AAT3103IJQ-1-T1 AAT [Advanced Analog Technology, Inc.], AAT3103IJQ-1-T1 Datasheet - Page 9

• Manufacturer Part Number: AAT3103IJQ-1-T1
• Description: 3-Channel Charge-Pump LED Driver
• Manufacturer: AAT [Advanced Analog Technology, Inc.]

Part Number Descriptions
S
(AAT3103-1/-2 only)
The LED output current of the AAT3103-1/-2 is controlled
by AnalogicTech’s S
current is programmable, no PWM or additional control
circuitry is needed to control the LED brightness. This
feature greatly reduces the burden on a microcontroller
or system IC to manage LED or display brightness, allow-
ing the user to “set it and forget it.” With its high-speed
serial interface (1MHz data rate), the LED current can be
ChargePump
3103.2008.03.1.0
S
2
Part Number
Cwire Serial Interface
2
AAT3103IJQ-1
AAT3103IJQ-2
AAT3103IJQ-4
C Data
Table 1: AAT3103-1 LED Current Settings,
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
EN Rising Edges D1-D3 Current (mA)
Data Reg
TM
EN/SET
2
Cwire serial interface. Since the LED
R
10
11
12
13
14
15
16
Interface
1
2
3
4
5
6
7
8
9
SET
S
S
2
2
PWM
Cwire
Cwire
= 14.3kΩ.
1
Current Control,
Figure 1: S
Inverting
2
16-step
8-step
Linear
20.1
18.8
17.5
16.1
14.8
13.4
12.1
10.7
1.34
0.67
9.4
8.1
6.7
5.4
4.0
2.7
T
w w w . a n a l o g i c t e c h . c o m
LO
n-1
2
0
Cwire Serial Interface Timing.
T
HI
n ≤ 16
T
LAT
changed quickly and easily. Also the non-pulsating LED
current reduces system noise and improves LED reliabil-
ity. The S
edges to the EN/SET pin to set the register. A typical
write protocol is a burst of EN/SET rising edges, followed
by a pause with EN/SET held high for at least t
The programmed current is then seen at the current
source outputs. When EN/SET is held low for an amount
of time longer than t
shutdown mode and draws less than 1μA from the input
and the internal data register is reset to zero.
The AAT3103-1/-2’s serial interface reduces the LED cur-
rent on each rising pulse of the enable input. If the
AAT3103 is in shutdown, the first rising edge of the EN/
SET input turns on the LED driver to the maximum cur-
rent. Successive rising edges decrease the LED current as
shown in Table 1 and Figure 2 for the AAT3103-1. For the
AAT3103-2, Table 2 and Figure 3 illustrate an 8-step LED
current control profile. .
Figure 2: AAT3103-1 Current Control Profile,
3-Channel Charge-Pump LED Driver
25
20
15
10
5
0
2
1
Cwire interface relies on the number of rising
2
3
n-1
4
S
OFF
R
2
5
PRODUCT DATASHEET
C Wire Interface Data Code
SET
(500μs), the AAT3103 enters into
T
6
OFF
= 14.3kΩ.
7
8
AAT3103
9
10 11 12 13 14 15 16
0
LAT
(500μs).
9