|
|
Número de pieza | A1354 | |
Descripción | High Precision 2-Wire Linear Hall Effect Sensor | |
Fabricantes | Allegro Micro Systems | |
Logotipo | ||
Hay una vista previa y un enlace de descarga de A1354 (archivo pdf) en la parte inferior de esta página. Total 22 Páginas | ||
No Preview Available ! A1354
High Precision 2-Wire Linear Hall Effect Sensor
with Pulse Width Modulated Output
Features and Benefits
www.da▪taDsehseiegt4nue.dcofmor 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
Continued on the next page…
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 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 sensor 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.
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 sensor is provided in a lead (Pb) free 4-pin single
inline package (KT suffix), with 100% matte tin leadframe
plating.
Not to scale
VCC
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
1 page A1354
High Precision 2-Wire Linear Hall Effect Sensor
with Pulse Width Modulated Output
www.datasheet4u.com
PROGRAMMING CHARACTERISTICS (continued) Valid over full operating temperature range, TA, and VCC, unless otherwise noted
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Unit1
CALIBRATION TEST MODE PROGRAMMING
Calibration Test Mode Selection Bit
– 1 – bit
LOCK BIT PROGRAMMING
Overall Programming Lock Bit
– 1 – bit
11 G (gauss) = 0.1 mT (millitesla).
2Raw device characteristic values before any programming.
3D(Q)UNIinit may be below the clamp duty cycle DCLP(LOW). D(Q) will not appear to respond to programming pulses until D(Q) > DCLP(LOW).
4D(Q)(max) is the value guaranteed with all programming fuses blown (maximum programming code set). The D(Q) range is the total range from
D(Q)init up to and including D(Q)(max). See Characteristic Definitions section.
5Bit for selecting between D(Q)BI and D(Q)UNI programming ranges.
6Step size is larger than required, in order to provide for manufacturing spread. See Characteristic Definitions section.
7Non-ideal behavior in the programming D-to-A converter (DAC) can cause the step size at each significant bit rollover code to be greater than twice
the maximum specified value of StepD(Q) , StepSENS , or StepfPWM.
8Overall programming value accuracy. See Characteristic Definitions section.
9fPWM(max) is the value available with all programming fuses blown (maximum programming code set). fPWM range is the total range from fPWMinit up
to and including fPWM(max). See Characteristic Definitions section.
10Bit for selecting between fPWM(fast) and fPWM(slow) programming ranges.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
5
5 Page A1354
High Precision 2-Wire Linear Hall Effect Sensor
with Pulse Width Modulated Output
wwLwin.deaatraistyheEert4rou.rciosmcalculated separately for the positive
(LinERRPOS) and negative (LinERRNEG ) applied magnetic fields.
Linearity error (%) is measured and defined as:
where:
Then:
LinERRPOS
=
¾– |