www.austriamicrosystems.com/LED-Driver-ICs/AS1113

Revision 1.04

18 - 24

AS1113

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 dis-

played 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 20 for use of an external test pattern.

Figure 20. Low-Current Diagnosis Mode with External Test Pattern – 64 Cascaded AS1113s

Cascading Devices

To cascade multiple AS1113 devices, pin SDO must be connected to pin SDI of the next AS1113 (see Figure 21). At

each rising edge of CLK the LSB of the shift register will be written into the shift register SDI of the next AS1113 in the

chain.

Note: When n*AS1113 devices are in one chain, n*16 clock pulses are needed to latch-in the input data.

Figure 21. Cascading AS1113 Devices

Temperature Error Code

Data2

Data1

Data2

Data3

GEF

GEF

T/O or S Error Code

Data0

Rising Edge of OEN

Acquisition of Error Status

Display

SDI

SDO

CLK

OEN

LD

1024x

1024x

3x Clocks

Low-Current

Mode

Clock for Error

Mode 1x/2x

Falling Edge of LD; Error Register

is copied into Shift Register

O or S Error Code

from Test Pattern

1024x

GEF = Global Error Flag

Low-Current Diagnosis Mode

≤ 50mA

≤ 50mA

Current

≤ 0.8mA

External all 1s Test Pattern

AS1113 #n-1

SDI

SDO

CLK

LD

OEN

SDI

CLK

LD

OEN

AS1113 #1

SDI

SDO

CLK

LD

OEN

AS1113 #2

SDI

SDO

CLK

LD

OEN