Download AC Direct LED Driver IC

AC Direct LED Driver IC
For the replacement of AC-DC Converters or SMPS
Controls power without the use of large capacitors & inductors over a range of AC input
voltages. Typically drives arrays of 75 to 84 single or multi-chip LEDs (e.g. 28 tri-chip, 13 hexchip.)
Designed, developed and manufactured by Login Digital, PC-R101B is a constant current IC
for supplying current to a load regardless of input voltage variation.
Key Benefits
• Space saving compared to using standard
PSU’s or SMPS
•High reliability and low lifetime cost
7x7x0.85mm
Features
•Wide input range: Maximum 300V AC
•LED Protection with constant current driving and
power compensation
•Drive max 40W @ 220V or max 30W @ 110V
•Adjustable efficiency and power factor via LED
array and group configuration
•Tap switching structure enables high power
factor
•83% typical efficiency, minimum power factor
0.95 using 1 tap
•No EMI issues
•Compact size
PC-R101B provides the load with constant current and adjusts the LED power so as to be less sensitive to variations
of the input voltage; also protecting the LED’s from overload. A high power factor is achieved by internal switching
circuits and an LED group separation scheme. Consequently, PC-R101B promotes longer LED life! Traditional LED
power circuits are complex and have problems of noise and LED life. The PC-R101B driver is purpose-designed to
enable the AC-direct concept without bulky inductors and capacitors. Using a properly designed ‘tap’ structure,
supported by the PC-R101B driver can achieve over 0.99 power factor (PF). A total of three LED groups are able to
be connected via two tap points: TP1, TP2. The overall PF is improved by applying this tap structure with the LED
groups.
[email protected]
01746 769 369
14/3 Stanmore Industrial Estate, Bridgnorth, Shropshire, WV15 5HR
Company No: 05541750 Vat No: 871 7917 84
PC-101B protects the LED’s at up to 30% line input over-voltage. The deviation of illumination intensity is minimised
by an internal power compensation circuit. Using a metal-backed PCB and/or adequate heat sinking, the PC-101B
Driver may power up to 40W of LED power at a nominal line input of 220~230V and 30W of LED power for nominal
line input of 100~120V.The minimum efficiency is 83% using two taps.
Block Diagram
The highlighted
section represents
PC-R101B
For optimal performance the LED chips should be grouped as above. Guidance grouping and optimum number of
LEDs is provided in the application note.
[email protected]
01746 769 369
14/3 Stanmore Industrial Estate, Bridgnorth, Shropshire, WV15 5HR
Company No: 05541750 Vat No: 871 7917 84
Pin Description
Application Circuit Description
Constant Current Supply to LED chips
Designed with functions for adjusting pre-set power.
Using a mirror circuit, power can be adjustable with
resistor values of R1 and R2.
Power Compensation Circuit
PC-R101B has a current mirror circuit inside: this acts
to protect the LEDs by maintaining a constant current
and controlling voltage.
Output LED Grouping and Switching Structure for
high power factor
LEDs should be serially connected for this AC-direct
structure. This improves the Power Factor by
controlling the output waveform (creating a step output
wave similar to a sine wave). This is affected by both
the LED grouping; number of LED’s and the resistor
values.
Circuit Diagram
F1
2
AC+
~
Fuse(option)
+ 3
4 V aristor(option)
~
1
AC-
D1
Bridge Diode
R2
C3
AN
LID_CHIP
R15 200k
R7
1
9, 10
AN
OUT
TP1
REF
TP2
V1
15,16
TAP1
8
17,19
TAP2
2
11, 12
KA
KA
R16 1k
R4
R12
3
V2
R8
14
C1
T1
R17 1k
20
R11
T2
R6
R14
4,18
7
GND
T_REF
C4
13
VM1
R13
5
6
COMP
VM2
C2
LID-PC-101B
GND
0
[email protected]
01746 769 369
14/3 Stanmore Industrial Estate, Bridgnorth, Shropshire, WV15 5HR
Company No: 05541750 Vat No: 871 7917 84
Item
Login Digital
AC Driver
Typical
Alternative
Description
Power Factor
>0.99
0.5 – 0.95
Power factor is optimised by Login Digital design.
The power lost by transformation and distribution
is reduced, allowing the achievement of power
factors > 99pf.
Power efficiency
83 – 90%
Around 80% with
SMPS <100W
Or 90% with SMPS
>100W
EMI
50-60 Hz
>30Khz
Login Digital’s Driver has no HF switching noise
since SMPS is not involved.
Life
50,000 hours
10,000 hours
Although LEDs may have long life, this is
normally severely limited by the power supply,
which is damaged by heat and stress. Login
Digital's Driver will resist temperatures up to
150oC. There are no capacitors or inductors to
burn out, thus achieving a longer life.
Size
7x7x.85mm,
(20x25mm for
the standard
module)
SMPS, ballast or
other converter
severely limits
space
Login Digital’s Driver allows greater flexibility in
design by using a very small space compared to
alternative power supplies.
Cost
Around 50% of
a normal 25w
converter
Variable
Login Digital’s AC Driver is a low cost solution
because it does not use a DC convertor, inductor
or capacitor and has less high cost parts.
LED array
Configured as
an AC-Direct
LED array
Generally only 10
LED’s in series or
LED’s arrayed in
lines
The optimised number of LED chips in the array
is 84 at 220V / 230V and 40 at 110V, with direct
connection to LED’s.
Power efficiency = total LED consumption /
overall power consumption.
Power efficiency of 90% can be achieved by
optimising the number of LEDs
[email protected]
01746 769 369
14/3 Stanmore Industrial Estate, Bridgnorth, Shropshire, WV15 5HR
Company No: 05541750 Vat No: 871 7917 84