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 communi-
cation. Many DS3881 functions are also pin-controllable
if software control is not desired.
Applications
Automotive LCDs
Instrument Clusters
Marine and Aviation LCDs
Features
o Single-Channel CCFL Controller for Backlighting
LCD Panels and Instrument Clusters in
Automotive Navigation/Infotainment Applications
o Minimal External Components Required
o I
2
C Interface
o Per-Channel Lamp-Fault Monitoring for Lamp-
Open, Lamp-Overcurrent, Failure to Strike, and
Overvoltage Conditions
o Status Register Reports Fault Conditions
o Accurate (5%) Independent On-Board Oscillators
for Lamp Frequency (40kHz to 100kHz) and DPWM
Burst-Dimming Frequency (22.5Hz to 440Hz)
o Lamp and DPWM Frequencies can be
Synchronized with External Sources to Reduce
Visual LCD Artifacts in Video Applications
o Spread-Spectrum Lamp Clock Reduces EMI
o Lamp Frequency can be Stepped Up or Down to
Move EMI Spurs Out of Band
o Lamp Current Overdrive Mode with Automatic
Turn-Off Quickly Warms Lamp in Cold
Temperatures
o Analog or Digital Brightness Control
o 300:1 Dimming Range Possible Using the Digital
Brightness Control Option
o Programmable Soft-Start Minimizes Audible
Transformer Noise
o On-Board Nonvolatile (NV) Memory Allows Device
Customization
o 8-Byte NV User Memory for Storage of Serial
Numbers and Date Codes
o Low-Power Standby Mode
o 4.75V to 5.25V Single-Supply Operation
o Temperature Range: -40C to +105C
o 24-Pin TSSOP Package
DS3881
Single-Channel Automotive CCFL Controller
______________________________________________ Maxim Integrated Products
1
24
23
22
1
2
3
4
5
6
7
GB1
GA1
SCL
SDA
A0
FAULT
TOP VIEW
V
CC
PDN
LCO
BRIGHT
LOSC
21
8
GND
PSYNC
20
9
STEP
POSC
19
10
N.C.
A1
18
11
OVD1
GND_S
17
12
LCM1
SVML
16
13
SVMH
15
14
V
CC
LSYNC
TSSOP
DS3881
Pin Configuration
Rev 0; 3/06
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
+Denotes lead-free package.
Ordering Information
Typical Operating Circuit appears at end of data sheet.
PART
TEMP RANGE
PIN-PACKAGE
DS3881E+
-40C to +105C
24 TSSOP (173 mils)
DS3881E+T&R
-40C to +105C
24 TSSOP (173 mils)
*Purchase of I
2
C components from Maxim Integrated Products, Inc., or one of its sublicensed Associated Companies, conveys a
license under the Philips I
2
C Patent Rights to use these components in an I
2
C system, provided that the system conforms to the I
2
C
Standard Specification as defined by Philips.
DS3881
Single-Channel Automotive CCFL Controller
2
_____________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED OPERATING CONDITIONS
(T
A
= -40C to +105C)
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.
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 .........................-40C to +105C
EEPROM Programming Temperature Range .........0C to +70C
Storage Temperature Range .............................-55C to +125C
Soldering Temperature...................See J-STD-020 Specification
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
V
CC
(Note 1)
4.75
5.25
V
Input Logic 1
V
IH
2.0
V
CC
+ 0.3
V
Input Logic 0
V
IL
-0.3
1.0
V
SVML/H Voltage Range
V
SVM
-0.3
V
CC
+
0.3
V
BRIGHT Voltage Range
V
BRIGHT
-0.3
V
CC
+
0.3
V
LCM Voltage Range
V
LCM
(Note 2)
-0.3
V
CC
+
0.3
V
OVD Voltage Range
V
OVD
(Note 2)
-0.3
V
CC
+
0.3
V
Gate-Driver Output Charge
Loading
Q
G
20
nC
ELECTRICAL CHARACTERISTICS
(V
CC
= +4.75V to +5.25V, T
A
= -40C to +105C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current
I
CC
G
A
, G
B
loaded with 600pF
12
mA
Input Leakage (Digital Pins)
I
L
-1.0
+1.0
A
Power-Down Current
I
PDN
1
mA
Output Leakage (SDA,
FAULT)
I
LO
High impedance
-1.0
+1.0
A
Low-Level Output Voltage
(LSYNC, PSYNC)
V
OL
I
OL
= 4mA
0.4
V
V
OL1
I
OL1
= 3mA
0.4
Low-Level Output Voltage
(SDA,
FAULT)
V
OL2
I
OL2
= 6mA
0.6
V
Low-Level Output Voltage
(GA1, GB1)
V
OL3
I
OL3
= 4mA
0.4
V
High-Level Output Voltage
(LSYNC, PSYNC)
V
OH
I
OH
= -1mA
2.4
V
DS3881
Single-Channel Automotive CCFL Controller
_____________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +4.75V to +5.25V, T
A
= -40C to +105C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
High-Level Output Voltage
(GA, GB)
V
OH1
I
OH1
= -1mA
V
CC
-
0.4
V
UVLO Threshold: V
CC
Rising
V
UVLOR
4.3
V
UVLO Threshold: V
CC
Falling
V
UVLOF
3.7
V
UVLO Hysteresis
V
UVLOH
200
mV
SVML/H Threshold: Rising
V
SVMR
2.03
2.08
2.15
V
SVML/H Threshold: Falling
V
SVMF
1.95
2.02
2.07
V
LCM and OVD DC Bias Voltage
V
DCB
1.1
V
LCM and OVD Input Resistance
R
DCB
50
k
Lamp Off Threshold
V
LOT
(Note 3)
0.22
0.25
0.28
V
Lamp Over Current
V
LOC
(Note 3)
2.2
2.5
2.8
V
Lamp Regulation Threshold
V
LRT
(Notes 3, 4)
0.9
1.0
1.1
V
OVD Threshold
V
OVDT
(Note 3)
0.9
1.0
1.1
V
Lamp Frequency Source
Frequency Range
f
LFS:OSC
40
100
kHz
Lamp Frequency Source
Frequency Tolerance
f
LFS:TOL
LOSC resistor 2% over temperature
-5
+5
%
Lamp Frequency Receiver
Frequency Range
f
LFR:OSC
40
100
kHz
Lamp Frequency Receiver
Duty Cycle
f
LFR:DUTY
40
60
%
DPWM Source (Resistor)
Frequency Range
f
DSR:OSC
22.5
440.0
Hz
DPWM Source (Resistor)
Frequency Tolerance
f
DSR:TOL
POSC resistor 2% over temperature
-5
+5
%
DPWM Source (Ext. Clk)
Frequency Range
f
DSE:OSC
22.5
440.0
Hz
DPWM Source (Ext. Clk)
Duty Cycle
f
DFE:DUTY
40
60
%
DPWM Receiver
Min Pulse Width
t
DR:MIN
(Note 5)
25
s
BRIGHT Voltage: Minimum
Brightness
V
BMIN
0.5
V
BRIGHT Voltage: Maximum
Brightness
V
BMAX
2.0
V
Gate Driver Output Rise/Fall Time
t
R
/ t
F
C
L
= 600pF
100
ns
GA1 and GB1 Duty Cycle
(Note 6)
44
%
DS3881
Single-Channel Automotive CCFL Controller
4
_____________________________________________________________________
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.
I
2
C AC ELECTRICAL CHARACTERISTICS (See Figure 9)
(V
CC
= +4.75V to +5.25V, T
A
= -40C to +105C, timing referenced to V
IL(MAX)
and V
IH(MIN)
.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SCL Clock Frequency
f
SCL
(Note 7)
0
400
kHz
Bus Free Time Between Stop and
Start Conditions
t
BUF
1.3
s
Hold Time (Repeated) Start
Condition
t
HD:STA
(Note 8)
0.6
s
Low Period of SCL
t
LOW
1.3
s
High Period of SCL
t
HIGH
0.6
s
Data Hold Time
t
HD:DAT
0
0.9
s
Data Setup Time
t
SU:DAT
100
ns
Start Setup Time
t
SU:STA
0.6
s
SDA and SCL Rise Time
t
R
(Note 9)
20+
0.1C
B
300
ns
SDA and SCL Fall Time
t
F
(Note 9)
20+
0.1C
B
300
ns
Stop Setup Time
t
SU:STO
0.6
s
SDA and SCL Capacitive
Loading
C
B
(Note 9)
400
pF
EEPROM Write Time
t
W
(Note 10)
20
30
ms
NONVOLATILE MEMORY CHARACTERISTICS
(V
CC
= +4.75V to +5.25V)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
EEPROM Write Cycles
+85C (Note 11)
30,000
DS3881
Single-Channel Automotive CCFL Controller
_____________________________________________________________________
5
ACTIVE SUPPLY CURRENT
vs. SUPPLY VOLTAGE
DS3881 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.20
5.15
4.80 4.85 4.90
5.00 5.05
4.95
5.10
4.5
5.0
5.5
6.0
6.5
7.0
4.0
4.75
5.25
DPWM = 10%
DPWM = 50%
DPWM = 100%
SVML< 2V
f
LF:OSC
= 64kHz
GATE Q
C
= 3.5nC
ACTIVE SUPPLY CURRENT
vs. TEMPERATURE
DS3881 toc02
TEMPERATURE (
C)
SUPPLY CURRENT (mA)
32.5
5.5
6.0
6.5
7.0
5.0
-40.0
105
V
CC
= 4.75V
V
CC
= 5.0V
V
CC
= 5.25V
DPWM = 100%
f
LF:OSC
= 64kHz
GATE Q
C
= 3.5nC
INTERNAL FREQUENCY CHANGE
vs. TEMPERATURE
DS3881 toc03
TEMPERATURE (
C)
FREQUENCY CHANGE (%)
32.5
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
-40.0
105
DPWM FREQUENCY
LAMP FREQUENCY
TYPICAL OPERATION AT 11V
DS3881 toc04
10
s
5.0V G
A
10
s
5.0V G
B
10
s
2.00V LCM
10
s
2.00V OVD
TYPICAL OPERATION AT 13V
DS3881 toc05
10
s
5.0V G
A
10
s
5.0V G
B
10
s
2.00V LCM
10
s
2.00V OVD
TYPICAL OPERATION AT 16V
DS3881
toc06
10
s
5.0V G
A
10
s
5.0V G
B
10
s
2.00V LCM
10
s
2.00V OVD
TYPICAL STARTUP WITH SVM
DS3881 toc07
2ms
5.0V SVML
2ms
5.0V G
B
2ms
2.00V LCM
2ms
2.00V OVD
BURST DIMMING AT 150Hz AND 10%
DS3881 toc08
1ms
5.0V G
A
1ms
5.0V G
B
1ms
2.00V LCM
1ms
2.00V OVD
BURST DIMMING AT 150Hz AND 50%
DS3881
toc09
1ms
5.0V G
A
1ms
5.0V G
B
1ms
2.00V LCM
1ms
2.00V OVD
Typical Operating Characteristics
(V
CC
= 5.0V, T
A
= +25C, unless otherwise noted.)
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