A1391 ALLEGRO [Allegro MicroSystems], A1391 Datasheet - Page 14

• Manufacturer Part Number: A1391
• Description: Micro Power 3 V Linear Hall Effect Sensors withTri-State Output and User-Selectable Sleep Mode
• Manufacturer: ALLEGRO [Allegro MicroSystems]

A1391, A1392,
A1393, and A1395
Multiple A139x devices can be connected to a single micro-
processor or A-to-D converter input. In this case, a single
device is periodically triggered and put into active mode by
the microprocessor. While one A139x device is in active
mode, all of the other A139x devices must remain in sleep
mode. While these devices are in sleep mode, their outputs
are in a high-impedance state. In this circuit configuration,
the microprocessor reads the output of one device at a time,
Application Circuit with Multiple Hall Devices and a Single A-to-D Converter
Figure 6. Application circuit showing multiple A139x devices, controlled by a single microprocessor.
Micro Power 3 V Linear Hall Effect Sensors with
Tri-State Output and User Selectable Sleep Mode
C filter
A1
A2
A3
A4
Vbat1
Supply pin
A1
A2
A3
A4
Microprocessor
according to microprocessor input to the S ¯ ¯ L ¯ ¯ E ¯ ¯ E ¯ ¯ P ¯ pins.
When multiple device outputs are connected to the same
microprocessor input, pulse timing from the microproces-
sor (for example, lines A1 through A4 in figure 6) must be
configured to prevent more than one device from being in the
awake mode at any given time of the application. A device
output structure can be damaged when its output voltage is
forced above the device supply voltage by more than 0.1 V.
I/O
C
C
C
C
bypass
bypass
bypass
bypass
Vbat2
Vbat2
Vbat2
Vbat2
GND
GND
VCC
OUT
GND
VCC
OUT
VCC
OUT
GND
VCC
OUT
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
A139x
A139x
A1391x
A139x
SLEEP
SLEEP
SLEEP
SLEEP
VREF
VREF
GND
VREF
GND
GND
VREF
GND
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