Omnipolar Digital Hall-effect Sensor ICs: 005917 Issue 3 SS351AT, SS451A, SS551AT Datasheet FEATURES SS351AT Simple activation from a North pole or a South pole and SS551AT sensitive magnetics SS451A Low voltage 3 Vdc capability Built-in reverse polarity protection Thermally balanced integrated circuit RoHS-compliant materials meet Directive 2002/95/EC POTENTIAL APPLICATIONS Commercial Speed and RPM (revolutions per minute) sensing in fitness equipment Magnetic encoder for building access DESCRIPTION Damper or valve position control in HVAC (heating, The SS351AT, SS451A, and SS551AT sensor ICs are small and ventilation, and air conditioning) equipment versatile digital Hall-effect devices operated by the magnetic Flow-rate sensing in appliances and water softeners field from a permanent magnet or an electromagnet. They are Printer head position sensing designed to respond to either a North pole or a South pole. These products have a typical operating point of 85 G at Industrial 25 C 77 F . Because they can be operated by a North pole Flow meters or a South pole, they do not require the magnet polarity to be Robotic control (cylinder position monitoring) identified, thus making the installation easier and potentially Float-based fluid level sensing reducing the system cost. These omnipolar sensors are Motion control sensitive and flexible devices designed to meet a wide range of Proximity sensing potential applications. Instrumentation Metering These products are available in three package styles: Medical SS351AT: Subminiature SOT-23 surface-mount package Position sensor in hospital beds and medical equipment supplied on tape and reel which allows for compact design Medication bin monitor on portable drug carts with automated component placement. SS451A: Flat TO-92-style package with straight leads in bulk PORTFOLIO packaging which allows for a compact PC board layout. The SS351AT, SS451A, and SS551A are part of Honeywells SS551AT: SOT-89B surface-mount package on tape and reel. family of Omnipolar Digital Hall-effect Sensor ICs, including: SL353HT, SL353LT Sensing and Productivity SolutionsOmnipolar Digital Hall-effect Sensor ICs: SS351AT, SS451A, SS551AT Table 1. Electrical and Environmental Specifications (At Vs = 3.0 Vdc to 24.0 Vdc, 20 mA load, T = -40 C to 150 C -40 F to 302 F except where otherwise specified. A Characteristic CCondition Min. Typ. Max. Unit Supply voltage: SS351AT -40 C to 125 C -40 F to 257 F 3.0 24.0 VVdc SS351AT 150 C 302 F 3.0 12.0 SS451A, SS551AT 3.0 24.0 Supply current: SS351AT, SS551AT V = 5 Vdc at 25 C 77 F 4.5 6.0 supply SS451A V = 5 Vdc at 25 C 77 F 4.0 6.0 mA supply SS351AT, SS451A, SS551AT V = 3 Vdc at 25 C 77 F 3.5 5.0 supply SS351AT, SS451A, SS551AT 9.0 Output current 20.0 mA at 20 mA, Gauss > Bop positive of V 0.4 V sat Gauss < Bop negative Gauss > Bop positive of Gauss < Output leakage current 10.0 A Bop negative Output switching time rse/fall time 25 C 77 F 1.5 s Thermal resistance: SS351AT C/W SS451A 303 SS551AT 233 Magnetic characteristics: Operate (Bop) positive 35 85 135 negative -135 -85 -35 Gauss Release (Brp) positive 10 40 120 negative -120 -40 -10 Differential 5 45 80 Operating temperature -40 -40 150 302 C F Storage temperature: -40 -40 150 302 C F Soldering temperatures and times: SS351AT infrared reflow process: peak temperature 245 C 473 F for 10 s max. SS451A wave soldering process: 250 C to 260 C 482 F to 500 F for 3 s max. SS551AT infrared reflow process: peak temperature 245 C 473 F for 10 s max. NOTICE NOTICE CAUTION These Hall-effect sensor ICs may have an The magnetic field strength (Gauss) ELECTROSTATIC SENSITIVE initial output in either the ON or OFF state required to cause the switch to change DEVICES if powered up with an applied magnetic state (operate and release) will be as DO NOT OPEN OR HANDLE field in the differential zone (applied specified in the magnetic characteristics. EXCEPT AT A STATIC FREE WORKSTATION magnetic field >Brp and <Bop). Honeywell To test the switch against the specified recommends allowing 10 s after supply limits, the switch must be placed in a ESD SENSITIVITY: voltage has reached 3 V (SS451A, uniform magnetic field. CLASS 2 SS551AT) or 5 V (SS351AT) for the output voltage to stabilize Table 2. Absolute Maximum Specifications Characteristic Min. Typ. Max. Unit Supply voltage -28.0 28.0 V Applied output voltage -0.5 28.0 V Output current 20.0 mA Magnetic flux no limit Gauss NOTICE Absolute maximum ratings are the extreme limits the device will momentarily withstand without damage to the device. Electrical and mechanical characteristics are not guaranteed if the specified voltage and/or currents are exceeded, nor will the device necessarily operate at absolute maximum ratings. Sensing and Productivity Solutions 2