LD1018
16 Channel Constant Current
Driver
LD1018
16 Channel Constant Current Driver
LD1018
16 Channel Constant Current LED Driver
Ver. 2.0 / Mar. 2009
This document is a general product description and is subject to change without notice.
LDT Inc. does NOT assume any responsibility for use of circuits described.
1
Ver2.0
LD1018
16 Channel Constant Current Driver
LD1018 Revision History
Version
Contents
Transfer Date
1.0
Preliminary Spec.
2008.08.12
2.0
1. Change : Supply Voltage Regulation : max ± 3% to Max 6%
2. Add : Rext vs Iout (3.3V) Diagram.
3. Add : DC Characteristics (3.3V)
4. Add : AC Characteristics (3.3V)
5. Change :Propagation Delays
2009.03.25
2
Ver2.0
LD1018
16 Channel Constant Current Driver
DESCRIPTION
The LD1018 is specifically designed for LED display applications. The constant current output can be
preset through an external resistor (IOUT = 3mA to 45mA). The device consists of 16bit shift register,
latch and constant current output driver. The LD1018 provides a constant output current for driving the
LEDs against for the variation of LED forward voltage( Vf ).
The LD1018’s excellent current matching characteristics among the output ports and fast output
response time will give you the best display quality for LED display system.
FEATURES
PIN CONNECTION
• 16 constant-current output channels
• Output current : set -up at 3mA to 45mA with an external resistor
• Pin to pin deviation : max ± 1.5%
• Chip to chip deviation : max ± 3%
• 3.3V/5V CMOS compatible input
• Delayed output to prevent inrush current
• Maximum data transfer rate : max 30MHz
• Fast response of OEB - OUTn (min) : 60ns @VDD=5V, 100ns @VDD=3.3V
• 3.3V/5V supply voltage
• Package : LD1018-SP (SOP-24), LD1018-SS (SSOP-24)
• “Pb_free & Green” Package
GND
DIN
CLOCK
STROBE
OUT0
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
VDD
R-EXT
DOUT
OEB
OUT15
OUT14
OUT13
OUT12
OUT11
OUT10
OUT9
OUT8
ORDERING INFORMATION
PART NUMBER
PACKAGE
TA
LD1018-SS
24 SSOP
-40°C to 85 °C
LD1018-SP
24 SOP
-40°C to 85 °C
BLOCK DIAGRAM
OUT0
R-EXT
OUT1
OUT15
I-REF
OEB
STROBE
Q
Q
16Bit Data Latch
Q
16
DIN
16Bit Shift Register
DOUT
CLOCK
3
Ver2.0
LD1018
16 Channel Constant Current Driver
TERMINAL DESCRIPTION
PIN NO
PIN NAME
FUNCTION
1
GND
Ground terminal
2
DIN
Serial input data
3
CLOCK
4
STROBE
5 -20
OUTn
Constant current outputs for LEDs, n = 0 ~ 15
21
OEB
Output Enable. Active Low
22
DOUT
Serial data output terminal for shifting the data to next chip
23
REXT
Connect the resistor between this pin and GND to set up the
constant output current for all the OUTn.
24
VDD
Supply voltage
Shift input clock for serial input data DIN( Rising Edge Clocking)
Data is transferred to the output latch at STROBE rising edge
EQUIVALENT CIRCUIT OF INPUTS AND OUTPUTS
1. OEB terminal
VDD
OEB
GND
3. CLOCK, DIN terminal
VDD
CLOCK,
DIN
GND
2. STROBE terminal
VDD
STROBE
GND
4. DOUT terminal
VDD
(DATA)
DOUT
GND
4
Ver2.0
LD1018
16 Channel Constant Current Driver
TIMING DIAGRAM
1
2
3
4
13
14
15
16
CLOCK
DIN
STROBE
OEB
OUT0
ON
OFF
OUT1
ON
OFF
OUT2
ON
OFF
OUT14
ON
OFF
OUT15
ON
OFF
DOUT
TRUTH TABLE
Input
CLOCK
Output
STROBE
OEB
DIN
OUT0
OUT7
OUT15
DOUT
H
L
Dn
Dn
Dn-7
Dn-15
No Change
L
L
Dn
*
H
Dn
OFF
OFF
H
L
Dn
Dn
Dn-7
L
L
Dn
*
H
Dn
No change
No Change
OFF
Dn-15
No change
OFF
OFF
No Change
Dn-15
Dn-15
OFF
Dn-15
[Note] 1) When the state of Dn ~ Dn-15 is “H”, the OUTn is turned ON( “L” : OUTn is turned OFF ).
2) * : Don’t Care
5
Ver2.0
LD1018
16 Channel Constant Current Driver
MAXIMUM RATINGS
(Ta = 25 ℃ unless otherwise noted)
Characteristic
Symbol
Rating
Unit
Supply Voltage
VDD
0 ~ 7.0
V
Output Voltage
VOUT
-0.5 ~ 7.0
V
Output Current
IOUT
60
mA
Input Voltage
VIN
-0.4 ~ VDD + 0.4
V
GND Terminal Current
IGND
725
mA
CLOCK Frequency
FCLK
30
MHz
Power
Dissipation
( On PCB, TA = 25 ℃)
Thermal Resistance
( On PCB, TA = 25 ℃)
SOP
1.67
PD
W
SSOP
1.48
SOP
75
℃/W
Rth(j-a)
SSOP
85
Operation Temperature
Topr
-40 ~ 85
℃
Storage Temperature
Tstg
-55 ~ 150
℃
6
Ver2.0
LD1018
16 Channel Constant Current Driver
DC CHARACTERISTICS (5.0V)
Characteristics
Symbol
Supply Voltage
VDD
Output Voltage
VOUT
OUTn
Output
Current
(Ta = 25 ℃ unless otherwise noted)
Condition
Min.
Typ.
Max.
Unit
3.0
5.0
5.5
V
5.5
-
IOUT
3
IOH
-1.0
45
mA
DOUT
IOL
Input
Voltage
Output
Voltage
1.0
‘H” Level
VIH
0.8VDD
-
1.0VDD
‘L” Level
VIL
GND
-
0.2VDD
VOL
GND
-
0.2VDD
VOH
0.8VDD
-
VDD
V
DOUT
‘L” Level
V
IOL1
REXT = 1.0 ㏀
ㅿIOL1
REXT = 1.0 ㏀
IOUT = 20mA
IOL2
REXT = 0.5 ㏀
ㅿIOL2
REXT = 0.5 ㏀
IOUT = 40mA
±1.5
%
Output Current vs.
Output Voltage Regulation
%/dVDS
VDS Within
1.0V and 3.0V
±0.2
%
Output Current vs.
Supply Voltage Regulation
%/dVDD
VDD Within
4.5V and 5.5V
6.0
%
Pull Up Resistor
RUP
100
200
400
㏀
Pull Down Resistor
RDOWN
100
200
400
㏀
Output Current1
Pint to Pin
Output Current2
Pin to Pin
Supply Current
20
mA
±1.5
40
%
mA
IDD(off)1
REXT = OPEN
1
2
mA
IDD(off)2
REXT = 1.0 ㏀
IOUTn = 20mA
3
5.4
mA
IDD(off)3
REXT = 0.5 ㏀
IOUT = 40mA
6
8
mA
IDD(on)1
REXT = 1.0 ㏀
IOUTn = 20mA
3
5.4
mA
IDD(on)2
REXT = 0.5 ㏀
IOUT = 40mA
6
8
mA
7
Ver2.0
LD1018
16 Channel Constant Current Driver
DC CHARACTERISTICS(3.3V)
Characteristics
Symbol
Supply Voltage
VDD
Output Voltage
VOUT
OUTn
Output
Current
(Ta = 25 ℃ unless otherwise noted)
Condition
Min.
Typ.
Max.
Unit
3.0
5.0
5.5
V
5.5
-
IOUT
3
IOH
-1.0
45
mA
DOUT
IOL
Input
Voltage
Output
Voltage
1.0
‘H” Level
VIH
0.8VDD
-
1.0VDD
‘L” Level
VIL
GND
-
0.2VDD
VOL
GND
-
0.2VDD
VOH
0.8VDD
-
VDD
V
DOUT
‘L” Level
V
IOL1
REXT = 1.0 ㏀
ㅿIOL1
REXT = 1.0 ㏀
IOUT = 20mA
IOL2
REXT = 0.5 ㏀
ㅿIOL2
REXT = 0.5 ㏀
IOUT = 40mA
±1.5
%
Output Current vs.
Output Voltage Regulation
%/dVDS
VDS Within
1.0V and 3.0V
±0.2
%
Output Current vs.
Supply Voltage Regulation
%/dVDD
VDD Within
4.5V and 5.5V
6.0
%
Pull Up Resistor
RUP
100
200
400
㏀
Pull Down Resistor
RDOWN
100
200
400
㏀
Output Current1
Pint to Pin
Output Current2
Pin to Pin
Supply Current
20
mA
±1.5
40
%
mA
IDD(off)1
REXT = OPEN
1
2
mA
IDD(off)2
REXT = 1.0 ㏀
IOUTn = 20mA
3
5.4
mA
IDD(off)3
REXT = 0.5 ㏀
IOUT = 40mA
6
8
mA
IDD(on)1
REXT = 1.0 ㏀
IOUTn = 20mA
3
5.4
mA
IDD(on)2
REXT = 0.5 ㏀
IOUT = 40mA
6
8
mA
8
Ver2.0
LD1018
16 Channel Constant Current Driver
AC CHARACTERISTICS (VDD=5.0V)
(Ta = 25 ℃ unless otherwise noted)
Characteristics
Propagation
Delay Time
(Low to High)
Propagation
Delay Time
(High to Low)
Pulse Width
Symbol
Condition
Min.
Typ.
Max.
Unit
110
ns
25
ns
110
ns
120
ns
110
ns
CLOCK-OUTn
TpLH1
50
CLOCK-DOUT
tpLH
20
STROBE-OUTn
tpLH2
50
OEB-OUTn
tpLH3
30
CLOCK-OUTn
tpHL1
50
CLOCK-DOUT
tpHL
20
-
25
ns
-
-
-
ns
90
ns
STROBE-OUTn
tpHL2
OEB-OUTn
tpHL3
CLOCK
tW_CLK
STROBE
tW_STB
OEB
tW_OEB
VDD = 5.0V
VOUT = 1.0V
VIH = VDD
VIL = GND
fCLK = 10MHz
REXT = 0.5㏀
IOUTn = 40mA
VL = 3.0V
CL = 10.0pF
RL = 50Ω
-
-
40
10
20
ns
40
60
Maximum CLOCK Frequency
fCLKMAX
Data Setup Time
tsD
10
Data Hold Time
thD
STROBE Setup Time
ns
-
ns
30
MHz
-
-
ns
10
-
-
ns
tsS
10
-
-
ns
STROBE Hold Time
thS
10
-
-
ns
Maximum Clock Rise Time
tr
50
ns
Maximum Clock Fall Time
tf
50
ns
Maximum Output Rise Time
tor
25
ns
Maximum Output Fall Time
tof
25
ns
9
Ver2.0
LD1018
16 Channel Constant Current Driver
AC CHARACTERISTICS (VDD=3.3V)
(Ta = 25 ℃ unless otherwise noted)
Characteristics
Propagation
Delay Time
(Low to High)
Propagation
Delay Time
(High to Low)
Pulse Width
Symbol
Condition
Min.
Typ.
Max.
Unit
160
ns
25
ns
160
ns
120
ns
160
ns
CLOCK-OUTn
TpLH1
60
CLOCK-DOUT
tpLH
-
STROBE-OUTn
tpLH2
50
OEB-OUTn
tpLH3
30
CLOCK-OUTn
tpHL1
60
CLOCK-DOUT
tpHL
-
-
25
ns
-
-
-
ns
180
ns
STROBE-OUTn
tpHL2
OEB-OUTn
tpHL3
CLOCK
tW_CLK
STROBE
tW_STB
OEB
tW_OEB
VDD = 5.0V
VOUT = 1.0V
VIH = VDD
VIL = GND
fCLK = 10MHz
REXT = 0.5㏀
IOUTn = 40mA
VL = 3.0V
CL = 10.0pF
RL = 50Ω
-
-
50
10
20
ns
40
80
Maximum CLOCK Frequency
fCLKMAX
Data Setup Time
tsD
10
Data Hold Time
thD
STROBE Setup Time
ns
-
ns
30
MHz
-
-
ns
10
-
-
ns
tsS
40
-
-
ns
STROBE Hold Time
thS
10
-
-
ns
Maximum Clock Rise Time
tr
50
ns
Maximum Clock Fall Time
tf
50
ns
Maximum Output Rise Time
tor
25
ns
Maximum Output Fall Time
tof
25
ns
10
Ver2.0
LD1018
16 Channel Constant Current Driver
DC CHARACTERISTIC TEST CIRCUIT
IDD
VDD
IIH
IIL
OUT0
CLOCK
IOUT
OEB
LD1018
OUT15
STROBE
VIH
VIL
DOUT
DIN
R-EXT
IOH
GND
IOL
Iref
Rext
AC CHARACTERISTIC TEST CIRCUIT
VIH
RL
VDD
CLOCK
OUT0
OEB
CL
Signal
Generator
LD1018
STROBE
VIL
RL
OUT15
DIN
DOUT
R-EXT
Rext
CL
GND
VL
11
Ver2.0
LD1018
16 Channel Constant Current Driver
TIMING WAVEFORM
CLOCK-DOUT, OUTn
tr
tf
90% 90%
50%
50%
10%
10%
tW_CLK
CLOCK
50%
DIN
50%
tsD
thD
50%
DOUT
tpLH , tpHL
CLOCK-STROBE
CLOCK
50%
50%
DIN
tw_STB
50%
STROBE
ON
50%
th
tsS
S
50%
OUTn
OFF
tpLH1 , tpHL1
tpLH2 , tpHL2
OEB-OUTn
tW_OEB
OEB
50%
50%
tpHL3
90% 90%
tpLH3
OUTn
50%
10%
tor
50%
10%
tof
12
Ver2.0
LD1018
16 Channel Constant Current Driver
ADJUSTING OUTPUT CURRENT
The output current is determined by an external resistor. The relationship between IOUT and REXT is as follows;
When VDD = 3.3V
When VDD = 5V
IOUT[A] = {1.16/(90+REXT)} * 21
IOUT[A] = {1.16/(90+REXT)} * 22
VDD = 5.0V
Rext ─ Iout
Rext (Ω)
VDD = 3.3V
Rext ─ Iout
Rext (Ω)
13
Ver2.0
LD1018
16 Channel Constant Current Driver
CONSTANT OUTPUT CURRENT
The LD1018 provides a constant current output characteristics for LED display application. The
pin to pin deviation is max +/- 1.5% and chip to chip deviation is max +/- 3%.
When VDD = 5.0V
45
40
35
0.5㏀
0.6㏀
1.0㏀
2.0㏀
3.0㏀
5.0㏀
25
20
IOUT (mA)
Current
30
15
10
5
0
4.8V
4.5V
4.2V
3.9V
3.6V
3.3V
3.0V
2.7V
2.4V
2.1V
1.8V
1.5V
1.2V
0.9V
0.6V
0.3V
0.0V
-5
VOUT
When VDD = 3.3V
45
40
35
0.5㏀
0.6㏀
1.0㏀
2.0㏀
3.0㏀
5.0㏀
25
20
15
10
5
0
2V
3.
0V
3.
8V
2.
6V
2.
4V
2.
2V
2.
0V
2.
8V
1.
6V
1.
4V
1.
2V
1.
0V
1.
8V
0.
6V
0.
4V
0.
2V
0.
0V
-5
0.
IOUT
(mA)
Current
30
VOUT
14
Ver2.0
LD1018
16 Channel Constant Current Driver
LED SUPPLY VOLTAGE( VLED )
VLED
•
VLED
•
RL
•
Vf
Vf
VOUT
VOUT
LD1018
•
LD1018
It is very important to select the proper value of Load Resistor( RL ). Because the optimal VOUT value
guarantees the constant output current and long life time of LED driver IC without over power consumption.
For example, let’s calculate the Load Resistor value at VLED=5V, Iout=20mA, LED Forward Voltage(Vf)=3V.
1. The full current of LD1018 = 20mA x 16 (channels) = 320mA
2. The power consumption is 320mA x VOUT voltage.
- when VOUT = 1V, the power consumption is 320mW.
- when VOUT= 2V, the power consumption is 640mW.
Therefore, the Load Resistor (RL) = (VLED – VOUT– Vf) / Iout
RL = (5V – VOUT – 3V) / 20mA = 50Ω (When VOUT = 1V)
15
Ver2.0
LD1018
16 Channel Constant Current Driver
PACKAGE POWER DISSIPATION( PD )
The LD1018 provides many package types such as 24-SOP package and 24-SSOP package. The
maximum allowable package power dissipation is determined as PD(max) = (Tj – Ta) / R_Theta_JA. When
16 output channels are turned on simultaneously, the actual power dissipation of package is PD(act) =
(IDD x VDD) + (IOUT x Duty x VOUT x 16). Therefore, to keep that PD(act) is less than PD(max).
The maximum allowable output current as a function of duty cycle is:
IOUT = {[(Tj – Ta) / R_Theta_JA] – (IDD x VDD)} / VOUT / Duty / 16
where Tj = 150C
85
70
55
25
95%
100%
90%
85%
80%
75%
70%
65%
60%
55%
50%
45%
40%
35%
30%
( R_Theta_JA = 75C/W )
25%
=
=
=
=
20%
5%
Ta
Ta
Ta
Ta
15%
45
40
35
30
25
20
15
10
5
0
10%
Iout(mA)
Iout vs Duty (24-SOP)
Duty
100%
95%
90%
85%
80%
75%
70%
65%
60%
55%
50%
45%
40%
35%
85
70
55 ( R_Theta_JA = 85C/W )
25
30%
=
=
=
=
25%
Ta
Ta
Ta
Ta
20%
10%
5%
Iout(mA)
45
40
35
30
25
20
15
10
5
0
15%
Iout vs Duty (24-SSOP)
Duty
Power Dissipation (W)
Package Power Dissipation
1.8
1.6
1.4
1.2
1
0.8
24SOP
24SSOP
0.6
0.4
0.2
0
10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Ambient Temperature (C)
16
Ver2.0
LD1018
16 Channel Constant Current Driver
APPLICATION CIRCUIT - CASE1
VLED = 5V
VDD
RL
VDD
CLOCK
DIN
OUT0
OEB
STROBE
LD1018
OEB
R-EXT DOUT
D07
D00
D015
VDD
DIN
STROBE
RL
RL
I0
I7
OUT7
I15
OUT15
GND
VLED = 5V
RL
RL
RL
CLOCK
VDD
CLOCK
DIN
D10
I0
I7
LD1018
OEB
R-EXT DOUT
D115
VDD
OUT0
STROBE
D17
OUT15
GND
I15
Data & Control Signal Connection for 16x2 Static Type Application
17
Ver2.0
LD1018
16 Channel Constant Current Driver
TIMING DIAGRAM – CASE1
16 Clocks
16 Clocks
16 Clocks
16 Clocks
CLOCK
DIN
D115~D10
D015 ~ D00
( 1st Data )
D115~D10
D015 ~ D00
(2nd Data)
STROBE
1st Data Display
2nd
OEB
Display On
Timing Diagram for 16x2 Static Type Application
TIMING DIAGRAM – CASE1-1
16 Clocks
16 Clocks
16 Clocks
16 Clocks
CLOCK
DIN
D115~D10
D015 ~ D00
( 1st Data )
D115~D10
D015 ~ D00
(2nd Data)
STROBE
OEB
2nd
1st Data Display
Display Off
Timing Diagram for 16x2 Static Type Application
18
Ver2.0
LD1018
16 Channel Constant Current Driver
APPLICATION CIRCUIT – CASE2
VDD
R
4
VLED = 5V
Q1
R
5
PNP
PNP
R
4
S0
R
4
Q0
PNP
R
5
S1
PNP
Q15
PNP
R
5
S15
PNP
RL
RL
RL
D00
D01
D015
RL
RL
RL
RL
RL
D150 D151
D10
RL
D11
D1515
D115
Controller
VDD
DATA
DIN
CLK
CLOCK
VDD
OUT0
OUT1
STB
STROBE
ESB
OEB
R-EXT
LD1018
OUT15
DOUT
GND
R
Data & Control Signal Connection for 16x16 Dynamic Type Application
19
Ver2.0
LD1018
16 Channel Constant Current Driver
TIMING DIAGRAM CASE2
16 Clocks
16 Clocks
16 Clocks
D115 ~ D10
( 2nd Display Data)
D1515 ~ D150
(16th Display Data)
CLOCK
STROBE
DIN
D015 ~ D00
(1st Display Data)
OEB
S0
(1st Display Data)
S1
(2nd Display Data)
S15
(16th Display Data)
Row Driver Non Overlap Time
Timing Diagram for 16x16 Dynamic Type Application
20
Ver2.0
LD1018
16 Channel Constant Current Driver
APPLICATION CIRCUIT – CASE3
VDD
R
4
VLED = 5V
Q0
S0
R
5
R
4
PNP
PNP
S15
PNP
RL
RL
D0000
D0015
Controller
RL
D1000
RL
D1015
RL
RL
RL
RL
D0150
D01515
D1150
D11515
VDD
DATA
DIN
CLK
Q15
R
5
PNP
VDD
OUT0
CLOCK
STB
STROBE
ESB
OEB
R-EXT
LD1018
OUT15
DOUT
GND
R
VDD
DIN
VDD
CLOCK
STROBE
OUT0
LD1018
OUT15
OEB
R-EXT
DOUT
GND
R
Data & Control Signal Connection for 32x16 Dynamic Type Application
21
Ver2.0
LD1018
16 Channel Constant Current Driver
TIMING DIAGRAM - CASE3
32 Clocks
32 Clocks
CLOCK
STROBE
DIN
D1015 ~ D1000, D0015 ~ D0000
(1st Display Data)
D11515 ~ D1150, D01515 ~ D0150
(16th Display Data)
OEB
S0
(1st Display Data)
S15
(16th Display Data)
Timing Diagram for 32x16 Dynamic Type Application
22
Ver2.0
LD1018
16 Channel Constant Current Driver
PACKAGE INFORMATION
LD1018-SP (SOP 24)
23
Ver2.0
LD1018
16 Channel Constant Current Driver
LD1018-SS (SSOP 24)
24
Ver2.0