AS1109-BSSU austriamicrosystems, AS1109-BSSU Datasheet - Page 11

• 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 - 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
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
Note: To test all LEDs, a test pattern that turns on all LEDs must be input to the AS1109.
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
(T
Table 5. Global Error Mode Selections
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*t
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.
www.austriamicrosystems.com/LED-Driver-ICs/AS1109
Pulses
FLAG,
Clock
OEN
SDO
CLK
SDI
0
1
2
3
4
LD
O
FLAG,
Output Port
Don't Care
Don't Care
Don't Care
Enabled
Enabled
t
SU(ERROR)
S
FLAG
t
TESTING
Acquisition of
) is delivered to pin SDO if any errors are encountered.
Error Status
Low-Current Diagnostic Mode
Over-Temperature Detection
t
GSW(ERROR)
Shorted-LED Detection
Error-Detection Mode
Open-LED Detection
Shutdown Mode
t
P4
Don’t
Care
t
P(I/O)
t
GSW(ERROR)
T
T
O
O
S
S
SDI = 1: Wakeup
SDI = 0: Shutdown
FLAG
FLAG
FLAG
FLAG
FLAG
FLAG
Revision 1.20
T
FLAG(IN)
= SDO = 1: No over-temperature warning.
= SDO = 0: Over-temperature warning.
= SDO = 1: No shorted-LED error.
= SDO = 0: Shorted-LED error.
t
= SDO = 1: No open-LED error.
= SDO = 0: Open-LED error.
SW(ERROR)
T
FLAG
Global Error Flag/Shutdown Condition
Don’t
Care
t
P(I/O)
(see Table
O
FLAG(IN)
(see Table
O
FLAG
5). In global error mode, an error flag
5).
Don’t
Care
t
P(I/O)
t
SW(ERROR)
P(I/O)
S
t
GSW(ERROR)
FLAG(IN)
+ t
S
FLAG
SW(ERROR)
11 - 26
at