A1356
High Precision Linear Hall-Effect Sensor IC
With an Open Drain Pulse Width Modulated Output
Features and Benefits
Description
▪ Simultaneous programming of PWM carrier frequency,
quiescent duty cycle, and sensitivity; for system
optimization
The A1356 device is a high precision, programmable open
drainHall-effectlinearsensorICwithapulsewidthmodulated
(PWM) output. The duty cycle (D) of the PWM output signal
is proportional to an applied magnetic field. TheA1356 device
converts an analog signal from its internal Hall element 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.
▪ Factory programmed sensitivity temperature coefficient
and quiescent duty cycle drift
▪ Programmability at end-of-line
▪ Pulse width modulated (PWM) output provides increased
noise immunity compared to an analog output
▪ Precise recoverability after temperature cycling
• Output duty cycle clamps provide short circuit diagnostic
capabilities
▪ Optional 50% duty cycle calibration test mode at device
power up
▪ Wide ambient temperature range: –40°C to 150°C
▪ Resistant to mechanical stress
▪ Advanced chopper stabilization circuits and differential
signal path design lead to very low output offset levels
▪ Proprietary on-chip filters provide high output resolution
▪ Wide power supply operating range: 4.5 to 18 V
TheBiCMOS,monolithiccircuitinsideoftheA1356integrates
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 for a greater sampling
rate, which increases the accuracy of the output signal and
results in faster signal processing capability.
Package: 3-pin SIP (suffix KB)
The A1356 sensor is provided in a lead (Pb) free 3-pin single
inline package (KB suffix), with 100% matte tin leadframe
plating.
Not to scale
Functional Block Diagram
PWM Carrier
Generation
VCC/
Programming
Regulator
PWM
Frequency Trim
1
2
2
1
Signal
Conditioning
PWMOUT
Signal
Recovery
Chopper
Switches
Amp
% Duty
Cycle
Sensitivity
Trim
Temperature
Compensation
% Duty Cycle
Temperature
Coefficient
GND
A1356-DS