Allegro MicroSystems A1569 User Manual

Overview
The A1569 is a unique integrated circuit which combines an
ultrasensitive Hall-effect switch with a linear programmable
current regulator which provides up to 150 mA for driving a
string of high brightness LEDs. This document accompanies
the Allegro A1569 Proto Board. The A1569 Proto Board is
intended to provide the user with a small format platform
for integrating the A1569 into their own prototype designs.
Refer to the latest A1569 datasheet for the operational speci-
fications of the A1569.
Description
The A1569 Proto Board is a small two-layer double-sided
PCB with the A1569 mounted on the front of the board. All
of the basic components are provided. If the A1569 Proto
Board is ordered with an LED installed (see below), the
only requirement is to connect power (VIN) and ground
(GND) via two of the through-hole connections on P1 (see
Figure 1, Figure 2, and Figure 3).
P1
3 SEN_EN
2
1
C
BYPASS
0.1 µF
P2
3
2
1
ASEK1569-UM
VIN
EXT
FADE
IREF
C R
FADE
IREF
1 µF
4.7 kΩ
Figure 1: A1569 Proto Board Schematic
A1569 Proto Board
Through-hole connections are provided for all of the exter-
nal connections that may be required for the target applica-
tion. All of the through-hole connections with square pads,
which are not labeled, are the ground connections. The
remaining through-hole connections, the ones with round
pads, are labeled for convenience on the bottom side of the
board (see Figure 3).
A mounting hole for a #2 screw is also provided (see upper-
right corner of Figure 2 and upper-left corner of Figure 3).
This screw should be nonferrous to prevent interference
with the operation of the Hall element.
LED Placement
There are three placement options for the LED supported by
the A1569 Demo Board. Only one option should be selected
at any given time, as the A1569 is designed to drive a single
string of LEDs.
The A1569 Proto Board can be ordered with an LED pre-
installed on the front side of the board (the same side as
1 4
LA
VIN LA
R
A1569KLJ-T
SEN_EN
4.7 kΩ
2
SEN_EN
3
EXT
5
FADE
6 9
IREF PAD
THTH 7 8
THTH GND
R
THTH
0 Ω (optional)
User Manual
By Peter Tengstrand
Allegro MicroSystems, LLC
LA
2
1
External
LED
LED1
Front
LED2
Back