SITI DD312

DD312
Version
: A.001
Issue Date : 2007/07/18
File Name : SP-DD312-A.001.doc
Total Pages : 20
HIGH CONSTANT CURRENT LED DRIVER
with ERROR DETECTION
新竹市科學園區展業一路 9 號 7 樓之 1
SILICON TOUCH TECHNOLOGY INC.
9-7F-1, Prosperity Road I, Science Based Industrial Park,
Hsin-Chu, Taiwan 300, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
DD312
HIGH CONSTANT CURRENT LED DRIVER
with ERROR DETECTION
General Description
DD312 is a high constant current driver designed for LED lighting application and power
LEDs. It incorporates a constant current circuitry with current value set by an external resistor. The
output enable terminal allows dimming control by system. The fast response of output current can
adapt to high dimming resolution and high refresh rate applications. Built-in LED open detection,
over temperature, and over current protection functions ensure the system reliability.
Features
z
z
z
Maximum output current: 1A (determined by the external resistor)
Minimum output voltage: 1V (Iout = 1A)
Maximum output voltage: 18V
z
z
z
z
z
z
Output enable terminal: 1MHz (max.)
Supply voltage range: 5V ~ 18V
Over current protection
Thermal shutdown
Thermal alarm (SOP8 only)
LED open detection (SOP8 only)
Applications
z
z
z
LED architectural or entertainment lighting
LED general or specialty illumination
LED backlighting applications
Package Types
z
TO-252 or SOP8 (with thermal pad)
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 1
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Block Diagram
Pin Connection
GND
1
8
VCC
EN
2
7
ALARM
OUT
3
6
REXT
RESERVED
4
5
REXT
SOP8
Pin Description
*1
PIN No.
PIN NAME
FUNCTION
TO252:3/SOP8:1
GND
TO252:5/SOP8:2
EN
TO252:2/SOP8:3
OUT
SOP8:4
RESERVED
Terminal for testing, user should leave this pin open.
TO252:1/SOP8:5,6
REXT*1
External resistor connected between REXT and GND
for driver current value setting.
SOP8:7
ALARM
Output open drain terminal: (connected to a pull-high resistor)
‘H’ for normal conditions,
‘L’ for LED open or chip overheated.
TO252:4/SOP8:8
VCC
Ground terminal.
Output current enable terminal.
Sink constant current outputs (open-drain).
Power supply terminal.
Notice that both REXT pins (SOP8: pin5 and pin6) should be connected in PCB layout.
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 2
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Maximum Ratings (Ta=25°C, Tj(max) = 125°C)
CHARACTERISTIC
SYMBOL
RATING
UNIT
Supply Voltage
VDD
-0.3 ~ 18
Input Voltage
VIN
-0.3 ~ VDD+0.3
Output Current
Iout
1.0
Output Voltage
Vout
-0.3 ~ 18
Enable Voltage
VEN
-0.3 ~ 18
Output Enable Frequency
FEN
1
MHz
GND Terminal Current
IGND
1.01
A
Power Dissipation
Pd
3.27 ( TO-252 )
1.67 ( SOP8 )
W
30.6 ( TO-252 )
60 ( SOP8 )
°C/W
V
A
V
Thermal Resistance (Junction to Air)
Rth(j-a)
*1
Operating Temperature
Top
-40 ~ 85
Storage Temperature
Tstg
-55 ~ 150
°C
Recommended Operating Condition
CHARACTERISTIC
Supply Voltage
SYMBOL
CONDITION
MIN.
TYP.
MAX.
UNIT
VDD
⎯
5.0
⎯
18
V
1.0
⎯
⎯
⎯
⎯
18
⎯
⎯
1.0
3.0
⎯
18
-0.3
⎯
1.0
DC
⎯
1
Driver On
Output Voltage
Vout
Driver Off
Output Current
Iout
*2
*3
OUT
VIH
Input Enable Voltage
A
VDD = 5V ~ 18V
VIL
Input Enable Frequency
V
FEN
Ven > 3.0V
V
MHz
*1
Base on JEDEC high conductivity test board (4-layer) simulation.
Notice that the power dissipation is limited to its package and ambient temperature.
*3
The driver output voltage including any overshoot stress has to be compliant with the maximum voltage (18V).
*2
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 3
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Electrical Characteristics (Ta = 25°C unless otherwise noted)
CHARACTERISTIC
SYMBOL
Input Enable Voltage “H” Level
CONDITION
VEN(IH)
MIN.
TYP.
MAX.
3.0
⎯
18
VDD = 5V ~ 18V
Input Enable Voltage “L” Level
Output Leakage Current
Output Current Skew
(Chip-to-Chip)
*1
Output Voltage Regulation
VEN(IL)
UNIT
V
-0.3
⎯
1.0
IOL
Vout = 18 V
Ven = 0 V
⎯
⎯
1.0
uA
IOL1
Vout = 1.0 V
REXT = 10 Ω
⎯
⎯
±5
%
% / Vout
REXT = 0.5 Ω
Vout = 0.8 V ~ 3 V
⎯
0.1
1
%/V
Supply Voltage Regulation
% / VDD
Alarm threshold temperature
REXT = 0.5 Ω
Talm
⎯
⎯
2
⎯
110
⎯
°C
⎯
180
⎯
°C
REXT = 0.5 KΩ
Shutdown threshold temperature
Supply Current
*1
*2
*2
Tstd
IDD1
VDD = 5 V
REXT = 0.5 Ω
⎯
1.2
⎯
IDD2
VDD = 12 V
REXT = 0.5 Ω
⎯
2.0
⎯
IDD3
VDD = 18 V
REXT = 0.5 Ω
⎯
2.8
⎯
mA
Chip-to-Chip skew is defined as the range into which any output current of any IC falls.
IO excluded.
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 4
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Switching Characteristics (Ta = 25°C unless otherwise noted)
CHARACTERISTIC
Propagation Delay
EN-to-OUT
(Driver On)
(‘L to ‘H’)
Propagation Delay
EN-to-OUT
(Driver Off)
(‘H’ to ‘L’)
Output Current Rise Time
SYMBOL
CONDITION
MIN.
TYP.
MAX.
tpLH
VIH = VDD
⎯
166
⎯
⎯
150
⎯
UNIT
VIL = GND
tpHL
tor
REXT = 0.5 Ω
VL = 5.0 V
ns
⎯
270
⎯
⎯
140
⎯
RL = 8 Ω
Output Current Fall Time
tof
CL = 13 pF
Transient Characteristics
VEN
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 5
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Constant-Current Output
Constant-current value of each output channel is set by an external resistor connected between
the REXT pin and GND. Varying the resistor value can adjust the current up to 1A. Notice that the
output current is a little increasing or decreasing until the device temperature and ambient
temperature are balance. The maximum power dissipation of the determined external resistor should
be large enough than the actual power consumption: 0.5(V ) × Iout ( A) need to be considered.
Approximate output current value can be calculated by following equation:
Output Current as a Function of REXT value
1100
1000
900
Vout = 1.0 V
Iout ( mA )
800
700
600
500
400
300
200
100
0
0
1
2
3
4
5
6
7
8
9
10
11
1.6
1.8
2.0
REXT( Ω )
Output Current as a Function of Output Voltage
1.2
Iout (A)
1.0
0.8
0.6
0.4
0.2
0.0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Vout (Volt)
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 6
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Alarm Function (SOP8 Only)
It can detect the operating status by connecting a pull-high resistor to the open-drain ALARM
pin. The ALARM pin is kept ‘H’ for normal conditions, and shifted to ‘L’ if there is any failure like
LED open, overheating or both occurrence. User can determine the different status from the truth
table below:
ALARM
EN
Status
H
don’t care
Normal Operation
HÆL
H
LED Open or Thermal issue
HÆL
L
Thermal Alarm or Shutdown
Thermal Alarm and Shutdown
During operation, when the junction temperature of the IC will reach about 110℃, the ALARM
pin will shift to low level and produce a warning signal. Suggested cooling measures is to start the
fan, lower the output currents and etc. If no cooling measures were activated, the junction
temperature might continue to rise. Once it reaches approximately above 180℃, it will cause the
driver to shutdown all the outputs. Basically, the IC will cool down and return to the safe operating
temperature which is approximately below 110℃. The ALARM pin will reset to high level, disable
the warning, and restart all the outputs at the same time. Operation in the thermal situation for a long
time may cause chip damage permanently.
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 7
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Power Dissipation
Notice that the power dissipation of a semiconductor chip is limited to its package and ambient
temperature, in which the device requires the maximum output current calculated for given
operating conditions. The maximum allowable power consumption can be calculated by the
following equation:
Pd(max)(Watt) =
Tj(junction temperature)(max)(°C)– Ta(ambient temperature)(°C)
Rth(junction-to-air thermal resistance)(°C/Watt)
The relationship between power dissipation and operating temperature can be refer to the figure
below:
Power Dissipation Pd(W)
4.0
TO-252
3.5
Tj(max)=125 °C
Rth(TO-252)=30.6 °C/Watt
3.0
Rth(SOP8)=60 °C/Watt
2.5
2.0
SOP8
1.5
1.0
0.5
0.0
0
20
40
60
80
100
120
140
Ambient Temperature Ta(°C)
Based on the Pd(max), the maximum allowable voltage of output terminal can be determined by the
following equation:
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 8
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Typical Application
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 9
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Typical Application
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 10
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Typical Application
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 11
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Package Outline Dimension
Unit: inch/mm
TO-252
DIMENSIONS IN INCH
SYMBOLS
MIN.
MAX.
MIN.
MAX.
A
0.086
0.094
2.184
2.388
A1
0.000
0.005
0.000
0.127
A2
0.040
0.050
1.016
1.270
b
0.020 TYP
0.508 TYP
b2
0.205
0.215
5.207
5.461
c
0.018
0.023
0.457
0.584
c1
0.018
0.023
0.457
0.584
D
0.210
0.220
5.334
5.588
D1
0.180
-
4.572
-
E
0.250
0.265
6.350
6.731
E1
0.150
-
3.810
e
0.050 BSC
1.270 BSC
H
0.370
0.410
9.398
10.414
L
0.055
0.070
1.397
1.778
L1
HIGH CONSTANT CURRENT LED DRIVER
DIMENSIONS IN MM
0.105 REF
2.667 REF
L2
0.06
0.08
1.524
2.032
Θ
0°
4°
0°
4°
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 12
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Package Outline Dimension
Unit: inch
SOP8 (exposed pad)
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 13
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
Product Ordering Information
Part Number
Package Type
Number / Weight ( typ.)
Tube / Tray
Reel ( Box included )
DD312-SOP
SOP8-150-1.27
100pcs / Tube
0.018kg ± 5%
－
DD312-TO252EX
TO252-1.27
(Exposed Pad)
80pcs / Tube
0.045kg ± 5%
－
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 14
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
DD312-SOP Package and Weight（4 Boxes Set）
SOP8 - 150 - 1.27
IC
SOP
100 pcs ICs per Tube
Tube
53cm
Box
100 Tubes per Box
17cm
10cm
61cm
4 Boxes per Carton
Carton
35cm
24cm
64cm
Weight
Item
1
2
3
4
Description
100 pcs DD312-SOP per Tube
Net Weight of one Box
Net Weight of one Carton
Weight ( Kg )
0.018±5%
0.40±5%
1.24±5%
Per Carton Set ( 4 Boxes, 40,000 pcs )
HIGH CONSTANT CURRENT LED DRIVER
10.04±5%
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 15
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
DD312-SOP Package and Weight（6 Boxes Set）
SOP8 - 150 - 1.27
IC
SOP
100 pcs ICs per Tube
Tube
53cm
Box
100 Tubes per Box
17cm
10cm
61cm
6 Boxes per Carton
Carton
35cm
34cm
64cm
Weight
Item
1
2
3
4
Description
100 pcs DD312-SOP per Tube
Net Weight of one Box
Net Weight of one Carton
Weight ( Kg )
0.018±5%
0.40±5%
1.44±5%
Per Carton Set ( 6 Boxes, 60,000 pcs )
HIGH CONSTANT CURRENT LED DRIVER
14.64±5%
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 16
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
DD312-TO252EX Package and Weight（4 Boxes Set）
TO252 - 1.27 ( Exposed Pad )
IC
TO252
80 pcs ICs per Tube
Tube
53cm
Box
40 Tubes per Box
17cm
10cm
61cm
4 Boxes per Carton
Carton
35cm
24cm
64cm
Weight
Item
1
2
3
4
Description
80 pcs DD312-TO252EX per Tube
Net Weight of one Box
Net Weight of one Carton
Weight ( Kg )
0.045±5%
0.40±5%
1.24±5%
Per Carton Set ( 4 Boxes, 12,800 pcs )
HIGH CONSTANT CURRENT LED DRIVER
10.04±5%
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 17
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
DD312-TO252EX Package and Weight（6 Boxes Set）
TO252 - 1.27 ( Exposed Pad )
IC
TO252
80 pcs ICs per Tube
Tube
53cm
40 Tubes per Box
Box
17cm
10cm
6 Boxes per Carton
61cm
Carton
35cm
34cm
64cm
Weight
Item
1
2
3
4
Description
80 pcs DD312-TO252EX per Tube
Net Weight of one Box
Net Weight of one Carton
Weight ( Kg )
0.045±5%
0.40±5%
1.44±5%
Per Carton Set ( 6 Boxes, 19,200 pcs )
HIGH CONSTANT CURRENT LED DRIVER
14.64±5%
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 18
點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
DD312
The products listed herein are designed for ordinary electronic applications, such as
electrical appliances, audio-visual equipment, communications devices and so on. Hence,
it is advisable that the devices should not be used in medical instruments, surgical
implants, aerospace machinery, nuclear power control systems, disaster/crime-prevention
equipment and the like. Misusing those products may directly or indirectly endanger
human life, or cause injury and property loss.
Silicon Touch Technology, Inc. will not take any responsibilities regarding the misusage
of the products mentioned above. Anyone who purchases any products described herein
with the above-mentioned intention or with such misused applications should accept full
responsibility and indemnify. Silicon Touch Technology, Inc. and its distributors and all
their officers and employees shall defend jointly and severally against any and all claims
and litigation and all damages, cost and expenses associated with such intention and
manipulation.
HIGH CONSTANT CURRENT LED DRIVER
Version:A.001
未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任
Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.
Page 19