AS1112 austriamicrosystems AG, AS1112 Datasheet - Page 10

• Manufacturer Part Number: AS1112
• Description: 16-Channel LED Driver
• Manufacturer: austriamicrosystems AG

AS1112
Datasheet - D e t a i l e d D e s c r i p t i o n
Figure 8. Error Detection Timing (GS=FFFF
Note: The rising edge of LD latches new data into the internal registers depending on the logic level of the pin
Delay Between Outputs
The AS1112 uses graduated delay circuits between OUTn outputs. These circuits are contained in the constant-current
driver block of the AS1112
The maximum delay is 450ns (typ) from OUT0 to OUT15. The delay scheme works by switching on and switching off
each output channel. Thus the on/off time of each channel is the same regardless of the delay. These delays prevent
large inrush currents and switching noise that can reduce bypass capacitance when the outputs are switched on.
OUTn Enable
All OUTn channels can be collectively switched off with one signal. When OEN is set to 1, all OUTn channels are dis-
abled, regardless of the device logic operations. The greyscale counter is also reset when OEN is set to 1.
When OEN is set to 0, all OUTn channels are in normal operation.
Table 10. Pin OEN Truth Table
Setting Maximum Channel Current
The maximum output current per channel is programmed by a single resistor, R
and GND. The voltage on pin I
equivalent to the current flowing through R
as:
Where:
V
R
Figure 5 on page 7
between I
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IREF
IREF
= 1.24V;
= User-selected external resistor.
MODE. If the pin MODE is tied GND, the greyscale registers are updated. If the pin MODE is tied to V
dot correction registers are updated.
OEN
REF
0
1
terminal to GND, and I
GSCLK
OEN
shows the maximum output current I
SID
LD
(see Figure 1 on page
Normal Operation
OUT0:OUT15
REF
Disabled
is set by an internal band gap V
OUT
is the constant output current of OUT0:OUT15.
Detection
IREF
HEX
Error
Start
multiplied by a factor of 31.5. The maximum output current is calculated
I
, DC=3F
MAX
1). The average-delay time is 30ns (typ).
=
Revision 1.06
LODn, LSDn
OUT
R
HEX
V
IREF
IREF
)
versus R
>1µs
x 31.5
IREF
IREF
(1.24V typ). The maximum channel current is
, where R
IREF
Detection
LODn+1, LSDn+1
IREF
, which is placed between pin I
Error
End
is the value of the resistor
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CC
(EQ 1)
10 - 18
, the
REF