INTEGRATED CIRCUITS DIVISION
DS-IX9908-R02 www.ixysic.com 1
IX9908
High Voltage, Dimmable
LED Driver with PFC Control
Features
•Single Stage , Primary Control with PFC and
Dimming F eat ures
•>90% Efficiency
•Power Factor >98%
•Wide Operating Voltage Range: Up to 600V
•Digital Soft-Start
•Cycle-by-Cycle Peak Current Control
Applications
•Incandescent Bulb Replacement
•Solid State Lighting
•Industrial and Commercial Lighting
Description
The IX9908 is a quasi-resonant controller optimized
f or phase -cut dimmable, off -line LED applications.
Precise PWM generation supports phase-cut dimming
and power factor correction.
The product features a wide oper ating range, up to
600V, and low power consumption. Multiple saf et y
f eat ures ensur e full system prot ection in failure
situations. The IX9908, with its st rong feature set and
low cost, is an e xcellent choice for quasi-resonant
flyback LED bulb designs.
Ordering Information
IX9908 Example Application
Part Description
IX9908N 8-Pin SOIC (100/Tube)
IX9908NTR 8-Pin SOIC (2000/Reel)
SNUBBER
AC
CIN
RIN1
RIN2
DVR
CVR
RCS
Q1
CC
DOUT
COUT
T1
Aux
LEDs
DVCC
CVCC
RZCV1
CZCV
RZCV2
VCC ZCV HV GD
CS
GNDVR
IX9908
+
-
INTEGRATED CIRCUITS DIVISION
IX9908
2www.ixysic.com R02
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Package Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Recommended Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.5 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.6 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Internal Supply Voltage During Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Soft-Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Manufacturing Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 Moisture Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 ESD Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3 Soldering Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.4 Board Wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.5 Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.6 Tape & Reel Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
INTEGRATED CIRCUITS DIVISION
IX9908
R02 www.ixysic.com 3
1. Specifications
1.1 Package Pinout
1.2 Absolut e Max imum Rating s
Absolute maximum electrical ratings are at 25°C .
Absolute maximum ra tings ar e st ress ratings.
Stresses in e xcess of these ratings can cause
permanent damage to the device. Functional
operation of the device at conditions beyond those
indicated in the operational sections of this data sheet
is not implied.
1.3 Pin Description
1.4 Recommended Operating Range
Note: Within the recommended oper ating r an ge , the
IC operates as described in the functional description.
1.5 Thermal Characteri stics
Parameter Symbol Ratings Unit
HV Voltage VHV600 V
VCC Supply Voltage VCC -0.3 to 40 V
VR Voltage VVR-0.3 to 5 V
ZCV Voltage VZC -0.3 to 5 V
CS Voltage VCS -0.3 to 5 V
GD Voltage VOUT -0.3 to 40 V
Maximum Current from ZCV Pin IZCmax 3mA
Junction Temperature TJ- 40 to +125 °C
Storage Temperature TSTG - 55 to +150 °C
ZCV
VR
CS
GD
GND
VCC
NC
HV
1
2
3
4
8
7
6
5
Pin# Name Description
1ZCVZero Crossing
2 VR Voltage Sense
3 CS Current Sense
4 GD Gate Drive Output
5 HV High Voltage Input
6 NC Not Connected
7VCC Controller Power Supply
8 GND Controller Ground
Parameter Symbol
Limit Values
Unit
Min Max
VCC Supply Voltage VCC 10.5 18 V
Junction Temperature TJ- 25 + 125 °C
Parameter Symbol Rating Units
Thermal Impedance
(Junction to Ambient) JA 125 °C/W
INTEGRATED CIRCUITS DIVISION
IX9908
4www.ixysic.com R02
1.6 Electrical Characteristics
TJ = - 25°C to +125°
1.6.1 Power Supply
Note: The electrical characterization involves the spread o f v alu es within the specified supply voltage and junction
temperature rang e TJ from - 25°C to +125°C. Typical v alues r epresent t he median values, which are related to 25°C.
If not otherwise stat ed, a supply voltage of VCC=18V is assumed.
1.6.2 Internal Voltage Reference
1.6.3 PWM Section
1.6.4 Current Sense
1.6.5 Soft Start
Parameter Conditions Symbol Minimum Typical Maximum Unit
VCC Charge Current VCC=0VICCcharge1 --35
mA
VCC=VCCon -0.2VICCcharge2 --35
Maximum Input Current of Startup Cell VCC=VCCon -0.2VIHV --35mA
Leakage Current of Startup Cell VHV=610V @ TJ=100°C IHV -0.250A
Supply Current in Normal Operation GD Low ICCNM -1.82.9mA
VCC Turn-On Threshold -VCCon 17 18 19 V
VCC Turn-Off Threshold -VCCoff 9.8 10.5 11.2 V
VCC Turn-On/Off Hysteresis -VCChys -7.5-V
Parameter Conditions Symbol Minimum Typical Maximum Unit
Internal Reference Voltage Measured at VR Pin, IVR=0 VVR 4.8 5 5.2 V
Parameter Conditions Symbol Minimum Typical Maximum Unit
VR Pull-Up Resistor - RVR 14 23 33 k
PWM-OP Gain - GPWM 2.95 3 3.05 -
Offset for Voltage Ramp - VPWM 0.63 0.7 0.77 V
Maximum On-Time in Normal Operation - tonMax 22 30 41 s
Parameter Conditions Symbol Minimum Typical Maximum Unit
Current Sense Threshold - VCSTH 0.97 1.03 1.09 V
Leading Edge Blanking Time - tBLKCS 200 330 460 ns
Parameter Conditions Symbol Minimum Typical Maximum Unit
Soft-Start Time - tSS 8.5 12 - ms
Soft-Start Time Step - tSS-S -3-ms
Internal Regulation Voltage at First Step - VSS1 -1.76- V
Internal Regulation Voltage Step at Soft Start - VSS-S -0.56- V
INTEGRATED CIRCUITS DIVISION
IX9908
R02 www.ixysic.com 5
1.6.6 Foldback Point Correction
1.6.7 Digital Zero Crossing
1.6.8 Protection
1.6.9 Gate Drive
Parameter Conditions Symbol Minimum Typical Maximum Unit
ZCV Current First Step Threshold - IZC_FS 0.35 0.5 0.621 mA
ZCV Current Last Step Threshold - IZC_LS 1.3 1.85 2.3 mA
CS Threshold Minimum IZC = 2.3 mA, VVR = 3.0VV
CSMF -0.66- V
Parameter Conditions Symbol Minimum Typical Maximum Unit
Zero Crossing Voltage - VZCCT 50 100 170 mV
Ringing Suppression Threshold - VZCRS -0.7-V
Minimum Ringing Suppression Time VZC > VZCRS tZCRS1 1.62 2.5 4.5 s
Maximum Ringing Suppression Time VZC < VZCRS tZCRS2 -42-s
Maximum Restart Time in Normal Operation - tOffMax 30 42 57.5 s
Parameter Conditions Symbol Minimum Typical Maximum Unit
VCC Overvoltage Threshold -VCCOVP 24 25 26 V
Output Overvoltage Detection Threshold at the ZCV Pin - VZCVOVP 3.55 3.7 3.87 V
Blanking Time for Output Overvoltage Protection -tZCVOVP -100-s
Threshold for Short Winding Protection -VCSSW 1.60 1.68 1.78 V
Blanking Time for Short Winding Protection - tCSSW -190-ns
Over-Temperature Protection - TJTSP -140-
°C
Parameter Conditions Symbol Minimum Typical Maximum Unit
Output Voltage at Logic Low VCC=18V, IOUT=10mA VGATElow --1V
Output Voltage at Logic High VCC=18V, IOUT= -10mA VGATEhigh 910-V
Output Voltage Active Shut-Down VCC=9V, IOUT=10mA VGATEasd --1V
Rise Time COUT=1nF, VGD=2V to 8Vtrise -117-ns
Fall Time COUT=1nF, VGD=8V to 2Vtfall -27-ns
INTEGRATED CIRCUITS DIVISION
IX9908
6www.ixysic.com R02
2. Functional Description
Figure 1. IX9908 Block Diagram
2.1 Internal Supply Voltage During Start-Up
The IX9908 integrat es a high v oltage startup cell. This
cell provides a const ant current to charg e the VCC
capacitor (CVCC) during the Power-up phase of
operation. Once the main input voltage is applied, a
rectified v oltage will be across CIN.
Figure 2. Start-Up
The start-up cell will sense this voltage, and source a
constant current of appro ximately 10 mA to CVCC. This
current will remain until VCC reaches VVCC_on or 18V
nominal. It will then be switched off, and a soft start
sequence will begin. VCC will then sag as the CVCC
capacitor supplies current to power the device, and is
not y et re ceiving energ y from th e auxiliary winding.
Once the output voltage is high enough t he auxiliary
winding will provide energy to CVCC and the VCC
v olt age will reach a constant value. This v alue
depends on the output load and t r an sformer
characteristics.
Ringing
Suppress
Blanking
Reference Voltage
Generator
Vcc Monitor
Over - Under
Voltage Lockout
High Voltage
Startup
Gate
Control
Control
Logic
Soft-Start
Control
Analog
Mux
LPF
Leading
Edge
Blanking
PFC
Leading
Edge
Blanking
Foldback
Sense Amp
Foldback
Correction
Over-Temp
Sensor
Leading
Edge
Blanking
ZCV
VR
CS
GND
GD
HV
Vcc
Vcc
Over-Voltage Protection
Shorted Winding Detection
VVCC_on
VVCC_off
tstartup
tstartup =VCC_on • CVCC
ICC_CHARGE
INTEGRATED CIRCUITS DIVISION
IX9908
R02 www.ixysic.com 7
2.2 Soft-Start
Once VCC reaches VVCC_on (typically 18V), t he device
will initiate a soft-st art sequence. This is intended to
minimize the electrical stresses on Q1, D OUT, DVCC,
and the transformer . The soft-start operates as sho wn
in Figure 3. The duration of this soft -start is 12mS
nominal and steps VCS, the current sense voltage, to
four values, as shown.
Figure 3. Soft-Start
2.3 Normal Ope r at io n
Because the IX9908 employs quasi-resonant
operation, its PWM switch-on is set by the z er o
crossing of the auxiliary winding voltage , and the
switch-off is set by the current sense voltage.
2.3.1 Zer o Cro ssing & Switch-On Determination
As the application schematic on Page 1 shows, the
v oltage from the auxiliary winding is connected to the
zero crossing pin, ZCV, through an RC network. This
network provides a dela y so that switch-on can occur
at voltage valley t hus enha ncing eff iciency. The
required time delay, t, should be approximately
one-fourth of the oscillation period (determined by
transformer primary inductor and drain-source
capacitance of Q1) minus the pr opagation delay from
zero-cross detect to Q1 switch-on, tdelay .
This time delay, t, should be matched by adjusting
the RC network.
After Q1 is turned off, its VDS wi ll s h ow some
oscillation. This will also show on the ZCV input. To
avoid a mis-triggered Q1 turn-on, a ringing
suppression circuit is implemented. The suppression
time has two values that depend on t he voltage at
ZCV. If VZCV is greater than 0.7V, then the time is
2.5S nominal. If VZCV is less than 0.7V, then the ti me
is 42S nominal. Turn-on of Q1 can not occur during
the suppression time, but does occur after a
zero-crossing is det ected. I n the case of a missed
zero-crossing, a maximum off-t ime is implemented.
After Q1 has been off for 42S nominal (toffMax), it is
turned back on.
2.3.2 Switch-Off Determination
In the application circuit, the primary current is sensed
by RCS. The voltage across this resistor, VCS, is
applied to the CS input of the device . It is processed
internally, and compared to the voltage at t he VR pin,
which is a scaled version of the rectified line voltage .
When the f ollo wing relation is true, the pow er switch,
Q1, is turned off.
Leading-edge bl anking is used to prevent a false
trigger caused by the voltage spike across RCS at the
moment of Q1 turn-on. This blanking t ime, tBLKCS , is
nominally 330nS. To prevent transf ormer saturatio n, a
maximum on-time circuit is implemented. Max on-time
for Q1 (GD=H) is 30S nominal.
Time (ms)
0123456789 101112131415
VCS_SST (V)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
Maximum Current (Sense Voltage)
During Soft-Start
t = tOSC - tdelay
4
tRC = CZCV (RZCV1 // RZCV2)
VCS 30.7V+VR
INTEGRATED CIRCUITS DIVISION
IX9908
8www.ixysic.com R02
2.3.3 Foldback Point Correction
When the AC line v olt age incre ases, the Q1 on-time
decreases, which increases the operating frequency.
As a result, with a const ant primary current limit, the
output power increases. To provide output power
regulation with respect to line voltage, the internal
foldback point correction circuit varies the VCS limit.
The VCS limit is decreased in response to an increase
in A C line voltage. The relationship between VCSMax
and VIN is shown in Figure 4.
Figure 4. VCSMax vs. VIN
The v ariation in AC line voltage is sensed by way of
the auxiliary winding and an internal clamp and
current sense circuit. When Q1 is on, a n egative
v olt age proportional to the line volta ge is coupled to
the auxiliary winding; the IC will hold the ZCV pin very
close to ground during this time. The line voltage is
thus sensed indirectly through the current in RZCV1.
This current is giv en b y:
The de vice uses IZCV to vary the VCS limit as shown in
Figure 4. The actual implementation is digital and is
shown below :
Figure 5. VCS vs. IZC
2.3.4 Protection Functions
The IX9908 provides comprehensive protection
f eat ures. The y are summariz ed in the t able below:
OUTPUT OVER-VOLTAGE
During the Q1 off-time the auxiliary winding voltage
(VAUX) will swing positive and in proportion to the
secondary voltage . VAUX is connected to ZCV through
a resistor divider. If the v olt age at ZCV exceeds a
preset threshold (VZCVOVP) f or longer than the blanking
time (tZCVOVP), then the IC is latched off.
SHORTED WINDING
If the voltage at CS exceeds a preset threshold
(VCSSW) during Q1 on time the device is latched off.
OVER-TEMPERATURE
If the die temperature exceeds 140°C, then the device
will enter the A uto-Restart Mode.
VCC OVER-VOLTAGE / UNDER-VOLTAGE
The IC continuously monitors the VCC v oltage. In case
of an ov er -v oltage, Q1 is turned off (GD=L) and VCC
will begin to f all. Once VCC goes below VVCC_off (10.5V
nominal), the startup circuit is activated, and begins to
charge CVCC. When VCC exceeds VVCC_on (18.0V
nominal), the device initiates a new soft-start. For an
under-v oltage the oper ation is t he same except that
the sequence begins with VCC < VVCC_off so GD=L and
the startup circuit is activ at ed. This operation
describes the Auto-Restart Mode.
During Latch-Off Mode, VCC also cycles between
VVCC_off and VVCC_on, but GD r emains low, and no
soft-start is initiated. The line voltage m ust be turned
off and on again to begin normal operation.
IZCV = VIN • Na
RZCV1 • Np
IZC (µA)
200 600 1000 1400 1800 2200
VCS (V)
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
1.05 VCS vs. IZC
Fault Condition Action Taken
Output Ove r-Voltage GD Latched Off
Shorted Winding GD Latched Off
Ove r-Temperature A uto-Restart Mode
VCC Over-Voltage Auto-Restart Mode
VCC Under-Voltage A uto-Restart Mode
INTEGRATED CIRCUITS DIVISION
IX9908
R02 www.ixysic.com 9
3. Manufacturing Information
3.1 Moisture Sensitivity
All plastic encapsulated semiconductor packages are susc eptible to moisture ingression. IXYS Integrated
Circuits Division classified all of its plastic encapsulated devices for moisture sensitivity according to the
latest v ersion of t he joint industry standard, IPC/JEDEC J-STD-020, in force at the time of product
e v alu ation. W e test all of our products to the maxim um conditions set forth in the standard, and guarantee
proper operation of our devices when handled according to the limitations and inf ormation in that standard as well as
to any limit ations set forth in the information or standards ref erenced below.
Failure to adhere to the warnings or limitations as estab l ished by the listed specifications could result in reduced
product performance, reduction of operable lif e, and/or reduction of overall reliability.
This product carries a Moisture Sensitivity Level (MSL) rating as shown belo w , and should be handled according to
the requirements of the latest version of the joint industry standard IPC/JEDEC J-STD-033.
3.2 ESD Sensitivi ty
This product is ESD Sensitive, and should be handled according to the industry standard
JESD-625.
3.3 Soldering Profile
This product has a maxim um body temperature and time rating f or lead-free reflo w processes as shown below. All
other guidelines of J-STD-020 m ust be observed.
3.4 Board Wash
IXYS Integr ated Circu it s Division recommends t he use of no-clean fl ux formulations. Ho wever, board washing to
remove flux residue is acceptable , a nd the use of a short drying bake may be necessary. Chlorine-based or
Fluorine-based solvents or flux es should not be used. Cleaning meth ods that emplo y ultrasonic energy should not be
used.
Device Moisture Sensitivity Level (MSL) Rating
IX9908N MSL 1
Device Maximum Temperature x Time
IX9908N 260°C for 30 seconds
INTEGRATED CIRCUITS DIVISION
IX9908
10 www.ixysic.com R02
3.5 Package Dimensions
3.6 Tape & Reel Dimensions
NOTES:
1. All dimensions are in mm (inches).
2. This package conforms to JEDEC Standard MS-012, Variation AA, Rev. F.
3. Dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed 0.15mm per end.
4. Dimension does not include interlead flash or protrusion. Interlead flash or protrusion shall not exceed 0.25mm per side.
5. Pin location tolerance = 0.10mm, pin tolerances are non-cumulative.
6. Dimensions in inches are calculated from mm, and are provided for convenience.
Recommended PCB Land Pattern
Dimensions
mm MIN - mm MAX
(inches MIN - inches MAX)
1.75 MAX
(0.069 MAX)
0.10 - 0.25
(0.004 - 0.010)
4.80 - 5.00
(0.189 - 0.197)
Note 3
Pin 1
0.31 - 0.51
(0.012 - 0.020)
x8
5.80 - 6.20
(0.228 - 0.244)
3.80 - 4.00
(0.150 - 0.157)
Note 4
1.27
(0.050)
5.40
(0.213) 1.55
(0.061)
0.60
(0.024)
1.25 MIN
(0.049 MIN)
0.40 - 1.27
(0.016 - 0.050)
0.10 - 0.25
(0.004 - 0.010)
0º - 8ºGauge Plane
Seating Plane
A
0.25 (0.010)
A
1.27
(0.05)
6x
Dimensions
mm
(inches)
NOTE: Tape dimensions not shown comply with JEDEC Standard EIA-481-2
Embossment
Embossed Carrier
Top Cover
Tape Thickness
0.102 MAX.
(0.004 MAX.)
330.2 DIA.
(13.00 DIA.)
K0= 2.10
(0.083)
W=12.00
(0.472)
B0=5.30
(0.209)
User Direction of Feed
A0=6.50
(0.256) P=8.00
(0.315)
For additional information please visit www.ixysic.com
IXYS Integrated Circuits Division makes no representations or warranties with respect to the accuracy or complet eness of th e contents of this publication and
reserves the right to make changes to specifications and product descriptions at any time wit hout notice. Neither circuit patent licenses or indemnity are expressed
or implied. Except as set forth in IXYS Integrated Circuits Division’s Standard Terms and Conditions of Sale, IXYS Integrated Circuits Division assumes no liability
whatsoever, and disclaims any express or implied w arranty relating to its products, including, but not limited to , the implied warranty of merch antability, fitness for a
particular purpose, or infringement of any intellectual property right.
The products described in this docu ment are not designed, intended, authorized, or warranted for use as components in systems intended for surgical implant into
the body, or in other applications intended to support or sustain life, or where malfunction of IXYS Integrated Circuits Division’s product may result in direct physical
harm, injury, or death to a person or severe property or environmental damage. IXYS Integrated Circuits Division reserves the right to discontin ue or make changes
to its products at any time without notice.
Specifications: DS-IX9 908-R02
© Copyright 2015, IXYS Integrated Circuits Division
All rights reserved. Printed in USA.
10/2/2015