A1174 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications Features and Benefits Micro-power latch operation 1.65 to 3.5 V battery operation Push-pull output eliminates the need for an external pullup resistor User configured, internally or externally controlled sample and sleep periods Floating the two clock pins results in the use of a fixed sampling clock internal to the device Toggling the clock pins allows the user to control the sampling and sleep times of the device for extreme low power operation External control of the clock pins allows the user to implement synchronous sampling of multiple sensors in direction detection systems Chopper stabilization Superior temperature stability Extremely low switchpoint drift Insensitive to physical stress Solid state reliability Small size Package: 6-contact MLP/DFN (suffix EW) 1.5 mm x 2 mm x 0.40 mm Description The A1174 is a micro-power, Hall-effect latch for use in portable devices that employ rotational detection systems, and have a power supply voltage between 1.65 and 3.5 V. The device has a single push-pull output structure and requires no external pull-up resistor for reliable operation. When a sufficient positive magnetic field is present on the device, the device output transitions to the low state and is latched in this state until a negative field of sufficient strength latches the device output into the high state. The latched output is ideal when using multiple sensors in rotational speed and direction sensing systems (for example, track ball and scroll bar systems in portable devices). The device includes an innovative clocking scheme that satisfies the micro-power needs of almost any application, including track balls for PDAs and cell phones. Using the EXTERNAL_CLK and DUAL_CLK pins as described in this datasheet, the device can be set into various working modes. In Dual Clock mode, the device switches between predefined slow and fast sampling rates. The average current consumption of the device is extremely low when rotation is not detected. In External Clock mode, the user sets the clock rate for the device to achieve the required on and off times for controlling average power. This user-determined clocking also helps to Continued on the next page... Not to scale +B Magnetic Flux Density BOP BOP BOP 0 BRP BRP BRP -B +V A1174 Output On Off On Off On Figure 1. Timing diagram for output switching A1174-DS, Rev. 7 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 Description (continued) achieve synchronous clocking of multiple devices. This allows a defined phase relationship between the output transitions of each device in direction detection systems. by integrating, on a single silicon chip, a Hall-voltage generator, a small-signal amplifier, chopper stabilization, a latch, and a MOSFET output. Improved stability is made possible through dynamic offset cancellation using chopper stabilization, which reduces the residual offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress. Solid state reliability is provided The device package is a 6-contact, 1.5 mm x 2 mm, 0.40 mm nominal overall height MLP/DFN, with exposed pad for enhanced thermal dissipation. It is lead (Pb) free, with NiPdAu leadframe plating. Selection Guide Part Number Packing1 Package A1174EEWLT-P2 DFN/MLP 1.5x2 mm; 0.40 mm maximum height 3000 pieces per 7-inch reel 1Contact Allegro(R) for additional packing options. 2Allegro products sold in DFN package types are not intended for automotive applications. Absolute Maximum Ratings Rating Units Forward Supply Voltage Characteristic Symbol VDD Notes 5.0 V Reverse Supply Voltage VRDD -0.3 V Output Voltage VOUT 5.0 V Reverse Output Voltage VROUT -0.3 V EXTERNAL_CLK and DUAL_CLK Pins Input Voltage VIN 5.0 V EXTERNAL_CLK and DUAL_CLK Pins Reverse Input Voltage VRIN -0.3 V IOUT(sink) -1 mA IOUT(source) 1 mA Continuous Output Current Magnetic Flux Density* B Operating Ambient Temperature TA Maximum Junction Temperature TJ(MAX) 165 C Tstg -65 to 170 C Storage Temperature Range E Unlimited G -40 to 85 C *1G = 0.1 mT (millitesla) Terminal List Pin-out Diagram VDD 1 NC 2 6 DUAL_CLK PAD VOUT 3 (Top View) 5 GND 4 EXTERNAL_CLK Number Name 1 VDD 2 NC 3 VOUT 4 EXTERNAL_CLK 5 GND 6 DUAL_CLK Function Supply Voltage No connect Output In combination with DUAL_CLK , allows external control of the device sampling period and duty cycle Ground In combination with EXTERNAL_CLK , drives the part in Dual Clock mode Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 Functional Block Diagram VDD VOUT Latch Amp Sample Control Block EXTERNAL_CLK DUAL_CLK Input Decoder Internal Clock GND Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 Operating Characteristics Valid over full operating voltage and ambient temperature ranges (unless otherwise specified) Characteristic Symbol Min. Typ.1 Max. Unit TA = 25C 1.65 - 3.5 V -40C TA 85C 1.8 - 3.5 V - 100 300 mV Test Conditions Electrical Characteristics Supply Voltage2 VDD Output On Voltage Supply Current VOUT(SAT) NMOS on, IOUT = 1 mA VOUT(HIGH) PMOS on, IOUT = 1 mA - mV IDD(EN) Chip in awake state (enabled) - - 2.0 mA IDD(DIS) Chip in sleep state (disabled) - - 8.0 A Normal Clock mode, VDD = 2.5 V - - 71 A IDD(AV) Internal Chopper Stabilization Clock Frequency fC EXTERNAL_CLK and DUAL_CLK Pins Input Current IIN Normal Clock mode, VDD = 3.0 V VEXTERNAL_CLK = VDD, VDUAL_CLK = VDD EXTERNAL_CLK and DUAL_CLK Pins Leakage Current IOFF VEXTERNAL_CLK = 0 V, VDUAL_CLK = 0 V Supply Slew Rate3 SR tOFF = 100 ms VDD - 300 VDD - 100 - - 82 A - 200 - kHz - 0.5 - A - 0.02 - A 0.1 - - V/ms Normal Clock Mode Characteristics4 Normal Mode Awake Duration tawake_norm - 25 46 s Normal Mode Period tperiod_norm - 0.7 1.05 ms Vth(HIGH) - - 0.75 x VDD V Vth(LOW) 0.25 x VDD - - V External Clock Mode Characteristics4 EXTERNAL_CLK and DUAL_CLK Pins Threshold External Clock Mode Awake Duration tawake_ext VEXTERNAL_CLK > Vth(HIGH) 46 - - s External Clock Mode Period tperiod_ext VEXTERNAL_CLK > Vth(HIGH) 80 - - s tdelay_ext - 25 46 s Dual Clock Mode Awake Duration tawake_dual - 25 46 s Dual Clock Mode Fast Sampling Period tperiod_fast - 8x tawake_dual - s Dual Clock Mode Slow Sampling Period tperiod_slow - 28 - ms ttimeout - 100 x tperiod_slow - ms State Transition Delay5 Dual Clock Mode Characteristics4 Dual Clock Mode Timeout6 Magnetic Characteristics2 Operate Point BOP South pole to device branded side 5 36 55 G Release Point BRP North pole to device branded side -55 -36 -5 G Hysteresis BHYS BOP - BRP - 72 110 G 1Typical values are at TA = 25C and VDD = 2.75 V. Performance may vary for individual units, within the specified maximum and minimum limits. 2Magnetic operate and release points vary with supply voltage. 3If the device power supply is chopped, power-up slew rate dV DD / dt has to be adjusted to ensure correct functioning of the device. tOFF is the time of the power cycle when VDD < VDD(min). 4Defined in the Functional Description section of this datasheet. 5Time between external clock transition and resulting transition of the device between the awake and sleep states. See Functional Description section. 6If no output transition is detected during the timeout interval, the device goes back into slow sampling. See Functional Description section. Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 4 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 Characteristic Performance Saturation Voltage versus Temperature Saturation Voltage versus Supply Voltage 300 300 250 250 VDD (V) 200 1.65 1.8 2.5 2.75 3.0 3.5 150 100 50 IOUT = 1 mA 200 VOUT(SAT) (mV) VOUT(SAT) (mV) IOUT = 1 mA -40 -20 0 20 40 60 80 85C -40C 25C 150 100 50 0 -60 TA (C) 0 100 1.0 1.5 2.0 TA (C) 100 100 90 90 VDD (V) 1.65 1.8 2.5 3.0 3.5 70 3.5 4.0 60 50 40 80 TA (C) 70 IDD(AV) (A) 80 IDD(AV) (A) 3.0 Average Supply Current versus Supply Voltage Average Supply Current versus Temperature 85C -40C 25C 60 50 40 30 30 20 20 10 10 0 0 -60 -40 -20 0 20 40 60 80 100 1.0 1.5 2.0 TA (C) 2.5 3.0 3.5 4.0 VDD (V) Normal Mode Period versus Supply Voltage Normal Mode Period versus Temperature 1000 1000 900 900 800 800 600 500 400 300 700 tperiod (s) VDD (V) 1.65 1.8 2.5 3.0 3.5 700 tperiod (s) 2.5 VDD (V) 600 TA (C) 500 85C -40C 25C 400 300 200 200 100 100 0 0 -60 -40 -20 0 20 TA (C) 40 60 80 100 1.0 1.5 2.0 2.5 3.0 3.5 4.0 VDD (V) Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 5 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 Dual Mode Fast Period versus Supply Voltage Dual Mode Fast Period versus Temperature 400 400 350 350 VDD (V) 250 1.65 1.8 2.5 3.0 3.5 3.5 200 150 100 50 300 tfast_period (s) tfast_period (s) 300 250 TA (C) 200 85C -40C 25C 150 100 50 0 -60 -40 -20 0 20 40 60 80 0 100 1.0 1.5 2.0 TA (C) 50 45 45 40 VDD (V) 1.65 1.8 2.5 3.0 3.5 35 30 25 20 t slow_period (ms) t slow_period (ms) 50 15 4.0 TA (C) 35 85C -40C 25C 30 25 20 15 10 5 5 0 -60 -40 -20 0 20 TA (C) 40 60 80 100 1.0 1.5 2.0 2.5 VDD (V) 3.0 3.5 4.0 Operate Point versus Supply Voltage Operate Point versus Temperature 55 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 50 45 VDD (V) 40 1.65 1.8 2.5 2.75 3.0 3.5 35 BOP (G) (G) 3.5 40 10 0 OP 3.0 Dual Mode Slow Period versus Supply Voltage Dual Mode Slow Period versus Temperature B 2.5 VDD (V) TA (C) 30 85C -40C 25C 25 20 15 10 5 -60 -40 -20 0 20 TA (C) 40 60 80 100 0 1.0 1.5 2.0 2.5 3.0 3.5 4.0 VCC (V) Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 6 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 Release Point versus Temperature Release Point versus Supply Voltage 0 0 -5 -5 -10 -10 -15 1.65 1.8 2.5 2.75 3.0 3.5 -25 -30 -35 -40 -45 BRP (G) BRP(G) -15 VDD (V) -20 TA (C) -25 85C -40C 25C -30 -35 -40 -45 -50 -55 -20 -50 -60 -40 -20 0 20 40 60 80 -55 100 1.0 TA (C) 1.5 2.5 3.0 3.5 4.0 VDD (V) Hysteresis versus Supply Voltage Hysteresis versus Temperature 110 110 100 100 90 90 70 60 50 40 30 20 10 VDD (V) 80 TA (C) 1.65 1.8 2.5 2.75 3.0 3.5 70 85C -40C 25C B HYS (G) 80 BHYS(G) 2.0 60 50 40 30 20 10 0 0 -60 -40 -20 0 20 TA (C) 40 60 80 100 1.0 1.5 2.0 2.5 3.0 3.5 4.0 VDD (V) Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 7 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 Functional Description Output State Operation The output state (VOUT pin) of this device switches to low (on) when an incident magnetic field, perpendicular to the Hall element, exceeds the operate point threshold, BOP . After turn-on, the output voltage is VOUT(SAT) (see figure 2). When the magnetic field is reduced below the release point, BRP , the device output goes high (off), VOUT(HIGH) . The difference in the magnetic operate and release points is the hysteresis, BHYS, of the device. This built-in hysteresis allows clean switching of the output even in the presence of external mechanical vibration and electrical noise. Removal of the magnetic field leaves the device output latched low (on) if the last crossed switchpoint is BOP , or latched high (off) if the last crossed switchpoint is BRP . This is illustrated in figure 3. The awake state duration, tawake_x , is common in all defined modes of operation. The sleep state duration is set at a longer duration than the awake period in order to conserve power. During the sleep state, current consumption is insignificant (equal to IDD(DIS)), but the device output does not switch in response to changing incident magnetic fields. The device shows maximum current consumption, IDD(EN) , during the awake state and minimal current consumption, IDD(DIS) , during the sleep state. Average current, IDD(AV) , for micro-power operation is derived from following formula: IDD(AV) = IDD(EN) x tawake_x + IDD(DIS) x tsleep_x tperiod_x . Three micro-power control modes are available: Powering-on the device in the hysteresis range (less than BOP and higher than BRP) gives an indeterminate output state. The correct state is attained after the first excursion beyond BOP or BRP . * Normal Clock mode Micro-power Operation Micro-power operation of the device involves duty cycle control achieved by: Selection of clock mode is determined by the configuration of the EXTERNAL_CLK pin and the DUAL_CLK pin, and applied voltages as illustrated in figure 4 and table 1. * powering all circuits in the chip and latching the device output state at the end of awake state periods, and * turning off the bias current to most circuits in the chip and maintaining the device output state through sleep state periods. V+ VOUT Switch to Low Switch to High VOUT(HIGH) (off) * External Clock mode * Dual Clock mode Normal Clock Mode When both device clock pins are left floating or are grounded, the internal timing circuitry activates the device for tawake_norm and deactivates it for the remainder, tsleep , of the duty cycle period, tperiod_norm. The short awake time IDD tperiod_x IDD(EN) BRP BHYS BOP 0 B+ tsleep_x Sample and output latched VOUT(SAT)(on) B- tawake_x IDD(DIS) 0 t Figure 3. Micro-power behavior of the device Figure 2. Device output switching logic Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 8 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 allows stabilization prior to the IC sampling and data latching on the falling edge of the timing pulse. The output during the sleep time, tsleep , is latched in the last sampled state. External Clock Mode Applying a voltage greater than Vth(HIGH) to both clock pins puts the device into the awake state (without automatic cycling through the sleep state). The device uses the maximum defined supply current, reaching maximum power consumption. Applying a voltage greater than Vth(HIGH) to the EXTERNAL_ CLK pin and a voltage lower than Vth(LOW) to the DUAL_CLK pin puts the device into the sleep state (without automatic cycling through the awake state), and latches the device output in the output state determined during the prior awake state. The duration of the awake and sleep periods can be controlled externally by applying a voltage greater than Vth(HIGH) to the EXTERNAL_CLK pin and applying an external clock to the DUAL_CLK pin. The user can define the input sampling time and frequency to reach a target consumption current level, but the minimum sample time must remain longer than tawake_ext. Note that the device should be periodically put into the awake state in order to update the device output state. State Transition Delay, text_delay , appears as the time between an external clock transition and the resulting transition of the device between the awake and the sleep state. This is illustrated in figure 5. Dual Clock Mode When the EXTERNAL_CLK pin is left floating, or is grounded, and the DUAL_CLK pin is pulled to a voltage greater than Vth(HIGH) , the device enters Dual Clock mode. Figure 6 gives an overview of the device operation algorithm in Dual Clock mode. Table 1. Clock Mode Selection Options Connection Mode Description EXTERNAL_CLK Pin DUAL_CLK Pin Low / NC Low / NC Normal Clock High External Clock, Awake State Low External Clock, Sleep State High Dual Clock High Low / NC Awake and sleep state durations defined by device internal clock Awake and sleep state durations defined by external clock Awake and sleep state durations defined by internal fast or slow clock High = V Vth(HIGH) , Low = V Vth(LOW) , NC = no connect (float or connect to ground) Power on EXTERNAL_CLK pin high? NO DUAL_CLK pin high? NO Dual Clock Mode DUAL_CLK pin high? NO External Clock Mode Sleep State Figure 4. Clock mode selection algorithm; determined by clock pins connections in the application tdelay_ext tdelay_ext Internal Clocking Normal Clock Mode YES External Clock Mode Awake State tawake_ext External Clocking YES YES tsleep_ext Device Awake State Supply Current Device Sleep State IDD(EN) IDD(DIS) Figure 5. External Clock mode clocking; tdelay_ext corresponding to the device transition delay into the awake or sleep states after an external clock transition Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 9 A1174 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications Initially, the device operates in the slow sampling state with a typical sleep time duration, tsleep_slow . The awake time duration, tawake , is common in all defined modes of operation. After the first output state transition, the device switches into the fast sampling state, with a sleep time duration, tsleep_fast , of 8 x tawake_dual. Fast input sampling ensures that the device does not miss any subsequent transitions of the incident magnetic field. This is advantageous in applications such as track ball monitoring, when Dual Clock Mode Initial State the track ball can be rotated at very high speeds. If there is no output switching for the duration of the specified timeout, ttimeout, then the device switches back into the slow sampling state to conserve battery life in handheld devices. Figure 7 shows the case in which the field does not change within the ttimeout period. The behavior of the device in the presence of a rapidly changing magnetic field is shown in figure 8. Set SleepTimer to tsleep_slow Magnetic field change? YES Update device output NO ReturnTimer expired ? NO Reset ReturnTimer to ttimeout YES Set SleepTimer to tsleep_slow Has SleepTimer expired? Set SleepTimer to tsleep_fast NO YES Sample magnetic field during tawake_dual Figure 6. Dual Clock mode operation algorithm Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 10 Magnetic Field (G) 50 0 -50 0 1000 2000 3000 (ms) 4000 5000 6000 0 1000 2000 3000 (ms) 4000 5000 6000 0 1000 2000 3000 (ms) 4000 5000 6000 0 1000 2000 3000 (ms) 4000 5000 6000 Output Off On Clock High Supply Current (A) Low 300 200 100 0 Magnetic Field (G) Figure 7. Device output response in Dual Clock mode with no change of the magnetic field for the duration of ttimeout 50 0 -50 0 1000 2000 3000 (ms) 4000 5000 6000 0 1000 2000 3000 (ms) 4000 5000 6000 0 1000 2000 3000 (ms) 4000 5000 6000 0 1000 2000 3000 (ms) 4000 5000 6000 Output Off On Clock High Low Supply Current (A) A1174 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications 400 200 0 Figure 8. Device output response in Dual Clock mode with a rapid change of the magnetic field Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 11 A1174 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications Application Information It is strongly recommended that an external bypass capacitor be connected (in close proximity to the Hall element) between the supply and ground of the device to reduce both external noise and noise generated by the chopper stabilization technique (0.1 F is a typical value). Additionally, it is recommended that, when possible, pins be tied to either the VDD pin or ground potential in order to improve the EMC performance of the device. However, it is feasible to float the EXTERNAL_CLK and DUAL_CLK pins in the application. In the case where these pins are floating, care should be taken to locate the device as far as possible from system antennas and transceivers. VDD EXTERNAL_CLK DUAL_CLK Vbat A1174 VOUT Cbypass (A) GND The schematics on this page represent typical application circuits. (A) Device is working in Normal Clock mode. Power consumption is determined by device internal clock. VDD EXTERNAL_CLK (B) Device is working in Dual Clock mode. Power consumption is determined by device internal clock; frequent usage of device in fast sampling state. (C) Device is working in External Clock mode; externally-controlled power consumption. Vbat A1174 VOUT DUAL_CLK Cbypass (B) GND (D) Device is working in External Clock mode; high power consumption. VDD Vbat EXTERNAL_CLK DUAL_CLK A1174 VOUT Cbypass (C) GND VDD EXTERNAL_CLK DUAL_CLK (D) Vbat A1174 VOUT Cbypass GND Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 12 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications A1174 Package EW 6-Contact MLP/DFN 1.50 0.15 0.75 F E 6 0.50 0.30 6 1.00 F 2.00 0.15 A 0.70 1.575 F 1 1 0.325 1.10 7X D SEATING PLANE 0.08 C C C PCB Layout Reference View 0.38 0.02 0.50 BSC B +0.055 0.325 -0.045 0.70 0.10 NN YWW 0.25 0.05 1 1 1.25 0.05 G Standard Branding Reference View N = Last two digits of device part number Y = Last digit of year of manufacture W = Week of manufacture 6 1.10 0.10 For Reference Only, not for tooling use (refernce DWG-2856; similar to JEDEC Type 1, MO-229X2BCD) Dimensions in millimeters Exact case and lead configuration at supplier discretion within limits shown A Terminal #1 mark area B Exposed thermal pad (reference only, terminal #1 identifier appearance at supplier discretion) C Reference land pattern layout (reference IPC7351 SON50P200X200X100-9M); All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary to meet application process requirements and PCB layout tolerances; when mounting on a multilayer PCB, thermal vias at the exposed thermal pad land can improve thermal dissipation (reference EIA/JEDEC Standard JESD51-5) D Coplanarity includes exposed thermal pad and terminals E Active Area Depth 0.15 mm REF F Hall Element (not to scale) G Branding scale and appearance at supplier discretion Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 13 A1174 Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications Revision History Revision Revision Date Rev. 7 October 26, 2011 Description of Revision Update Selection Guide Copyright (c)2008-2011, 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 14