Rev 1; 8/07
Single-Channel Automotive CCFL Controller
General Description
The DS3881 is a single-channel cold-cathode fluores-
cent lamp (CCFL) controller for automotive applications
that provides up to 300:1 dimming. It is ideal for driving
CCFLs used to backlight liquid crystal displays (LCDs)
in navigation and infotainment applications and for dri-
ving CCFLs used to backlight instrument clusters. The
DS3881 is also appropriate for use in marine and avia-
tion applications.
The DS3881 features EMI suppression functionality and
provides a lamp current overdrive mode for rapid lamp
heating in cold weather conditions. The DS3881 sup-
ports a single lamp configuration with fully independent
lamp control and minimal external components.
Multiple DS3881 controllers can be cascaded to sup-
port applications requiring more than one lamp. Control
of the DS3881, after initial programming setup, can be
completely achieved through I
2
C software communica-
tion. Many DS3881 functions are also pin-controllable if
software control is not desired.
Features
♦
Single-Channel CCFL Controller for Backlighting
LCD Panels and Instrument Clusters in
Automotive Navigation/Infotainment Applications
♦
Minimal External Components Required
♦
I
2
C Interface
♦
Per-Channel Lamp-Fault Monitoring for Lamp-
Open, Lamp-Overcurrent, Failure to Strike, and
Overvoltage Conditions
♦
Status Register Reports Fault Conditions
♦
Accurate (±5%) Independent On-Board Oscillators
for Lamp Frequency (40kHz to 100kHz) and DPWM
Burst-Dimming Frequency (22.5Hz to 440Hz)
♦
Lamp and DPWM Frequencies can be
Synchronized with External Sources to Reduce
Visual LCD Artifacts in Video Applications
♦
Spread-Spectrum Lamp Clock Reduces EMI
♦
Lamp Frequency can be Stepped Up or Down to
Move EMI Spurs Out of Band
♦
Lamp Current Overdrive Mode with Automatic
Turn-Off Quickly Warms Lamp in Cold
Temperatures
♦
Analog or Digital Brightness Control
♦
300:1 Dimming Range Possible Using the Digital
Brightness Control Option
♦
Programmable Soft-Start Minimizes Audible
Transformer Noise
♦
On-Board Nonvolatile (NV) Memory Allows Device
Customization
♦
8-Byte NV User Memory for Storage of Serial
Numbers and Date Codes
♦
Low-Power Standby Mode
♦
4.75V to 5.25V Single-Supply Operation
♦
Temperature Range: -40°C to +105°C
♦
24-Pin TSSOP Package
DS3881
Applications
Automotive LCDs
Instrument Clusters
Marine and Aviation LCDs
Pin Configuration
TOP VIEW
A0 1
SDA 2
SCL 3
LSYNC 4
LOSC 5
BRIGHT 6
PSYNC 7
POSC 8
A1 9
GND_S 10
SVML 11
SVMH 12
24 FAULT
23 GB1
22 GA1
21 V
CC
DS3881
20 PDN
19 LCO
18 GND
17 STEP
16 N.C.
15 OVD1
14 LCM1
13 V
CC
Ordering Information
PART
DS3881E+
DS3881E+T&R
TEMP RANGE
-40°C to +105°C
-40°C to +105°C
PIN-PACKAGE
24 TSSOP (173 mils)
24 TSSOP (173 mils)
+Denotes
lead-free package.
TSSOP
Typical Operating Circuit appears at end of data sheet.
______________________________________________
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.
Single-Channel Automotive CCFL Controller
DS3881
ABSOLUTE MAXIMUM RATINGS
Voltage Range on V
CC
, SDA, and
SCL Relative to Ground.....................................-0.5V to +6.0V
Voltage Range on Leads Other than V
CC
, SDA, and
SCL ......................-0.5V to (V
CC
+ 0.5V), not to exceed +6.0V
Operating Temperature Range .........................-40°C to +105°C
EEPROM Programming Temperature Range .........0°C to +85°C
Storage Temperature Range .............................-55°C to +125°C
Soldering Temperature...................See J-STD-020 Specification
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation 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.
RECOMMENDED OPERATING CONDITIONS
(T
A
= -40°C to +105°C)
PARAMETER
Supply Voltage
Input Logic 1
Input Logic 0
SVML/H Voltage Range
BRIGHT Voltage Range
LCM Voltage Range
OVD Voltage Range
Gate-Driver Output Charge
Loading
SYMBOL
V
CC
V
IH
V
IL
V
SVM
V
BRIGHT
V
LCM
V
OVD
Q
G
(Note 2)
(Note 2)
(Note 1)
CONDITIONS
MIN
4.75
2.0
-0.3
-0.3
-0.3
-0.3
-0.3
TYP
MAX
5.25
V
CC
+ 0.3
1.0
V
CC
+
0.3
V
CC
+
0.3
V
CC
+
0.3
V
CC
+
0.3
20
UNITS
V
V
V
V
V
V
V
nC
ELECTRICAL CHARACTERISTICS
(V
CC
= +4.75V to +5.25V, T
A
= -40°C to +105°C.)
PARAMETER
Supply Current
Input Leakage (Digital Pins)
Power-Down Current
Output Leakage (SDA,
FAULT)
Low-Level Output Voltage
(LSYNC, PSYNC)
Low-Level Output Voltage
(SDA,
FAULT)
Low-Level Output Voltage
(GA1, GB1)
High-Level Output Voltage
(LSYNC, PSYNC)
SYMBOL
I
CC
I
L
I
PDN
I
LO
V
OL
V
OL1
V
OL2
V
OL3
V
OH
High impedance
I
OL
= 4mA
I
OL1
= 3mA
I
OL2
= 6mA
I
OL3
= 4mA
I
OH
= -1mA
2.4
-1.0
CONDITIONS
G
A
, G
B
loaded with 600pF
-1.0
MIN
TYP
12
+1.0
1
+1.0
0.4
0.4
0.6
0.4
MAX
UNITS
mA
µA
mA
µA
V
V
V
V
2
_____________________________________________________________________
Single-Channel Automotive CCFL Controller
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +4.75V to +5.25V, T
A
= -40°C to +105°C.)
PARAMETER
High-Level Output Voltage
(GA, GB)
UVLO Threshold: V
CC
Rising
UVLO Threshold: V
CC
Falling
UVLO Hysteresis
SVML/H Threshold: Rising
SVML/H Threshold: Falling
LCM and OVD DC Bias Voltage
LCM and OVD Input Resistance
Lamp Off Threshold
Lamp Over Current
Lamp Regulation Threshold
OVD Threshold
Lamp Frequency Source
Frequency Range
Lamp Frequency Source
Frequency Tolerance
Lamp Frequency Receiver
Frequency Range
Lamp Frequency Receiver
Duty Cycle
DPWM Source (Resistor)
Frequency Range
DPWM Source (Resistor)
Frequency Tolerance
DPWM Source (Ext. Clk)
Frequency Range
DPWM Source (Ext. Clk)
Duty Cycle
DPWM Receiver
Min Pulse Width
BRIGHT Voltage: Minimum
Brightness
BRIGHT Voltage: Maximum
Brightness
Gate Driver Output Rise/Fall Time
GA1 and GB1 Duty Cycle
SYMBOL
V
OH1
V
UVLOR
V
UVLOF
V
UVLOH
V
SVMR
V
SVMF
V
DCB
R
DCB
V
LOT
V
LOC
V
LRT
V
OVDT
f
LFS:OSC
f
LFS:TOL
f
LFR:OSC
f
LFR:DUTY
f
DSR:OSC
f
DSR:TOL
f
DSE:OSC
f
DFE:DUTY
t
DR:MIN
V
BMIN
V
BMAX
t
R
/ t
F
C
L
= 600pF
(Note 6)
2.0
100
44
(Note 5)
POSC resistor ±2% over temperature
LOSC resistor ±2% over temperature
(Note 3)
(Note 3)
(Notes 3, 4)
(Note 3)
0.22
2.2
0.9
0.9
40
-5
40
40
22.5
-5
22.5
40
25
0.5
2.03
1.95
3.7
200
2.08
2.02
1.1
50
0.25
2.5
1.0
1.0
0.28
2.8
1.1
1.1
100
+5
100
60
440.0
+5
440.0
60
2.15
2.07
I
OH1
= -1mA
CONDITIONS
MIN
V
CC
-
0.4
4.3
TYP
MAX
UNITS
V
V
V
mV
V
V
V
kΩ
V
V
V
V
kHz
%
kHz
%
Hz
%
Hz
%
µs
V
V
ns
%
DS3881
_____________________________________________________________________
3
Single-Channel Automotive CCFL Controller
DS3881
I
2
C AC ELECTRICAL CHARACTERISTICS (See Figure 9)
(V
CC
= +4.75V to +5.25V, T
A
= -40°C to +105°C, timing referenced to V
IL(MAX)
and V
IH(MIN)
.)
PARAMETER
SCL Clock Frequency
Bus Free Time Between Stop and
Start Conditions
Hold Time (Repeated) Start
Condition
Low Period of SCL
High Period of SCL
Data Hold Time
Data Setup Time
Start Setup Time
SDA and SCL Rise Time
SDA and SCL Fall Time
Stop Setup Time
SDA and SCL Capacitive
Loading
EEPROM Write Time
SYMBOL
f
SCL
t
BUF
t
HD:STA
t
LOW
t
HIGH
t
HD:DAT
t
SU:DAT
t
SU:STA
t
R
t
F
t
SU:STO
C
B
t
W
(Note 9)
(Note 10)
20
(Note 9)
(Note 9)
(Note 8)
(Note 7)
CONDITIONS
MIN
0
1.3
0.6
1.3
0.6
0
100
0.6
20+
0.1C
B
20+
0.1C
B
0.6
400
30
300
300
0.9
TYP
MAX
400
UNITS
kHz
µs
µs
µs
µs
µs
ns
µs
ns
ns
µs
pF
ms
NONVOLATILE MEMORY CHARACTERISTICS
(V
CC
= +4.75V to +5.25V)
PARAMETER
EEPROM Write Cycles
SYMBOL
CONDITIONS
+85°C (Note 11)
MIN
30,000
TYP
MAX
UNITS
Note 1:
All voltages are referenced to ground unless otherwise noted. Currents into the IC are positive, out of the IC negative.
Note 2:
During fault conditions, the AC-coupled feedback values are allowed to be below the absolute max rating of the LCM1 or
OVD1 pin for up to 1 second.
Note 3:
Voltage with respect to V
DCB
.
Note 4:
Lamp overdrive and analog dimming (based on reduction of lamp current) are disabled.
Note 5:
This is the minimum pulse width guaranteed to generate an output burst, which will generate the DS3881’s minimum burst
duty cycle. This duty cycle may be greater than the duty cycle of the PSYNC input. Once the duty cycle of the PSYNC input
is greater than the DS3881’s minimum duty cycle, the output’s duty cycle will track the PSYNC’s duty cycle. Leaving
PSYNC low (0% duty cycle) disables the GA1 and GB1 outputs in DPWM receiver mode.
Note 6:
This is the maximum lamp frequency duty cycle that will be generated at GA1 or GB1 outputs with spread-spectrum modu-
lation disabled.
Note 7:
I
2
C interface timing shown is for fast-mode (400kHz) operation. This device is also backward compatible with I
2
C standard-
mode timing.
Note 8:
After this period, the first clock pulse can be generated.
Note 9:
C
B
—total capacitance allowed on one bus line in picofarads.
Note 10:
EEPROM write time applies to all the EEPROM memory. EEPROM write begins after a stop condition occurs.
Note 11:
Guaranteed by design.
4
_____________________________________________________________________
Single-Channel Automotive CCFL Controller
Typical Operating Characteristics
(V
CC
= 5.0V, T
A
= +25°C, unless otherwise noted.)
ACTIVE SUPPLY CURRENT
vs. SUPPLY VOLTAGE
DS3881 toc01
DS3881
ACTIVE SUPPLY CURRENT
vs. TEMPERATURE
7.0
V
CC
= 5.0V
SUPPLY CURRENT (mA)
6.5
V
CC
= 4.75V
V
CC
= 5.25V
DS3881 toc02
INTERNAL FREQUENCY CHANGE
vs. TEMPERATURE
0.8
FREQUENCY CHANGE (%)
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
105
-40.0
32.5
TEMPERATURE (°C)
105
LAMP FREQUENCY
DPWM FREQUENCY
DS3881 toc03
7.0
DPWM = 100%
6.5
SUPPLY CURRENT (mA)
6.0
5.5
5.0
4.5
4.0
GATE Q
C
= 3.5nC
f
LF:OSC
= 64kHz
SVML< 2V
DPWM = 10%
DPWM = 50%
1.0
6.0
5.5
f
LF:OSC
= 64kHz
5.0
GATE Q
C
= 3.5nC
-40.0
DPWM = 100%
32.5
TEMPERATURE (°C)
4.75 4.80 4.85 4.90 4.95 5.00 5.05 5.10 5.15 5.20 5.25
SUPPLY VOLTAGE (V)
TYPICAL OPERATION AT 11V
DS3881 toc04
TYPICAL OPERATION AT 13V
DS3881 toc05
TYPICAL OPERATION AT 16V
DS3881 toc06
10μs
5.0V
G
A
10μs
5.0V
G
B
10μs
2.00V LCM
10μs
2.00V OVD
10μs
5.0V
G
A
10μs
5.0V
G
B
10μs
5.0V
G
A
10μs
5.0V
G
B
10μs
2.00V LCM
10μs
2.00V OVD
10μs
2.00V LCM
10μs
2.00V OVD
TYPICAL STARTUP WITH SVM
DS3881 toc07
BURST DIMMING AT 150Hz AND 10%
DS3881 toc08
BURST DIMMING AT 150Hz AND 50%
DS3881 toc09
2ms
5.0V SVML
2ms
5.0V
G
B
1ms
5.0V
G
A
1ms
5.0V
G
B
1ms
5.0V
G
A
1ms
5.0V
G
B
1ms
2.00V LCM
1ms
2.00V OVD
2ms
2.00V LCM
2ms
2.00V OVD
1ms
2.00V LCM
1ms
2.00V OVD
_____________________________________________________________________
5
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