www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 12 - 24
AS1110
Datasheet - Detailed Description
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.
8.5.2 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 V
THH 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.
8.5.3 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 6. Open LED Detection Modes
Output Port State
Effective Output
Point Conditions
Detected Open-LED
Error Status Code
Meaning
On V
DS < VTHL 0 Open Circuit
On VDS > VTHL 1 Normal
Table 7. Shorted LED Detection Modes
Output Port State
Effective Output
Point Conditions
Detected Shorted-LED
Error Status Code
Meaning
On V
DS > VTHH 0 Short Circuit
On V
DS < VTHH 1 Normal
Table 8. Overtemperature Modes
Output Port State
Effective Output
Point Conditions
Detected Overtemperature
Status Code
Meaning
Don’t Care Temperature > T
OV1 0 Overtemperature Condition
Don’t Care Temperature < T
OV1 1Normal
www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 13 - 24
AS1110
Datasheet - Detailed Description
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
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.
Global Flag Readout Detailed Error Report Readout
tH(L)
tP4
tP4
SDI
OEN
LD
CLK
SDO
New Data Input
TFLAG
DBit15
Undefined
Don’t
Care
Don’t
Care
Temperature Error Report Output
DBit14 DBit13 DBit12 DBitn DBit2 DBit1 DBit0
TBit0
t(SU)ERROR
tP1
For detailed timing information see Timing Diagrams on page 9.
tGSW(ERROR)
www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 14 - 24
AS1110
Datasheet - Detailed Description
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
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:
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.
Input Data:1111111111111111 1111111111111111 1111111111111111
LED Status:1111111111111111 111XX11111111X11 1111111111111111
Failure Code:1111111111111111 1110011111111011 1111111111111111
Acquisition of
Error Status
Global Flag Readout Detailed Error Report Readout
SDI
OEN
LD
CLK
SDO
tH(L)
Open Error Report Output
New Data Input
tP4
tP1
tP4
tSW(ERROR)
tSU(ERROR)
tTESTING
DBit0DBit1DBit2DBitnDBit12DBit13DBit14
OBit0OBit1OBit2OBitnOBit12OBit13OBit14
Don’t
Care
Don’t
Care
OBit15
TFlag OFlag
DBit15
For detailed timing information see Timing Diagrams on page 9.
tGSW(ERROR)
tGSW(ERROR)
tGSW(ERROR)

AS1110-BSST

Mfr. #:
Manufacturer:
ams
Description:
LED Display Drivers AS1110-BSST QSOP24 LF T&R
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet