A1354 Datasheet, PDF (1/22 Pages) Allegro MicroSystems – High Precision 2-Wire Linear Hall Effect Sensor IC with Pulse Width Modulated Output

A1354
High Precision 2-Wire Linear Hall Effect Sensor IC
with Pulse Width Modulated Output
Features and Benefits
▪ Designed for automotive, battery-powered applications
▪ Customer programmable quiescent duty cycle, sensitivity,
and PWM carrier frequency, through VCC pin
▪ Simultaneous programming of duty cycle, sensitivity, and
PWM carrier frequency, for system optimization
▪ Factory programmed sensitivity temperature coefficient
and quiescent duty cycle drift
▪ Selectable unidirectional or bidirectional quiescent
duty cycles
▪ Pulse width modulated (PWM) output provides increased
noise immunity compared to analog output
▪ Temperature-stable quiescent duty cycle output and
sensitivity
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Package: 4-pin SIP (suffix KT)
1 mm case thickness
Description
The A1354 device is a high precision, programmable 2-wire
Hall effect linear sensor IC with a pulse width modulated
(PWM) output. The duty cycle (D) of the PWM output signal
is proportional to the applied magnetic field. The A1354
device converts an analog signal from its internal Hall circuit
to a digitally encoded PWM output signal. The coupled noise
immunity of the digitally encoded PWM output is far superior
to the noise immunity of an analog output signal.
The BiCMOS, monolithic circuit inside of theA1354 integrates
a Hall element, precision temperature-compensating circuitry
to reduce the intrinsic sensitivity and offset drift of the Hall
element, a small-signal high-gain amplifier, proprietary
dynamic offset cancellation circuits, and PWM conversion
circuitry. The dynamic offset cancellation circuits reduce
the residual offset voltage of the Hall element. Hall element
offset is normally caused by device overmolding, temperature
dependencies, and thermal stress. The high frequency offset
cancellation (chopping) clock allows a greater sampling rate,
which increases the accuracy of the output signal and results
in faster signal processing capability.
The A1354 device is provided in a lead (Pb) free 4-pin single
inline package (KT suffix), with 100% matte tin leadframe
plating.
Not to scale
V_CC
VCC
Functional Block Diagram
Regulator
Programming
Logic
PWM Carrier
Generation
and Trimming
1
2
Switched
2
Capacitor
Control
1
Chopper
Switches
Amp
Temperature
Compensation
Programming
Interface
Sensitivity
and Sensitivity
TC Trim
Signal
Recovery
% Duty
Cycle
% Duty Cycle
Temperature
Coefficient
Voltage
Controlled
Current
Source
GND
RSens
A1354-DS, Rev. 1