AS1109-BSSU austriamicrosystems, AS1109-BSSU Datasheet - Page 18

• Manufacturer Part Number: AS1109-BSSU
• Description: IC LED 4-BIT CC DRIVER 16-SSOP
• Manufacturer: austriamicrosystems
• Type: General Purposer

Specifications of AS1109-BSSU

• Constant Current: *
• Constant Voltage: *
• Topology: *
• Number Of Outputs: *
• Internal Driver: *
• Type - Primary: *
• Type - Secondary: *
• Frequency: *
• Voltage - Supply: *
• Voltage - Output: *
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP
• Operating Temperature: *
• Current - Output / Channel: *
• Internal Switch(s): Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Efficiency: -

AS1109
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
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. Low-Current Diagnosis Mode with External Test Pattern – 128 Cascaded AS1109s
Cascading Devices
To cascade multiple AS1109 devices, pin SDO must be connected to pin SDI of the next AS1109
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
www.austriamicrosystems.com/LED-Driver-ICs/AS1109
Display
OEN
Current
CLK
LD
SDO
OEN
CLK
SDI
SDI
LD
Figure 22
External all 1s Test Pattern
SDI
T/O or S Error Code
for the use of an external test pattern.
Data1
1024x
Data0
AS1109 #1
CLK
≤ 100mA
LD
Low-Current
3x Clocks
OEN
Mode
SDO
≤ 0.8mA
SDI
Clock for Error
Mode 1x/2x
Rising Edge of OEN
Acquisition of Error Status
GEF
2µs Low-Current Diagnosis Mode
AS1109 #2
CLK
Falling Edge of LD; Error Register
is copied into Shift Register
Revision 1.20
LD
O or S Error Code
from Test Pattern
Data2
1024x
OEN
SDO
≤ 100mA
(see Figure
GEF
SDI
GEF = Global Error Flag
23). At each rising edge of CLK the
AS1109 #n-1
CLK
Temperature Error Code
LD
Data2
1024x
Data3
OEN
SDO
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