Fairchild FL7701MX Smart led lamp driver ic with pfc function Datasheet

FL7701
Smart LED Lamp Driver IC with PFC Function
Features
Description

Digitally Implemented Active PFC Function
(No Additional Circuit Necessary for High PF)













Built-in HV Supplying Circuit: Self Biasing
The FL7701 LED lamp driver is a simple IC with PFC
function. The special “adopted digital” technique of the
IC can automatically detect input voltage condition and
send an internal reference signal for achieving high
power factor. When AC input is applied to the IC, PFC
function is automatically enabled. Otherwise, when DC
input is applied to the IC, PFC function is automatically
disabled. The FL7701 does not need a bulk capacitor
(electrolytic capacitor) for supply rail stability, which can
significantly affect to LED lamp system.
Application Input Range: 80 VAC ~ 308 VAC
AOCP Function with Auto-Restart Mode
Built-in Over-Temperature Protection Function
Cycle-by-Cycle Current Limit
Current-Sense Pin Open Protection
Low Operating Current: 0.85 mA (Typical)
Related Resources
Under-Voltage Lockout with 5 V Hysteresis

Evaluation Board: FEBFL7701_L30U003A
Programmable Oscillation Frequency
Programmable LED Current
Analog Dimming Function
Soft-Start Function
Precise Internal Reference: ±3%
Applications


LED Lamp for Decorative Lighting
LED Lamp for Low-Power Lighting
Ordering Information
Part Number
Operating
Temperature Range
Package
Packing Method
FL7701MX
-40°C to +125°C
8-Lead, Small Outline Integrated Circuit (SOIC),
JEDEC MS-012, .150-inch Narrow Body
Tape & Reel
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
FL7701 — Smart LED Lamp Driver IC with PFC Function
June 2013
BD
L1
LED
D1
L3
Fuse
C2
C1
CS
HV
OUT
NV
VCC
GND
D2
Q1
R2
ADIM
RT
C3
R1
U1
C4
R3
L2
Figure 1. Typical Application
Block Diagram
VCC 3
JFET
VCC
8
HV
ZCD
UVLO
time
IAD
ADIM
ZCD
5
DAC
TSD
Soft start
Digital Block
RT
4
S
Oscillator
2 OUT
Q
R
Reference
+
1
LEB
GND 6
CS
Leading Edge
Blanking
+
AOCP
2.5V
Figure 2. Block Diagram
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
2
FL7701 — Smart LED Lamp Driver IC with PFC Function
Application Diagram
CS
VCC
FL7701
OUT
HV
NV
GND
RT
ADIM
Figure 3. Pin Configuration
Pin Definitions
Pin #
Name
Description
1
CS
Current Sense. Limits output current depending on the sensing resistor voltage. The CS pin is
also used to set the LED current regulation
2
OUT
OUT. Connects to the MOSFET gate.
3
VCC
VCC. Supply pin for stable IC operation ZCD signal detection used for accurate PFC function.
4
RT
5
ADIM
Analog Dimming. Connect to the internal current source and can change the output current
using an external resistor. If ADIM is not used, it is recommended to connect a 0.1 µF bypass
capacitor between the ADIM and GND.
6
GND
GROUND. Ground for the IC.
7
NC
No Connection
8
HV
High Voltage. Connect to the high voltage line and supply current to the IC
RT. Programmable operating frequency using external resistor and the IC has pre-fixed
frequency when this pin is open or floating.
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
3
FL7701 — Smart LED Lamp Driver IC with PFC Function
Pin Configuration
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device
reliability. The absolute maximum ratings are stress ratings only.
Symbol
Parameter
Min.
Max.
Unit
V
VCC
IC Supply Voltage
20
HV
High Voltage Sensing
500
V
IO+/IO-
Peak Drive Output Current (Sourcing / Sinking)
250
mA
VADIM
Analog Dimming
5
V
VRT
RT Pin Voltage
5
V
VCS
Allowable Current Sensing Detection Voltage
5
V
TA
Operating Ambient Temperature Range
-40
+125
C
TJ
Operating Junction Temperature
-40
+150
C
-65
+150
C
135
C/W
660
mW
TSTG
Storage Temperature Range
θJA
Thermal Resistance Junction-Air
PD
Power Dissipation
ESD
(1,2)
Electrostatic Discharge Capability
Human Body Model, JESD22-A114
2000
Charged Device Model, JESD22-C101
1000
V
Notes:
1. Thermal resistance test board. Size: 76.2 mm x 114.3 mm x 1.6 mm (1S0P); JEDEC standard: JESD51-2, JESD513.
2. Assume no ambient airflow.
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
4
FL7701 — Smart LED Lamp Driver IC with PFC Function
Absolute Maximum Ratings
Typical values are at TA = +25°C. Specifications to -40°C ~ 125°C are guaranteed by design based on final
characterization results.
Symbol
Parameter
Conditions
Min.
Typ.
Max.
Unit
VCC Bias Section
VCC
VCC Regulator Output Voltage
VHV=100 VDC
14.0
15.5
17.0
V
VCCST+
UVLO Positive Going Threshold
VCC Increasing
12
13
14
V
VCCST-
UVLO Negative Going Threshold
VCC Decreasing
7
8
9
V
VCCHY
UVLO Hysteresis
4
5
6
V
0.85
1.10
mA
120
150
μA
VHV=100 VDC,
CL=150 pF, RT=Open
IHV
HV Pin Current
IST
Startup Current
Switching Section
fOSC
tMIN
DMAX
Operating Frequency
RT=5.95 kΩ
200
250
300
kHz
RT=87 kΩ
16
20
24
kHz
RT Open
40.5
45.0
49.5
kHz
Minimum On Time
Maximum Duty Cycle
tLEB
Leading Edge Blanking Time
VRT
Voltage Reference of RT pin
(3)
400
ns
50
%
350
ns
1.5
V
Soft-Start Section
tss
Soft-Start Time
DC Mode
(3)
48
AC Mode
60
72
ms
7
Periods
Reference Section
VCS1
Internal Reference Voltage of CS Pin
VCS2
DC Mode
AC Mode
(3)
0.354
0.365
0.376
0.485
0.500
0.515
17.7
18.7
19.7
V
Protection Section
OVPVCC
VAOCP
tAOCP
Over-Voltage Protection on VCC Pin
Abnormal OCP Level at CS Pin
Abnormal Detection Time
(3)
(3)
tTSDH
Thermal Shutdown Threshold
tTSDHY
Thermal Shutdown Threshold
(3)
Hysteresis
(3)
140
Dimming Section
Analog Dimming Positive Going
VADIM(ST+)
(3)
Threshold
Analog Dimming Negative Going
VADIM(ST-)
(3)
Threshold
IAD
3.15
Internal Current Source for ADIM Pin
9
V
2.5
V
70
ns
150
°C
50
°C
3.50
3.85
V
0.50
0.75
V
12
15
μA
Note:
3. These parameters, although guaranteed, are not 100% tested in production.
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
5
FL7701 — Smart LED Lamp Driver IC with PFC Function
Electrical Characteristics
The FL7701 is a basic PWM controller for buck
converter topology in Continuous Conduction Mode
(CCM) with intelligent PFC function using a digital
control algorithm. The FL7701 has an internal selfbiasing circuit that uses the high-voltage switching
device. The IC does not need an auxiliary powering
path to the VCC pin typical in flyback control ICs or PSR
product family.
power for the IC, has voltage ripple as well as the
rectification voltage after bridge, changing voltage level
according to the VCC capacitor value. Using this kind of
voltage fluctuation on the VCC pin, the IC can detect
the time reference and create the internal ZCD signal.
For precise and reliable internal reference for input
voltage signal, the FL7701 uses a digital technique
(sigma/delta modulation) and creates a new internal
signal (DAC_OUT) that has the same phase as the
input voltage, as shown in Figure 5. This signal enters
the final comparator and is compared with current
information from the sensing resistor.
When the input voltage applied to the HV pin is over
25 V to 500 V, the FL7701 maintains a 15.5 V DC
voltage at the VCC pin for stable operation. The FL7701
has UVLO block functions such that when the VCC
voltage rises higher than VCCST+, the internal UVLO
block releases and starts operation. Otherwise the VCC
goes down to the VCCST- and IC operation stops.
Normally, the hysteresis function provides stable
operation even if the input voltage is operating under
the very noisy or unstable circumstances.
Vbridge
Bridge Diode
Output Voltage
Input Voltage
Peak
JFET Output
Voltage
t
Vdd Charging Voltage
VCC
The FL7701 has a smart internal digital block for
determining input condition: AC or DC. When an AC
source with 50 Hz or 60 Hz is applied to the IC, the IC
automatically changes its internal reference signal,
which is similar to input signal, for creating high power
factor. Otherwise, once the DC source connects to the
IC, the internal reference immediately changes to DC.
JFET Output Voltage
t
ZCD
t
DAC_OUT
t
1. Soft-Start Function
Figure 5. Internal PFC Function
The FL7701 has an internal soft-start function to reduce
inrush current at startup. When the IC starts operation
following an internal sequence, the internal reference
slowly increases for a pre-determined fixed time. After
this transient period, the internal reference goes to a
steady-state level. In this time, the IC continually tries to
find phase information from the VCC pin. If the IC
succeeds in getting phase information, it automatically
follows a similar shape reference made during the
transient times, 7 periods. If not, the IC has a DC
reference level.
3. Self-Biasing Function
The self-biasing function, using an HV device, can
supply enough operating current to the IC and
guarantee similar startup time across the whole input
voltage range (80 V~308 VAC). However, self-biasing
has a weakness in high-voltage condition. Normally,
the HV device acts as constant current source, so the
internal HV device has power loss when high input
voltage connects to the HV pin. This power loss is
proportional to input voltage. To reduce this power
loss, one of the possible solutions is an additional
resistor between the input voltage source and the HV
pin, as shown in Figure 6.
Vbridge
Bridge
Diode
EMI filter
ILED
U1
T/2 = 1/(Input Frequency * 2)
7*(T/2)
Normal Operation
ADIM
RT
Figure 4. Soft Starting Function in AC Input Mode
VCC
HV
OUT
CS
GND
2. Internal PFC Function: How to Achieve
High Power Factor
Figure 6. High-Voltage Application
The FL7701 has a simple, but smart, internal PFC
function that does not require additional detection pins
for detecting input phase information or an electrolytic
capacitor for supply voltage stabilization. For achieving
high PF, the FL7701 does not use the rectification
capacitor after the bridge diode. This is important
because the IC instead uses fluctuation in the signal on
the VCC pin. Basically, the VCC pin, which is supplies
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
6
FL7701 — Smart LED Lamp Driver IC with PFC Function
Functional Description
In DCM Mode, inductance is:
The FL7701 uses the ADIM pin for analog or 0 V to
10 V dimming by using a resistive divider. The peak
voltage of internal reference, which is DAC_OUT signal
in Figure 5, is changed by the VADIM level, as shown in
Figure 7, and has different peak level according to the
operating mode.
Lm 
n  V f  (1  Dmin )
f s   i rip
I LED ( ave. peak)   icon 
AC mode
I LED ( rms) 
0. 5 V
3 . 5V
 irip
[A]
(3)
2
In FL7701, the LED RMS current determines the
inductance parameter. To drive for CCM Mode, define
LED RMS current first, as:
DC mode
0.365V
(2)
If the peak current is fixed at 350 mApk, the formula for
the peak current is:
VDAC _ OUT
0 .5 V
[H ]
I LED ( ave. peak) [A]
2
(4)
Substituting Equation (2) for Equation
inductance of inductor is obtained.
VADIM
(4),
the
Figure 7. VADIM vs. VDAC_OUT(peak)
VIN
5. Inductor Design
Π
The FL7701 prefixed internal duty ratio range is below
50%, or around 400 ns, from timing point of view. The
range is dependent on the input voltage and LED
numbers in its string.
Dmin 
4Π
t
Bridge Diode
Output Voltage
Vbridge
Input Voltage
Peak
Minimum duty is calculated as:
3Π
2Π
Vdd Charging
Voltage
t
ZCD
t
n V f
DAC
(1)
  Vin (max)
t
VLED
where:
η is efficiency of system;
VIN(max) is maximum input voltage;
Vf is forward drop voltage of LED; and
n is LED number in series connection.
Vdrain
t
Input Voltage
Peak
t
ILED
Input Voltage
Peak
Current Limit
Average
LED Current
t
∆irip
IFRD
t
IMOSFET
ton toff
Dmin 1-Dmin
(a) DCM Mode
t
Iinput
Current peak at LED current
maximum point (ILED(peak))
Current peak at LED average
current maximum point
(ILED(ave.peak))
DCM
Average
LED Current (ILED(ave))
∆i
0.5∆i
t
DCM
T/2 = 1/(Input Frequency * 2)
0.5∆i
T = 1/Input Ferquency
Figure 9. Typical Performance Characteristics
CCM
Current min at LED current
maximum point (ILED(min))
Dmin
1-Dmin
ton toff
(b) CCM Mode
Figure 8. DCM and CCM Operation
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
7
FL7701 — Smart LED Lamp Driver IC with PFC Function
4. Dimming Function
FL7701 — Smart LED Lamp Driver IC with PFC Function
Example Application Circuits
BD
L1
LED
D1
L3
Fuse
C2
C1
CS
HV
OUT
NV
VCC
GND
D2
Q1
R2
ADIM
RT
C3
U1
R1
C4
R3
L2
Figure 10. Application without an Electrolytic Capacitor
BD
L1
LED
C5
D1
L3
Fuse
C2
C1
CS
HV
OUT
NV
VCC
GND
D2
Q1
R2
RT
C3
R1
ADIM
U1
C4
R3
L2
Figure 11. Application with an Electrolytic Capacitor
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
8
17.0
6.0
5.5
VCC HY [V ]
VCC [V ]
16.5
16.0
15.5
15.0
5.0
4.5
14.5
14.0
-40
-20
0
20
40
60
80
100
4.0
-40
120
-20
0
Temperature [°C]
40
60
80
100
120
Temperature [°C]
Figure 12. VCC vs. Temperature
Figure 13. VCCHY vs. Temperature
14.0
150
140
IST [uA ]
VCC ST+ [V ]
13.5
130
13.0
120
12.5
110
12.0
-40
-20
0
20
40
60
Temperature [°C]
80
100
100
-40
120
-20
0
20
40
60
80
100
120
Temperature [°C]
Figure 14. VCCST+ vs. Temperature
Figure 15. IST vs. Temperature
9.0
50
48
8.5
fOSC [kHz]
VCC ST- [V ]
20
8.0
46
44
7.5
42
7.0
-40
-20
0
20
40
60
Temperature [°C]
80
100
120
-40
Figure 16. VCCST- vs. Temperature
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
-20
0
20
40
60
Temperature [°C]
80
100
120
Figure 17. fOSC vs. Temperature (Rt=Open)
www.fairchildsemi.com
9
FL7701 — Smart LED Lamp Driver IC with PFC Function
Typical Characteristics
52
22
51
D MAX
fOSC [kHz]
24
20
49
18
16
-40
50
-20
0
20
40
60
80
100
48
-40
120
-20
0
Temperature [°C]
20
40
60
80
100
120
Temperature [°C]
Figure 19. DMAX vs. Temperature
Figure 18. fOSC vs. Temperature (Rt=87 kΩ)
1.7
300
280
fOSC [kHz]
1.6
V RT
260
1.5
240
1.4
220
200
-40
-20
0
20
40
60
80
100
1.3
-40
120
Temperature [°C]
-20
0
20
40
60
80
100
120
Temperature [°C]
Figure 21. VRT vs. Temperature
Figure 20. fOSC vs. Temperature (Rt=5.95 kΩ)
500
0.376
0.372
V CS1
TMIN
450
400
0.368
0.364
0.360
350
0.356
300
-40
-20
0
20
40
60
Temperature [°C]
80
100
-40
120
Figure 22. tMIN vs. Temperature
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
-20
0
20
40
60
Temperature [°C]
80
100
120
Figure 23. VCS1 vs. Temperature
www.fairchildsemi.com
10
FL7701 — Smart LED Lamp Driver IC with PFC Function
Typical Characteristics
15
19.5
19.0
IAD[uA]
OVP VCC
14
18.5
13
12
11
10
18.0
-40
-20
0
20
40
60
80
100
9
120
Figure 24. OVPVCC vs. Temperature
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
-40
-20
0
20
40
60
80
100
120
Temperature [°C]
Temperature [°C]
Figure 25. . IAD vs. Temperature
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FL7701 — Smart LED Lamp Driver IC with PFC Function
Typical Characteristics
FL7701 — Smart LED Lamp Driver IC with PFC Function
Physical Dimensions
5.00
4.80
A
0.65
3.81
8
5
B
1.75
6.20
5.80
PIN ONE
INDICATOR
4.00
3.80
1
5.60
4
1.27
(0.33)
1.27
0.25
C B A
LAND PATTERN RECOMMENDATION
SEE DETAIL A
0.25
0.10
0.25
0.19
C
1.75 MAX
0.10
0.51
0.33
OPTION A - BEVEL EDGE
0.50 x 45°
0.25
R0.10
GAGE PLANE
R0.10
OPTION B - NO BEVEL EDGE
0.36
NOTES: UNLESS OTHERWISE SPECIFIED
8°
0°
0.90
0.40
A) THIS PACKAGE CONFORMS TO JEDEC
MS-012, VARIATION AA.
B) ALL DIMENSIONS ARE IN MILLIMETERS.
C) DIMENSIONS DO NOT INCLUDE MOLD
FLASH OR BURRS.
D) LANDPATTERN STANDARD: SOIC127P600X175-8M.
E) DRAWING FILENAME: M08Arev14
F) FAIRCHILD SEMICONDUCTOR.
SEATING PLANE
(1.04)
DETAIL A
SCALE: 2:1
Figure 26. 8-Lead, Small-Outline Integrated Circuit (SOIC), JEDEC MS-012, .150-Inch Narrow Body
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify
or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically
the warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
12
FL7701 — Smart LED Lamp Driver IC with PFC Function
© 2011 Fairchild Semiconductor Corporation
FL7701 • Rev. 1.0.4
www.fairchildsemi.com
13
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