19-6028; Rev 0; 10/11
EVALUATION KIT AVAILABLE
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 efficien-
cy 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 V
CC
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
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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
Operating Temperature Range ........................ -40NC to +125NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion 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 (B
JA
) (based on S8+2) ...........................136NC/W
Junction-to-Case Thermal
Resistance (B
JC
) (based on S8+2) .............................38NC/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
(V
IN
= 12V, T
A
= T
J
= -40NC to +125NC, unless otherwise noted. Typical values are at T
A
= +25NC.) (Note 2)
PARAMETER
IN Operating Range
IN Undervoltage Threshold
IN Overvoltage Threshold
SYMBOL
V
IN
UVLOR
IN
OVLOR
IN
V
IN
rising, V
HYST
= 1V
V
IN
rising, V
HYST
= 1.8V
NDRV not switching, V
TH
= 0V
IN Input Supply Current
I
IN
NDRV switching, 177.5kW/330pF on
NDRV, V
TH
= 5V, V
COMP
= 2V,
V
CS
= 0V, V
REFI
= 2.35V
V
IN
= 8V
TH
TH Operating Range
TH Threshold Voltage
TH Input Supply Current
REFI
REFI Operating Range
REFI Input Supply Current
DIMOUT
DIMOUT
On-Resistance
TH to
DIMOUT
Propagation
Delay
INTERNAL OSCILLATOR
RT = 47.5KI
Oscillator Frequency
RT = 177.5kI
RT = 297.5kI
160
270
50
180
300
200
330
kHz
DIMOUT
= IN
DIMOUT
= GND
V
TH
rising
V
TH
falling
20
20
40
40
40
40
80
80
I
ns
V
REFI
V
REFI
= 2V
0.5
48.5
50
3.25
51.5
V
FA
V
TH
V
TH
rising, hysteresis = 150mV
V
TH
= 0V
0
1.17
1.215
0.16
4
1.26
0.3
V
V
FA
CONDITIONS
MIN
11
9.5
21
0.7
1.7
10
22
1.3
2.7
1.6
TYP
MAX
20
10.5
23
2.6
4.2
mA
UNITS
V
V
V
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Maxim Integrated Products
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MAX16841
Controller IC for Dimmable Offline LED Lamps
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 12V, T
A
= T
J
= -40NC to +125NC, unless otherwise noted. Typical values are at T
A
= +25NC.) (Note 2)
PARAMETER
RT Resistance Range
Oscillator Decode Resolution
Dither Frequency Range
Frequency Dither Ramping DAC
Dither Frequency
CURRENT SENSE
CS Input Bias Current
CS Voltage at Current Limit
CS Voltage at Current Limit
Soft-Start
CS Voltage at Hiccup Current
Limit
CS Hiccup Shutdown
Hiccup Detection Cycles
CS Regulation Voltage
TRANSCONDUCTANCE AMPLIFIER
Transconductance
COMP Sink Current
COMP Source Current
NDRV
NDRV Operating Range
NDRV On-Resistance
NDRV Dead Time
NDRV Rise Time
NDRV Fall Time
NDRV Reference Current
THERMAL SHUTDOWN
Thermal-Shutdown Threshold
Thermal Hysteresis
T
J
rising
164
20
NC
NC
I
NDRV
= 50mA to 100mA
I
NDRV
= -50mA to -100mA
Rising or falling
NDRV = 1nF, 10% to 90%
NDRV = 1nF, 90% to 10%
Startup only
7.5
0
2
1.25
5
15
15
8
8.5
V
IN
5.0
2.5
V
I
Ns
ns
ns
FA
G
m
I
SINK
I
SOURCE
V
COMP
= 2.2V, V
REFI
= 2.35V,
V
CS
= 0.45V
Q0.05V
V
COMP
= 2V, V
REFI
= 2.35V, V
CS
= 0V
V
COMP
= 2V, V
REFI
= 2.35V,
V
CS
= 0.9V
95
45
45
135
65
65
175
85
85
FS
FA
FA
V
COMP
= 2V, V
REFI
= 2.35V,
V
CS
= 0.45V
448
CS > hiccup
2.6
V
CS_LIMIT
V
CS
= 2V, V
COMP
= 4V
V
CS
= 2V, V
COMP
= 0.7V
-1
60
2.1
0
90
2.2
10
2.7
1.2
3
450
462
2.8
+1
130
2.3
FA
V
ms
V
s
Times
V
45kHz to 330kHz
SYMBOL
CONDITIONS
MIN
47.5
6
1.875
7
1.5
TYP
MAX
297.5
UNITS
kW
Bits
%
Bits
kHz
Note 2:
All parameters are tested at T
A
= +25NC only. Limits over temperature are guaranteed by design.
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Maxim Integrated Products
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MAX16841
Controller IC for Dimmable Offline LED Lamps
Typical Operating Characteristics
(T
A
= T
J
= +25NC, 12 series LED load.)
AVERAGE V
CS
vs. TEMPERATURE
MAX16841 toc01
V
CS
vs. V
REFI
700
600
V
CS
(mV)
500
400
300
200
QUIESCENT CURRENT vs. V
IN
MAX16841 toc02
MAX16841 toc03
310
309
308
AVERAGE V
CS
(mV)
307
306
305
304
303
302
301
300
-40
-20
0
20
40
60
80
800
3.0
2.5
QUIESCENT CURRENT
CURRENT-SENSE
RESISTOR = 3.3I
CURRENT-SENSE
RESISTOR = 3.3I
2.0
1.5
1.0
0.5
CS (mV)
100 120
100
0
0
1
2
V
REFI
(V)
CS (mV)
0
3
4
I
Q
mA (V
TH
= 0V)
I
Q
mA (V
TH
= 5V)
9
11
13
15
V
IN
(V)
17
19
TEMPERATURE (°C)
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Maxim Integrated Products
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MAX16841
Controller IC for Dimmable Offline LED Lamps
Pin Configuration
TOP VIEW
REFI
COMP
TH
DIMOUT
1
2
3
4
+
8
IN
NDRV
CS
GND
MAX16841
7
6
5
SO
Pin Description
PIN
1
2
3
NAME
REFI
COMP
TH
FUNCTION
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 G
m
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.
Ground
Switch Current-Sense Input
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.
4
5
6
7
8
DIMOUT
GND
CS
NDRV
IN
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Maxim Integrated Products
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