 2V, V

COMP

VCS = 0.9V

I

= 50mA to 100mA 2 5.0

NDRV

I

= -50mA to -100mA 1.25 2.5

NDRV

= 4V -1 0 +1

COMP

= 0.7V 60 90 130

COMP

2.1 2.2 2.3 V

2.6 2.7 2.8 V

= 2.35V,

REFI

= 2.35V,

REFI

= 2.35V, VCS = 0V 45 65 85

REFI

= 2.35V,

REFI

448 450 462 V

95 135 175

45 65 85

10 ms

IN

kW

FA

FS

FA

V

I

FA

NC

�� Maxim Integrated Products 3

Controller IC for Dimmable Offline LED Lamps

04

(TA = TJ = +25NC, 12 series LED load.)

MAX16841

Typical Operating Characteristics

AVERAGE VCS vs. TEMPERATURE

310

CURRENT-SENSE

309

RESISTOR = 3.3I

308

307

(mV)

306

CS

305

304

AVERAGE V

303

302

301

300

-40 120 TEMPERATURE (°C)

CS (mV)

1008040 600 20-20

MAX16841 toc01

(mV)

CS

V

800

700

600

500

400

300

200

100

CURRENT-SENSE RESISTOR = 3.3I

0

VCS vs. V

V

REFI

MAX16841 toc02

QUIESCENT CURRENT

CS (mV)

321

(V)

QUIESCENT CURRENT vs. V

3.0

2.5

2.0

1.5

1.0

0.5

0

9

V

(V)

IN

IQ mA (VTH = 0V) IQ mA (VTH = 5V)

IN

MAX16841 toc03

1917151311

�� Maxim Integrated Products 4

MAX16841

Controller IC for Dimmable Offline LED Lamps

Pin Configuration

TOP VIEW

REFI

COMP

TH

PIN NAME FUNCTION

1 REFI

2 COMP

3 TH

4

5 GND Ground 6 CS Switch Current-Sense Input

7 NDRV

8 IN

DIMOUT

Current Reference Input. The IC sources 50FA current out of this pin. Connect a resistor from REFI to GND to set the input-current reference.

Compensation Component Connection for the Switching Stage. Connect a suitable RC network to ground. This is the output of the Gm amplifier.

Sets the Voltage Threshold on the Input at Which Switching Starts. This threshold is set at 1.24V. Connect a resistor-divider from the bridge rectifier output, TH, and GND.

DIMOUT Drives an External FET to Provide a Resistive Path for the Triac when Input is Low. DIMOUT is also used to drive an external FET that sets the programmed current to zero when the input voltage is low.

Gate Drive for the Switching MOSFET. Connect a resistor across NDRV and GND to set the switching frequency.

Input. Bypass with a 0.1FF or a higher value ceramic capacitor to ground.

+

1

2

3

4

MAX16841

SO

IN

8

NDRV

7

CS

6

GND

5DIMOUT

Pin Description

�� Maxim Integrated Products 5

MAX16841

Controller IC for Dimmable Offline LED Lamps

Functional Diagram

COMP

OSCILLATOR

10ms

2.2V

200ns

VIN OV

VIN UVLO

2.7V

2.4V

P-P

CS LIMIT

COMPARATOR

HICCUP

COMPARATOR

1s TIMER

SET

SQ

RQ

CLR

IN

NDRV

GND

CS

V

CC

IN

BIAS

VCC2.2V 2.3V 1.24V

MAX16841

G

m

THERMAL SHUTDOWN

NDRV

SOFT-START

BLANKING

GND

100mV

1/5

TH

1.24V

50µA

REFI

DIMOUT

�� Maxim Integrated Products 6