AAT2400 Datasheet, PDF (17/32 Pages) Skyworks Solutions Inc. – Sixteen-Channel White LED Driver Solution

DATA SHEET
AAT2400/2401
Sixteen-Channel White LED Driver Solution
with Full LED Current and Timing Control
Fault Reporting
Each device possesses fault reporting registers and a
fault flag. An open or short condition on each current
sink is reported in one of four fault registers. An open
fault condition is only monitored for LED current sink on-
times of greater than 10µs. An over-temperature condi-
tion is reported in one of two registers. These conditions
may selectively be reported on the open drain Fault pin.
Bits in separate fault reporting registers can be set or
reset to enable or disable a particular fault condition.
The shorted LED fault condition is handled in a special
way because of the uncertainty associated with shorted
LEDs and the LED forward voltage variation. To detect a
shorted LED fault in the system, all LED channels should
be programmed to be conducting for at least 1ms. The
fault flag will only be valid 1ms after a given LED string
has begun conducting. If the fault flag becomes active,
the fault registers must be read while the channels remain
conducting. The fault reporting register defaults to the
condition of reporting the short detect, so this register
must be cleared prior to checking for shorted LEDs.
Severe LED forward voltage (V_F) mismatches between
channels will also be reported as a short fault condition
with the lower V_F channels indicating the fault condition.
Fault Registers
The fault registers can be read anytime during opera-
tion.
ADDR:
E2h
Fault2:
This Register Reports Fault
Conditions and High Voltage CS Pins
Bit
Bit Name Default Access
Description
1:0
CS5
Fault
00h
3:2
CS6
Fault
00h
R
00: no fault, 01: open,
10: short
R
00: no fault, 01: open,
10: short
5:4
CS7
Fault
00h
R
00: no fault, 01: open,
10: short
7:6
CS8
Fault
00h
R
00: no fault, 01: open,
10: short
Table 12: Fault2 Register Settings.
ADDR:
E4h
Fault3:
This Register Reports Fault
Conditions And High Voltage CS Pins
Bit
Bit Name Default Access
Description
1:0
CS9
Fault
00h
3:2
CS10
Fault
00h
5:4
CS11
Fault
00h
7:6
CS12
Fault
00h
R
00: no fault, 01: open,
10: short
R
00: no fault, 01: open,
10: short
R
00: no fault, 01: open,
10: short
R
00: no fault, 01: open,
10: short
Table 13: Fault3 Register Settings.
Fault1:
This Register Reports Fault
ADDR: E0h Conditions And High Voltage CS Pins
Bit
Bit Name Default Access
Description
1:0
CS1
Fault
00h
3:2
CS2
Fault
00h
5:4
CS3
Fault
00h
7:6
CS4
Fault
00h
R
00: no fault, 01: open,
10: short
R
00: no fault, 01: open,
10: short
R
00: no fault, 01: open,
10: short
R
00: no fault, 01: open,
10: short
Table 11: Fault1 Register Settings.
Fault4:
This Register Reports Fault
ADDR: E6h Conditions and High Voltage CS Pins
Bit
Bit Name Default Access
Description
1:0
CS13
Fault
00h
3:2
CS14
Fault
00h
R
00: no fault, 01: open,
10: short
R
00: no fault, 01: open,
10: short
5:4
CS15
Fault
00h
R
00: no fault, 01: open,
10: short
7:6
CS16
Fault
00h
R
00: no fault, 01: open,
10: short
Table 14: Fault4 Register Settings.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
202307A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 24, 2012
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