AS1112BQFT austriamicrosystems, AS1112BQFT Datasheet - Page 11

• Manufacturer Part Number: AS1112BQFT
• Description: IC, LED DRIVER, CONSTANT CURRENT, TQFN32
• Manufacturer: austriamicrosystems

Specifications of AS1112BQFT

• Led Driver Application: LED Displays, LED Signboards And Display Backlights
• No. Of Outputs: 16
• Output Current: 80mA
• Output Voltage: 15V
• Input Voltage: 3V To 5.5V
• Topology: Constant Current
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AS1112
Data Sheet - D e t a i l e d D e s c r i p t i o n
Power Dissipation
To ensure proper operation of the device, the total power dissipation of the AS1112 must be below the power dissipa-
tion rating of the device package. Total power dissipation is calculated as:
Where:
V
I
V
I
DCn is the maximum dot correction value for OUTn;
n is the number of OUTn driving LED at the same time;
d
Operating Modes
The AS1112 operates in two modes
registers are in reset state at power-up.
Table 11. Operating Modes
Setting Dot Correction
The AS1112 can perform independent fine-adjustments to the output current of each channel, i.e., dot correction. Dot
correction is used to adjust brightness deviations of LEDs connected to the output channels (OUT0:OUT15).
The 16 channels can be individually programmed with a 6-bit word. The channel output can be adjusted in 64 steps
from 0 to 100% of the maximum output current (I
Where:
I
DCn is the programmed dot correction value for output (DCn = 0 to 63);
n = 0 to 15
Dot correction data are simultaneously entered for all channels. The complete dot correction data format consists of 16
x 6-bit words, which forms a 96-bit serial data packet
is clocked in with the MSB first.
Figure 9. Dot Correction Data Packet Format
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CC
MAX
MAX
PWM
CC
OUT
is the device supply current;
is the device supply voltage;
is the LED current adjusted by R
is the maximum programmable output current for each output;
DC15.5
is the device OUTn voltage when driving LED current;
is the duty cycle defined by pin OEN or the greyscale PWM value.
MSB
95
Mode
0
1
DC OUT15
...
DC15.0
90
Input Shift Register
DC14.5
89
PD = (V
192-bit
96-bit
(see Table
IREF
CC
;
x I
CC
11). Greyscale operating mode
MAX
I
OUTn
) + (V
DC OUT14:DC OUT1
). The output current for each OUTn channel can be calculated as:
Revision 1.04
(see Figure
= I
OUT
MAX
...
x I
x
MAX
DCn
63
9). Channel data is put on one by one, and the data
x n x
Dot Correction Data Input Mode
DCn
63
Greyscale PWM Mode
Operating Mode
(see Figure 12 on page 13)
d
PWM
DC1.0
6
)
DC0.5
5
DC OUT0
...
and the shift
DC0.0
LSB
0
(EQ 2)
(EQ 3)
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