AS1110 Datasheet

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design.
Datasheet: AS1110 Constant-Current, 16-Channel LED Driver
with Diagnostics
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A S1110
Co nstant-C urrent, 16-C hannel LED Driver with Diagnostics
1 General Description
2 Key Features
16 Constant-current output channels
The AS1110 is designed to drive up to 16 LEDs through a fast serial
interface and features 16 output constant current drivers and an onchip diagnostic read-back function.
Excellent output current accuracy
- Between channels: <±3%
- Between devices: <±3%
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: 0.5mA 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.
Diagnostic 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: 10µA
Fast serial interface: 50MHz
The AS1110 also features a low-current diagnostic mode to minimize
display flicker during fault testing.
Cascaded configuration
The AS1110 is available in a 24-pin SSOP and the 28-pin QFN
(5x5mm) package.
Extremely fast output drivers suitable for PWM
24-pin SSOP and 28-pin QFN (5x5mm) 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
AS1110
SDI
CLK
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LD
OEN
OUTN15
OUTN14
OUTN13
OUTN12
OUTN11
OUTN10
OUTN9
OUTN8
OUTN7
OUTN6
OUTN5
OUTN4
OUTN3
OUTN2
OUTN1
OUTN0
+VLED
SDO
REXT
Revision 1.6
GND
VDD
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AS1110
Datasheet
4 Pin Assignments
OUTN8
OUTN9
OUTN10
OUTN11
OUTN12
22
OUTN13
23
OUTN14
VDD
REXT
24
OUTN15
GND
25
OEN
GND
26
SDO
GND
27
REXT
GND
28
CLK
1
21 SDO
VDD
SDI
Figure 2. Pin Assignments (Top View)
24 23 22 21 20 19 18 17 16 15 14 13
OUTN3
6
16 OUTN12
OUTN4
7
AS1110
24-pin SSOP
14
1
GND
13
OUTN10
OUTN7
12
OUTN9
OUTN6
11
N/C
10
OUTN8
9
OUTN5
15 OUTN11
8
2
3
4
5
6
7
8
9
10 11 12
OUTN7
17 OUTN13
OUTN6
5
OUTN5
OUTN2
OUTN4
18 OUTN14
OUTN3
28-pin QFN 5x5
OUTN2
4
OUTN1
OUTN1
OUTN0
AS1110
19 OUTN15
LD
20 OEN
3
CLK
2
SDI
LD
OUTN0
4.1 Pin Descriptions
Table 1. Pin Descriptions
Pin Number
Pin Name
Description
SSOP
QFN
1
24:27
GND
Ground
2
28
SDI
Serial Data Input
3
1
CLK
Serial Data Clock. The rising edge of the CLK signal is used to clock data into and out of the
AS1110 shift register. In error mode, the rising edge of the CLK signal is used to switch error
modes.
4
2
LD
Serial Data Load
5:20
3:10
12:19
OUTN0:15
Output Current Drivers. These pins are used as LED drivers or for input sense for
diagnostic modes. Data is transferred to the data register at the rising edge of these pins.
OEN
Output Enable. The active-low pin OEN signal can always enable output drivers to sink
current independent of the AS1110 mode.
0 = Output drivers are enabled.
1 = Output drivers are disabled.
21
20
22
21
SDO
Serial Data Output. In normal mode SDO is latched out 8.5 clock cycles after SDI is latched
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.
23
22
REXT
External Resistor Connection. This pin connects through the external resistor (REXT) to
GND, to setup the load current.
24
23
VDD
Positive Supply Voltage
-
11
N/C
Not connected
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Revision 1.6
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AS1110
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
VDD to GND
0
7
V
Input Voltage
-0.4
VDD
+0.4
V
Output Voltage
-0.4
15
V
2000
mA
24-pin SSOP package
2800
mA
28-pin QFN (5x5mm) package
88
ºC/W
on PCB, 24-pin SSOP package
23
ºC/W
on PCB, 28-pin QFN (5x5mm) package
GND Pin Current
Thermal Resistance ΘJA
Comments
Ambient Temperature
-40
+85
ºC
Storage Temperature
-55
150
ºC
Humidity
5
86
%
Non-condensing
kV
Norm: MIL 833 E method 3015
mA
EIA/JESD78
ºC
The reflow peak soldering temperature (body temperature)
specified is in accordance with IPC/JEDEC J-STD-020D
“Moisture/Reflow Sensitivity Classification for NonHermetic Solid State Surface Mount Devices”.
The lead finish for Pb-free leaded packages is matte tin
(100% Sn).
Electrostatic Discharge
Digital Outputs
2
All Other Pins
2
-100 (INOM x 0.5)
Latch-Up Immunity
Package Body Temperature
Moisture Sensitivity
Level
+100 +
INOM
+260
SOIC
3
Represents a maximum floor life of 168h
QFN
1
Represents an infinite floor lifetime
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Revision 1.6
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AS1110
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, TAMB = -40°C to +85ºC (unless otherwise specified).
Table 3. Electrical Characteristics
Symbol
Parameter
Condition
VDD
Supply Voltage
VDS
Output Voltage
IOUT
IOH
IDS(OFF)
VOL
VOH
V
V
100
SDO
-1.0
CLK, OEN, LD, SDI
SDO
5.5
15.0
Low Level
Output
Voltage
3.0
0
High Level
Output Leakage Current
Unit
0.5
SDO
Input Voltage
Max
OUTN0:15
Output Current
VIL
Typ
OUTN0:15, VDD = 5V (see Figure 7)
IOL
VIH
Min
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
V
µA
V
IAV(LC1)
Device-to-Device Average Output Current
from OUTN0 to OUTN15
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 OUTN15
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 OUTN15
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
VDS = 0.8V, VDD = 5.0V,
REXT = 372Ω, OUTN0:15 = On
%/ΔVDS
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)
Pulldown Resistance
LD
250
500
800
kΩ
VTHL
Error Detection Threshold Voltage
0.25
0.3
0.45
V
VTHH
Error Detection Threshold Voltage
VDD = 3.0V
1.2
1.3
1.4
VDD = 5.0V
2.0
2.2
2.4
TOV1
Overtemperature Threshold Flag
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26
mA
±3
%
51.55
mA
±2
%
104
mA
±1
±2
%
0.6
0.8
mA
10
20
µA
±1
49.50
±1
98
0.4
150
Revision 1.6
V
ºC
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AS1110
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‚ OUTN0:15 = Off
2.7
6
REXT = 744Ω‚ OUTN0:15 = Off
4.3
8
REXT = 372Ω‚ OUTN0:15 = Off
5.4
9
REXT = 186Ω, OUTN0:15 = Off
9.3
13
REXT = 744Ω‚ OUTN0:15 = On
6.2
11
REXT = 372Ω‚ OUTN0:15 = On
10.5
15
REXT = 186Ω‚ OUTN0:15 = On
19.5
26
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 for VDD = 5V
Symbol
Parameter
Conditions
Typ
Max
CLK - SDO
5
10
LD - OUTNn
100
200
OEN - OUTNn
100
200
tP1
tP2
Propagation Delay Time
(Without Staggered Output Delay)
tP3
tP4
Propagation Delay Time
10
tW(CLK)
tW(L)
tF
CLK
15
LD
15
OEN (@IOUT < 60mA)
200
Pulse Width
tW(OE)
tR
Min
Unit
ns
ns
ns
*
CLK Rise Time
500
ns
*
CLK Fall Time
500
ns
tOR
Output Rise Time of VOUT (Turn Off)
100
200
ns
tOF
Output Fall Time of VOUT (Turn On)
100
300
ns
tSU(D)
Setup Time for SDI
5
ns
tH(D)
Hold Time for SDI
5
ns
tSU(L)
Setup Time for LD
5
ns
tH(L)
Hold Time for LD
5
ns
tTESTING
OEN Time for Error Detection
2000
ns
tSTAG
Staggered Output Delay
tSU(OE)
Output Enable Setup Time
20
ns
tGSW(ERROR)
Global Error Switching Setup Time
10
ns
tSU(ERROR)
Global Error Detection Setup Time
10
ns
tP(I/O)
Propagation Delay Global Error Flag
5
ns
tSW(ERROR)
Switching Time Global Error Flag
10
ns
fCLK
Maximum Clock Frequency
(Cascade Operation)
tP3,ON
tP3,OFF
20
30
Low-Current Test Mode
Propagation Delay Time
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Revision 1.6
40
50
ns
MHz
Turn ON
3
5
µs
Turn OFF
0.05
0.1
µs
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AS1110
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 4. Switching Characteristics for VDD = 5V
Symbol
Parameter
Conditions
Typ
Max
Unit
tREXT2,1
External Resistor Reaction Time
Change from REXT1 = 372Ω, IOUT1
= 50.52mA to REXT2 = 37.2kΩ,
IOUT2 < 1mA
Min
0.5
1
µs
tREXT2,1
External Resistor Reaction Time
Change from REXT1 = 37.2kΩ,
IOUT1 = 0.5mA to REXT2 = 372Ω,
IOUT2 > 25mA
0.5
1
µs
*
If multiple AS1110 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.
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Revision 1.6
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AS1110
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; VDS = 0.8V, TAMB = 25°C
Figure 4. Relative Output Current Error vs. VDD,
[email protected]=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
-2
3
10000
3.5
4
REXT (Ω)
Figure 5. Output Current vs. VDS;
VDD = 5V, TAMB = 25°C
5
5.5
Figure 6. Output Current vs. VDS;
VDD = 5V, TAMB = 25°C
120
120
100
100
REXT = 186Ω
80
IOUT (mA) .
IOUT (mA) .
4.5
VDD (V)
REXT = 251Ω
60
REXT = 372Ω
40
20
REXT = 186Ω
80
REXT = 251Ω
60
REXT = 372Ω
40
20
REXT = 744Ω
0
REXT = 744Ω
0
0
3
6
9
12
15
0
VDS (V)
0.2
0.4
0.6
0.8
1
1.2
1.4
VDS (V)
Figure 7. Output Current vs. VDD
120
IOUT (mA) .
100
VDS = 0.8V
80
VDS = 0.7V
60
VDS = 0.6V
40
VDS = 0.5V
20
0
3
3.5
4
4.5
5
5.5
VDD (V)
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Revision 1.6
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AS1110
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
The AS1110 is designed to drive up to 16 LEDs through a fast serial interface and 16 constant-current output drivers. Furthermore, the AS1110
provides diagnostics for detecting open- or shorted-LEDs, as well as over-temperature conditions for LED display systems, especially LED traffic
sign applications.
The AS1110 contains an 16-bit shift register and an 16-bit data register, which convert serial input data into parallel output format. At AS1110
output stages, sixteen 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 AS1110 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 AS1110 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 15).
Figure 8. AS1110 - Block Diagram
Temperature
Detection
REXT
16-Bit Open
Detection & Error
Register
16-Bit Short
Detection & Error
Register
OUTN15
OUTN14
OUTN13
OUTN12
OUTN11
OUTN10
OUTN9
OUTN8
OUTN7
OUTN6
OUTN5
OUTN4
OUTN3
OUTN2
OUTN1
OUTN0
+VLED
AS1110
Current
Generators
OEN
LD
16-Bit Data
Register
CLK
Detailed
Error
Detection
Global Error
Detection
16-Bit Shift
Register
SDI
Control Logic
SDO
Indicates 16 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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AS1110
Datasheet - D e t a i l e d D e s c r i p t i o n
The 16-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 9. Normal Mode Timing Diagram
tW(CLK)
50%
CLK
tSU(D)
SDI
50%
50%
tH(D)
50%
50%
SDO
50%
tP1
tW(L)
LD
50%
50%
tSU(L)
OEN
tH(L)
OEN Low = Output Enabled
OUTNx
OUTNx High = Output Off
50%
OUTNx Low = Output On
tP2
Figure 10. Output Delay Timing Diagram
tW(OE)
OEN
50%
50%
tP3
OUTN0
tP3
90%
90%
50%
tOR
tOF
tSTAG
tSTAG
50%
OUTN1
50%
14XtSTAG
50%
OUTN15
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50%
10%
10%
Revision 1.6
14XtSTAG
50%
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AS1110
Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 11. Data Input Timing Diagram
OEN
tW(OE)
tSU(L)
LD
tSU(OE)
16 CLK Pulses
tW(L)
CLK
tSU(D)
Data Bit
15
SDI0
Data Bit
14
Data Bit
13
Data Bit
12
Data Bit
n
Data Bit
2
Data Bit
1
Data Bit
0
Don’t Care
tH(D)
Old Data
Bit 15
SDO0
Old Data
Bit 14
Old Data
Bit 13
Old Data
Bit 12
Old Data
Bit n
Old Data
Bit 2
Old Data
Bit 1
Old Data
Bit 0
Don’t Care
tP1
Figure 12. Data Input Example Timing Diagram
Time =
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
CLK
SDI
D1
LD
OEN
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
OUTN0
OUTN1
OUTN2
OUTN3
OUTN4
OUTN5
OUTN6
OUTN7
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
OUTN8
OUTN9
OUTN10
OUTN11
OUTN12
OUTN13
OUTN14
OUTN15
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AS1110
Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 13. 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
tP4
Acquisition of Error
Status
OFLAG(IN)
Don’t
Care
TFLAG
OFLAG
tSW(ERROR)
SFLAG(IN)
Don’t
Care
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 AS1110.
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 AS1110s 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 AS1110, 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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AS1110
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 AS1110 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 and will be shown as a logic 1 in the detailed error report.
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 AS1110 shorted-LED detection is based on the comparison between VDS and VTHH. The shortened LED status is aquired 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:OUTN15 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 and will be shown as a logic 1 in the detailed error report.
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 AS1110 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/AS1110
Effective Output
Point Conditions
Temperature > TOV1
Temperature < TOV1
Detected Overtemperature
Status Code
0
1
Revision 1.6
Meaning
Overtemperature Condition
Normal
12 - 24
AS1110
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. At 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*16 clock cycles (n is the number of AS1110s in a chain) via pin SDO. At the
same time new data can be written into the shift register, which is loaded on the next rising edge of pin LD. This pattern is shown 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. SDI must be 1 for the first device.
Bit0 of the 16bit data word represents the temperature flag of the chip.
Figure 14. 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
DBit15
DBit14 DBit13 DBit12
DBitn
DBit2
DBit1
DBit0
Don’t
Care
New Data Input
TFLAG
SDO
Undefined
Temperature Error Report Output
tP4
TBit0
Don’t
Care
tP1
For detailed timing information see Timing Diagrams on page 9.
Detailed Temperature Warning Report Example
Consider a case where four AS1110s are cascaded in one chain. The detailed error report lists the temperatures for each device in the chain:
IC1:[70°] IC2:[85°] IC3:[170°] IC4:[60°]
In this case, IC3 is overheated and will generate a global error, and therefore 4*16 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:
XXXXXXXXXXXXXXX1 XXXXXXXXXXXXXXX1 XXXXXXXXXXXXXXX0 XXXXXXXXXXXXXXX1
The 0 in the detailed temperature warning report indicates that IC3 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 1.6
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AS1110
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. SDI must be 1 for the first device.
Figure 15. 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)
tSW(ERROR)
DBit15
DBit14 DBit13 DBit12 DBitn
DBit2
DBit1
Don’t
Care
DBit0
New Data Input
TFlag
OFlag
OBit15 OBit14 OBit13 OBit12 OBitn
tP4
OBit2
Open Error Report Output
OBit1
OBit0
Don’t
Care
tP1
For detailed timing information see Timing Diagrams on page 9.
Detailed Open-LED Error Report Example
Consider a case where three AS1110s 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:[1111111111111111] IC2:[111XX11111111X11] IC3:[1111111111111111]
IC2 has three open LEDs switched on due to input. 3*16 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 1 1 1 1 1 1 1 1
1111111111111111
1111111111111111
LED Status: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 XX1 1 1 1 1 1 1 1 X1 1
1111111111111111
Failure Code: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1110011111111011
1111111111111111
Comparing this report with the input data indicates that IC2 is the device with two open LEDs at position 4 and 5 and one open LED at position
14. For such a test it is recommended to enter low-current diagnostic mode first (see Low-Current Diagnostic Mode on page 15) to reduce screen
flickering.
This test can be used also on-the-fly without using an all 1s test pattern (see Figure 19 on page 17).
Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested and will show a logic 1 in the
detailed error report.
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Revision 1.6
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AS1110
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 11).
SDI must be 1 for the first device.
Figure 16. 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)
DBit15
DBit14 DBit13 DBit12
tSW(ERROR)
TTFLAG
FLAG OFLAG
SFLAG
DBitn
DBit2
DBit1
New Data Input
SBit15
SBit14 SBit13 SBit12
SBitn
SBit2
SBit1
Shorted-LED Error Report Output
tP4
Don’t
Care
DBit0
SBit0
Don’t
Care
tP1
For detailed timing information see Timing Diagrams on page 9.
Detailed Shorted-LED Error Report Example
Consider a case where three AS1110s 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 on-the-fly.
IC1:[11111XX111111111] IC2:[1111111111111111] IC3:[X100011111111111]
IC1 has two shorted LEDs which are switched on, IC3 has one shorted LED switched off due to input. 3*16 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 1 1 1 1 1 1 1 1
1111111111111111
0100011111111111
LED Status: 1 1 1 1 1 X X 1 1 1 1 1 1 1 1 1
1111111111111111
X111111111111111
Failure Code: 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1
1111111111111111
1111111111111111
Showing IC1 as the device with two shorted LEDs at position 6 and 7, and IC3 with one shorted LED at position 1. The shorted LED at position 1
of IC3 cannot be detected, since LEDs turned off at test time are not tested and will show a logic "1" at the detailed error report. To test all LEDs
this test should be run with an all 1s test pattern. For a test with an all on test pattern, low-current diagnostic mode should be entered first to
reduce on-screen flickering.
Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested and will show a logic 1 in the
detailed error report.
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 diagnostic mode require additional cables, resistors, and other components to reduce the current. The
AS1110 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.
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Revision 1.6
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AS1110
Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 17. Switching into Low-Current Diagnostic Mode Timing Diagram
Low-Current
Diagnosis Mode
OEN
tTESTING
Load Internal all 1s Test
Pattern
(optional)
tSU(ERROR)
LD
tGSW(ERROR)
tH(L)
CLK
tGSW(ERROR)
tSW(ERROR)
SDI
SDO
Re-entering Error Detection
Mode
(see Figure 15)
(see Figure 16)
Don’t
Care
TFLAG OFLAG SFLAG
Normal Operation Current
tP1
For detailed timing information see Timing Diagrams on page 9.
8.7 Shutdown Mode
The AS1110 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 AS1110 devices are in a chain. At the rising edge of the 4th clock pulse the shutdown bit will be read out and the AS1110 will shutdown
or wakeup.
Note: In shutdown mode the supply current drops down to <10µA.
Figure 18. 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/AS1110
0 = Shutdown
tSU(D)
Revision 1.6
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AS1110
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 AS1110 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 19). LEDs turned off at test time are not tested and will show
a logic "1" at the detailed error report.
Figure 19. Normal Operation with Error Detection During Operation – 64 Cascaded AS1110s
Display
SDI
SDO
CLK
OEN
Data1
Data2
Data2
Data3
Data4
Data3
T/O or S Error Code Data0
Data0
T/O or S Error Code
Data1
GEF
Clock for Error
Mode 0x/1x/2x
T/O or S Error Code
Data2
GEF
Clock for Error
Mode 0x/1x/2x
1024x
1024x
1024x
Rising Edge of OEN
Acquisition of Error Status
Rising Edge of OEN
Acquisition of Error Status
Falling Edge of LD; Error Register is copied
into Shift Register
LD
Current
Falling Edge of LD; Error Register is copied
into Shift Register
≤ 100mA
GEF = Global Error Flag
9.1.2
Error Detection with Low-Current Diagnosis Mode
This unique feature of the AS1110 uses an internal all 1s test pattern for a flicker free diagnosis of all LEDs. This error detection mode can be
started at the end of each input cycle (see Figure 20).
Figure 20. Low-Current Diagnosis Mode with Internal All 1s Test Pattern – 64 Cascaded AS1110s
Low-Current Diagnosis Mode
Display
Data0
Data1
Data2
SDI
Data1
Data2
Data3
SDO
T/O or S Error Code
Data0
GEF
O or S Error Code from
GEF
All 1s Test Pattern
GEF
Temperature Error Code
3x Clocks Low- Clock for Error Mode
Current Mode
1x/2x
CLK
OEN
1024x
1024x
Rising Edge of OEN
Acquisition of Error Status
Use Internal All 1s Test Falling Edge of LD; Error Register is copied into Shift Register
Pattern
LD
Current
1024x
≤ 100mA
≤ 100mA
≤ 0.8mA
www.ams.com/LED-Driver-ICs/AS1110
GEF = Global Error Flag
Revision 1.6
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AS1110
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
The last pattern written into the shift register will be saved before starting low-current diagnosis mode and can be displayed immediately after the
test has been performed.
Low-current diagnostic mode is started with 3 clock pulses during error detection mode. Then OEN should be enabled for ≥2µs for testing. With
the rising edge of OEN the LED test is stopped, and while LD is high the desired error mode can be selected with the corresponding clock
pulses. After LD and OEN go low again the previously saved pattern can be displayed at the outputs.
With the next data input the detailed error code will be clocked out at pin SDO.
Note: See Figure 21 for use of an external test pattern.
Figure 21. Low-Current Diagnosis Mode with External Test Pattern – 64 Cascaded AS1110s
Low-Current Diagnosis Mode
Display
SDI
Data1
Data2
Data2
External all 1s Test Pattern
T/O or S Error Code
Data0
SDO
CLK
O or S Error Code
from Test Pattern
GEF
3x Clocks
Low-Current
Mode
Data3
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
≤ 100mA
≤ 100mA
≤ 0.8mA
GEF = Global Error Flag
9.2 Cascading Devices
To cascade multiple AS1110 devices, pin SDO must be connected to pin SDI of the next AS1110 (see Figure 22). At each rising edge of CLK the
LSB of the shift register will be written into the shift register SDI of the next AS1110 in the chain.
Note: When n*AS1110 devices are in one chain, n*16 clock pulses are needed to latch-in the input data.
Figure 22. Cascading AS1110 Devices
SDI
SDI
AS1110 #1
CLK
LD
SDO
OEN
SDI
AS1110 #2
CLK
LD
SDO
OEN
SDI
AS1110 #n-1
CLK
LD
SDO
OEN
CLK
LD
OEN
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Revision 1.6
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AS1110
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9.3 Constant Current
In LED display applications, the AS1110 provides virtually no current variations from channel-to-channel and from AS1110-to-AS1110. This is
mostly due to 2 factors:
While IOUT ≥ 10mA, the maximum current skew is less than ±3% between channels and less than ±6% between AS1110 devices.
In the saturation region, the characteristic curve of the output stage is flat (see Figure 5 on page 7). Thus, the output current can be kept
constant regardless of the variations of LED forward voltages (VF).
9.4 Adjusting Output Current
The AS1110 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 7 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 50.52mA at 372Ω and 25.26mA at 744Ω. Figure 3 on page 7 shows the relationship
curve between the IOUT TARGET of each channel and the corresponding external resistor (REXT).
9.5 Package Power Dissipation
The maximum allowable package power dissipation (PD) is determined as:
PD(MAX) = (TJ-TAMB)/RTH(J-A)
When 16 output channels are turned on simultaneously, the actual package power dissipation is:
PD(ACT) = (IDD*VDD) + (IOUT*Duty*VDS*16)
(EQ 4)
(EQ 5)
Therefore, to keep PD(ACT) ≤ PD(MAX), the maximum allowed output current as a function of duty cycle is:
IOUT = {[(TJ-TAMB)/RTH(J-A)]-(IDD*VDD)}/VDS/Duty/16
(EQ 6)
Where:
TJ = 150ºC
9.6 Delayed Outputs
The AS1110 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 ... OUTN15 has 300ns delay.
This delay prevents large inrush currents, which reduce power supply bypass capacitor requirements when the outputs turn on (see Figure 11 on
page 10)
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 AS1110 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 23.
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Revision 1.6
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AS1110
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
Figure 23. Voltage Reducer using Resistor (Left) and Zener Diode (Right)
Voltage Supply
Voltage Supply
}
VLED
VF
VDROP
VDROP
{
VF
VDS
VDS
AS1110
AS1110
www.ams.com/LED-Driver-ICs/AS1110
VLED
Revision 1.6
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AS1110
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 AS1110 is available in a 28-pin QFN (5x5mm) package and a 24-pin SSOP package.
-A-
Figure 24. 28-pin QFN (5x5mm) Package
D
INDEX AREA
(D/2 xE/2)
D2
D2/2
D/2
-B-
2
1
N N-1
6
INDEX AREA
(D/2 xE/2)
TOP VIEW
SEE
DETAIL B
4
Datum A or B
NXb
-A-
aaa C 2x
-BSEE
DETAIL B
aaa C 2x
5
bbb
ddd
C A B
C
BTM VIEW
0.08 C
A
L1
ccc C
NX
ODD TERMINAL SIDE
Min
0.70
0.00
0.45
0.03
SEATING
PLANE
-C-
SIDE VIEW
Typ
0.75
0.02
0.20 REF
0.55
0.15
0.10
0.10
0.05
0.08
0.10
Terminal Tip
5
Max
0.80
0.05
0.65
0.15
Notes
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2
Symbol
D BSC
E BSC
D2
E2
K
b
e
N
ND
NE
A3
A1
e
Symbol
A
A1
A3
L
L1
aaa
bbb
ccc
ddd
eee
ggg
E2
E
e
E2/2
NXL
E/2
4
Min
3.00
3.00
0.20
0.18
Typ
5.00
5.00
3.15
3.15
0.25
0.50
28
7
7
Max
3.25
3.25
0.30
Notes
1, 2
1, 2
1, 2
1, 2
1, 2
1, 2, 5
1, 2
1, 2, 5
1, 2, 5
Notes: Unilateral coplanarity zone applies to the exposed heat sink slug as well as the terminals.
1.
2.
3.
4.
Dimensioning and tolerancing conform to ASME Y14.5M-1994.
All dimensions are in millimeters; angles in degrees.
N is the total number of terminals.
The terminal #1 identifier and terminal numbering convention shall conform to JEDEC 95 SPP-012. Details of terminal #1 identifier are
optional but must be located within the zone indicated. The terminal #1 identifier may be either a mold or marked feature.
5. Dimension b applies to metallized terminal and is measured between 0.15 and 0.30mm from terminal tip. If one end of the terminal has the
optional radius, the b dimension should not be measured in that radius area.
6. Dimensions ND and NE refer to the number of terminals on each D and E side, respectively.
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Revision 1.6
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AS1110
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 25. 24-pin SSOP Package
Symbol
A
A1
A2
b
C
D
E
E1
e
h
L
θ
Min
Max
1.35
1.75
0.10
0.25
1.37
1.57
0.20
0.30
0.19
0.25
8.55
8.74
5.79
6.20
3.81
3.99
0.635 BSC
0.22
0.49
0.40
1.27
0º
8º
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AS1110
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
Description
Delivery Form
Package
AS1110-BSSU
Constant-Current, 16-Channel LED Driver with Diagnostics
Tubes
24-pin SSOP
AS1110-BSST
Constant-Current, 16-Channel LED Driver with Diagnostics
Tape and Reel
24-pin SSOP
AS1110-BQFR
Constant-Current, 16-Channel LED Driver with Diagnostics
Tray
28-pin QFN (5x5mm)
AS1110-BQFT
Constant-Current, 16-Channel LED Driver with Diagnostics
Tape and Reel
28-pin QFN (5x5mm)
Note: All products are RoHS compliant and Pb-free.
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 1.6
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AS1110
Datasheet
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:
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