A1140 Allegro MicroSystems, A1140 Datasheet - Page 8

• Manufacturer Part Number: A1140
• Description: Sensitive Two-Wire Chopper-Stabilized Unipolar Hall-Effect Switches
• Manufacturer: Allegro MicroSystems

For additional general application information, visit the Allegro
MicroSystems Web site at www. allegromicro.com.
Typical Application Circuit
The A114x family of devices must be protected by an external
bypass capacitor, C
and the ground, GND, of the device. C
noise and the noise generated by the chopper-stabilization func-
tion. As shown in fi gure 3, a 0.01 µF capacitor is typical.
Installation of C
the A114x pins are no greater than 5 mm in length.
All high-frequency interferences conducted along the supply
lines are passed directly to the load through C
only to protect the A114x internal circuitry. As a result, the load
ECU (electronic control unit) must have suffi cient protection,
other than C
A series resistor on the supply side, R
nation with C
information on EMC is provided on the Allegro MicroSystems
Web site.)
When determining the minimum V
device, the voltage drops across R
R
R
A1140-DS
SENSE
SENSE
, must be taken into consideration. The typical value for
is approximately 100 Ω.
BYP
BYP
Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches
, installed in parallel with the A114x.
BYP
, creates a fi lter for EMI pulses. (Additional
BYP
must ensure that the traces that connect it to
, connected between the supply, VCC,
S
CC
and the ECU sense resistor,
S
requirement of the A114x
BYP
(not shown), in combi-
reduces both external
BYP
, and it serves
Application Information
A1140/41/42/43
Figure 3. Typical application circuit
V+
A
GND
A114x
ECU
VCC
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
R
GND
SENSE
A
B
Package UA Only
Maximum separation 5 mm
B
B
C
0.01 uF
BYP
8