A1373 and A1374 High Precision, Output Pin Programmable Linear Hall Effect Sensors Features and Benefits Description ▪ ▪ ▪ ▪ ▪ The A1373 and A1374 high precision linear Hall effect sensors are sensitive, temperature stable, linear devices with externally programmable features. This device family incorporates a chopper-stabilized amplifier, voltage regulator, programming logic, and an output amplifier on a single IC. The patented dynamic offset cancellation used with a chopper-stabilization technique provides extremely low offset and minimal temperature drift. A high frequency clock is used for chopping, to ensure high frequency signal processing capability. The A1373 and A1374 are ideal for use in automotive and industrial linear position-sensing applications that require increased reliability and accuracy over conventional contacting-potentiometer solutions. Key applications include: throttle position sensors, pedal position sensors, and suspension height sensors. ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ Output pin programming Field-programmable for optimal application integration Selectable coarse and fine gain and quiescent output voltage Selectable sensitivity temperature coefficient Selectable output clamp voltage level, including noclamp (rail-to-rail) Selectable output polarity Unipolar or bipolar operation Ratiometric sensitivity, clamps, and quiescent output voltage Chopper-stabilized Hall technique Wide operating temperature range On-chip regulator for over/under voltage protection On-chip regulator provides EMI robustness Wide lead-spacing with KB package The design and manufacturing flexibility of the A1373 and A1374 complement the Allegro linear Hall effect family of devices by offering programmable gain, quiescent offset voltage for unipolar or bipolar operation, temperature coefficient, clamps, and polarity. The device can be set up in a magnetic circuit and programmed with a train of serial pulses via the output pin. Once the right combination of gain, quiescent Package: 3 pin SIP (suffix KB) Continued on the next page… Not to scale Functional Block Diagram VCC Pin 1 Voltage Regulator Amp Filter Dynamic Offset Cancellation To all subcircuits Out Hall drive circuit Gain Temperature Coefficient Trim Control GND Pin 2 A1373-DS, Rev. 8 Offset VOUT Pin 3 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Description (continued) output voltage, and temperature coefficient has been selected, the codes can be locked for one-time programming. In this manner, manufacturing tolerances can be reduced and the assembly process can be simplified. These devices are available in the KB package, a 3-pin SIP (single inline package). The lead (Pb) free version has a 100% matte tin plated leadframe. Selection Guide Part Number Pb-free1 A1373EKB – A1373EKB–T Yes A1373EKBTI – A1373EKBTI–T Yes A1373LKB–T Yes A1373LKBTI – A1373LKBTI–T A1374EKB Bulk, 500 pcs./bag –40 to 85 14.24-in. reel, 2000 pcs/reel Bulk, 500 pcs./bag 14.24-in. reel, 2000 pcs/reel Yes – A1374EKB–T Yes A1374EKBTI – A1374EKBTI–T Yes A1374LKB–T Yes A1374LKBTI A1374LKBTI–T Ambient, TA (ºC) Packing2 –40 to 150 Bulk, 500 pcs./bag –40 to 85 14.24-in. reel, 2000 pcs/reel Bulk, 500 pcs./bag – 14.24-in. reel, 2000 pcs/reel Yes –40 to 150 1Pb-based variants are being phased out of the product line. Certain variants cited in this footnote are in production but have been determined to be DISCONTINUED. Status date change October 31, 2006. These variants include: A1373LKB and A1374LKB. 2Contact Allegro for additional packing options. Absolute Maximum Ratings Characteristic Symbol Notes Rating Units Supply Voltage VCC 16 V Reverse Supply Voltage VRCC –16 V Output Voltage VOUT 16 V Reverse-Output Voltage Output Source Current Output Sink Current When blowing fuses during device programming, a voltage of 28 V may be applied to VOUT. VROUT –0.1 V IOUTSOURCE 3 mA 10 mA Range E –40 to 85 ºC Range L –40 to 150 ºC IOUTSINK Operating Ambient Temperature TA Maximum Junction Temperature TJ(max) 165 ºC Tstg –65 to 170 ºC Storage Temperature Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 2 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 CHARACTERISTIC PARAMETERS Characteristic Symbol Test Conditions Min. Typ. ELECTRICAL CHARACTERISTICS over operating temperature range, VCC= 5.0 V, unless otherwise noted Operation within specification, Supply Voltage VCC 4.5 5.0 Tj < 165°C Max Units 5.5 V – 8.2 10 mA VCC = –16 V, TA = 25°C – – 16 mA CLOAD = 10 nF, 90% full scale VOUT – – 300 μs – 200 – kHz – – 2.5 20 – – kHz kHz OUTPUT CHARACTERISTICS over operating temperature range, VCC= 5.0 V, unless otherwise noted – 6 A1373 peak-to-peak, CLOAD > 1 nF, Noise2,3 VN A1374 2.5 mV/G – 14 16 26 mV mV Supply Current ICC Reverse-Supply Current IRCC Power-On Time1 tPO Chopping Frequency fC Internal Bandwidth BW Output Capacitance Load CLOAD Output Resistive Load RLOAD Phase Shift ∆Φ VOUT(Sat)HIGH Output Voltage VOUT(Sat)LOW Output Resistance A1373 A1374 Small signal -3 dB VOUT pin to GND pin – – 10 nF 4700 – – Ω A1373 Magnetic signal freq. = 100 Hz – 3 – (°) A1374 Magnetic signal freq. = 1000 Hz – 3 – (°) 4.65 4.7 – V – 0.2 0.25 V – 1.5 – Ω – 20 – G/μs IOUTSINK = 1.2 mA, B(kG) > (VCC–VOUT(Q)) / Sens (mV/G) IOUTSOURCE = 1.2 mA, B(kG) < VOUT(Q) / Sens (mV/G) ROUT MAGNETIC CHARACTERISTICS Magnetic Slew Rate SLR V / ms / Sens PRE-PROGRAMMING TARGET (Prior to coarse and fine trim) over operating temperature range, VCC= 5.0 V, unless otherwise noted Pre-Programming Quiescent Output Voltage Pre-Programming Sensitivity Pre-Programming Sensitivity Temperature Coefficient VOUT(Q)PRE SensPRE TCPRE B = 0 G, TA = 25°C 1.62 1.80 1.98 V TA = 25°C 1.05 1.31 1.75 mV/G –0.016 0.05 0.104 %/°C TA relative to 25°C INITIAL COARSE PROGRAMMING over operating temperature range, VCC= 5.0 V, unless otherwise noted Initial Coarse Quiescent Output Voltage Initial Coarse Sensitivity VOUT(Q)INITLOW TA = 25°C – 0.55 – V VOUT(Q)INITMID Reference VOUT(Q)PRE – –- – V VOUT(Q)INITHIGH TA = 25°C – 3.25 – V SensINITLOW Reference SensPRE – – – mV/G SensINITMID TA = 25°C – 2.8 – mV/G SensINITHIGH TA = 25°C – 5.5 – mV/G Continued on the next page... Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 3 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 CHARACTERISTIC PARAMETERS (continued) Characteristic Symbol Test Conditions Min. Typ. Max Units QUIESCENT OUTPUT VOLTAGE PROGRAMMING over operating temperature range, VCC= 5.0 V, unless otherwise noted VOUT(Q)LOW 0.7 – 1.9 V Quiescent Output Voltage Range VOUT(Q)MID B = 0 G, TA = 25°C 2.0 – 3.2 V VOUT(Q)HIGH 3.5 – 4.5 V Average Quiescent Output Voltage StepVOUT(Q) TA = 25°C 3.0 3.275 3.5 mV Step Size4,5,6 Quiescent Output Voltage Fine programming value selection ±0.5 × ErrPROGVOUT(Q) – – mV StepVOUT(Q) Programming Resolution accuracy Quiescent Output Voltage Drift Over Operating Temperature Range Quiescent Output Voltage Programming Bits ΔVOUT(Q) – VOUTCLP10HIGH 10% Output Clamp Option7 VOUTCLP10LOW VOUTCLP20HIGH 20% Output Clamp Option7 VOUTCLP20LOW Delay to Clamp tCLP VOUT(Q) = VOUT(Q)LOW – – ±40 mV VOUT(Q) = VOUT(Q)MID – – ±40 mV VOUT(Q) = VOUT(Q)HIGH – – ±55 mV – – 4.350 4.300 0.4 0.3 3.925 3.900 0.9 0.8 – – 2 9 – – – – – – – – – – – – 4.565 4.650 0.6 0.6 4.125 4.200 1.1 1.1 2 100 Bit Bit V V V V V V V V μs μs 2.8 5.7 11.25 14 28 56 mV/G mV/G mV/G μV/G μV/G μV/G – μV/G Coarse (Range selection) Fine (Value selection) A1373 High-side output clamp A1374 A1373 Low-side output clamp A1374 A1373 High-side output clamp A1374 A1373 Low-side output clamp A1374 A1373 A1374 SENSITIVITY PROGRAMMING over operating temperature range, VCC= 5.0 V, unless otherwise noted SensLOW 1.75 – Sensitivity Range8 SensMID TA = 25°C 3.5 – SensHIGH 7.0 – StepSENSLOW 6 9.5 Average Sensitivity Step Size4,5,6 StepSENSMID TA = 25°C 12 18.7 StepSENSHIGH 22 37.0 Sensitivity Programming Resolution Sensitivity Programming Bits Fine programming value selection accuracy – – Coarse (Range selection) Fine (Value selection) – – 2 8 – – Bit Bit – Negative Sensitivity – 1 – Bit ErrPROGSENS ±0.5 × StepSENS POLARITY PROGRAMMING Polarity Programming Bit Continued on the next page... Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 4 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 CHARACTERISTIC PARAMETERS (continued) Characteristic Symbol Test Conditions Min. Typ. Max Units SENSITIVITY TEMPERATURE COEFFICIENT PROGRAMMING over operating temperature range, VCC= 5.0 V, unless otherwise noted Sensitivity Temperature Coefficient Range TC Sensitivity T/C codes 0 to 11, minimum (absolute) positive temperature coefficient attainable Sensitivity T/C codes 16 to 27, minimum (absolute) negative temperature coefficient attainable Average Sensitivity StepTC Temperature Coefficient Step TA = 150°C 5 6 4, , Size Sensitivity Temperature – Coefficient Programming Bits ONE-TIME PROGRAMMING – Device Programming Lock Bit RATIOMETRY over operating temperature range, VCC= 5.0 V, unless otherwise noted RatVOUT(Q) Quiescent Voltage Error VCC at VOPERATING RatSENS Sensitivity Error VCC at VOPERATING Clamp Error RatVOUTCLP VCC at VOPERATING LINEARITY over operating temperature range, VCC= 5.0 V, unless otherwise noted Positive Linearity Error Lin+ VCC at VOPERATING Lin– Negative Linearity Error VCC at VOPERATING SYMMETRY over operating temperature range, VCC= 5.0 V, unless otherwise noted Sym Symmetry Error VCC at VOPERATING – VCC ADDITIONAL CHARACTERISTICS Sensitivity Drift9 Package Thermal Resistance ΔSens RθJA 1 layer PCB with copper limited to solder pads; see Allegro web site for additional thermal information – 0.07 – %/°C – –0.016 – %/°C – 0.01 – %/°C – 5 – Bit – 1 – Bit – ±0.25 ±1.0 ±1.5 – % – % – % ±0.5 ±0.5 – % – – % – ±0.35 – % – – ±2 % – 177 – °C/W – – 18 4 mA mA – – – FAULT CONDITIONS over operating temperature range, VCC= 5.0 V, unless otherwise noted VOUT pin to VCC pin – IOUTSHT Shorted Output Wire VOUT pin to GND pin – 1 tPO does not include tCLP , specified in the Quiescent Programming section of this table. Peak to peak value exceeded: 0.3% (6σ). 3 For A1373, no digital noise is present at the output. 4 Step size is larger than required for the specified range, to take into account manufacturing spread. 5 Individual code step sizes can be greater than 2× larger than the step size at each significant bit rollover. 6 Average fine code step size in a given range = (Output value at highest fine code in the range – Output value at code 0 of the range) / Total quantity of steps (codes) in the range. 7 Values indicated are valid if any additional magnetic field does not exceed B(kG)= ±2 (V) / Sens (mv/G), after V OUTCLP is reached. 8 Program the Sensitivity T/C register before programming Sensitivity Coarse and Sensitivity Fine, due to a worst case shift of ±3% in sensitivity at 25°C at the maximum values for Sensitivity T/C: Positive T/C and Sensitivity T/C: Negative T/C. The Programming Guidelines section in this document lists a complete recommended order for programming individual values. 9Drift due to temperature cycling is due to package effects on the Hall transducer. The stress is reduced when the package is baked. However, it will recover over time after removal from the bake. 2 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 5 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Typical Characteristics Temperature Coefficient Code Profile TA = 150°C, Magnetically Back-Biased VOUT(Q) = VOUT(Q)PRE, Sens = 5 mV/G 3.4 3.2 Positive Programming Codes VOUT(Q) (V) 3.0 Negative Programming Codes 2.8 2.6 2.4 2.2 2.0 0 5 10 15 20 25 30 Sensitivity TC Code Code 0 1 – 11 12 – 15 16 – 27 28 – 31 Application Initial code Positive TC codes, use to increase TC value [Unused, same effect as 4 – 7, respectively] Negative TC codes, use to decrease TC value [Unused, same effect as 20 – 23, respectively] Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 6 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Sensitivity Temperature Coefficient Range, TC 0.25 0.20 Typical maximum attainable positive TC programming range 0.15 Extended Range Not Guaranteed TCPRE(max) 0.10 A TC (% / °C) TC(typ), for positive programming 0.05 Guaranteed Programmable Range 0 TC Range Before Programming TC(typ), for negative programming TCPRE(min) –0.05 Extended Range Not Guaranteed –0.10 Typical maximum attainable negative TC programming range –0.15 A –0.20 Units with a TC in the range TC(min) < TC < TCPRE(max) before programming may not be programmable to the maximum attainable negative TC programming value –0.25 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 7 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Average Supply Current (Icc) vs Temperature Vcc = 5V 10.0 Average Supply Current (mA) 9.5 9.0 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 -50 -25 0 25 50 75 100 125 150 Temperature (°C) Average Ratiometry, Voq Average Ratiometry, Sens 101.0 Average Ratiometry (Sens) (%) Average Ratiometry (Voq) (%) 101.0 100.8 4.5 to 5.0 V 100.6 5.5 to 5.0 V 100.4 100.2 100.0 99.8 99.6 99.4 99.2 99.0 -50 100.8 4.5 to 5.0 V 100.6 5.5 to 5.0 V 100.4 100.2 100.0 99.8 99.6 99.4 99.2 99.0 -25 0 25 50 75 100 125 -50 150 -25 0 101.0 101.0 100.8 100.8 100.6 100.6 Average Linearity (%) Average Symmetry (%) 50 75 100 125 150 Average Linearity vs Temperature Average Symmetry vs Temperature Linearity + Linearity - 100.4 100.4 100.2 100.2 100.0 100.0 99.8 99.6 99.8 99.6 99.4 99.4 99.2 99.2 99.0 99.0 -50 25 Temperature (°C) Temperature (°C) -25 0 25 50 Temperature (°C) 75 100 125 150 -50 -25 0 25 50 75 100 125 150 Temperature (°C) Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 8 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Average Delta Sensitivity (percent change relative to 25°C) Average Delta Sensitivity over TC Codes (percent change relative to 25°C) Initial Coarse Range 25 Sensitivity Low 6 Initial Delta Sensitivity (%) Average Delta Sensitivity (%) 8 Sensitivity Mid Sensitivity High 4 2 0 -2 -4 -6 20 Sensitivity Low - TC Code 0 Sensitivity Low - TC Code 11 15 Sensitivity Low - TC Code 27 10 5 0 -5 -10 -50 -25 0 25 50 75 Temperature (°C) 100 125 -15 150 -50 -25 Average Delta Sensitivity (percent per degree Celsius change relative to 25°C) Average Delta Sensitvity (%/°C) Average Delta Sensitvity (%/°C) 50 75 Temperature (°C) 100 125 150 0.20 0.06 Sensitivity Low Sensitivity Mid 0.04 Sensitivity High 0.02 0 -0.02 -0.04 -0.06 Sensitivity Low - TC Code 0 0.15 Sensitivity Low - TC Code 11 Sensitivity Low - TC Code 27 0.10 0.05 0 -0.05 -0.10 -0.15 -50 -25 0 25 50 75 Temperature (°C) 100 125 150 -0.20 -50 0 25 50 75 Temperature (°C) 100 125 150 10 15 TC Code 1 TC Code 2 TC Code 4 TC Code 8 TC Code 11 5 TC Contribution to Delta Sensitivity (%) 10 5 0 -5 -10 -25 Negative TC Contribution to Delta Sensitivity Positive TC Contribution to Delta Sensitivity TC Contribution to Delta Sensitivity (%) 25 Average Delta Sensitivity (percent per degree Celsius change relative to 25°C) Initial Coarse Low 0.08 -0.08 0 -50 -25 0 25 50 75 Temperature (°C) 100 125 150 0 TC Code 16 TC Code 17 TC Code 18 TC Code 20 TC Code 24 TC Code 27 -5 -10 -15 -20 -50 -25 0 25 50 75 Temperature (°C) 100 125 150 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 9 High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Average Quiescent Output Voltage Average Delta Quiescent Output Voltage Relative to 25°C, Initial Sensitivity 3.5 6 Vout(q)Low - Initial Vout(q)Mid - Initial Vout(q)High - Initial 2.5 2.0 1.5 1.0 0.5 0 -50 4 Average Delta Vout(q) (mV) Average Vout(q) (V) 3.0 2 0 -2 -4 Vout(q)Low Vout(q)Mid Vout(q)High -6 -8 -10 -25 0 25 50 75 Temperature (°C) 100 125 150 -50 25 50 75 100 125 150 Average Initial Quiescent Output Voltage vs Supply Voltage TA = 25°C 6 4.0 5 Average Vout(q) (V) 3.5 4 3 2 1 Vout(q)Low - Initial Vout(q)Mid - Initial Vout(q)High - Initial 3.0 2.5 2.0 1.5 1.0 Vout(q)Low - Max Code Vout(q)Mid - Max Code Vout(q)High - Max Code 0.5 0 -25 0 25 50 75 100 125 150 4 4.5 Temperature (°C) 5 Supply Voltage (V) 5.5 6 Average Quiescent Output Voltage over Sensitivity 1.85 1.83 Average Vout(q) (V) Average Vout(q) (max Code - 511) (V) 0 Temperature (°C) Average Quiescent Output Voltage Max Code (511) 0 -50 -25 Vout(q)Mid - SensLow Vout(q)Mid - SensMid Vout(q)Mid - SensHigh 1.81 1.79 1.77 1.75 -50 -25 0 25 50 75 100 125 150 Temperature (°C) 10 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Average Saturation Voltage Average Clamp Values 5 Average Clamp Voltage (V) 5 VOUT(sat) (V) 4 3 VOUT(sat)+ 2 VOUT(sat)– 1 4 10% High Clamp 3 10% Low Clamp 20% High Clamp 2 20% Low Clamp 1 0 0 -50 -25 0 25 50 75 Temperature (°C) 100 125 150 -50 -25 0 25 50 75 100 125 150 Temperature (°C) 11 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Chopper Stabilization Technique pass through a low-pass filter, while the modulated dc offset is suppressed. Chopper stabilization is a unique approach used to minimize Hall offset on the chip. The patented Allegro technique, namely Dynamic Quadrature Offset Cancellation, removes key sources of the output drift induced by thermal and mechanical stresses. This offset reduction technique is based on a signal modulationdemodulation process. The undesired offset signal is separated from the magnetic field-induced signal in the frequency domain, through modulation. The chopper stabilization technique uses a 200 kHz high frequency clock. For demodulation process, a sample and hold technique is used, where the sampling is performed at twice the chopper frequency (400 kHz). This high-frequency operation allows a greater sampling rate, which results in higher accuracy and faster signal-processing capability. The subsequent demodulation acts as a modulation process for the offset, causing the magnetic field-induced signal to recover its original spectrum at baseband, while the dc offset becomes a high-frequency signal. The magnetic-sourced signal then can This approach desensitizes the chip to the effects of thermal and mechanical stresses, and produces devices that have extremely stable quiescent Hall output voltages and precise recoverability after temperature cycling. This technique is made possible through the use of a BiCMOS process, which allows the use of low-offset, low-noise amplifiers in combination with high-density logic integration and sample-and-hold circuits. Regulator Hall Element Amp Sample and Hold Clock/Logic Low-Pass Filter Concept of Chopper Stabilization Technique 12 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Definitions of Terms Linear: A type of Hall-Effect sensor that produces an analog output voltage proportional to the strength of a sensed magnetic field. Ratiometric: A linear Hall-Effect sensor that, when not subjected to a significant magnetic field, has an output that is a ratio of its supply voltage. A ratiometric performance of 100% indicates the output follows the supply with no percentage error. Gauss: Standard unit of measuring magnetic flux density. 1 gauss is equal to 1 Maxwell per square centimeter or 10-4 tesla. (For reference, the earth’s magnetic field is approximately 0.5 gauss.) Blowing: Applying a pulse of sufficient voltage and duration to permanently set a bit, by blowing a fuse internal to the device. Once a bit (fuse) has been blown, it cannot be reset. The terms trimming and programming can be used interchangeably with blowing in this context. Programming modes: Testing the results is the only valid method to guarantee successful programming, and multiple modes are provided to support this. The programming modes are described in the section Mode Selection State. Code: The number used to identify the register and the bitfield to be programmed, expressed as the decimal equivalent of the binary value. The LSB of a register is denoted as bit 0. Typical Application Drawing VREG 1 VCC A1373 A1374 CBYPASS 0.1 μF GND 2 Sensor Output VOUT 3 RLOAD 4.7 kΩ CLOAD 1 nF 13 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Characteristic Definitions Quiescent Output Voltage. In the quiescent state (no significant magnetic field: B = 0), the output, VOUTQ, equals a ratio of the supply voltage, VCC, throughout the entire operating ranges of VCC and ambient temperature, TA. Due to internal component tolerances and thermal considerations, there is a tolerance on the quiescent output voltage, ∆VOUTQ, which is a function of both ∆VCC and ∆TA. For purposes of specification, the quiescent output voltage as a function of temperature, ∆VOUTQ(∆TA), is defined as: ΔVOUTQ(ΔΤΑ) = VOUTQ(ΤΑ) – VOUTQ(25ºC) (1) Sens(25ºC) The ratiometric change in the quiescent output voltage, RATVOUT(Q) (%), is defined as: RATVOUT(Q) = Sensitivity. The presence of a south-polarity (+B) magnetic field, perpendicular to the branded face of the device package, increases the output voltage, VOUT, in proportion to the magnetic field applied, from VOUTQ toward the VCC rail. Conversely, the application of a north polarity (–B) magnetic field, in the same orientation, proportionally decreases the output voltage from its quiescent value. This proportionality is specified as the magnetic sensitivity of the device and is defined as: RATSens = RATVCLP = Lin– = Sens(ΤΑ) – Sens(25ºC) Sens(25ºC) × 100% 5V × 100% (4) Sens(VCC) Sens(5V) VCC 5V × 100% (5) (3) Ratiometric. The A1373 and A1374 feature ratiometric output. This means that the quiescent voltage output, VOUTQ, VCLP(VCC) VCC VCLP(5V) × 100% 5V (6) Linearity and Symmetry. The on-chip output stage is designed to provide linear output at a supply voltage of 5 V. Although the application of very high magnetic fields does not damage these devices, it does force their output into a nonlinear region. Linearity in percent is measured and defined as: The stability of the device magnetic sensitivity as a function of ambient temperature, ∆ Sens (∆TA) (%) is defined as: ΔSens(ΔΤΑ) = VCC Note that clamping effect is applicable only when clamping is enabled by programming of the device. Lin+ = 2B VOUTQ(5V) the ratiometric change in sensitivity is defined as: (2) Sens = VOUTQ(VCC) and the ratiometric change in clamp voltage is defined as: where Sens is in mV/G, and the result is the device equivalent accuracy, in gauss (G), applicable over the entire operating temperature range. VOUT(–B) – VOUT(+B) magnetic sensitivity, Sens, and clamp voltage, VOUTCLP , are proportional to the supply voltage, VCC. VOUT(+B) – VOUTQ 2 (VOUT(+B½) – VVOUTQ ) VOUT(–B) – VOUTQ 2(VOUT(–B½) – VOUTQ) × 100% × 100% (7) (8) and output symmetry as: Sym = VOUT(+B) – VOUTQ VOUTQ – VOUT(–B) × 100% (9) 14 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Pulse Generation Several parameters can be field-programmed. To do so, a coded series of voltage pulses through the VOUT pin is used to set bitfields in onboard registers. The effect on the device output can be monitored, and the registers can be cleared and set repeatedly until the required output results are achieved. To make the setting permanent, bitfield-level solid state fuses are blown, and finally, a device-level fuse is blown, blocking any further coding. Although any programmable variable power supply can be used to generate the pulsed waveforms, Allegro highly recommends using the Allegro Sensor Evaluation Kit, available on the Allegro Web site On-line Store. The manual for that kit is available for download free of charge, and provides additional information on programming these devices. There are three voltage levels that must be taken into account when programming. For purposes of explanation in this document, the signal levels are referred to simply as high programming voltage, VPH , mid, VPM , and low, VPL . The rising edge of the high level, VPH , pulse generates a state change. The falling edge of the high level, VPH , pulse increments the mode, register, or bitfield selection by one, when allowed to drop below the low level, VPL , threshold. A delay on the falling edge, at the mid level, VPM , range is required to guarantee proper programming level recognition. When it is not desirable to increment these fields further, it is acceptable to hold the signal at the mid level, VPM , range and then transition to another high level, VPH, pulse. Referring to the Programming State Machine diagram, when using Blow Fuse mode the fourth high level, VPH , pulse (including the key sequence to enable Blow Fuse mode), will blow the selected key-code combination. If fuse blowing is not desired, it is recommended to reset the A137x by toggling the supply pin. If the high level, VPH, pulse is not generated, and the A137x is not reset, then the next key sequence to change states will blow the unwanted key-code combination. For multiple register addressing without fuse blowing, Try Value mode must be used. PROGRAMMING PROTOCOL CHARACTERISTICS, over operating temperature range, unless otherwise noted Characteristic Symbol Programming Current2 Pulse Width Min. Typ. Max. Units 0 – 5 V 14 – 16 V VPH Low voltage range, for addressing registers and bitfields Mid voltage range, for addressing bitfields and for separating programming signals High voltage range, for enabling state changes and for fuse blowing 25 26 27 V IPP tr = 11 μs; 5 V → 28 V; CPROG = 0.1 μF – 209 – mA tPHE High pulse duration for enabling state change 20 – – μs tPHP High pulse duration for blowing fuses 100 – – μs tPLA Low pulse duration for bitfield addressing 6 – – μs tPME Mid pulse delay on falling edge of high pulse, VPH 15 – – μs tPMA Mid pulse duration for bitfield addressing 6 – – μs VPL Programming Voltage1 Test Conditions VPM VPL to VPH or VPM; maximum may be application 5 – 100 dependent VPH or VPM to VPL; maximum may be application Pulse Fall Time tf 5 – 100 dependent 1Programming voltages are measured at pin #3, VOUT, of the A137x. 2A minimum capacitance of 0.1 μF must be connected from VOUT to the GND pin of the A137x in order to provide the current necessary to blow the fuse. Pulse Rise Time tr μs μs 15 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 The mid voltage range, VPM , is a neutral level used to separate VPH and VPL pulses from each other. required, then the output drive signal must be released to allow the output level to be read for each bitfield increment (see panels A and B, below). The low level, VPL, pulse is used to increment the mode, register, and bitfield addresses that are to be set. The device generates a VPL pulse on the falling edge of the mid-level to low-level transition, VPM to VPL. To guarantee proper pulse recognition, each level must be held for the predefined durations specified in the Programming Protocol Characteristics table. Failure to follow the specifications may produce undefined results. Examples of common pulse trains are shown in panels C and D, below. In Try Value mode,the programming drive signal can be held at 5 V or less if no code search is required. If a code search is Mode Select Register Select (Code 1) (Code 3) Bitfield Select (Code 10) Mode Select Register Select (Code 3) (Code 1) Mode Select (Code 1) 30 Bitfield Select (Code 10) Mode Select (Code 1) 30 }V }V PH PH 25 = Programming edge 20 tPLA tPME 15 tPMA }V PM tPHE 10 1 1 2 3 1 2 3 4 5 6 7 8 9 10 Programming Level (V) Removing the output drive signal after each VPM allows measurement of the output pin 20 }V 15 PM 10 1 1 5 1 2 3 1 2 3 4 5 6 7 8 10 9 1 5 Time (μs) Register Select (Code 3) VPL Bitfield Select (Code 8) B. Try Value Mode. Code search with drive signal released after each VPM, allows output to be measured after each code increment. Blow Fuse Mode Select (Code 3) 30 Register Select Bitfield Select (Code 0) (Code 1) Lock (blow Lock Bit fuse) 30 }V }V PH Programming Level (V) Blow Fuse mode selected 20 PH 25 Sensitivity Fine register selected Bitfield 8 address selected Lock Device mode selected Programming Level (V) 25 20 }V 15 PM 10 tPME tPLA tPMA }V 15 PM tPHE tPHP 10 1 2 1 2 3 1 2 3 4 5 6 7 1 8 5 2 3 1 5 0 1 Holding at VPM is allowed when no VPL is required; dropping to VPL will increment by 1 bitfield VPL VPL Time (μs) C. Blow Fuse Mode: Code 8 / bit 4 is programmed. 800 750 700 650 600 550 500 450 400 350 300 250 200 150 100 50 0 1350 1300 1200 1250 1150 1100 1050 1000 950 900 850 800 750 700 650 600 550 500 450 400 350 300 250 200 150 50 0 100 0 1350 1300 1250 1200 2.0 1150 1100 1050 950 1000 900 850 800 750 700 2.6 2.7 2.8 2.9 3.0 Time (μs) A. Try Value Mode. Code search with drive signal held at 5 V. Mode Select (Code 2) 650 2.2 2.3 2.4 2.5 600 500 450 400 350 200 150 300 VOUT measurements 2.1 2.0 0 1350 1300 1200 1250 1150 1100 1050 950 1000 900 850 0 550 VPL 250 Try Mode selected 50 10th address selected 800 750 700 650 600 550 500 450 350 300 250 200 150 50 100 0 0 400 Sensitivity Fine selected (Sensitivity Coarse) (Qvo Fine) Try Mode selected 100 Programming Level (V) 25 Time (us) D. Lock Device Mode. Device-level Lock Bit is programmed; device programming is then permanently disabled. 16 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Programming State Machine POWER UP INITIAL STATE VPH VPH MODE SELECT VPL VPL TRY 1 VPL BLOW 2 VPH VPL LOCK 3 VPH VPH REGISTER SELECT VPL QVO VPL Coarse 0 VPH QVO Fine 1 VPL SENS. VPL Coarse 2 VPH SENS. Fine 3 VPH VPL VPH 0 VPH VPL [Optional: Measure] 1 VPL VPH VPL VPH BITFIELD SELECT [Optional: Measure] SENS. TC 4 VPH BLOW OR LOCK MODE? 6 VPH [Optional: Measure] 2 POLAR [Write Mode] VPL 2^N -1 VPL VPH No CLAMP VPL 5 VPH Yes FUSE BLOWING User generated transition Internally generated transition 17 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Programming Protocol and State Machine Description INITIAL STATE After system power-up, the programming logic is reset to a known state. This is referred to as the Initial state. All the registers that have intact fuses are set to logic 0. While in the Initial state, any VPL pulses on the VOUT pin are ignored. To enter the Mode Selection state, send one VPH pulse on the VOUT pin. MODE SELECTION STATE This state allows the selection of the programming mode: • Sens. Fine. Register for setting the value within the range set in the Sens. Coarse register (8 bits) • [Sensitivity] TC Register. Register for setting the temperature coefficient for the device (5 bits). • Clamp [VOUTCLP] Bit. Register for setting the clamping voltage of the output (2 bits) • Polarity Bit. Register setting the polarity of the output (1 bit) To select a register, increment through the register bitfields by sending VPL pulses on the VOUT pin. Note that the programming of registers should follow the order shown in item 7 in the section Programming Guidelines, not the bitfield selection order shown here. The bitfield selection order is: • Try Value Mode. In this mode, the user provisionally downloads settings to the device registers, without blowing the bits. The user can increment through the codes of each parameter, and evaluate the results of various code settings. • Blow Fuse Mode. In this mode, after downloading the settings, the user can blow the fuses in specific registers. • Lock Device Mode. This mode is similar to Blow Fuse mode, except that the fuse that is blown permanently prevents any further programming of any bits in the device. This register wraps by default. To select a mode, increment through the register bitfields by sending VPL pulses on the VOUT pin, as follows: To enter the Bitfield Selection state, send one VPH pulse on the VOUT pin. 0 pulses – No effect 1 pulse – Try Value mode 2 pulses – Blow Fuse mode 3 pulses – Lock Device mode This register wraps by default. This means that sending additional VPL pulses traverses the register again. Any VPH pulse sent before a VPL pulse has no effect. To enter the Register Selection state, after sending a valid quantity of VPL pulses, send one VPH pulse on the VOUT pin. REGISTER SELECTION STATE 0 pulses – QVO Coarse register 1 pulse – QVO Fine register 2 pulses – Sens. Coarse register 3 pulses – Sense Fine register 4 pulses – TC Register register 5 pulses – Clamp Bit register 6 pulses – Polarity Bit register BITFIELD SELECTION STATE (Write Mode) This state allows the selection of the individual bitfields to be programmed, in the register selected in the Register Selection state. In Try Value mode, the total value of the bitfields selected increments by 1 with each VPL pulse on the VOUT pin. The parameter being programmed changes with each additional pulse, so measurements can be taken after each pulse to determine if the desired result has been acquired. This state allows the selection of the register containing the bitfields to be programmed. Selecting the register corresponds to selecting the parameter to be set. For bit codes, see the section Programming Logic. In Blow Fuses mode, each bitfield to be blown must be selected individually. • QVO [VOUT(Q)] Coarse. Register for setting the range of the operating dc point (2 bits) • QVO Fine. Register for setting the value within the range set in the QVO Coarse register (9 bits) • Sens. [Sensivity] Coarse. Register for setting the overall gain of the device (2 bits) To leave this state, send one VPH pulse on the VOUT pin. If the current mode is Try Value, the bitfields remain set and the device reverts to the Mode Selection state. If the current mode is Blow Fuse, the selected bitfield fuse is blown, and the device reverts to the Mode Selection state. For bit codes and wrapping for these registers, see the section Programming Logic. 18 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Programming Logic Binary Bitfield Address Decimal Equivalent Code Description QVO Coarse register 00 0 VOUT(Q) mid range 01 1 VOUT(Q) low range 10 2 VOUT(Q) high range 11 3 Register wraps to 00 000000000 0 Initial value in selected QVO Coarse range 111111111 511 QVO Fine register Maximum value in selected QVO Coarse range Sens. Coarse register 00 0 Sens low range 01 1 Sens mid range 10 2 Sens high range 11 3 Register wraps to 00 00000000 0 Initial value in selected Sens. Coarse range 11111111 255 Sens. Fine register Maximum value in selected Sens. Coarse range TC Register register (See also chart Sensitivity Temperature Coefficient Code Profile in Typical Characteristics section) 00000 0 initial TC 00001 through 01011 1 through 11 01100 through 01111 12 through 15 Positive TC programming range Unused: equal to codes 4 to 7, respectively 10000 through 11011 16 through 27 Negative TC prgramming range; Value for 16 equals 1 step less than the value for the Initial TC Value (00000) 11100 through 11111 28 through 31 Unused: equal to codes 20 to 23, respectively Clamp Bit register 00 0 Rail-to-rail output swing 01 1 0.5 V and VCC– 0.5V rails 10 2 1 V and VCC – 1 V rails 00 3 Register wraps to 00 0 0 Positive (VOUT increases when a positive (south) magnetic field is applied to the device ) 1 1 Negative (VOUT increases when a negative (north) magnetic field is applied to the device ) 0 0 Unlocked 1 1 Locked (register 0, bitfield 1) Polarity Bit register Lock Bit register 19 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1373 and A1374 High Precision, Output Pin Programmable Linear Hall Effect Sensors Programming Guidelines • A bypass capacitor rated at 0.1μF must be mounted between the VOUT pin and the GND pin during programming. The power supply used for programming should be capable of delivering 28 V and 300 mA. • Before beginning any Blow Fuse mode or Lock Device mode code sequence, the device MUST be reset by cycling VCC poweroff and power-on again. Cycling power resets the device by setting all bitfields that have intact fuses to 0. Bitfields with blown fuses are unaffected. In Try Value mode, to retain register settings from previous code sequences, do not cycle power between sequences. When a register is selected in Register Selection mode, when the VPH pulse is sent to enter the Bitfield Selection mode, the bitfields with intact fuses in that register are reset to 0. • In Try Value mode, all bits in the register can be set in one code sequence. For example, setting the binary value 0110 and sending a VPH pulse sets code 6. However, because of the power requirement, blowing fuses in Blow Fuse mode must be performed one bitfield at a time. In order to program (blow fuses) for binary 0110, the bitfields MUST be programmed (blown) in two different code sequences:one setting the 0100 bit, and the other setting the 0010 bit (in either order). Power must be cycled before each of the two sequences. • Although a bitfield cannot be reset once its fuse is blown, additional bitfields can be blown at any time, until the device is locked by setting the Lock bit. For example, if bit 1 (0010) has been blown, it is possible to blow bit 0 (0001). Because bit 1 was already blown, the end result will be 0011 (code 3). • Before powering down the device after programming, observe the recommended delay at the mid voltage level, to ensure that the last VPH pulse has decayed before voltage drops to the VPL voltage. This will avoid the generation of overlapping VPL and VPH pulses. At the end of a Lock Device mode code sequence, the delay is not necessary. • Programming order is important in both Try Value mode and in Blow Fuse mode. There will be a slight parametric shift in sensitivity after programming the temperature coefficient, and a slight quiescent voltage shift with polarity. Subsequent changes to sensitivity can cause a shift in the quiescent output voltage. The following order is recommended: a. b. c. d. e. g. Polarity TC Register Sens Coarse QVO Coarse Sens Fine QVO Fine The Clamp Bit register can be programmed at any point in the order, as no parametric shift is observed due to clamps. • The actual distribution of parametric programming ranges are wider than the specified programming ranges, in order to take in to account manufacturing spread. The maximum possible attainable range can be used with the understanding that other specified parameters might be out of datasheet specification in the extended range. (For an example, see the chart Sensitivity Temperature Coefficient Range, in the Typical Characteristics section.) 20 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1373 and A1374 High Precision, Output Pin Programmable Linear Hall Effect Sensors Programming Example This example demonstrates the programming of the devices by setting the register for Sensitivity Temperature Coefficient to 00110. 1. Power-on the system. This will reset the unprogrammed bits in all registers to 0. The device enters the Initial state. 2. Send one VPH pulse to enter the Mode Selection state. 3. Send one VPL pulse to select Try Value mode. 4. Send one VPH pulse to enter the Register Selection state. 5. Send four VPL pulses to select the TC register. 6. Send one VPH pulse to enter Bitfield Selection state (Write mode). The TC register is reset to 00000 (assuming all of those bitfields have intact fuses). 7. Send five VPL pulses to set bitfields 0 and 2 (00101). Now we can measure the device output to see if this is the desired value. We may find that the value we programmed is not correct. So we will proceed to change it, as follows: 8. Send one VPL pulse to increase the code to 6 (setting bitfields 1 and 2: 00110). We measure the device and find that this is the correct TC we require. We are finished with trying values, and now want to set the value permanently. In the following steps, remember that blowing fuses is done one bit at a time. 9. Send one VPH pulse to exit Bitfield Selection mode. (The device returns to the Mode Selection state.) 10. RESET the device by powering it off and on. 11. Send one VPH pulse to enter the Mode Selection state. 12. Send two VPL pulses to select Blow Fuse mode. 13. Send one VPH pulse to enter the Register Selection state. 14. Send four VPL pulses to select the TC register. 15. Send one VPH pulse to enter Bitfield Selection state (Write Mode). The TC register is reset to 00000. 16. Send four VPL pulses to set bit 2 (00100, decimal 4). 17. Send one VPH pulse to exit Bitfield Selection state. The bitfield fuse is blown, and the device returns to the Mode Selection state. One of the two bitfields is programmed. Now we program the other bitfield. 18. Repeat steps 10 to 15 to select the TC register again. This time, however, the register resets to 00100, because bit 2 has been permanently set. 19. Send two VPL pulses to set bit 1 (00010, decimal 2). 20. Send one VPH pulse to exit Bitfield Selection state. The bitfield fuse is blown, and the device returns to the Mode Selection state. After repeating the above steps to program all parameters, we can lock the device: 21. RESET the device by powering it off and on. 22. Send one VPH pulse to enter the Mode Selection state. 23. Send three VPL pulses to select Lock Device mode. 24. Send one VPH pulse to enter the Bitfield Selection state. (We do not need to select a register for locking the device). 25. Send one VPL pulse to set the Lock bit to 1. 26. Send one VPH pulse to exit Bitfield Selection state. The bitfield fuse is blown, and the device returns to the Mode Selection state. 27. Programming the device is complete. Optionally, test the results, or power-off the device. 21 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com High Precision, Output Pin Programmable Linear Hall Effect Sensors A1373 and A1374 Package KB, 3-Pin SIP .208 5.28 .203 5.16 45° BSC C .1025 2.60 NOM .063 1.60 .059 1.50 .0520 1.32 NOM .138 3.51 .133 3.38 D 45° BSC B A .085 2.16 MAX .033 0.84 REF .020 0.51 REF .0173 0.44 .0138 0.35 .600 .560 15.24 14.22 Dimensions in inches Millimeters in brackets, for reference only Dimensions exclusive of mold flash, gate burrs, or dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Dambar removal protrusion (6X) B Ejector mark on opposite side C Active Area Depth .0165 [0.42] NOM D Hall element (not to scale) 1 .023 .018 Terminal List Name VCC GND VOUT Number 1 2 3 0.58 0.46 2 3 .075 1.91 NOM Description Connects power supply to chip Ground Output from circuit, terminal for programming pluses The products described herein are manufactured under one or more of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283; 5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,650,719; 5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents pending. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. Allegro products are not authorized for use as critical components in life-support devices or systems without express written approval. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use. Copyright © 2005, 2006, Allegro MicroSystems, Inc. 22 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com