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A1354 High Precision 2-Wire Linear Hall Effect Sensor with Pulse Width Modulated Output
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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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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 the A1354 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.
Package: 4-pin SIP (suffix KT)
1 mm case thickness
Not to scale
Functional Block Diagram
VCC VCC Regulator 1 2 2 Programming Logic 1 Switched Capacitor Control
PWM Carrier Generation and Trimming
Chopper Switches Sensitivity and Sensitivity TC Trim
Amp
Signal Recovery Voltage Controlled Current Source % Duty Cycle Temperature Coefficient GND RSens
Temperature Compensation Programming Interface
% Duty Cycle
A1354-DS
A1354
High Precision 2-Wire Linear Hall Effect Sensor with Pulse Width Modulated Output
www.datasheet4u.com Features and Benefits
(continued) ▪ Wide ambient temperature range: –40°C to 125°C ▪ Resistant to mechanical stress ▪ Extremely thin package: 1 mm case thickness
▪ Output duty cycle clamps provide short circuit diagnostic capabilities ▪ Optional 50% duty cycle calibration test mode at device power-up
Selection Guide
Part Number
A1354KKTTN-T
Packing*
4000 pieces per 13-in. reel
*Contact Allegro® for additional packing options
Absolute Maximum Ratings
Characteristic Forward Supply Voltage Reverse Supply Voltage Forward Supply Current Reverse Supply Current Operating Ambient Temperature Maximum Junction Temperature Storage Temperature Symbol VCC VRCC ICC IRCC TA TJ(max) Tstg Range K Notes Rating 28 –16 50 –50 –40 to 125 165 –65 to 165 Unit V V mA mA ºC ºC ºC
Pin-out Diagram
Branded Face
Terminal List
Number 1 2 3 4 Name VCC NC NC GND Function Input power supply; use bypass capacitor to connect to ground Not connected Not connected Ground
1
2
3
4
Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com
2
A1354
High Precision 2-Wire Linear Hall Effect Sensor with Pulse Width Modulated Output
www.datasheet4u.com noted
OPERATING CHARACTERISTICS (A) Valid with CBYPASS = 0.01 μF, over full operating temperature range, TA, and VCC, unless otherwise
Characteristics ELECTRICAL CHARACTERISTICS Supply Voltage2 Supply Current Supply Current Ratio3 VCC ICC(LOW) ICC(HIGH) ICC(rat) tPO VZ BWi fC TA = 25°C, CL (of test probe)= 10 pF, Sens = 0.1%/G, fPWM = fPWM(slow) TA = 25°C, CL (of test probe)= 10 pF, Sens = 0.1%/G, fPWM = fPWM(fast) TA = 25°C, ICC = ICC(max) + 3 mA Small signal –3 dB, 100 G(P-P) magnetic input signal TA = 25°C TA = 25°C, Impulse magnetic field of 300 G, Sens = 0.1%/G, fPWM = fPWM(slow) TA = 25°C, Impulse magnetic field of 300 G, Sens = 0.1%/G, fPWM = fPWM(fast) TA = 25°C TA = –10°C to 85°C, Sens = 0.12%/G, Measured over 1000 Output PWM clock periods TA = –10°C to 85°C, Sens = 0.12%/G, Measured over 1000 Output PWM clock periods 4.5 – 13 2 – – 28.5 – – 12 6 – – 100 25 32 200 200 16 9 19 – – – – – – V mA mA – ms ms V Hz kHz Symbol Test Conditions Min. Typ. Max. Unit1
Power-On
Time4
Supply Zener Clamp Voltage Internal Bandwidth Chopping Frequency5 OUTPUT CHARACTERISTICS
– – 90 5 – –
100 25 92.5 7.5 ±0.05 ±0.42
– – 95 10 – –
ms ms % % % G
Response
Time4
tRESPONSE
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