high
performance
needs great
design.
Datasheet: AS1109 8-Bit LED Driver with Diagnostics
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austriamicrosystems and TAOS are now ams.
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A S 110 9
Constant-Current, 8-Bit LED Driver with Diagnostics
1 General Description
2 Key Features
8 Constant-Current Output Channels
The AS1109 is designed to drive up to 8 LEDs through a fast serial
interface and features 8 output constant current drivers and an onchip diagnostic read-back function.
Excellent Output Current Accuracy
- Between Channels: ±2%
- Between AS1109 Devices: ±2%
The high clock-frequency (up to 50MHz), adjustable output current,
and flexible serial interface makes the device perfectly suited for
high-volume transmission applications.
Output Current Per Channel: 0.5 to 100mA
Output current is adjustable (up to 100mA/channel) using an external
resistor (REXT).
Controlled In-Rush
Current
Over-Temperature, Open-LED, Shorted-LED
The serial interface with Schmitt trigger inputs includes an integrated
shift register. Additionally, an internal data register stores the
currently displayed data.
Diagnostics Functions
Low-Current Test Mode
The device features integrated diagnostics for overtemperature, open-LED, and shorted-LED conditions. Integrated
registers store global fault status information during load as well as
the detailed temperature/open-LED/shorted-LED diagnostics results.
Global Fault Monitoring
Low Shutdown Mode Current: 3µA
Fast Serial Interface: up to 50MHz
The AS1109 also features a low-current diagnostic mode to minimize
display flicker during fault testing.
Cascaded Configuration
With an operating temperature range from -40 to +125°C the
AS1109 is also ideal for industrial applications.
Fast Output Drivers Suitable for PWM
16-pin SOIC-150,
The AS1109 is available in a 16-pin SOIC-150, a 16-pin QFN
(4x4mm) and the 16-pin QSOP-150 package.
16-pin QFN (4x4mm) and 16-pin QSOP-150
Package
3 Applications
The device is ideal for fixed- or slow-rolling displays using static or
multiplexed LED matrix and dimming functions, large LED matrix
displays, mixed LED display and switch monitoring, displays in
elevators, public transports (underground, trains, buses, taxis,
airplanes, etc.), large displays in stadiums and public areas, price
indicators in retail stores, promotional panels, bar-graph displays,
industrial controller displays, white good panels, emergency light
indicators, and traffic signs.
Figure 1. Main Diagram and Pin Assignments
+VLED
16 VDD
GND 1
OUTN0
OUTN1
OUTN2
OUTN3
OUTN4
OUTN5
OUTN6
OUTN7
CLK
LD
www.ams.com/LED-Driver-ICs/AS1109
OEN
15 REXT
CLK 3
14 SDO
LD 4
AS1109
SDI
SDI 2
SDO
REXT
GND
Revision 1.21
VDD
OUTN0 5
AS1109
13 OEN
12 OUTN7
OUTN1 6
11 OUTN6
OUTN2 7
10 OUTN5
OUTN3 8
9 OUTN4
1 - 24
AS1109
Datasheet
4 Pin Assignments
Figure 2. Pin Assignments (Top View)
SDI
15 REXT
CLK 3
14 SDO
LD 4
13 OEN
AS1109
OUTN0 5
12 OUTN7
OUTN1 6
11 OUTN6
OUTN2 7
10 OUTN5
LD
2
OUTN0
3
OUTN1
4
9 OUTN4
14
13
11 OEN
AS1109
16-pin QFN
(4x4mm)
10 OUTN7
9
5
16-pin QSOP-150
16-pin SOIC-150
15
12 SDO
OUTN2
OUTN3 8
1
6
7
8
OUTN5
SDI 2
CLK
OUTN4
16 VDD
GND VDD REXT
OUTN3
GND 1
16
OUTN6
4.1 Pin Descriptions
Table 1. Pin Descriptions
Pin Number
Pin Name
Description
16-pin QSOP-150
16-pin SOIC-150
16-pin QFN
(4x4mm)
1
15
GND
Ground
2
16
SDI
Serial Data Input
3
1
CLK
Serial Data Clock. The rising edge of the CLK signal is used to clock data into and at
the falling edge out of the AS1109 shift register. In error mode, the rising edge of the CLK
signal is used to switch error modes.
4
2
LD
Serial Data Load. Data is transferred to the data register at the rising edge of this pin.
5:12
3:10
OUTN0:7
13
11
Output Current Drivers. These pins are used as LED drivers or for input sense for
diagnostic modes.
OEN
Output Enable. The active-low pin OEN signal can always enable output drivers to sink
current independent of the AS1109 mode.
0 = Output drivers are enabled.
1 = Output drivers are disabled.
14
12
SDO
Serial Data Output. In normal mode SDO is clocked out 8.5 clock cycles after SDI is
clocked in.
In global error detection mode this pin indicates the occurrence of a global error.
0 = Global error mode returned an error.
1 = No errors.
15
13
REXT
External Resistor Connection. This pin connects through the external resistor (REXT)
to GND, to setup the load current.
16
14
VDD
Positive Supply Voltage
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Revision 1.21
2 - 24
AS1109
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in Table 2 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 Electrical Characteristics on page 4 is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
Parameter
Min
Max
Units
Comments
Electrical Parameters
VDD to GND
-0.3
7
V
Input Voltage
-0.4
VDD + 0.4
V
Output Voltage
-0.4
15
V
1000
mA
100
mA
Norm: JEDEC 78
2
kV
Norm: MIL 883 E method 3015
33
ºC/W
on PCB, 16-pin SOIC-150 package
113
ºC/W
on PCB, 16-pin QSOP-150 package
ºC/W
on PCB, 16-pin QFN (4x4mm) package
GND Pin Current
Input Current (latch-up immunity)
-100
Electrostatic Discharge
Electrostatic Discharge HBM
Temperature Ranges and Storage Conditions
Thermal Resistance ΘJA
32
Storage Temperature Range
-55
+150
Package Body Temperature
Humidity non-condensing
Moisture Sensitive Level
5
ºC
+260
ºC
85
%
The reflow peak soldering temperature (body
temperature) specified is in accordance with IPC/
JEDEC J-STD-020“Moisture/Reflow Sensitivity
Classification for Non-Hermetic Solid State Surface
Mount Devices”.
The lead finish for Pb-free leaded packages is matte tin
(100% Sn).
QFN and QSOP
1
Represents a maximum floor life time of unlimited
Moisture Sensitive
Layer (SOIC)
3
Represents a maximum floor life of 168h
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Revision 1.21
3 - 24
AS1109
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
VDD = +3.0V to +5.5V, Typical values measured at VDD = 5V, TAMB = 25°C (unless otherwise specified).
Table 3. Electrical Characteristics
Symbol
Parameter
Condition
Min
TAMB
Operating Temperature Range
Device fully functional up to 125°C
VDD
Supply Voltage
VDS
Output Voltage
IOUT
IOH
Max
Unit
-40
+85
°C
3.0
5.5
V
OUTN0:7
0
15.0
V
OUTN0:7, VDD = 5V (see Figure 8)
0.5
100
SDO
-1.0
Output Current
IOL
SDO
VIH
High Level
Input Voltage
VIL
CLK, OEN, LD, SDI
Low Level
IDS(OFF)
VOL
Output Leakage Current
Output
Voltage
VOH
SDO
Typ
mA
1.0
0.7 x
VDD
VDD +
0.3
-0.3
0.3 x
VDD
OEN = 1, VDS = 15.0V
0.5
IOL = +1.0mA
0.4
IOH = -1.0mA
VDD 0.4V
24.5
IAV(LC1)
Device-to-Device Average Output Current
from OUTN0 to OUTN7
VDS = 0.5V, VDD = Const.,
REXT = 744Ω
ΔIAV(LC1)
Current Skew
(Between Channels)
VDS ≥ 0.5V, VDD = Const.,
REXT = 744Ω
IAV(LC2)
Device-to-Device Average Output Current
from OUTN0 to OUTN7
VDS = 0.6V, VDD > 3.3V,
REXT = 372Ω
ΔIAV(LC2)
Current Skew
(Between Channels)
VDS ≥ 0.6V, VDD = Const.,
REXT = 372Ω
IAV(LC3)
Device-to-Device Average Output Current
from OUTN0 to OUTN7
VDS = 0.8V, VDD = 5.0V,
REXT = 186Ω
ΔIAV(LC3)
Current Skew
(Between Channels)
VDS ≥ 0.8V, VDD = Const.,
REXT = 186Ω
ILC
Low-Current Diagnosis Mode
VDS = 0.8V, VDD = 5.0V
IPD
Power Down Supply Current
%/ΔVDS
V
µA
V
25.26
26
mA
±0.9
±3
%
50.52
51.55
mA
±0.8
±2
%
101
104
mA
±0.5
±2
%
0.6
0.8
mA
VDS = 0.8V, VDD = 5.0V,
REXT = 372Ω, OUTN0:7 = On
3
20
µA
Output Current vs.
Output Voltage Regulation
VDS within 1.0 and 3.0V
±0.1
%/V
%/ΔVDD
Output Current vs.
Supply Voltage Regulation
VDD within 3.0 and 5.0V
±1
%/V
RIN(UP)
Pullup Resistance
OEN
250
500
800
kΩ
RIN(DOWN)
VTHL
49.50
98
0.4
Pulldown Resistance
LD
250
500
800
kΩ
*
Open Error Detection Threshold Voltage
No load
0.25
0.35
0.45
V
*
Short Error Detection Threshold Voltage
VDD = 3.0V, no load
1.2
1.3
1.4
VDD = 5.0V, no load
2.0
2.2
2.4
VTHH
TOV1
Overtemperature Threshold Flag
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150
Revision 1.21
V
ºC
4 - 24
AS1109
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
Table 3. Electrical Characteristics (Continued)
Symbol
Parameter
Condition
IDD(OFF)0
IDD(OFF)1
Off
IDD(OFF)2
IDD(OFF)3
Supply Current
IDD(ON)1
IDD(ON)2
On
IDD(ON)3
Min
Typ
Max
REXT = Open‚ OUTN0:7 = Off
1.3
2
REXT = 744Ω‚ OUTN0:7 = Off
3.0
3.68
REXT = 372Ω‚ OUTN0:7 = Off
4.7
5.37
REXT = 186Ω, OUTN0:7 = Off
8.1
8.73
REXT = 744Ω‚ OUTN0:7 = On
4.5
5
REXT = 372Ω‚ OUTN0:7 = On
7.5
8
REXT = 186Ω‚ OUTN0:7 = On
13.7
15
Unit
mA
6.1 Switching Characteristics
VDD = 3.0 to 5.5V, VDS = 0.8V, VIH = VDD, VIL = GND, REXT = 372Ω, VLOAD = 4.0V, RLOAD = 64Ω, CLOAD = 10pF; guaranteed by design.
Table 4. Switching Characteristics
Symbol
tP1
tP2
tP3
tP4
tW(CLK)
tW(L)
tW(OE)
tR
*
*
tF
tOR
tOF
tSU(D)
tH(D)
tSU(L)
tH(L)
tTESTING
tSTAG
tSU(OE)
tGSW(ERROR)
tSU(ERROR)
tP(I/O)
tSW(ERROR)
fCLK
tP3,ON
tTP3,OFF
tREXT2,1
tREXT2,1
Parameter
Propagation Delay Time
Conditions
CLK - SDO
LD - OUTNn
OEN - OUTNn
Propagation Delay Time (Without Staggered
Output Delay)
Min
Typ
5
100
100
Propagation Delay Time
CLK
LD
Pulse Width
OEN (@IOUT < 60mA)
External Resistor Reaction Time
ns
ns
ns
500
Maximum CLK Fall Time
External Resistor Reaction Time
Unit
15
15
200
Maximum CLK Rise Time
Output Rise Time of VOUT (Turn Off)
Output Fall Time of VOUT (Turn On)
Setup Time for SDI
Hold Time for SDI
Setup Time for LD
Hold Time for LD
Minimum OEN Time for Error Detection
Staggered Output Delay
Output Enable Setup Time
Global Error Switching Setup Time
Global Error Detection Setup Time
Propagation Delay Global Error Flag
Switching Time Global Error Flag
Maximum Clock Frequency
(Cascade Operation)
Low-Current Test Mode
Propagation Delay Time
Max
10
200
200
10
ns
500
ns
100
100
200
300
20
40
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
5
5
5
5
2000
20
10
10
5
10
30
Turn ON
Turn OFF
Change from REXT1 = 372Ω, IOUT1
= 50.52mA to REXT2 = 37.2kΩ,
IOUT2 < 1mA
Change from REXT1 = 37.2kΩ,
IOUT1 = 0.5mA to REXT2 = 372Ω,
IOUT2 > 25mA
50
MHz
3
0.05
0.5
5
0.1
1
µs
µs
µs
0.5
1
µs
*
If multiple AS1109 devices are cascaded and tr or tf is large, it may be critical to achieve the timing required for data transfer between two
cascaded LED drivers.
Note: All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality
Control) methods.
www.ams.com/LED-Driver-ICs/AS1109
Revision 1.21
5 - 24
AS1109
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
Figure 3. Output Current vs. REXT,
VDD = 5V; VOUT = 0.8V, TAMB = 25°C
Figure 4. Relative Output Current Error vs. VDD,
Iout/Iout@VDD = 5V - 1, TAMB = 25°C
2
Relative Output Current Error (%)
.
100
IOUT (mA) .
1.5
1
0.5
10
REXT = 744Ω;
VDS = 0.5V
0
-0.5
REXT = 186Ω;
VDS = 0.8V
REXT = 372Ω;
VDS = 0.6V
-1
-1.5
1
100
1000
REXT (Ohm)
3
3.5
5
5.5
160
REXT = 127Ω
140
120
IOUT (mA) .
REXT = 150Ω
100
REXT = 186Ω
80
REXT = 251Ω
60
REXT = 372Ω
40
140
REXT = 127Ω
120
REXT = 150Ω
100
REXT = 186Ω
80
REXT = 251Ω
60
REXT = 372Ω
40
REXT = 744Ω
20
REXT = 744Ω
20
0
0
0
2
4
6
8
10
12
14
0
0.2
0.4
VDS (V)
0.6
0.8
1
1.2
1.4
VDS (V)
Figure 7. Relative IOUT Error vs. Temperature
VDD = 5V, Iout/Iout@25°C - 1, TAMB = 25°C
Figure 8. Output Current vs. VDD
1
Relative Output Current Error (%)
.
4.5
Figure 6. Output Current vs. VDS;
VDD = 5V, TAMB = 25°C
160
160
VDS = 1V
140
REXT = 372Ω;
VDS = 0.6V
IOUT (mA) .
0.5
0
4
VDD (V)
Figure 5. Output Current vs. VDS;
VDD = 5V, TAMB = 25°C
IOUT (mA) .
-2
10000
REXT = 186Ω;
VDS = 0.8V
REXT = 744Ω;
VDS = 0.5V
-0.5
120
VDS = 0.9V
100
VDS = 0.8V
80
VDS = 0.7V
60
VDS = 0.6V
40
VDS = 0.5V
20
-1
-50
0
-25
0
25
50
75
100
3
Temperature (°C)
www.ams.com/LED-Driver-ICs/AS1109
3.5
4
4.5
5
5.5
VDD (V)
Revision 1.21
6 - 24
AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
The AS1109 is designed to drive up to 8 LEDs through a fast serial interface and 8 constant-current output drivers. Furthermore, the AS1109
provides diagnostics for detecting open- or shorted-LEDs, as well as over-temperature conditions for LED display systems, especially LED traffic
sign applications.
The AS1109 contains an 8-bit shift register and an 8-bit data register, which convert serial input data into parallel output format. At AS1109 output
stages, eight regulated current sinks are designed to provide uniform and constant current with excellent matching between ports for driving
LEDs within a wide range of forward voltage variations. External output current is adjustable from 0.5 to 100mA using an external resistor for
flexibility in controlling the brightness intensity of LEDs. The AS1109 guarantees to endure 15V maximum at the outputs.
The serial interface is capable of operating at a minimum of 30 MHz, satisfying the requirements of high-volume data transmission.
Using a multiplexed input/output technique, the AS1109 adds additional functionality to pins SDO, LD and OEN. These pins provide highly useful
functions (open- and shorted-LED detection, over-temperature detection), thus reducing pin count. Over-temperature detection will work on-therun, whereas the open- and shorted-LED detection can be used on-the-run or in low-current diagnostic mode (see page 14).
Figure 9. AS1109 - Block Diagram
+VLED
OUTN0
OUTN1
OUTN2
OUTN3
OUTN4
Temperature
Detection
REXT
OUTN5
8-Bit Open Detection & Error Register
OUTN6
8-Bit Short
Detection & Error
Register
OUTN7
AS1109
Current
Generators
OEN
LD
8-Bit Data
Register
CLK
Detailed
Error
Detection
Global Error
Detection
8-Bit Shift
Register
SDI
Control Logic
SDO
Indicates 8 Bit Path
8.1 Serial Interface
Data accesses are made serially via pins SDI and SDO. At each CLK rising edge, the signal present at pin SDI is shifted into the first bit of the
internal shift register and the other bits are shifted ahead of the first bit. The MSB is the first bit to be clocked in. In error-detection mode the shift
register will latch-in the corresponding error data of temperature-, open-, and short-error register with each falling edge of LD.
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Revision 1.21
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AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
The 8-bit data register will latch the data of the shift register at each rising edge of LD. This data is then used to drive the current generator output
drivers to switch on the corresponding LEDs as OEN goes low.
8.2 Timing Diagrams
This section contains timing diagrams referenced in other sections of this data sheet.
Figure 10. Normal Mode Timing Diagram
tW(CLK)
50%
CLK
tSU(D)
SDI
50%
50%
50%
tH(D)
50%
SDO
50%
tP1
tW(L)
LD
50%
50%
tH(L)
tSU(L)
OEN
OEN Low = Output Enabled
OUTNx
OUTNx High = Output Off
50%
OUTNx Low = Output On
tP2
Figure 11. Output Delay Timing Diagram
tW(OE)
OEN
50%
50%
tP3
OUTN0
tP3
90%
90%
50%
tOR
tOF
tSTAG
tSTAG
50%
OUTN1
50%
7XtSTAG
50%
OUTN7
www.ams.com/LED-Driver-ICs/AS1109
50%
10%
10%
Revision 1.21
7XtSTAG
50%
8 - 24
AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 12. Data Input Timing Diagram
OEN
tW(OE)
tSU(L
LD
8 CLK Pulses
tSU(OE)
tW(L)
CLK
tSU(D)
Data Bit
7
SDI
Data Bit
6
Data Bit
5
Data Bit
4
Data Bit
3
Data Bit
2
Data Bit
1
Data Bit
0
Don’t Care
tH(D)
Old Data
Bit 7
SDO
Old Data
Bit 6
Old Data
Bit 5
Old Data
Bit 4
Old Data
Bit 3
Old Data
Bit 2
Old Data
Bit 1
Old Data
Bit 0
Don’t Care
tP1
Figure 13. Data Input Example Timing Diagram
Time = 0
1
2
3
4
5
6
7
D6
D5
D4
D3
D2
D1
D0
CLK
SDI
D7
LD
OEN
OUTN0
Off
On
OUTN1
Off
On
OUTN2
Off
On
OUTN3
Off
On
OUTN4
Off
On
OUTN5
Off
On
OUTN6
Off
On
OUTN7
Off
On
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AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 14. Switching Global Error Mode Timing Diagram
OEN
tTESTING
tGSW(ERROR)
LD
tGSW(ERROR)
tSU(ERROR)
tP(I/O)
tP(I/O)
tP(I/O)
tGSW(ERROR)
CLK
TFLAG(IN)
SDI
Don’t
Care
SDO
Acquisition of Error
Status
tP4
OFLAG(IN)
Don’t
Care
TFLAG
OFLAG
SFLAG(IN)
Don’t
Care
tSW(ERROR)
SFLAG
tSW(ERROR)
8.3 Error-Detection Mode
Acquisition of the error status occurs at the rising edge of OEN. Error-detection mode is started on the rising edge of LD when OEN is high. The
CLK signal must be low when entering error detection mode. Error detection for open- and shorted-LEDs can only be performed for LEDs that
are switched on during test time. To switch between error-detection modes clock pulses are needed (see Table 5).
Note: To test all LEDs, a test pattern that turns on all LEDs must be input to the AS1109.
8.4 Global Error Mode
Global error mode is entered when error-detection mode is started. Clock pulses during this period are used to select between temperature,
open-LED, and shorted-LED tests, as well as low-current diagnostic mode and shutdown mode (see Table 5). In global error mode, an error flag
(TFLAG, OFLAG, SFLAG) is delivered to pin SDO if any errors are encountered.
Table 5. Global Error Mode Selections
Clock
Pulses
Output Port
Error-Detection Mode
0
Don't Care
Over-Temperature Detection
1
Enabled
Open-LED Detection
2
Enabled
Shorted-LED Detection
3
Don't Care
Low-Current Diagnostic Mode
4
Don't Care
Shutdown Mode
Global Error Flag/Shutdown Condition
TFLAG = SDO = 1: No over-temperature warning.
TFLAG = SDO = 0: Over-temperature warning.
OFLAG = SDO = 1: No open-LED error.
OFLAG = SDO = 0: Open-LED error.
SFLAG = SDO = 1: No shorted-LED error.
SFLAG = SDO = 0: Shorted-LED error.
SDI = 1: Wakeup
SDI = 0: Shutdown
Note: For a valid result SDI must be 1 for the first device.
If there are multiple AS1109s in a chain, the error flag will be gated through all devices. To get a valid result at the end of the chain, a logic 1 must
be applied to the SDI input of the first device of the chain. If one device produces an error this error will show up after n*tP(I/O) + tSW(ERROR) at
pin SDO of the last device in the chain. This means it is not possible to identify which device in the chain produced the error. Therefore, if a global
error occurs, the detailed error report can be run to identify which AS1109, or LED produced the error.
Note: When no error has occurred, the detailed error report can be skipped, setting LD and subsequently OEN low.
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AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
8.5 Error Detection Functions
8.5.1
Open-LED Detection
The AS1109 open-LED detection is based on the comparison between VDS and VTHL. The open LED status is aquired at the rising edge of
OEN and stored internally. While detecting open-LEDs the output port must be turned on. Open LED detection can be started with 1 clock pulse
during error detection mode while the output port is turned on.
Note: LEDs which are turned off at test time cannot be tested.
Table 6. Open LED Detection Modes
Output Port State
On
On
8.5.2
Effective Output
Point Conditions
VDS < VTHL
VDS > VTHL
Detected Open-LED
Error Status Code
0
1
Meaning
Open Circuit
Normal
Shorted-LED
The AS1109 shorted-LED detection is based on the comparison between VDS and VTHH. The shortened LED status is acquired at the rising
edge of OEN and stored internally. While detecting shorted-LEDs the output port must be turned on. Shorted-LED detection can be started with
2 clock pulses during error detection mode while the output port is turned on.
For valid results, the voltage at OUTN0:OUTN7 must be lower then VTHH under low-current diagnostic mode operating conditions. This can be
achieved by reducing the VLED voltage or by adding additional diodes, resistors or LED’s.
Note: LEDs which are turned off at test time cannot be tested.
Table 7. Shorted LED Detection Modes
Output Port State
On
On
8.5.3
Effective Output
Point Conditions
VDS > VTHH
VDS < VTHH
Detected Shorted-LED
Error Status Code
0
1
Meaning
Short Circuit
Normal
Overtemperature
Thermal protection for the AS1109 is provided by continuously monitoring the device’s core temperature. The overtemperature status is aquired
at the rising edge of OEN and stored internally.
Table 8. Overtemperature Modes
Output Port State
Don’t Care
Don’t Care
www.ams.com/LED-Driver-ICs/AS1109
Effective Output
Point Conditions
Temperature > TOV1
Temperature < TOV1
Detected Overtemperature
Status Code
0
1
Revision 1.21
Meaning
Overtemperature Condition
Normal
11 - 24
AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
8.6 Detailed Error Reports
The detailed error report can be read out after global error mode has been run. On the falling edge of LD, the detailed error report of the selected
test is latched into the shift register and can be clocked out with n*8 clock cycles (n is the number of AS1109s in a chain) via pin SDO. At the
same time new data can be written into the shift register, which will load on the next rising edge of pin LD. This data will show at the output
drivers, at the falling edge of OEN.
8.6.1
Detailed Temperature Warning Report
The detailed temperature warning report can be read out immediately after global error mode has been run. Bit0 of the 8bit data word represents
the temperature flag of the chip.
Figure 15. Detailed Temperature Warning Report Timing Diagram
Global Flag Readout
Detailed Error Report Readout
OEN
tH(L)
tGSW(ERROR)
LD
t(SU)ERROR
tP4
CLK
SDI
DBit7
DBit6
DBit5
DBit4
DBit3
DBit2
DBit1
DBit0
Don’t
Care
New Data Input
SDO
TFLAG
Undefined
tP4
For detailed timing information see Timing Diagrams on page 8.
Temperature Error Report Output
TBit0
Don’t
Care
tP1
Detailed Temperature Warning Report Example
Consider a case where five AS1109s are cascaded in one chain. The detailed error report lists the temperatures for each device in the chain:
IC1:[70°] IC2:[85°] IC3:[66°] IC4:[160°] IC5:[76°]
In this case, IC4 is overheated and will generate a global error, and therefore 5*8 clock cycles are needed to write out the detailed temperature
warning report, and optionally read in new data. The detailed temperature warning report would look like this:
XXXXXXX1 XXXXXXX1 XXXXXXX1 XXXXXXX0 XXXXXXX1
The 0 in the detailed temperature warning report indicates that IC4 is the device with the over-temperature condition.
Note: In an actual report there are no spaces in the output.
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Revision 1.21
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AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
8.6.2
Detailed Open-LED Error Report
The detailed open-LED error report can be read out immediately after global error mode has been run.
Figure 16. Detailed Open-LED Error Report Timing Diagram
Global Flag Readout
Detailed Error Report Readout
OEN
tTESTING
LD
tH(L)
tSU(ERROR)
tGSW(ERROR)
tP4
tGSW(ERROR)
CLK
SDI
SDO
Acquisition of
Error Status
tGSW(ERROR)
DBit7
tSW(ERROR)
DBit6
DBit5
DBit4
DBit3
DBit2
DBit1
Don’t
Care
DBit0
New Data Input
TFlag
OFlag
OBit7
tP4
OBit6
OBit5
OBit4
OBit3
OBit2
OBit1
Open Error Report Output
OBit0
Don’t
Care
tP1
For detailed timing information see Timing Diagrams on page 8.
Detailed Open-LED Error Report Example
Consider a case where five AS1109s are cascaded in one chain. A 1 indicates a LED is on, a 0 indicates a LED is off, and an X indicates an open
LED. The open-LED test is only applied to LEDs that are turned on. This test is used with a test pattern where all LEDs are on at test time.
IC1:[11111111] IC2:[111XX111] IC3:[11111111] IC4:[1X111111] IC5:[11111111]
IC2 has two open LEDs and IC4 has one open LED switched on due to input. 5*8 clock cycles are needed to write the entire error code out. The
detailed error report would look like this:
Input Data: 1 1 1 1 1 1 1 1
11111111
11111111
11111111
11111111
LED Status: 1 1 1 1 1 1 1 1
111XX111
11111111
1X111111
11111111
Failure Code: 1 1 1 1 1 1 1 1
11100111
11111111
10111111
11111111
Comparing this report with the input data indicates that IC2 is the device with two open LEDs at position 4 and 5 and IC4 with an open LED at
second position. For such a test it is recommended to enter low-current diagnostic mode first (see Low-Current Diagnostic Mode on page 14) to
reduce onscreen flickering.
Note: In an actual report there are no spaces in the output.
LEDs turned off during test time cannot be tested.
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Revision 1.21
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AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
8.6.3
Detailed Shorted-LED Error Report
The detailed shorted-LED error report can be read out immediately after global error mode has been run (see Global Error Mode on page 10).
Figure 17. Detailed Shorted-LED Error Report Timing Diagram
Global Flag Readout
Detailed Error Report Readout
OEN
tTESTING
LD
tSU(ERROR)
tH(L)
tGSW(ERROR)
tP4
tGSW(ERROR)
CLK
SDI
SDO
Acquisition of Error
Status
tGSW(ERROR)
DBit7
DBit6
DBit5
tSW(ERROR)
TTFLAG
FLAG OFLAG
DBit4
DBit3
DBit2
DBit1
Don’t
Care
DBit0
New Data Input
SFLAG
SBit7
SBit6
SBit5
SBit4
SBit3
SBit2
SBit1
SBit0
Shorted-LED Error Report Output
tP4
Don’t
Care
tP1
For detailed timing information see Timing Diagrams on page 8.
Detailed Shorted-LED Error Report Example
Consider a case where five AS1109s are cascaded in one chain. A 1 indicates a LED is on, a 0 indicates a LED is off, and an X indicates a
shorted LED. This test is used with a test pattern where all LEDs are on at test time. Additionally, this test should be run after starting low-current
diagnostic mode (see Low-Current Diagnostic Mode on page 14).
IC1:[11111XX1] IC2:[11111111] IC3:[11111111] IC4:[111X1111] IC5:[11111111]
IC2 has two shorted LEDs and IC4 has one shorted LED switched on due to input. 5*8 clock cycles are needed to write the entire error code out.
The detailed error report would look like this:
Input Data: 1 1 1 1 1 1 1 1
11111111
11111111
11111111
11111111
LED Status: 1 1 1 1 1 X X 1
11111111
11111111
111X1111
11111111
Failure Code: 1 1 1 1 1 0 0 1
11111111
11111111
11101111
11111111
Showing IC1 as the device with two shorted LEDs at position 6 and 7, and IC4 with one shorted LED at position 4.
Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested.
8.6.4
Low-Current Diagnostic Mode
To run the open- or shorted-LED test, a test pattern must be used that will turn on each LED to be tested. This test pattern will cause a short
flicker on the screen while the test is being performed. The low-current diagnostic mode can be initiated prior to running a detailed error report to
reduce this on-screen flickering.
Note: Normally, displays using such a diagnosis mode require additional cables, resistors, and other components to reduce the current. The
AS1109 has this current-reduction capability built-in, thereby minimizing the number of external components required.
Low-current diagnostic mode can be initiated via 3 clock pulses during error-detection mode. After the falling edge of LD, a test pattern displaying
all 1s can be written to the shift register which will be used for the next error-detection test.
On the next falling edge of OEN, current is reduced to ILC. With the next rising edge of OEN the current will immediately increase to normal
levels and the detailed error report can be read out entering error-detection mode.
www.ams.com/LED-Driver-ICs/AS1109
Revision 1.21
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AS1109
Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 18. Switching into Low-Current Diagnostic Mode Timing Diagram
2µs Low-Current Diagnosis Mode
Global Flag Readout
Load Internal all 1s Test
Pattern
(optional)
OEN
LD
tSU(ERROR)
tH(L)
tGSW(ERROR)
tP4
tTESTING
tH(L)
CLK
tGSW(ERROR)
tSW(ERROR)
SDI
SDO
tGSW(ERROR)
Re-entering Error Detection
Mode
Don’t
Care
TFLAG OFLAG SFLAG
tP1
For detailed timing information see Timing Diagrams on page 8.
Normal Operation Current
8.7 Shutdown Mode
The AS1109 features a shutdown mode which can be entered via 4 clock pulses during error-detection mode. To enable the shutdown mode a 0
must be placed at SDI after the rising edge of the 3rd clock pulse.
To disable shutdown mode a 1 must be placed at SDI after the 3rd clock pulse. The shutdown/wakeup information will be latched through if
multiple AS1109 devices are in a chain. At the rising edge of the 4th clock pulse the shutdown bit will be read out and the AS1109 will shutdown
or wakeup.
Note: In shutdown mode the supply current drops down to typically 3µA.
Figure 19. Shutdown Mode Timing Diagram
OEN
LD
tSU(ERROR)
CLK
1 = Wakeup
SDI
SDO
0 = Shutdown
1 = Wakeup
TFLAG
OFLAG
SFLAG
tP4
www.ams.com/LED-Driver-ICs/AS1109
0 = Shutdown
tSU(D)
Revision 1.21
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AS1109
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9 Application Information
9.1 Error Detection
The AS1109 features two types of error detection. The error detection can be used on-the-fly, for active LEDs, without any delay, or by entering
into low-current diagnosis mode.
9.1.1
Error Detection On-The-Fly
Error detection on-the-fly will output the status of active LEDs during operation. Without choosing an error mode this will output the temperature
flag at every input/output cycle. Triggering one clock pulse for open or two clock pulses for short detection during error detection mode outputs
the detailed open- or short-error report with the next input/output cycle (see Figure 20). LEDs that are turned off cannot be tested and their digits
at the error output must be ignored.
Figure 20. Normal Operation with Error Detection During Operation – 128 Cascaded AS1109s
Display
SDI
SDO
CLK
OEN
Data1
Data2
Data2
GEF
T/O or S Error Code
Data1
Clock for Error
Mode 0x/1x/2x
1024x
Rising Edge of OEN
Acquisition of Error Status
Current
Data4
Data3
T/O or S Error Code Data0
Data0
LD
Data3
GEF
T/O or S Error Code
Data2
Clock for Error
Mode 0x/1x/2x
1024x
1024x
Rising Edge of OEN
Acquisition of Error Status
Falling Edge of LD; Error Register is copied
into Shift Register
Falling Edge of LD; Error Register is copied
into Shift Register
≤ 100mA
GEF = Global Error Flag
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Revision 1.21
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AS1109
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9.1.2
Error Detection with Low-Current Diagnosis Mode
This unique feature of the AS1109 uses an internal all 1s test pattern for a flicker free diagnosis of all LEDs. This error detection mode can be
started anytime, and does not require any SDI input (see Figure 21).
Figure 21. Low-Current Diagnosis Mode with Internal All 1s Test Pattern – 128 Cascaded AS1109s
2µs Low-Current Diagnosis Mode
Display
Data0
Data1
SDI
Data1
SDO
O or S Error Code of
All 1s Test Patern
GEF
3x Clocks LowCurrent Mode
Data2
GEF
Temperature Error Code
Clock for Error Mode
1x/2x
1024x
CLK
1024x
Rising Edge of OEN
Acquisition of Error Status
OEN
Falling Edge of LD; Error Register is copied into Shift Register
LD
Load Internal All 1s Test Pattern
Current
≤ 100mA
≤ 100mA
≤ 0.8mA
GEF = Global Error Flag
Low-current diagnosis mode is started with 3 clock pulses during error detection mode. After the three pulses of CLK, a pulse of LD loads the
internal all 1s test pattern. Then OEN should be enabled for 2µs for testing. With the rising edge of OEN the test of the LEDs is stopped and
while LD is high the desired error mode can be selected with the corresponding clock pulses.
With the next data input the detailed error code will be clocked out at SDO.
Note: See Figure 22 for the use of an external test pattern.
Figure 22. Low-Current Diagnosis Mode with External Test Pattern – 128 Cascaded AS1109s
Display
SDI
SDO
CLK
2µs Low-Current Diagnosis Mode
Data1
Data2
Data2
External all 1s Test Pattern
T/O or S Error Code
Data0
GEF
Temperature Error Code
Clock for Error
Mode 1x/2x
1024x
1024x
1024x
Rising Edge of OEN
Acquisition of Error Status
OEN
Falling Edge of LD; Error Register is copied into Shift Register
LD
Current
O or S Error Code
from Test Pattern
GEF
3x Clocks
Low-Current
Mode
Data3
≤ 100mA
≤ 100mA
≤ 0.8mA
GEF = Global Error Flag
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Revision 1.21
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AS1109
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9.2 Cascading Devices
To cascade multiple AS1109 devices, pin SDO must be connected to pin SDI of the next AS1109 (see Figure 23). At each rising edge of CLK the
LSB of the shift register will be written into the shift register SDI of the next AS1109 in the chain. Data at the SDI pin is clocked in at the rising
edge of the CLK pulse and is clocked out at the SDO pin 8.5 clock cycles later at the falling edge of the CLK pulse.
Note: When n*AS1109 devices are in one chain, n*8 clock pulses are needed to latch-in the input data.
Figure 23. Cascading AS1109 Devices
SDI
SDI
AS1109 #1
CLK
LD
SDO
OEN
SDI
AS1109 #2
CLK
SDO
LD
SDI
OEN
AS1109 #n-1
CLK
LD
SDO
OEN
CLK
LD
OEN
9.3 Constant Current
In LED display applications, the AS1109 provides virtually no current variations from channel-to-channel and from AS1109-to-AS1109. This is
mostly due to 2 factors:
While IOUT ≥ 50mA, the maximum current skew is less than ±2% between channels and less than ±2% between AS1109 devices.
In the saturation region, the characteristics curve of the output stage is flat
(see Figure 5 on page 6). Thus, the output current can be kept
constant regardless of the variations of LED forward voltages (VF).
9.4 Adjusting Output Current
The AS1109 scales up the reference current (IREF) set by external resistor (REXT) to sink a current (IOUT) at each output port. As shown in
Figure 3 on page 6 the output current in the saturation region is extremely flat so that it is possible to define it as target current (IOUT TARGET).
IOUT TARGET can be calculated by:
VREXT = 1.253V
IREF = VREXT/REXT (if the other end of REXT is connected to ground)
IOUT TARGET = IREF*15 = (1.253V/REXT)*15
(EQ 1)
(EQ 2)
(EQ 3)
Where:
REXT is the resistance of the external resistor connected to pin REXT.
VREXT is the voltage on pin REXT.
The magnitude of current (as a function of REXT) is around 100mA at 186Ω, 50.52mA at 372Ω and 25.26mA at 744Ω. Figure 3 on page 6
shows the relationship curve between the IOUT TARGET of each channel and the corresponding external resistor (REXT).
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Revision 1.21
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AS1109
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9.5 Package Power Dissipation
The maximum allowable package power dissipation (PD) is determined as:
PD(MAX) = (TJ-TAMB)/RTH(J-A)
When 8 output channels are turned on simultaneously, the actual package power dissipation is:
(EQ 4)
PD(ACT) = (IDD*VDD) + (IOUT*Duty*VDS*8)
(EQ 5)
Therefore, to keep PD(ACT) ≤ PD(MAX), the allowable maximum output current as a function of duty cycle is:
IOUT = {[(TJ-TAMB)/RTH(J-A)]-(IDD*VDD)}/VDS/Duty/8
(EQ 6)
Where:
TJ = 150ºC
9.6 Delayed Outputs
The AS1109 has graduated delay circuits between outputs. These delay circuits can be found between OUTNn and constant current block.
The fixed delay time is 20 ns (typ) where OUTN0 has no delay, OUTN1 has 20ns delay, OUTN2 has 40ns delay ... OUTN7 has 140ns delay. This
delay prevents large inrush currents, which reduce power supply bypass capacitor requirements when the outputs turn on (see Figure 12 on
page 9)
9.7 Switching-Noise Reduction
LED drivers are frequently used in switch-mode applications which normally exhibit switching noise due to parasitic inductance on the PCB.
9.8 Load Supply Voltage
Considering the package power dissipation limits (see EQ 4:6), the AS1109 should be operated within the range of
VDS = 0.4 to 1.0V.
For example, if VLED is higher than 5V, VDS may be so high that PD(ACT) > PD(MAX) where VDS = VLED - VF. In this case, the lowest possible
supply voltage or a voltage reducer (VDROP) should be used. The voltage reducer allows
VDS = (VLED -VF) - VDROP.
Note: Resistors or zener diodes can be used as a voltage reducer as shown in Figure 24.
Figure 24. Voltage Reducer using Resistor (Left) and Zener Diode (Right)
Voltage Supply
Voltage Supply
}
VLED
VF
VDROP
VDROP
{
VF
VDS
AS1109
AS1109
www.ams.com/LED-Driver-ICs/AS1109
VLED
VDS
Revision 1.21
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AS1109
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
10 Package Drawings and Markings
The product is available in a 16-pin SOIC-150, 16-pin QSOP-150, and 16-pin QFN 4x4mm package.
Figure 25. 16-pin SOIC-150 Package
AS1109B
YYWWRZZ
Symbol
A
A1
A2
b
c
D
E
E1
e
L
L1
L2
R
Min
0.10
1.25
0.31
0.17
0.40
0.07
Nom
9.90 BSC
6.00 BSC
3.90 BSC
1.27 BSC
1.40 REF
0.25 BSC
-
Max
1.75
0.25
0.51
0.25
1.27
-
Symbol
R1
h
Θ
Θ1
Θ2
aaa
bbb
ccc
ddd
eee
fff
ggg
N
Min
0.07
0.25
0º
5º
0º
-
Nom
0.10
0.20
0.10
0.25
0.10
0.15
0.15
16
Max
0.50
8º
15º
-
Notes:
1. Dimensioning & tolerancing conform
to ASME Y14.5M-1994.
2. All dimensions are in millimeters.
Angles are in degrees.
Marking: YYWWRZZ.
YY
WW
R
ZZ
Last two digits of the current year
Manufacturing Week
Plant identifier
Traceability code
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Revision 1.21
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AS1109
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
Figure 26. 16-pin QSOP-150 Package
AS1109B
YYWWRZZ
Symbol
A
A1
A2
b
c
D
E
E1
e
L
L1
L2
R
R1
h
Θ
Θ1
Θ2
aaa
bbb
ccc
ddd
eee
fff
N
Notes:
1. Dimensioning & tolerancing conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters. Angles are in degrees.
3. Datums A & B to be determined at Datum H.
Min
0.10
1.24
0.20
0.15
0.41
0.08
0.08
0.25
0º
5º
0º
-
Nom
4.90 BSC
6.00 BSC
3.91 BSC
0.635 BSC
1.04 REF
0.25 BSC
0.10
0.20
0.10
0.18
0.10
0.15
16
Max
1.75
0.25
0.30
0.25
1.27
0.51
8º
15º
-
Marking: YYWWRZZ.
YY
WW
R
ZZ
Last two digits of the current year
Manufacturing Week
Plant identifier
Traceability code
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Revision 1.21
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AS1109
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
Figure 27. 16-pin QFN 4x4mm Package
AS
1109B
YYWW
QZZ
Symbol
A
A1
A3
L
b
D
E
e
D2
E2
aaa
bbb
ccc
ddd
eee
fff
N
Notes:
1.
2.
3.
4.
5.
Dimensioning & tolerancing conform to ASME Y14.5M-1994.
All dimensions are in millimeters. Angles are in degrees.
Coplanarity applies to the exposed heat slug as well as the terminal.
Radius on terminal is optional.
N is the total number of terminals.
Min
0.70
0
0.45
0.25
2.00
2.00
-
Nom
0.75
0.02
0.20 REF
0.55
0.30
4.00 BSC
4.00 BSC
0.65 BSC
2.15
2.15
0.15
0.10
0.10
0.05
0.08
0.10
16
Max
0.80
0.05
0.65
0.35
2.25
2.25
-
Marking: YYWWQZZ.
YY
WW
Q
ZZ
Last two digits of the current year
Manufacturing Week
Plant identifier
Traceability code
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Revision 1.21
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AS1109
Datasheet - O r d e r i n g I n f o r m a t i o n
11 Ordering Information
The device is available as the standard products shown in Table 9.
Table 9. Ordering Information
Ordering Code
Marking
Description
Delivery Form
Package
AS1109-BSOU
AS1109B
Constant-Current, 8-Bit LED Driver with Diagnostics
Tubes
16-pin SOIC-150
AS1109-BSOT
AS1109B
Constant-Current, 8-Bit LED Driver with Diagnostics
Tape and Reel
16-pin SOIC-150
AS1109-BSSU
AS1109B
Constant-Current, 8-Bit LED Driver with Diagnostics
Tubes
16-pin QSOP-150
AS1109-BSST
AS1109B
Constant-Current, 8-Bit LED Driver with Diagnostics
Tape and Reel
16-pin QSOP-150
AS1109-BQFR
AS1109B
Constant-Current, 8-Bit LED Driver with Diagnostics
Tray
16-pin QFN (4x4mm)
AS1109-BQFT
AS1109B
Constant-Current, 8-Bit LED Driver with Diagnostics
Tape and Reel
16-pin QFN (4x4mm)
Note: All products are RoHS compliant.
Buy our products or get free samples online at www.ams.com/ICdirect
Technical Support is available at www.ams.com/Technical-Support
For further information and requests, email us at [email protected]
(or) find your local distributor at www.ams.com/distributor
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Revision 1.21
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AS1109
Datasheet - O r d e r i n g I n f o r m a t i o n
Copyrights
Copyright © 1997-2012, ams AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights
reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the
copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by ams AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. ams AG makes no
warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described
devices from patent infringement. ams AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior
to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in normal
commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability
applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing
by ams AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard
production flow, such as test flow or test location.
The information furnished here by ams AG is believed to be correct and accurate. However, ams AG shall not be liable to recipient or any third
party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or
indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the
technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of ams AG rendering of technical or other
services.
Contact Information
Headquarters
ams AG
Tobelbaderstrasse 30
A-8141 Unterpremstaetten, Austria
Tel
Fax
: +43 (0) 3136 500 0
: +43 (0) 3136 525 01
For Sales Offices, Distributors and Representatives, please visit:
http://www.ams.com/contact
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