High Sensitivity Low Power TMR Switch Position Sensing > LF21215TMR TMR Omni-polar Switch 17 Gauss 1.5uA PushPull Sensor Description The LF21215TMR TMR Switch is a digital omni-polar magnetic switch that integrates TMR and CMOS technology in order to provide a magnetically triggered digital switch with high sensitivity, high speed, and low power consumption. It contains a TMR magnetic sensor and CMOS signal processing circuitry within the same package, including an on-chip TMR voltage generator for precise magnetic sensing, a TMR voltage amplifier and comparator plus a Schmitt trigger to provide switching hysteresis for noise rejection, CMOS push-pull output and X axis sensing direction. An internal band gap regulator is used to provide a temperature compensated supply voltage for internal circuits, permitting a wide range of supply voltages. It draws only 1.5A (see Features below) resulting in low power operation, additionally it has fast response, accurate switching points, excellent thermal Functional Block Diagram stability, and immunity to stray field interference. It is available in the SOT23-3 Vcc package. The output of the LF21215TMR switches low (turns on) when the Power regulator magnetic field parallel to the sensing axis exceeds the operate point threshold, with temperature compensation BOP. When the magnetic field is reduced below the release point BRP device output switches high (turns off). The difference between the BOP and the BRP is the hysteresis BH of the device. Offset TMR Latch Vout cancellation Sensor Features Tunneling Magnetoresistance (TMR) High Frequency up to 1kHz Technology Operation with North or South Pole GND Low Power Consumption at 1.5A 1.8V to 5.5V Operating Range X axis sensing direction TMR Switch Typical Applications Circuit Benefits Low switching points for high Wider airgap capability sensitivity Operates with smaller magnets for Vcc Excellent thermal stability cost reduction High tolerance to external magnetic RoHS compliant Vcc field interference TMR Out 0.1F Out Applications GND Proximity detection High speed sensing Utility meters including gas, water, Low power applications electric, and heat meters Rotary sensing GND Output Behavior Versus Magnetic Pole Note: It is strongly recommended that an external bypass capacitor be connected in-close- proximity to the device between the supply and ground pins to reduce noise. The recommended Parameter Test Conditions Output (volts) value for the external bypass capacitor is 0.1F. B > B Low (On) OPS South Pole 0 < B < B High (Off) RPS B < B Low (On) OPN North Pole 0 > B > B High (Off) RPN Note: When power is turned on under Zero magnetic field, the output is High. 2020 Littelfuse Revised: 01/10/20 littelfuse.com Specifications are subject to change without notice.High Sensitivity Low Power TMR Switch Position Sensing > LF21215TMR Absolute Maximum Ratings ( TA = +25C, unless otherwise specified) Symbol Characteristics Values Unit V Supply Voltage 7.0 V CC V Reverse Supply Voltage 0.3 V RCC I Output Current 9.0 mA OUTSINK B Magnetic Flux Density 2800 Gauss V ESD level(HBM) 4 kV ESD T Operating Temperature -40 ~ 125 C A T Storage Temperature -50 ~ 150 C stg Note: Stresses greater than the Absolute Maximum Ratings specified above may cause permanent damage to the device. These are stress ratings only functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time. Electrical Characteristics ( TA = +25C, Vcc = 3.0V) Symbol Characteristics Min. Typ. Max. Unit Conditions V Supply Voltage 1.8 3.0 5.5 V Operating CC V OH Output High Voltage Vcc -0.3 Vcc V V OL Output Low Voltage 0 0.2 V Icc Supply Current 1.5 A Output Open Freq Response Frequency 1.0 kHz Magnetic Characteristics ( TA = +25C, Vcc = 3.0V) Symbol Characteristics Min. Typ. Max. Unit B OPS 10 17 30 Gauss Operation Point B -30 -17 -10 Gauss OPN B 5 10 20 Gauss RPS Release Point B -20 -10 -5 Gauss RPN B Hysteresis -- 7 -- Gauss H 2020 Littelfuse Revised: 01/10/20 littelfuse.com Specifications are subject to change without notice.