A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Package EH, 6-pin MLP/DFN VCC 1 6 VREF OUT 2 5 SLEEP GND 3 4 GND These linear Hall effect sensor integrated circuits (ICs) provide a voltage output that is directly proportional to an applied magnetic field. Before amplification, the sensitivity of typical Hall effect ICs (measured in mV/G) is directly proportional to the current flowing through the Hall effect transducer element inside the ICs. In many applications, it is difficult to achieve sufficient sensitivity levels with a Hall effect sensor IC without consuming more than 3 mA of current. The A1391 and A1392 minimize current consumption to less than 25 μA through the addition of a user-selectable sleep mode. This makes these devices perfect for battery-operated applications such as: cellular phones, digital cameras, and portable tools. End users can control the current consumption of the A1391 and A1392 by applying a logic level signal to the ¯S¯L ¯¯E ¯¯E ¯¯P pin. The outputs of the devices are not valid (high-impedance mode) during sleep mode. The high-impedance output feature allows the connection of multiple A1391 and A1392 Hall effect devices to a single A-to-D converter input. The quiescent output voltage of these devices is 50 % nominal of the ratiometric supply reference voltage applied to the VREF pin of the device. The output voltage of the device is not ratiometric with respect to the SUPPLY pin. Despite the low power consumption of the circuitry in the A1391 and A1392, the features required to produce a highly-accurate linear Hall effect IC have not been compromised. Each BiCMOS monolithic circuit integrates a Hall element, improved temperature-compensating circuitry to reduce the intrinsic sensitivity drift of the Hall element, a small-signal high-gain amplifier, and proprietary dynamic offset cancellation circuits. End of line, postpackaging, factory programming allows precise control of device sensitivity and offset. This device is available in a small 2.0 × 3.0 mm, 0.75 mm nominal height micro leaded package (MLP). It is Pb (lead) free, with 100 % matte tin leadframe plating. ABSOLUTE MAXIMUM RATINGS* Supply Voltage, VCC ............................................. 8 V Reverse-Supply Voltage, VRCC ....................... –0.1 V Ratiometric Supply Reference Voltage, VREF ...... 7 V Reverse-Ratiometric Supply Reference Voltage, VRREF ......................... –0.1 V Logic Supply Voltage, V¯S¯L¯¯E¯¯E¯P¯ (VCC > 2.5 V)............................................... 32 V Reverse-Logic Supply Voltage, VR¯S¯¯L¯¯E¯¯E¯P¯ ......... –0.1 V Output Voltage, VOUT ............................ VCC + 0.1 V Reverse-Output Voltage, VROUT...................... –0.1 V Temperatures Operating Ambient, TA , Range S .... –20ºC to 85ºC Junction, TJ(MAX) .......................................165ºC Storage, TS ................................. –65ºC to 170ºC *All ratings with reference to ground. Features and Benefits • High-impedance output during sleep mode • Compatible with 2.5 to 3.5 V power supplies • 10 mW power consumption in the active mode • Miniature MLP package • Ratiometric output scales with the ratiometric supply reference voltage (VREF pin) • Temperature-stable quiescent output voltage and sensitivity • Wide ambient temperature range: –20°C to 85°C • ESD protection greater than 3 kV • Solid-state reliability • Preset sensitivity and offset at final test Use the following complete part numbers when ordering: Part Number Sensitivity Packing* (mV / G, Typ.) A1391SEHLT-T 1.25 7-in. reel, 3000 pieces/reel A1392SEHLT-T 2.50 7-in. reel, 3000 pieces/reel *Contact Allegro for additional packing options. A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Functional Block Diagram VCC VREF To all subcircuits RRatio / 2 Hall Element Regulator Amp Filter Dynamic Offset Cancellation RRatio / 2 Out Gain OUT Offset Programming Logic SLEEP Circuit Reference Current GND Terminal List Table Pin Name 1 VCC Function Supply 2 OUT Output 3 GND Ground 4 GND Ground 5 ¯S¯¯ L¯¯ E¯¯ E¯¯ P¯ 6 VREF Toggle sleep mode Supply for ratiometric reference 2 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Device Characteristics Tables ELECTRICAL CHARACTERISTICS valid through full operating ambient temperature range, unless otherwise noted Characteristic Supply Voltage Nominal Supply Voltage Supply Zener Clamp Voltage Ratiometric Reference Voltage2 Ratiometric Reference Zener Clamp Voltage ¯S ¯¯ L¯¯ E ¯¯ E ¯¯ P¯ Input Voltage Symbol VCC VCCN VCCZ VREF VREFZ ¯S¯¯ L¯¯ E¯¯ E¯¯ P ¯ Input Threshold VINH VINL Ratiometric Reference Input Resistance RREF Chopper Stabilization Chopping Frequency fC ISLEEP ¯S ¯¯ L¯¯ E ¯¯ E¯¯ P¯ Input Current Supply Current3 ICC Quiescent Output Power Supply Rejection4 PSRVOQ Test Conditions ICC = 7 mA, TA = 25°C IVREF = 3 mA, TA = 25°C For active mode For sleep mode VSLEEP > VINH , VCC = VCCN, TA = 25°C VSLEEP < VINL, VCC = VCCN, TA = 25°C VCC = VCCN, TA = 25°C VSLEEP = 3 V, VCC = VCCN VSLEEP < VINL, VCC = VCCN, TA = 25°C VSLEEP > VINH , VCC = VCCN, TA = 25°C fAC < 1 kHz Min. 2.5 – 6 2.5 6 –0.1 – – Typ.1 – 3.0 8.3 – 8.3 – 0.45 × VCC 0.20 × VCC Max. 3.5 – – VCC – VCC + 0.5 – – Units V V V V V V V V 250 – – kΩ – 5 – MΩ – 200 – kHz – 1 – μA – 0.025 – mA – 3.2 – mA – –60 – dB 1Typical data are for initial design estimations only, and assume optimum manufacturing and application conditions, such as T = 25°C. Performance A may vary for individual units, within the specified maximum and minimum limits. 2 Voltage applied to the VREF pin. Note that the V voltage must be less than or equal to V . Degradation in device accuracy will occur with applied REF voltages of less than 2.5 V. 3 If the VREF pin is tied to the VCC pin, the supply current would be I 4f AC cc CC + VREF / RREF is any ac component frequency that exists on the supply line. 3 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode OUTPUT CHARACTERISTICS valid through full operating ambient temperature range, unless otherwise noted Characteristic Output Voltage Saturation Limits2 Symbol VOUTH VOUTL Test Conditions B = X, VCC = VCCN, VREF ≤ VCC B = –X, VCC = VCCN, VREF ≤ VCC Maximum Voltage Applied to Output VOUTMAX VSLEEP < VINL Min. – – Typ.1 VREF – 0.1 0.1 Max. – – Units V V – – VCC + 0.1 V 1.18 2.35 1.25 2.50 mV/G mV/G Sensitivity3 Sens A1391 TA = 25°C, VCC = VREF = VCCN A1392 TA = 25°C, VCC = VREF = VCCN Quiescent Output VOUTQ TA = 25°C, B = 0 G – 0.500 × VREF Output Resistance4 ROUT fout = 1 kHz, VSLEEP > VINH , active mode fout = 1 kHz, VSLEEP < VINL, sleep mode Output to ground Output to ground –3 dB point, VOUT = 1 Vpp sinusoidal, VCC = VCCN Cbypass = 0.1 μF, BWexternalLPF = 2 kHz 1391 Cbypass = 0.1 μF, no load 1392 Cbypass = 0.1 μF, no load – – 15 – 20 4M – – 1.31 2.65 (0.500 × VREF ) ± 0.030 – – – 10 – 10 – kHz – 6 12 mVpp – – – – 20 40 mVpp mVpp Output Load Resistance Output Load Capacitance RL CL Output Bandwidth BW Noise5,6 Vn V Ω Ω kΩ nF 1Typical data are for initial design estimations only, and assume optimum manufacturing and application conditions, such as TA = 25°C. Performance may vary for individual units, within the specified maximum and minimum limits. 2This test requires positive and negative magnetic fields sufficient to swing the output driver between fully OFF and saturated (ON), respectively. The value of vector X is NOT intended to indicate a range of linear operation. 3For V REF values other than VREF = VCCN , the sensitivity can be derived from the following equation: 0.416 × VREF. 4f OUT is the output signal frequency 5Noise specification includes digital and analog noise. 5Values for BW externalLPF do not include any noise resulting from noise on the externally-supplied VREF voltage. 4 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode OUTPUT TIMING CHARACTERISTICS1 TA = 25°C Characteristic Power-On Time3 Power-Off Time4 Symbol tPON tPOFF Test Conditions Min. – – Typ.2 40 1 Max. 60 – Units μs μs 1See figure 1 for explicit timing delays. data are for initial design estimations only, and assume optimum manufacturing and application conditions, such as TA = 25°C. Performance may vary for individual units, within the specified maximum and minimum limits. 3Power-On Time is the elapsed time after the voltage on the SLEEP pin exceeds the active mode threshold voltage,V INH, until the time the device output reaches 90% of its value. When the device output is loaded with the maximum capacitance of 10 nF, the Power-On Time range is guaranteed for input SLEEP pin frequencies less than 10 Hz. 4Power-Off Time is the duration of time between when the signal on the SLEEP pin switches from HIGH to LOW and when I CC drops to under 100 μA. During this time period, the output goes into the HIGH impedance state. 2Typical MAGNETIC CHARACTERISTICS TA = 25°C Characteristic Symbol Ratiometry ΔVOUTQ(ΔV) Ratiometry ΔSens(ΔV) Positive Linearity Lin+ Negative Linearity Lin– Symmetry Sym Test Conditions Min. – – – – – Typ.* 100 100 100 100 100 Max. – – – – – Units % % % % % *Typical data are for initial design estimations only, and assume optimum manufacturing and application conditions, such as TA = 25°C. Performance may vary for individual units, within the specified maximum and minimum limits. 5 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Electrical Characteristic Data Supply Current versus Ambient Temperature A1391 and A1392, VCC = VREF = 3 V 3.5 ICC (mA) 3.0 2.5 2.0 Active Mode Sleep Mode 1.5 1.0 0.5 0 -20 -5 10 25 40 55 70 85 TA (°C) Ratiometric Reference Input Current versus Ambient Temperature 19 SLEEP Input Current versus Ambient Temperature A1391 and A1392, VCC = VREF= VSLEEP = 3 V 17 ISLEEP (µA) IREF (µA) 15 13 11 9 7 5 3 1 -20 -5 10 25 40 TA (°C) 55 70 85 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 -20 A1391 and A1392, VCC = VREF= VSLEEP = 3 V -5 10 25 40 55 70 85 TA (°C) 6 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Magnetic Characteristic Data Average Ratiometry, VOUTQ , versus Ambient Temperture (A139x) Average Ratiometry, Voq (%) 101.0 100.8 2.5 to 3 V 3.5 to 3 V 100.6 100.4 100.2 100.0 99.8 99.6 99.4 99.2 99.0 -20 -5 10 25 40 TA (°C) 55 70 Average Ratiometry, Sens, versus Ambient Temperture (A1392) 102.0 102.0 101.5 101.5 Average Ratiometry, Sens (%) Average Ratiometry, Sens (%) Average Ratiometry, Sens, versus Ambient Temperture (A1391) 101.0 2.5 to 3 V 3.5 to 3 V 100.5 100.0 99.5 99.0 98.5 98.0 85 97.5 101.0 100.5 2.5 to 3 V 3.5 to 3 V 100.0 99.5 99.0 98.5 98.0 97.5 -20 -5 10 25 40 TA (°C) 55 70 85 -20 -5 Average Symmetry, Vcc=Vref=Vsleep=3V (A139x) 25 40 TA (°C) 55 70 85 70 85 Average Linearity (A139x) 102.0 102.0 101.5 Average Linearity (%) 101.5 Average Symetry (%) 10 101.0 100.5 100.0 99.5 99.0 101.0 100.5 100.0 99.5 99.0 Linearity - , Vcc=3.5V Linearity +, Vcc=3.5V Linearity +, Vcc=2.5V Linearity -, Vcc = 2.5V 98.5 98.5 98.0 98.0 97.5 97.0 97.5 -20 -5 10 25 40 TA (°C) 55 70 85 -20 -5 10 25 40 55 TA (°C) 7 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information Characteristic Symbol RθJA Package Thermal Resistance Test Conditions* Min. Units 1-layer PCB with copper limited to solder pads 221 ºC/W 2-layer PCB with 0.6 in.2 of copper area each side, connected by thermal vias 70 ºC/W 4-layer PCB based on JEDEC standard 50 ºC/W *For additional information, see Allegro Web site. Power Dissipation versus Ambient Temperature 4500 4000 Power Dissipation, PD (m W) 3500 4-layer PCB (RθJA = 50 ºC/W) 3000 2-layer PCB (RθJA = 70 ºC/W) 2500 2000 1-layer PCB (RθJA = 221 ºC/W) 1500 1000 500 0 20 40 60 80 100 120 Temperature (°C) 140 160 180 8 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Characteristics Definitions Ratiometric. The A1391 and A1392 devices feature ratiometric output. The quiescent voltage output and sensitivity are proportional to the ratiometric supply reference voltage. The percent ratiometric change in the quiescent voltage output is defined as: ΔVOUTQ(ΔV) = ΔVOUTQ(VREF)÷ ΔVOUTQ(3V) VREF ÷ 3 V × 100 % (1) Linearity and Symmetry. The on-chip output stage is designed to provide a linear output with maximum supply voltage of VCCN. Although application of very high magnetic fields will not damage these devices, it will force the output into a non-linear region. Linearity in percent is measured and defined as Lin+ = and the percent ratiometric change in sensitivity is defined as: ΔSens(ΔV) = ΔSens(VREF)÷ ΔSens(3V) VREF ÷ 3 V × 100% (2) Lin– = VOUT(+B) – VOUTQ 2(VOUT(+B / 2) – VOUTQ ) VOUT(–B) – VOUTQ 2(VOUT(–B / 2) – VOUTQ ) × 100 % (3) × 100 % (4) × 100 % (5) and output symmetry as Sym = VOUT(+B) – VOUTQ VOUTQ – VOUT(–B) 9 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Device Low-Power Functionality A1391 and A1392 are low-power Hall effect sensor ICs that are perfect for power sensitive customer applications. The current consumption of these devices is typically 3.2 mA, while the device is in the active mode, and less than 25 uA when the device is in the sleep mode. Toggling the logic level signal connected to the ¯S¯L ¯¯E ¯¯E ¯¯P pin drives the device into either the active mode or the sleep mode. A logic low sleep signal drives the device into the sleep mode, while a logic high sleep signal drives the device into the active mode. In the case in which the VREF pin is powered before the VCC pin, the device will not operate within the specified limits until the supply voltage is equal to the reference voltage. When the device is switched from the sleep mode to the active mode, a time defined by tPON must elapse before the output of the device is valid. The device output transitions into the high impedance state approximately tPOFF seconds after a logic low signal is applied to the ¯S¯L ¯¯E ¯¯E ¯¯P pin (see figure 1). If possible, it is recommended to power-up the device in the sleep mode. However, if the application requires that the device be powered on in the active mode, then a 10 kΩ resistor in series with the ¯S¯L ¯¯E ¯¯E ¯¯P pin is recommended. This resistor will limit the current that flows into the ¯S¯L ¯¯E ¯¯E ¯¯P pin if certain semiconductor junctions become forward biased before the ramp up of the voltage on the VCC pin. Note that this current limiting resistor is not required if the user connects the ¯S¯L ¯¯E ¯¯E ¯P ¯ pin directly to the VCC pin. The same precautions are advised if the device supply is powered-off while power is still applied to the ¯S¯L ¯¯E ¯¯E ¯¯P pin. VCC VSLEEP ICC +B B field 0 –B VOUT HIGH IMPEDANCE HIGH IMPEDANCE HIGH IMPEDANCE tPON tPOFF tPON tPOFF Figure 1. A1391/A1392 Timing Diagram 10 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Device Supply Ratiometry Application Circuit Figures 2 and 3 present applications where the VCC pin is connected together with the VREF pin of the A1391/A1392. Both of these pins are connected to the battery, Vbat2. In this case, the device output will be ratiometric with respect to the battery voltage. The only difference between these two applications is that the ¯S¯L ¯¯E ¯¯E ¯¯P pin in figure 2 is connected to the Vbat2 potential, so the device is always in the active mode. In figure 3, the ¯S¯L ¯¯E ¯¯E ¯¯P pin is toggled by the microprocessor; therefore, the device is selectively Cbypass Vbat1 and periodically toggled between active mode and sleep mode. In both figures, the device output is connected to the input of an A-to-D converter. In this configuration, the converter reference voltage is Vbat1. It is strongly recommended that an external bypass capacitor be connected, in close proximity to the A1391/-92 device, between the VCC and GND pins of the device to reduce both external noise and noise generated by the chopper-stabilization circuits inside of the A1391/A1392. Vbat2 Supply pin VCC MicroI/O processor VREF A1391/A1392 OUT SLEEP GND GND I/O Figure 2. Application circuit showing sleep mode disabled and output ratiometirc to the A1391/A1392 supply. Cbypass Vbat1 Supply pin MicroI/O processor Vbat 2 VCC VREF A1391/A1392 OUT SLEEP GND GND I/O Figure 3. Application circuit showing microprocessor-controlled sleep mode and output ratiometirc to the A1391/A1392 supply. 11 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Application Circuit with User-Configurable Ratiometry In figures 4 and 5, the microprocessor supply voltage determines the ratiometric performance of the A1391/A1392 output signal. As in the circuits shown in figures 2 and 3, the device is powered by the Vbat2 supply, but in this case, ratiometry is determined by the microprocessor supply, Vbat1. between the active and sleep modes. The ¯S¯L ¯¯E ¯¯E ¯¯P pin is triggered by the output logic signal from the microprocessor in figure 5, while in figure 4, the ¯S¯L ¯¯E ¯¯E ¯¯P pin is connected to the device power supply pin. Therefore, the device as configured in figure 4 is constantly in active mode, while the device as confiugred in figure 5 can be periodically toggled It is strongly recommended that an external bypass capacitor be connected, in close proximity to the A1391/A1392 device, between the VCC and GND pins of the device to reduce both external noise and noise generated by the chopper-stabilization circuits inside of the A1391/A1392. Cfilter The capacitor Cfilter is optional, and can be used to prevent possible noise transients from the microprocessor supply reaching the device reference pin, VREF. Cbypass Vbat2 Vbat 1 Supply pin VCC Micro- I/O processor I/O VREF A1391/A1392 OUT SLEEP GND GND Figure 4. Application circuit showing ratiometry of VREF . Sleep mode is disabled and the VREF pin is tied to the microprocessor supply. Cbypass Vbat2 Cfilter Vbat1 Supply pin Micro- I/O processor I/O VCC VREF A1391/A1392 OUT SLEEP GND GND Figure 5. Application circuit showing device reference pin, VREF, tied to microprocessor supply. The device sleep mode also is controlled by the microprocessor. 12 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Summary of Single-Device Application Circuits Device Pin Connections Application Circuit Cbypass Vbat1 VREF pin (Ratiometric Reference Supply) VCC MicroI/O processor VREF A1391/A1392 OUT SLEEP GND GND I/O Cbypass Connected to A1391/A1392 device supply, VCC Connected to A1391/A1392 device supply, VCC Ratiometric to device supply (VCC), and always valid Connected to A1391/A1392 device supply, VCC Controlled by microprocessor Ratiometric to device supply (VCC), and controlled by the microprocessor Connected to microprocessor supply Connected to A1391/A1392 device supply, VCC Ratiometric to microprocessor supply, and always valid Connected to microprocessor supply Controlled by microprocessor Ratiometric to microprocessor supply, and controlled by the microprocessor Vbat 2 Supply pin VCC VREF A1391/A1392 MicroI/O processor OUT SLEEP GND GND I/O Cfilter Device Output Vbat2 Supply pin Vbat1 ¯S¯¯ L¯¯ E¯¯ E¯¯ P¯ pin Cbypass Vbat2 Vbat 1 Supply pin VCC Micro- I/O processor I/O VREF A1391/A1392 OUT SLEEP GND GND Cbypass Vbat2 Cfilter Vbat1 Supply pin Micro- I/O processor I/O VCC VREF A1391/A1392 OUT SLEEP GND GND 13 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Application Circuit with Multiple Hall Devices and a Single A-to-D Converter Multiple A1391/A1392 devices can be connected to a single microprocessor or A-to-D converter input. In this case, a single device is periodically triggered and put into active mode by the microprocessor. While one A1391/A1392 device is in active mode, all of the other A1391/A1392 devices must remain in sleep mode. While these devices are in sleep mode, their outputs are in a high-impedance state. In this circuit configuration, the microprocessor reads the output of one device at a time, according to microprocessor input to the ¯S¯L ¯¯E ¯¯E ¯¯P pins. When multiple device outputs are connected to the same microprocessor input, pulse timing from the microprocessor (for example, lines A1 through A4 in figure 6) must be configured to prevent more than one device from being in the awake mode at any given time of the application. A device output structure can be damaged when its output voltage is forced above the device supply voltage by more than 0.1 V. Cbypass Vbat2 VCC VREF A1391/A1392 OUT SLEEP GND GND VCC VREF Cbypass Vbat2 A1391/A1392 C filter Vbat1 Supply pin OUT SLEEP GND GND VCC VREF Microprocessor A1 A2 A1 I/O Cbypass Vbat2 A3 A1391/A1392 A4 A2 A3 OUT SLEEP GND GND A4 Cbypass Vbat2 VCC VREF A1391/A1392 OUT SLEEP GND GND Figure 6. Application circuit showing multiple A1391/A1392 devices, controlled by a single microprocessor. 14 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1391 and A1392 Micro Power 3 V Linear Hall Effect Sensor with Tri-State Output and User-Selectable Sleep Mode Package EH, 6-pin MLP 2.15 .085 1.85 .073 A 1 .0394 NOM C B D 6 Preliminary dimensions, for reference only (reference JEDEC MO-229 WCED) Dimensions in millimeters U.S. Customary dimensions (in.) in brackets, for reference only Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown .0591 NOM C 1.5 C 3.15 .124 2.85 .112 A Terminal #1 mark area A B Exposed thermal pad C Hall Element (not to scale); U.S. customary dimensions controlling D Active Area Depth, 0.34 [.013] E Reference pad layout (reference IPC7351); adjust as necessary to meet application process requirements; when mounting on a multilayer PCB, thermal vias at the exposed thermal pad land can improve thermal dissipation (reference EIA/JEDEC Standard JESD51-5) 1 2 5X SEATING PLANE 0.08 [.003] C 6X 0.30 .012 0.18 .007 C 0.80 .031 0.70 .028 0.10 [.004] M C A B 0.05 [.002] M C 0.20 .008 REF 0.50 .020 0.05 .002 0.00 .000 0.50 .020 E 0.30 .012 6 1 1.00 .039 2 0.65 .026 0.45 .018 3.70 .146 1.25 .049 0.225 .009 REF B 1.224 .0482 NOM 0.25 .010 6 1 0.25 .010 0.95 .037 1.042 .0410 NOM 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 Allegro MicroSystems, Inc. 15 A1391-DS Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com