A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality, Analog Output, and Miniature Package Options Features and Benefits Description * Low power consumption using 3 V supply * Factory programmed sensitivity temperature coefficient (0.13%/C nominal) * Programmability at end-of-line * Ratiometric sensitivity, quiescent voltage output, and clamps for interfacing with application DAC * Temperature-stable quiescent voltage output and sensitivity * Precise recoverability after temperature cycling * Output voltage clamps provide short circuit diagnostic capabilities * Wide ambient temperature range: -40C to 150C * Resistant to mechanical stress * Miniature package options The Allegro(R) A1386 programmable, linear, Hall effect sensor IC is designed for low power, high accuracy, and small package size applications. The accuracy of this device is enhanced via programmability on the output pin for end-of-line optimization without the added complexity and cost of a fully programmable device. The A1386 has two operating modes, normal and low power. In normal operation mode the A1386 operates much like its predecessors, the A1381, A1382, A1383, and A1384, as a highly accurate, user-programmable linear sensor IC with a ratiometric output. In low power mode, the device actually disengages some internal components in order to reduce power consumption. Although the accuracy of the device is substantially reduced during low power operation, it remains effective as a detector of magnetic regions (such as north and south poles on a rotating ring magnet). This unique feature allows the device to be used in systems that are put to sleep, during which time there may be only 3 V available, or in applications that have start-up conditions where the available supply voltage may drop below 4.5 V for a period of time. This ratiometric Hall effect device provides a voltage output that is proportional to the applied magnetic field over the entire Packages 3-pin ultramini SIP 1.5 mm x 4 mm x 3 mm (suffix UA) Continued on the next page... Approximate scale Functional Block Diagram V+ VCC Amp To all subcircuits Filter Dynamic Offset Cancellation CBYPASS Chip Reference Currents Out Hall Drive Circuit Gain Gain Temperature Coefficient Trim Control GND A1386-DS, Rev. 4 Offset VOUT 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 Description (continued) 2.7 to 5.5 V supply operating region. Both the quiescent voltage output and magnetic sensitivity are user adjustable. The quiescent voltage output can be set to approximately 50% of the supply voltage, and the sensitivity adjusted between 1.90 and 3.50 mV/G for VCC = 5 V. The sensitivity temperature coefficient is programmed at the factory, at 0.13%/C nominal, to compensate for Neodymium-style magnets. The features of this linear device make it ideal for the high accuracy requirements of automotive and industrial applications. Performance is guaranteed over an extended temperature range, -40C to 150C. Each device contains a BiCMOS monolithic circuit that integrates a Hall element, temperature-compensating circuitry to reduce the intrinsic sensitivity drift of the Hall element, a small-signal high-gain amplifier, a clamped low-impedance output stage, and a proprietary dynamic offset cancellation technique. The A1386 device is provided in a 3-pin ultramini single-in-line package (UA suffix), and a 3-pin surface mount SOT-23W package (LH suffix). Both packages are lead (Pb) free, with 100% matte tin leadframe plating. Selection Guide Part Number Package TA (C) Surface mount Through hole -40 to 150 Packing* A1386LLHLT-T Tape and reel, 3000 pieces/reel A1386LUA-T Bulk bag, 500 pieces/bag *Contact Allegro for additional packing options. Absolute Maximum Ratings Characteristic Symbol Notes Rating Units Forward Supply Voltage VCC 8 V Reverse Supply Voltage VRCC -0.1 V Forward Output Voltage VOUT 28 V Reverse Output Voltage VROUT -0.1 V Output Source Current IOUT(SOURCE) VOUT to GND 8 mA IOUT(SINK) VCC to VOUT 2 mA Output Sink Current Operating Ambient Temperature TA -40 to 150 C Storage Temperature Tstg -65 to 165 C TJ(max) 165 C Maximum Junction Temperature Range L Pin-out Diagrams LH Package UA Package 3 1 Terminal List Table Number 2 1 2 3 LH UA 1 1 3 2 Name Description VCC Input power supply; use bypass capacitor to connect to ground 2 GND Ground 3 VOUT Output signal Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options OPERATING CHARACTERISTICS, valid over full operating temperature range, TA; CBYPASS= 0.1 F, unless otherwise specified Characteristic Min. Typ. Max. Units1 VCC(NORM) 4.5 - 5.5 V VCC(LOWPWR) 2.8 - 3.2 V Symbol Test Conditions Electrical Characteristics Supply Voltage Supply Voltage Turn On Time Operation Mode Threshold Voltage2 tVCC VTHRESH Supply Zener Clamp Voltage VZ Supply Current ICC Power-On Time2 Internal Bandwidth Chopping Frequency3 tPO BWi fC - - 10 ms VCC(LOWPWR) VCC(NORM) - 4.1 - V VCC(NORM) VCC(LOWPWR) - 3.7 - V TA = 25C, ICC = 11 mA 6 8.3 - V VCC = VCC(NORM) , RL(PULLDWN) = 10 k - 6.4 8 mA VCC = VCC(LOWPWR) , RL(PULLDWN) = 10 k - - 4 mA VCC = VCC(NORM), TA = 25C, CBYPASS = open, CL (of test probe) = 4.7 nF - 30 - s VCC = VCC(LOWPWR), TA = 25C, CBYPASS = open, CL (of test probe) = 4.7 nF - 50 - s Small signal -3 dB, 100 G(p-p), magnetic input signal - 20 - kHz TA = 25C - 200 - kHz VCC = 5 V, TA = 25C, B = 750 G, Sens = 3.3 mV/G, RL(PULLDWN) = 10 k 4.39 4.5 4.58 V VCC = 3 V, TA = 25C, B = 750 G, Sens = 3.3 mV/G, RL(PULLDWN) = 10 k 2.62 2.7 2.78 V VCC = 5 V, TA = 25C, B = -750 G, Sens = 3.3 mV/G, RL(PULLDWN) = 10 k 0.39 0.5 0.58 V VCC = 3 V, TA = 25C, B = -750 G, Sens = 3.3 mV/G, RL(PULLDWN) = 10 k 0.19 0.3 0.37 V VCC = VCC(NORM), TA = 25C, CL = 4.7 nF, Sens = 3.3 mV/G, no external filter - 18 - mV VCC = VCC(LOWPWR), TA = 25C, CL = 4.7 nF, Sens = 1.75 mV/G, no external filter - 18 - mV Output Characteristics VCLP(HIGH) VOUT Voltage Clamp4 VCLP(LOW) VOUT Noise (peak to peak) VOUT DC Output Resistance VOUT Load Capacitance VOUT Load Resistance VOUT Output Slew Rate VN(p-p) - <1 - CL VOUT to GND - - 4.7 nF RL(PULLDWN) VOUT to GND 10 - - k VCC = VCC(NORM), CL = 4.7 nF - 140 - V/ms VCC = VCC(LOWPWR), CL = 4.7 nF - 50 - V/ms ROUT SR Continued on the next page... Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options OPERATING CHARACTERISTICS (continued), valid over full operating temperature range, TA; CBYPASS= 0.1 F, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ. Max. Units1 Pre-Programming Targets Pre-Programming Quiescent Voltage Output VOUT(Q)PRE Pre-Programming Sensitivity SensPRE VCC = 3 V, B = 0 G, TA = 25C 1.34 - 1.53 V VCC = 5 V, B = 0 G, TA = 25C - 2.5 - V VCC = 3 V, TA = 25C - - 1.14 mV/G VCC = 5 V, TA = 25C - 1.4 - mV/G 2.4 - 2.6 V - 5 - bit Quiescent Voltage Output Programming Guaranteed Quiescent Voltage Output Range4,5.6 VOUT(Q) VCC = 5 V, B = 0 G, TA = 25C Quiescent Voltage Output Programming Bits Average Quiescent Voltage Output Step Size7,8 StepVOUT(Q) VCC = 5 V 12 16 18 mV Quiescent Voltage Output Programming Resolution9 ErrPGVOUT(Q) VCC = 5 V - StepVOUT(Q) x 0.5 - mV - 3.3 mV/G Sensitivity Programming Guaranteed Sensitivity Range 4,5,10 Sens VCC = 5 V, TA = 25C 1.9 - 6 - bit Average Sensitivity Step Size7,8 StepSENS VCC = 5 V, TA = 25C 30 40 50 V/G Sensitivity Programming Resolution9 ErrPGSENS VCC = 5 V, TA = 25C - StepSENS x 0.5 - mV/G - 1 - bit - 0.13 - %/C 0.10 - 0.16 %/C VCC = VCC(NORM) - 1.5 - % VCC = VCC(LOWPWR) - 2 - % VCC = VCC(NORM) - 1.5 - % VCC = VCC(LOWPWR) - 2 - % VCC = VCC(NORM) - 1.5 - % VCC = VCC(LOWPWR) - 2.5 - % Sensitivity Programming Bits Lock Bit Programming Overall Programming Lock Bit LOCK Factory Programmed Sensitivity Temperature Coefficient Factory Programmed Sensitivity Temperature Coefficient Target TCSENS(TGT) Factory Programmed Sensitivity Temperature Coefficient Range11 TCSENS VCC = 5 V, TA = 150C Error Components Linearity Sensitivity Error2 Symmetry Sensitivity Error2 LinERR SymERR Ratiometry Quiescent Voltage Output Error2,12 RatERRVOUT(Q) Ratiometry Sensitivity Error2,13 RatERRSENS Ratiometry Clamp Error2,13 RatERRCLP VCC = VCC(NORM) - 1.5 - % VCC = VCC(LOWPWR) - 2.5 - % VCC = VCC(NORM) , TA = 25C - 1.5 - % VCC = VCC(LOWPWR) , TA = 25C - 2.5 - % Continued on the next page... Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 4 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options OPERATING CHARACTERISTICS (continued), valid over full operating temperature range, TA; CBYPASS= 0.1 F, unless otherwise specified Characteristic Min. Typ. Max. Units1 VCC = VCC(NORM), Sens = 3.3 mV/G, TA = 25C to 150C - - 35 mV VCC = VCC(LOWPWR), Sens = 1.75 mV/G, TA = 25C to 150C - 35 - mV VCC = VCC(NORM) - 3 - % VCC = VCC(LOWPWR) - 5 - % TA = 25C; after temperature cycling - 2 - % Symbol Test Conditions Drift Characteristics Quiescent Voltage Output Drift Through Temperature Range2 VOUT(Q) Maximum Sensitivity Drift Through Temperature Range14,15 SensTC Sensitivity Drift Due to Package Hysteresis2,15 SensPKG 11G (gauss) = 0.1 mT (millitesla). Characteristic Definitions section. 3f varies up to approximately 20% over the full operating ambient temperature range, T , and process. C A 4Sens, V OUT(Q), VCLP(LOW) , and VCLP(HIGH) scale with VCC due to ratiometry. 5For optimal device accuracy in the V CC(NORM) operating range, the device should be programmed with VCC = 5 V. 6V OUT(Q)(max) is the value available with all programming fuses blown (maximum programming code set). The VOUT(Q) range is the total range from VOUT(Q)init up to and including VOUT(Q)(max). See Characteristic Definitions section. 7Step size is larger than required, to account for manufacturing spread. See Characteristic Definitions section. 8Non-ideal behavior in the programming DAC can cause the step size at each significant bit rollover code to be greater than twice the maximum specified value of StepVOUT(Q) or StepSENS. 9Overall programming value accuracy. See Characteristic Definitions section. 10Sens(max) is the value available with all programming fuses blown (maximum programming code set). Sens range is the total range from Sens init up to and including Sens(max). See Characteristic Definitions section. 11Factory programmed at 150C and calculated relative to 25C. 12Percent change from actual value at V CC = 3 V or VCC = 5 V, for a given temperature, over the guaranteed supply voltage operating range. 13Percent change from actual value at V CC = 3 V or VCC = 5 V, with TA = 25C, over the guaranteed supply voltage operating range. 14Sensitivity drift from expected value of V OUT at TA , after programming TCSENS. See Characteristic Definitions section. 15Guaranteed by design only. Parameter is not tested in production flow. 2See Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 5 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information Characteristic Symbol RJA Package Thermal Resistance Test Conditions* Value Units Package LH, 1-layer PCB with copper limited to solder pads 228 C/W Package LH, 2-layer PCB with 0.463 in.2 of copper area each side connected by thermal vias 110 C/W Package UA, 1-layer PCB with copper limited to solder pads 165 C/W *Additional thermal information available on Allegro website. Power Derating Curve 6 Maximum Allowable VCC (V) VCC(max) 5 1-layer PCB, Package LH (RQJA = 228 C/W) 1-layer PCB, Package UA (RQJA = 165 C/W) 2-layer PCB, Package LH (RQJA = 110 C/W) 4 3 VCC(min) 2 1 0 20 40 60 80 100 120 140 160 180 Temperature (C) Power Dissipation, PD (mW) Power Dissipation versus Ambient Temperature 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 2l (R aye rP QJ C A = 11 B, P 0 ac 1-la C/ ka W (R yer PC ) ge L QJA = B, P H 165 ack C/ a W) ge U A 1-lay er P (R CB, QJA = 228 Packag C/W e LH ) 20 40 60 80 100 120 Temperature (C) 140 160 180 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 6 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options Characteristic Definitions Supply Voltage Turn On Time To ensure that the internal compo- nents of the A1386 device are initialized to their proper values, the supply voltage, VCC, must be powered up within a specified time interval. Supply Voltage Turn On Time, tVCC, is defined as the time it takes for the supply voltage to transition from 10% to 90% of its steady state value. Operating Mode Threshold The A1386 has two modes of operation, Normal and Low Power. In Low Power mode, certain components of the device are disengaged to limit the current consumption of the device. As a result, the overall device accuracy is limited. In Normal mode, all components are fully functional. The VCC supply level is used by the device to determine the mode of operation. The threshold voltage, VTHRESH , is the VCC threshold voltage required to switch from Low Power operation to Normal operation (VCC(LOWPWR) VCC(NORM)) or from Normal operation to Low Power operation (VCC(NORM) VCC(LOWPWR)). A region of hysteresis exists between the Normal VCC operational range and the Low Power VCC operational range, as shown in figure 1. At the initial power up, the device remains in the Low Power operating mode until reaching the VCC(LOWPWR) VCC(NORM) VTHRESH voltage. Power-On Time When the supply is ramped to its operating volt- age, the device requires a finite time to power its internal components before responding to an input magnetic field. Power-On Time, tPO , is defined as: the time it takes for the output voltage to settle within 10% of its steady state value under an applied magnetic field, after the power supply has reached its minimum specified operating voltage, VCC(min), as shown in figure 2. Quiescent Voltage Output In the quiescent state (no significant magnetic field: B = 0 G), the output, VOUT(Q), has a constant ratio to the supply voltage, VCC , throughout the entire operating ranges of VCC and ambient temperature, TA. Guaranteed Quiescent Voltage Output Range The quiescent voltage output, VOUT(Q), can be programmed around its nominal value of 2.5 V, within the guaranteed quiescent voltage range limits, VOUT(Q)(min) and VOUT(Q)(max). The available guaranteed Initial power-up operating mode V VCC VCC(typ.) Normal Switch to Normal Mode VCC(LOWPWR) m VCC(NORM) Low Power Switch to Low Power Mode VCC(NORM) m VCC(LOWPWR) Operating Mode VOUT 90% VOUT VCC(min.) tPO t1 t2 t1= time at which power supply reaches minimum specified operating voltage t2= time at which output voltage settles within 10% of its steady state value under an applied magnetic field 0 2.7 VTHRESH +t 5.5 VCC (V) Figure 1. Operating Mode relationship to VCC, with VCC shown over the full operating range Power-On Time Figure 2. VCC and VOUT during power-on time interval Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 7 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 programming range for VOUT(Q) falls within the distributions of the initial, VOUT(Q)init, and the maximum programming code for setting VOUT(Q), as shown in figure 3. Average Quiescent Voltage Output Step Size The average qui- escent voltage output step size for a single device is determined using the following calculation: VOUT(Q)maxcode -VOUT(Q)init . StepVOUT(Q) = (1) 2n-1 where: n is the number of available programming bits in the trim range, 2n-1 is the value of the maximum programming code in the range, and VOUT(Q)maxcode is the quiescent voltage output at code 2n-1. Quiescent Voltage Output Programming Resolution The programming resolution for any device is half of its programming step size. Therefore, the typical programming resolution will be: ErrPGVOUT(Q)(typ) = 0.5 x StepVOUT(Q)(typ) . (2) Quiescent Voltage Output Drift Through Temperature Range Due to internal component tolerances and thermal considerations, the quiescent voltage output, VOUT(Q), may drift from its nominal value over the operating ambient temperature, TA. For purposes of specification, the Quiescent Voltage Output Drift Through Temperature Range, VOUT(Q) (mV), is defined as: VOUT(Q) = VOUT(Q)(TA) -VOUT(Q)(25C) . (3) VOUT(Q) should be calculated using the actual measured values of VOUT(Q)(TA) and VOUT(Q)(25C) , rather than programming target values. Sensitivity The presence of a south polarity magnetic field, per- pendicular to the branded surface of the package face, increases the output voltage from its quiescent value toward the supply voltage rail. The amount of the output voltage increase is proportional to the magnitude of the magnetic field applied. Conversely, the application of a north polarity field decreases the output voltage from its quiescent value. This proportionality is specified as the magnetic sensitivity, Sens (mV/G), of the device, and it is defined as: Sens = VOUT(BPOS) - VOUT(BNEG) BPOS - BNEG (4) , where BPOS and BNEG are two magnetic fields with opposite polarities. Sensitivity Temperature Coefficient Device sensitivity changes as temperature changes, with respect to its programmed sensitivity temperature coefficient, TCSENS. TCSENS is programmed at 150C, and calculated relative to the nominal sensitivity programming temperature of 25C. TCSENS (%/C) is defined as: SensT2 - SensT1 1 (5) , TCSens = 100% x Sens T2-T1 T1 where T1 is the nominal Sens programming temperature of 25C, and T2 is the TCSENS programming temperature of 150C. The expected value of Sens over the full ambient temperature range, SensEXPECTED(TA), is defined as: SensEXPECTED(TA) = SensT1 [100% + TCSENS (TA -T1)] . (6) SensEXPECTED(TA) should be calculated using the actual measured values of SensT1 and TCSENS rather than programming target values. Sensitivity Drift Through Temperature Range Second order VOUT(Q)init(typ) Guaranteed Output Programming Range, VOUT(Q) Distribution for VOUT(Q)init Distribution for Max Code VOUT(Q) VOUT(Q)(min) VOUT(Q)(max) Figure 3. Relationship of the guaranteed quiescent output voltage and overall VOUT(Q) values. sensitivity temperature coefficient effects cause the magnetic sensitivity, Sens, to drift from its expected value over the operating ambient temperature range, TA. For purposes of specification, the sensitivity drift through temperature range, SensTC, is defined as: SensTA - SensEXPECTED(TA) SensTC = x 100% . (7) SensEXPECTED(TA) Sensitivity Drift Due to Package Hysteresis Package stress and relaxation can cause the device sensitivity at TA = 25C to change during and after temperature cycling. Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 8 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options For purposes of specification, the sensitivity drift due to package hysteresis, SensPKG, is defined as: Sens(25C)2 - Sens(25C)1 SensPKG = x 100% Sens(25C)1 , (8) where Sens(25C)1 is the programmed value of sensitivity at TA = 25C, and Sens(25C)2 is the value of sensitivity at TA = 25C, but after temperature cycling TA up to 150C, down to -40C, and back to up 25C. Linearity Sensitivity Error The A1386 is designed to provide a linear output in response to a ramping applied magnetic field. Consider two magnetic fields, B1 and B2. Ideally, the sensitivity of a device is the same for both fields, for a given supply voltage and temperature. Linearity error is present when there is a difference between the sensitivities measured at B1 and B2. Linearity Error is calculated separately for the positive (LinERRPOS) and negative (LinERRNEG ) applied magnetic fields. Linearity error (%) is measured and defined as: SensBPOS2 x 100% LinERRPOS = 1- SensBPOS1 , SensBNEG2 x 100% LinERRNEG = 1- SensBNEG1 , (9) |VOUT(Bx) - VOUT(Q)| Bx (10) , and BPOSx and BNEGx are positive and negative magnetic fields, with respect to the quiescent voltage output such that |BPOS2| > |BPOS1| and |BNEG2| > |BNEG1|. Then: LinERR = max( LinERRPOS , LinERRNEG ) SensBPOS SymERR = 1- SensBNEG x 100% , (12) where SensBx is as defined in equation 10, and BPOS and BNEG are positive and negative magnetic fields such that |BPOS| = |BNEG|. Ratiometry Error The A1386 device features a ratiometric output. This means that the quiescent voltage output, VOUT(Q) , magnetic sensitivity, Sens, and clamp voltages, VCLP(HIGH) and VCLP(LOW), are proportional to the supply voltage, VCC. In other words, when the supply voltage increases or decreases by a certain percentage, each characteristic also increases or decreases by the same percentage. Error is the difference between the measured change in the supply voltage relative to 5 V, and the measured change in each characteristic. The ratiometric error in quiescent voltage output, RatERRVOUT(Q) (%), for a given supply voltage, VCC, is defined as: VOUT(Q)(VCC) / VOUT(Q)(5V) x 100% RatERRVOUT(Q) = 1- VCC / 5 V . (13) The ratiometric error in magnetic sensitivity, RatERRSens (%), for a given supply voltage, VCC, is defined as: where: SensBx = Symmetry error, SymERR (%), is measured and defined as: . (11) Symmetry Sensitivity Error The magnetic sensitivity of the A1386 device is constant for any two applied magnetic fields of equal magnitudes and opposite polarities. Sens(VCC) / Sens(5V) x 100% RatERRSens = 1- VCC / 5 V . (14) The ratiometric error in the clamp voltages, RatERRCLP (%), for a given supply voltage, VCC, is defined as: VCLP(VCC) / VCLP(5V) x 100% RatERRCLP = 1- VCC / 5 V . (15) where VCLP is either VCLP(HIGH) or VCLP(LOW). Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 9 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options Typical Application Drawing V+ VCC VOUT CL CBYPASS GND Chopper Stabilization Technique When using Hall-effect technology, a limiting factor for switchpoint accuracy is the small signal voltage developed across the Hall element. This voltage is disproportionally small relative to the offset that can be produced at the output of the Hall element. This makes it difficult to process the signal while maintaining an accurate, reliable output over the specified operating temperature and voltage ranges. 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 modulation-demodulation process. The undesired offset signal is separated from the magnetic field-induced signal in the frequency domain, through modulation. The subsequent demodulation acts as a modulation process for the offset, causing the magnetic field-induced signal to recover its original spectrum at base band, while the DC offset becomes a high-frequency signal. The magnetic-sourced signal then can pass through a low-pass filter, while the modulated DC offset is suppressed. The chopper stabilization technique uses a 200 kHz high frequency clock. For the 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. 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 sampleand-hold circuits. Regulator Clock/Logic Amp Sample and Hold Hall Element Low-Pass Filter Chopper Stabilization Technique Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 10 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 Programming Guidelines Overview Definition of Terms Programming is accomplished by sending a series of input voltage pulses serially through the VOUT pin of the device. A unique combination of different voltage level pulses controls the internal programming logic of the device to select a target programmable parameter and change its value. There are two programming pulses, referred to as a high voltage pulse, VPH, consisting of a VP(LOW) -VP(HIGH) -VP(LOW) sequence and a mid voltage pulse, VPM, consisting of a VP(LOW) -VP(MID) -VP(LOW) sequence. Register. The section of the programming logic that controls the choice of programmable modes and parameters. The A1386 features Try mode, Blow mode, and Lock mode: * In Try mode, the value of a single programmable parameter may be set and measured. The parameter value is stored temporarily, and resets after cycling the supply voltage. Note that other parameters cannot be accessed simultaneously in this mode. * In Blow mode, the value of a single programmable parameter may be permanently set by blowing solid-state fuses internal to the device. Additional parameters may be blown sequentially. * In Lock mode, a device-level fuse is blown, blocking the further programming of all parameters. The programming sequence is designed to help prevent the device from being programmed accidentally; for example, as a result of noise on the supply line. Although any programmable variable power supply can be used to generate the pulse waveforms, Allegro highly recommends using the Allegro Sensor IC Evaluation Kit, available on the Allegro website On-line Store. The manual for that kit is available for download free of charge, and provides additional information on programming these devices. Bit Field. The internal fuses unique to each register, represented as a binary number. Incrementing the bit field of a particular register causes its programmable parameter to change, based on the internal programming logic. Key. A series of VPM voltage pulses used to select a register, with a value expressed as the decimal equivalent of the binary value. The LSB of a register is denoted as key 1, or bit 0. Code. The number used to identify the combination of fuses activated in a bit field, expressed as the decimal equivalent of the binary value. The LSB of a bit field is denoted as code 1, or bit 0. Addressing. Incrementing the bit field code of a selected register by serially applying a pulse train through the VOUT pin of the device. Each parameter can be measured during the addressing process, but the internal fuses must be blown before the programming code (and parameter value) becomes permanent. Fuse Blowing. Applying a VPH voltage pulse of sufficient duration at the VP(HIGH) level to permanently set an addressed bit by blowing a fuse internal to the device. Once a bit (fuse) has been blown, it cannot be reset. Blow Pulse. A VPH voltage pulse of sufficient duration at the VP(HIGH) level to blow the addressed fuse. Cycling the Supply. Powering-down, and then powering-up the supply voltage. Cycling the supply is used to clear the programming settings in Try mode. Programming Pulse Requirements, Protocol at TA = 25C Characteristic Symbol Notes Min. Typ. - - 5.5 V 14 15 16 V 26 27 28 V Minimum supply current required to ensure proper fuse blowing. In addition, a minimum capacitance, CBLOW = 0.1 F, must be connected between the VOUT and GND pins during programming to provide the current necessary for fuse blowing. 300 - - mA tOFF(HIGH) Duration at VP(LOW) level following a VP(HIGH) level. 30 - - s tOFF(MID) Duration at VP(LOW) level following a VP(MID) level. 5 - - s VP(LOW) Programming Voltage VP(MID) Measured at the VOUT pin. VP(HIGH) Programming Current Pulse Width IP Max. Units tACTIVE(HIGH) Duration of VP(HIGH) level for VPH pulses during key/code selection. 30 - - s tACTIVE(MID) Duration of VP(MID) level for VPH pulses during key/code selection. 15 - - s Duration at VP(HIGH) level for fuse blowing. 30 - - s Pulse Rise Time tBLOW tPr Rise time required for transitions from VP(LOW) to either VP(MID) or VP(HIGH). 1 - 100 s Pulse Fall Time tPf Fall time required for transitions from VP(HIGH) to either VP(MID) to VP(LOW). 1 - 100 s Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 11 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 Programming Procedures Parameter Selection Each programmable parameter can be accessed through a specific register. To select a register, a sequence of voltage pulses consisting of a VPH pulse, a series of VPM pulses, and a VPH pulse (with no VCC supply interruptions) must be applied serially to the VOUT pin. The number of VPM pulses is called the key, and uniquely identifies each register. The pulse train used for selection of the first register, key 1, is shown in figure 4. The A1386 has two registers that select among the three programmable parameters: * Register 1: Sensitivity, Sens * Register 2: Quiescent voltage output, VOUT(Q) Overall device locking, LOCK When addressing the bit field, the number of VPM pulses is represented by a decimal number called a code. Addressing activates the corresponding fuse locations in the given bit field by incrementing the binary value of an internal DAC. The value of the bit field (and code) increments by one with the falling edge of each VPM pulse, up to the maximum possible code (see the Programming Logic table). As the value of the bit field code increases, the value of the programmable parameter changes. Measurements can be taken after each pulse to determine if the desired result for the programmable parameter has been reached. Cycling the supply voltage resets all the locations in the bit field that have unblown fuses to their initial states. Fuse Blowing VP(HIGH) VP(HIGH) VP(MID) VP(MID) VP(LOW) Code 2n - 1 V+ Code 2n - 2 V+ Code 2 After a programmable parameter has been selected, a VPH pulse transitions the programming logic into the bit field addressing state. Applying a series of VPM pulses to the VOUT pin of the device, as shown in figure 5, increments the bit field of the selected parameter. Code 1 Bit Field Addressing After the required code is found for a given parameter, its value can be set permanently by blowing individual fuses in the appropriate register bit field. Blowing is accomplished by applying a VPH pulse, called a blow pulse, of sufficient duration at the VP(HIGH) level to permanently set an addressed bit by blowing a fuse internal to the device. Due to power requirements, the fuse for each bit in the bit field must be blown individually. To accomplish this, the code representing the desired parameter value VP(LOW) tLOW 0 tACTIVE Figure 4. Parameter selection pulse train. This shows the sequence for selecting the register corresponding to key 1, indicated by a single VPM pulse. 0 Figure 5. Bit field addressing pulse train. Addressing the bit field by incrementing the code causes the programmable parameter value to change. The number of bits available for a given programming code, n, varies among parameters; for example, the bit field for VOUT(Q) has 6 bits available, which allows 63 separate codes to be used. Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 12 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 must be translated to a binary number. For example, as shown in figure 6, decimal code 5 is equivalent to the binary number 101. Therefore bit 2 (code 4) must be addressed and blown, the device power supply cycled, and then bit 0 (code 1) addressed and blown. An appropriate sequence for blowing code 5 is shown in figure 7. The order of blowing bits, however, is not important. Blowing bit 0 first, and then bit 2 is acceptable. Locking the Device Note: After blowing, the programming is not reversible, even after cycling the supply power. Although a register bit field fuse cannot be reset after it is blown, additional bits within the same register can be blown at any time until the device is locked. For example, if bit 1 (binary 10) has been blown, it is still possible to blow bit 0. The end result would be binary 11 (decimal code 3). The additional guidelines in this section should be followed to ensure the proper behavior of these devices: Bit Field Selection Address Code Format (Decimal Equivalent) Code 5 Code in Binary (Binary) 1 0 1 Fuse Blowing Target Bits Bit 2 Fuse Blowing Address Code Format After the desired code for each parameter is programmed, the device can be locked to prevent further programming of any parameters. Additional Guidelines * A 0.1 F blowing capacitor, CBLOW, must be mounted between the VOUT pin and the GND pin during programming, to ensure enough current is available to blow fuses. * The CBLOW blowing capacitor must be replaced in the final application with a suitable CL. (The maximum load capacitance is 10 nF for proper operation.) * The power supply used for programming must be capable of delivering at least 26 V and 300 mA. * Be careful to observe the tLOW delay time before powering down the device after blowing each bit. Bit 0 * The following programming order is recommended: Code 4 Code 1 (Decimal Equivalents) 1. Sens 2. VOUT(Q) 3. LOCK (only after all other parameters have been programmed and validated, because this prevents any further programming of the device) Figure 6. Example of code 5 broken into its binary components, which are code 4 and code 1. V+ VP(HIGH) VP(MID) VP(LOW) Register Selection (Key 1) 0 Addressing (Code 4) Register Selection (Key 1) Blow (Code 4 in Key 1) Blow (Code 1 in Key 1) tBLOW VCC = 0 V VCC = 0 V Addressing (Code 1) VCC = 0 V Programming of Code 5 in Key 1 Figure 7. Example of programming pulses applied to the VOUT pin that result in permanent parameter settings. In this example, the register corresponding to key 1 is selected and code 5 is addressed and blown. Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 13 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options Programming Modes Try Mode Blow Mode Try mode allows a single programmable parameter to be tested without permanently setting its value. Multiple parameters cannot be tested simultaneously in this mode. After powering the VCC supply, select the desired parameter register and address its bit field. When addressing the bit field, each VPM pulse increments the value of the parameter register, up to the maximum possible code (see Programming Logic table). The addressed parameter value remains stored in the device even after the programming drive voltage is removed from the VOUT pin, allowing the value to be measured. Note that for accurate time measurements, the blow capacitor, CBLOW, should be removed during output voltage measurement. After the required value of the programmable parameter is found using Try mode, its corresponding code should be blown to make its value permanent. To do this, select the required parameter register, and address and blow each required bit separately (as described in the Fuse Blowing section). The supply must be cycled between blowing each bit of a given code. After a bit is blown, cycling the supply will not reset its value. It is not possible to decrement the value of the register without resetting the parameter bit field. To reset the bit field, and thus the value of the programmable parameter, cycle the supply (VCC) voltage. Lock Mode To lock the device, address the LOCK bit and apply a blow pulse with CBLOW in place. After locking the device, no future programming of any parameter is possible. Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 14 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 Programming State Machine Power-Up VPM Initial VPH VPH Parameter Selection VPM VPM Sens VPM VOUT(Q), LOCK VPH Bit Field Addressing VPM 1 VPM VPM 2 3 VPM 2n - 1 n = total bits in register VPM VPH Fuse Blowing VPM = VP(LOW) , VP(MID) , VP(LOW) VPH = VP(LOW) , VP(HIGH) , VP(LOW) User Power-Down Required Initial State After system power-up, the programming logic is Bit Field Addressing State This state allows the selection of the reset to a known state. This is referred to as the Initial state. All the bit field locations that have intact fuses are set to logic 0. While in the Initial state, any VPM pulses on the VOUT pin are ignored. To enter the Parameter Selection state, apply one VPH pulse on the VOUT pin. individual bit fields to be programmed in the selected parameter Parameter Selection State This state allows the selection of the parameter register containing the bit fields to be programmed. To select a parameter register, increment through the keys by applying VPM pulses on the VOUT pin. Register keys select among the following programming parameters: * 1 pulse - Sens register (see Programming Logic table). To leave this state, either cycle device power or blow the fuses for the selected code. Note that merely addressing the bit field does not permanently set the value of the selected programming parameter; fuses must be blown to do so. Fuse Blowing State To blow an addressed bit field, apply a VPH pulse on the VOUT pin. Power to the device should then be * 2 pulses - VOUT(Q) and LOCK cycled before additional programming is attempted. Note: Each To enter the Bit Field Addressing state, apply one VPH pulse on the VOUT pin. bit representing a decimal code must be blown individually (see the Fuse Blowing section). Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 15 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 Programming Logic Table Programmable Parameter (Register Key) Sens (1) VOUT(Q) , LOCK (2) Bit Field Address Binary Format [MSB LSB] Decimal Equivalent Code 000000 0 Description Initial value (Sensinit) 111111 63 Maximum value of sensitivity (Sens) in range 000000 0 Initial value (VOUT(Q)init) 011111 31 Maximum value of quiescent voltage output (VOUT(Q)) in range; B = 0 G 100000 32 LOCK bit, enables permanent locking of all programming bit fields in the device Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 16 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 Package LH, 3 Pin; (SOT-23W) +0.12 2.98 -0.08 1.49 D 44 3 A +0.020 0.180-0.053 0.96 D +0.10 2.90 -0.20 +0.19 1.91 -0.06 2.40 0.70 D 0.25 MIN 1.00 2 1 0.55 REF 0.25 BSC 0.95 Seating Plane Gauge Plane 8X 10 REF B PCB Layout Reference View Branded Face 1.00 0.13 +0.10 0.05 -0.05 0.95 BSC 0.40 0.10 For Reference Only; not for tooling use (reference dwg. 802840) Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Active Area Depth, 0.28 mm REF B Reference land pattern layout All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary to meet application process requirements and PCB layout tolerances C Branding scale and appearance at supplier discretion D Hall element, not to scale NNT 1 C Standard Branding Reference View N = Last two digits of device part number T = Temperature code Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 17 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options A1386 Package UA, 3-Pin SIP +0.08 4.09 -0.05 45 B C E 2.04 1.52 0.05 1.44 E +0.08 3.02 -0.05 Mold Ejector Pin Indent 2X10 E Branded Face 45 1 D Standard Branding Reference View A 1.02 MAX 0.51 REF = Supplier emblem N = Last two digits of device part number T = Temperature code 0.79 REF 1 2 3 +0.03 0.41 -0.06 14.99 0.25 +0.05 0.43 -0.07 NNT For Reference Only; not for tooling use (reference DWG-9013) Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Dambar removal protrusion (6X) B Gate and tie bar burr area C Active Area Depth, 0.50 mm REF D Branding scale and appearance at supplier discretion E Hall element, not to scale 1.27 NOM Please note that there are changes to the existing UA package drawing pending. Please contact the Allegro Marketing department for additional information. Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 18 A1386 5 V Field-Programmable Linear Hall Effect Sensor IC with 3 V Supply Functionality Analog Output, and Miniature Package Options Copyright (c)2009, Allegro MicroSystems, Inc. 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's products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the failure of that life support device or system, or to affect the safety or effectiveness of that device or system. 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. For the latest version of this document, visit our website: www.allegromicro.com Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 19