MICROSEMI LX1686EIPW

LX1686E
®
TM
Digital Dimming CCFL Controller IC
P RODUCTION D ATA
KEY FEATURES
DESCRIPTION
ƒ
ƒ
ƒ
ƒ
Notebooks
Instrumentation Display
Desktop Computer Monitors
Low Ambient Light Displays
(used in Aircraft, Automobiles,
and Hand-Held Equipment)
ƒ Extremely High Efficiency From
3.3V to 5V Power Supplies
ƒ Lower Cost Than Conventional
Buck / Royer Inverter Topologies
ƒ Improved Lamp Strike Capability
ƒ Improved Over-Voltage Control
PRODUCT HIGHLIGHT
5
Power Used (Watts)
APPLICATIONS
BENEFITS
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
Protected by U.S. Patents 5,615,093; 5,923,129; 5,930,121; 6,198,234; Patents Pending
Standard Analog
Dimming Inverter
4
ƒ RangeMAX™ Wide Range
Dimming (>100:1)
ƒ Synchronizable to Display Video
Frequency
ƒ High Voltage Feedback Loop
Directly Controls Maximum Open
Lamp
ƒ Micro-Amp Sleep Mode
ƒ User Programmable Fixed
Frequency Operation
ƒ Under-Voltage Lockout Feature
With Power-Up Reset
ƒ Built-In Soft-Start Feature
ƒ Operates With 3.3V or 5V power
Supplies
ƒ 100mA Output Drive Capability
WWW . Microsemi .C OM
Safety and reliability features include
a new dual feedback control loop that
permits regulation of maximum lamp
strike voltage as well as lamp current.
Regulating maximum lamp voltage
permits the designer to provide for
ample worst case lamp strike voltage
while at the same time conservatively
limit maximum open circuit voltage.
An innovative new strike voltage
generation technique enables the
module designer to optimize high
voltage
transformer
design
for
maximum operating efficiency with no
power dissipating overhead to guarantee
strike capability
Direct drive topology is a nonresonant, oscillator-controlled PWM
regulation method.
The LX1686E
allows a wide choice of fixed operating
frequencies to match lamp current
frequency to the lamp’s most efficient
operating point, and to minimize high
frequency interference.
The LX1686E Backlight Controller
IC provides all the control functions
needed to implement Microsemi’s
direct drive inverters used to operate
cold cathode fluorescent lamps
(CCFL’s). This IC can be used to
control single or multiple-lamp
configurations. CCFL’s are used for
back or edge lighting of liquid crystal
flat panel displays (LCD’s) and
typically find application in notebook
computers, web browsers, automotive
and industrial instrumentation, and
entertainment systems.
The LX1686E includes a PWM
controlled lamp current burst circuit
that can provide a > 100:1 dimming
range from a simple zero to 2.5V
potentiometer input.
The PWM
dimming burst rate is easily
synchronized to the LCD panel’s frame
rate to prevent interference from
optical beat frequencies.
SHEET
3
Microsemi's
RangeMAX
2
1
0
0
30
45
60
75
90
LX1686E
Light emitted by a CCFL is proportional to the current flowing through it.
There are two ways to control the current: by adjusting the amplitude of a
continuous AC current; or, as with RangeMAX technology, by varying the
amount of time a burst of full current is present. RangeMAX technology
frees the backlight inverter module designer to operate in a lower
brightness and lower power consumption mode than is possible with
conventional amplitude control methods.
105
Light Output (Nits)
PACKAGE ORDER INFO
TA (°C)
PW
Plastic TSSOP
24-PIN
RoHS compliant / Pb-free
0 to 85
-40 to 85
Copyright © 2004
Rev. 1.1, 2006-02-27
LX1686ECPW
LX1686EIPW
Note: Available in Tape & Reel. Append the
letters “TR” to the part number. (i.e.
LX1686ECPW-TR)
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
LX1686E
®
TM
Digital Dimming CCFL Controller IC
P RODUCTION D ATA
ABSOLUTE MAXIMUM RATINGS
SHEET
PACKAGE PIN OUT
AOUT
VSS_P
VSS
AFD_C
RAMP_C
RAMP_R
FVERT
PD_CR
VCO_C
BRT_POS
BRITE
DIG_DIM
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
BOUT
VDD_P
VDD
TRI_C
OLSNS
ISNS
ICOMP
VSNS
VCOMP
BRT
I_R
ENABLE
PW PACKAGE
Note:
Exceeding these ratings could cause damage to the device. All voltages are with respect to
Ground. Currents are positive into, negative out of specified terminal
(Top View)
WWW . Microsemi .C OM
Supply Voltage (VDD, VDD_P) .................................................................................. 6.5V
Digital Inputs ........................................................................................ -0.3 to VDD +0.5V
Analog Inputs........................................................................................ -0.3 to VDD +0.5V
Digital Outputs...................................................................................... -0.3 to VDD +0.5V
Analog Outputs ..................................................................................... -0.3 to VDD +0.5V
Maximum Operating Junction Temperature ..............................................................150°C
Storage Temperature ................................................................................... -65°C to 150°C
RoHS / Pb-free Peak Package Solder Reflow Temperature
(40 second maximum exposure)....................................................................260°C (+0, -5)
RoHS / Pb-free 100% Matte Tin lead Finish
THERMAL DATA
PW
PACKAGE
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
100°C/W
Junction Temperature Calculation: TJ = TA + (PD x θJA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
PACKAGE DATA
Copyright © 2004
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
LX1686E
®
TM
Digital Dimming CCFL Controller IC
P RODUCTION D ATA
SHEET
PIN NAME
DESCRIPTION
AOUT
Output driver A, typical 10K pull down resistor to VSS_P.
VSS_P
Power ground for output drivers only.
VSS
AFD_C
Signal ground.
Connects to an external capacitor, CAFD. Forcing to ground or VDD will make the VCO oscillate at approximately
50% of the maximum VCO frequency. Forcing to VDD/2 will make the VCO oscillate at 2x the FVERT frequency.
RAMP_C
Connects to external capacitor CRAMP for setting Direct Drive PWM operating frequency.
RAMP_R
Connects to external resistor RRAMP for setting Direct Drive PWM operating frequency.
FVERT
Vertical frequency reference digital input. Has internal pull down.
PD_CR
Phase Detector Filter. Part of phase lock loop. Connects to external capacitor and resistor network.
VCO_C
Connects to external capacitor CVCO
BRT_POS
BRITE
Brightness control polarity. Has internal pull up. Leave open or pull up to VDD for dimming brightness
proportional to BRITE voltage, connect to ground for brightness inversely proportional to BRITE voltage.
Analog voltage input for brightness control.
DIG_DIM
Digital Dimming Enable internal pull up. Leave open or pull up to VDD for operating in digital dimming mode.
Connect to ground for analog dimming mode.
ENABLE
Chip Enable internal pull up. High enables the chip. Low disables.
I_R
Current Reference Resistor. External resistor to ground (Ri) determines internal capacitor CICOMP.
BRT
Current Error Amplifier non-inverting input
VCOMP
Voltage Error Amplifier output. Connects to external frequency compensation capacitor CVCOMP. Controls softstart timing.
VSNS
Voltage Error Amplifier inverting input.
ICOMP
Current Error Amplifier output. Connects to external frequency compensation capacitor CICOMP.
ISNS
Current Error Amplifier inverting Input.
Open Lamp Sense Input.
TRI_C
Connects to external capacitor CTRI for setting strike Frequency ramp slope.
VDD
VDD_P
Dedicated VDD for output buffers only.
BOUT
Output Driver B typical 10K pull down resistor to VSS_P.
Copyright © 2004
Rev. 1.1, 2006-02-27
PACKAGE DATA
OLSNS
VDD
WWW . Microsemi .C OM
FUNCTIONAL PIN DESCRIPTION
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
LX1686E
®
TM
Digital Dimming CCFL Controller IC
P RODUCTION D ATA
SHEET
Unless otherwise specified, the following specifications apply over the operating ambient temperature -0°C ≤ TA ≤ 85°C for the LX1686E
CPW and -40°C ≤ TA ≤ 85°C for the LX1686E IPW except where otherwise noted. Test conditions: VDD = VDD_P = 3.0 to 5.5V, Ri =
40kΩ, CVCO = 0.01µF, CAFD = 0.22µF, CTRI = 0.83µF, CRAMP = 208pF, RRAMP = 15kΩ, CPD = 0.22µF, CPDB = 0.047µF, RPD = 110kΩ
Parameter
Power Supply Voltage
Operating Current
Power Supply Voltage
Output Buffer Operating Current
UVLO Threshold
UVLO Hysteresis
`
Test Conditions
VDD
IDD
VDD_P
IDD_P
VTH_UVLO
VH_UVLO
VDD = VDD_P
VDD = VDD_P = 5V
VDD = VDD_P
Volsns = VDD = VDD_P = 5V, CA = CB = 1000pF
DIRECT DRIVE RAMP BLOCK
Triangular Wave Generator Analog
VP_TRI
Output Peak Voltage
Triangular Wave Generator Analog
VV_TRI
Output Valley Voltage
Triangular Wave Generator Oscillation
F_TRI
Frequency
Triangular Wave Generator Oscillation
ICHG_TRI
Charge Current
Triangular Wave Generator Oscillation
IDISCHG_TRI
Discharge Current
Ramp Generator Analog Output Peak
VP_RAMP
Voltage
Ramp Generator Analog Output Valley
VV_RAMP
Voltage
Ramp Frequency Change Threshold
Ramp Generator Oscillation
Frequency – Nominal
Ramp Generator Oscillation
Frequency – Maximum
OLSNS Threshold Voltage
OLSNS Hysteresis
OLSNS-to-ICOMP Propagation Delay
`
Symbol
Auto-Frequency Detection Response
BRITE Voltage Range
Full-Brightness Brite Input Voltage
Full-Darkness Brite Input Voltage
Copyright © 2004
Rev. 1.1, 2006-02-27
LX1686E
Typ
Max
3
160
V
mA
V
mA
V
mV
2.25
V
0.75
V
10
Hz
5
3
2
2.7
5.5
10
5.5
10
2.9
Units
Tri_c = 0V
-2.3
-2.55
-2.9
µA
Tri_c = 3V
2.3
2.65
2.9
µA
V
0.75
V
1.35
1.35
1.6
1.6
1.65
1.85
V
V
0 < VTRI_C < 1.35V
84
100
116
KHz
FRAMP_HI
VTRI_C = 2.25V
170
200
256
KHz
VTH_OLSNS
VH_OLSNS
TD_OLSNS
VDD = 3V
VDD = 3V
GBD
200
300
45
1
400
mV
mV
µS
200
Hz
VTH_RAMP_R
FRAMP
VDD = 3V
VDD = 5.5V
2.25
45
FR_FVERT
VTH_FVERT
RFVERT
VP_VCO
VV_VCO
FR_VCO_I_SRC
FX_VCO
TD_AFD
Design Reference Only
Design Reference Only
VPD_CR = 3V, VDD = 3V
AFC_C = 0V, CVCO = 0.01µF
-6.4
FVERT Frequency is 200Hz, VDD = 3V
VR_BRITE
VBRITE_FULL VBRT_POS = VDD or float; BRITE = 2.5V
VBRT_POS = 0V, BRITE = 0.5V
VBRITE_DARK VBRT_POS = VDD or float, BRITE = 0.5V
VBRT_POS = 0V, BRITE = 2.5V
VDD/2
50
2.5
0.65
-5.6
250
-5.1
1000
0
2.25
2.25
0.35
0.35
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
2.5
2.5
0.5
0.5
V
kΩ
V
V
µA
Hz
ms
VDD
2.65
2.65
0.65
0.65
V
V
V
V
V
Page 4
ELECTRICALS
DIGITAL DIMMER BLOCK
FVERT Input Frequency Capture
Range
FVERT Logic Threshold
FVERT Input Resistance
VCO Analog Output Peak Voltage
VCO Analog Output Valley Voltage
VCO Forced Source Current
Forced VCO Oscillation Frequency
Min
WWW . Microsemi .C OM
ELECTRICAL CHARACTERISTICS
LX1686E
®
TM
Digital Dimming CCFL Controller IC
P RODUCTION D ATA
SHEET
Unless otherwise specified, the following specifications apply over the operating ambient temperature -0°C ≤ TA ≤ 85°C for the LX1686E
CPW and -40°C ≤ TA ≤ 85°C for the LX1686E IPW except where otherwise noted. Test conditions: VDD = VDD_P = 3.0 to 5.5V, Ri =
40kΩ, CVCO = 0.01µF, CAFD = 0.22µF, CTRI = 0.83µF, CRAMP = 208pF, RRAMP = 15kΩ, CPD = 0.22µF, CPDB = 0.047µF, RPD = 110kΩ
Parameter
`
`
Min
LX1686E
Typ
Max
Units
TD_BRITE
300
VDD/2
VDD/2
ns
V
V
DIRECT DRIVE PWM BLOCK
ISNS Threshold Voltage Range
VAMP Transconductance
VAMP Output Source Current
VAMP Output Sink Current
VAMP Output Voltage Range
VSNS Threshold Voltage
VCOMP Discharge Current
IAMP Transconductance
IAMP Output Source Current
IAMP Output Sink Current
IAMP Output Voltage Range
VCMP Input Offset Voltage
VCOMP-to-Output Propagation Delay
ICMP Input Offset Voltage
ICOMP-to-Output Propagation Delay
`
Test Conditions
DIGITAL DIMMING BLOCK (CONTINUED)
BRITE-to-ICOMP Propagation Delay
BRITE_POS Logic Threshold
DIG-DIM Logic Threshold
`
Symbol
VR_ISNS
GM_VAMP
IS_VAMP
ISK_VAMP
VR_VAMP
VTH_VSNS
ID_VCOMP
GM_IAMP
IS_IAMP
ISK_IAMP
VR_IAMP
VOS_VCMP
TD_VCOMP
VOS_ICMP
TD_ICOMP
DIG_DIM = VDD
VCOMP = 1.25V
VCOMP = 1.5V
VCOMP = 1.5V
VCOMP = VSNS
VCOMP = 0.5V, VDD = 3V
BRITE = 0.5 – 2.6V
ICOMP = 1.5V, VDD = 3V
ICOMP = 1.5V, VDD = 3V
VCOMP = 1.25V, VDD = 3V
VDD = 3V
ICOMP = 0.5 to 2.25V, VDD = 3V
BRITE = 1.25V, RAMP_C = 2V, VDD = 3V
0
10
15
0
1.12
0.8
70
-15
20
0
-10
-10
2.5
400
50
70
1.25
1.5
200
-40
60
3
250
3
1100
110
120
VDD
1.38
10
700
-80
100
VDD
10
500
10
WWW . Microsemi .C OM
ELECTRICAL CHARACTERISTICS
V
µmho
µA
µA
V
V
mA
µmho
µA
µA
V
mV
ns
mV
ns
OUTPUT BUFFER BLOCK
Output Sink Current
ISK_OUTBUF
Output Source Current
ISOUT_BUF
AOUT, BOUT = 1V, VDD = 3V
AOUT, BOUT = VDD = 3V
AOUT, BOUT = 0V, VDD = 3V
AOUT, BOUT = 2V, VDD = 3V
20
25
-35
-20
200
300
-300
-200
mA
mA
mA
mA
1.02
V
µA
V
V
mV
mV
BIAS CONTROL BLOCK
Voltage at Pin I_R
Pin I_R Maximum Source Current
ENABLE Logic Threshold – 3V
ENABLE Logic Threshold – 5.5V
ENABLE Threshold Hysteresis – 3V
ENABLE Threshold Hysteresis – 5.5V
VIR
IMAX_IR
VEN3V
VEN5.5
VH_EN3
VH_EN5.5
.975
Design Reference Only
VDD = 3V
VDD = 5.5V
0.8
0.8
50
1.4
1.4
20
300
2.0
2.0
ELECTRICALS
Copyright © 2004
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
LX1686E
®
TM
Digital Dimming CCFL Controller IC
P RODUCTION D ATA
SHEET
WWW . Microsemi .C OM
BLOCK DIAGRAM
CICOMP
CVCOMP
BRT ISNS VSNS
Dimming Control
Output
Drivers
ICOMP
VCOMP
PD_CR
PWM
Controllers
RPD
CPDN
Voltage
Error
Amp
-
Phase
Detector
CPD
+
VCO
VAMP
1.25V
FVERT
IAMP
-
ICOMP
-
+
Current
Error Amp
AFD_C
0.5 - 2.5V
CAFD
VCO_C
+
Q
Current
Comparator
CLK
OUT
2.5V
0V
-
A
Q
+
VCOMP
VDD_P
AOUT
BOUT
B
RAMP_DOUT
Auto Freq.
Detect
-
Output
Steering
Logic
Voltage
Comparator
VSS_P
Bias Generator,
UVLO, and VREF
VDD
ENA
+
CVCO
PWR_GD
Burst
Comparator
2.50V
ENABLE
VDD_SW
I_R
BRITE
Ri
50k
VSS
50k
ENA
1.5V
Triangle
Wave Gen.
VDD VDD
+
300mV
255mV
Ignite
Open Lamp
Comparator
0-3V
BRT_POS
BLOCK DIAGRAM
DIG_DIM
PWM Ramp
Generator
RAMP_C
CRAMP
RAMP_R
RRAMP2
TRI_C OLSNS
RRAMP1
CTRI
VDD
Copyright © 2004
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 6
LX1686E
®
TM
Digital Dimming CCFL Controller IC
P RODUCTION D ATA
SHEET
PW
WWW . Microsemi .C OM
PACKAGE DIMENSIONS
24-Pin Thin Small Shrink Outline (TSSOP)
Dim
3 21
P
E
F
D
A H
SEATING PLANE
B
G
L
C
M
A
B
C
D
E
F
G
H
L
M
P
*LC
MILLIMETERS
MIN
MAX
0.85
0.95
0.19
0.30
0.09
0.20
7.70
7.90
4.30
4.50
0.65 BSC
0.05
0.15
–
1.10
0.50
0.75
0°
8°
6.25
6.55
–
0.10
INCHES
MIN
MAX
0.033
0.037
0.007
0.012
0.0035 0.008
0.303
0.311
0.169
0.177
0.025 BSC
0.002
0.005
–
.0433
0.020
0.030
0°
8°
0.246
0.256
–
0.004
* Lead Coplanarity
Note:
1. Dimensions do not include mold flash or protrusions;
these shall not exceed 0.155mm(.006”) on any side.
Lead dimension shall not include solder coverage.
MECHANICALS
Copyright © 2004
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 7
LX1686E
TM
®
Digital Dimming CCFL Controller IC
P RODUCTION D ATA
SHEET
WWW . Microsemi .C OM
NOTES
NOTES
PRODUCTION DATA – Information contained in this document is proprietary to
Microsemi and is current as of publication date. This document may not be modified in
any way without the express written consent of Microsemi. Product processing does not
necessarily include testing of all parameters. Microsemi reserves the right to change the
configuration and performance of the product and to discontinue product at any time.
Copyright © 2004
Rev. 1.1, 2006-02-27
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 8