AMG-SM101 Inductive Proximity Sensor IC 1. Functional Description of the AMG-SM101 The AMG-SM101 is a sensor IC for inductive proximity applications and can be used with a range of inductive transducers. It does have the analog front end, the detection logic, output stage and the LED drivers integrated. 2. Features Supply voltage 5.5VDC … 38VDC Fully integrated low cost proximity sensor IC User-adjustable sensing range User-adjustable hysteresis (0…15%) Can work with a broad selection of inductive transducers Voltage regulator to improve immunity against fluctuations of supply voltage Inactive output during start-up NPN open collector output with guaranteed sink current of 150mA Output overload/overcurrent protection Broad range of operating frequency: 100kHz…1MHz Broad operating temperature range: -25°C...90°C Package QFN24 3. Application The AMG-SM101 is suitable for many inductive proximity detection applications. AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 1 of 17 AMG-SM101 Inductive Proximity Sensor IC 3.1. Example Application Vcc P-LED D-LED OSCout OSCin AMG-SM101 OUTN Vref GND Rref Rh RCL Cdet CCL Vlin Figure 1: Example Application 3.2. Application Notes Please see AMG-AN-SM101. AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 2 of 17 AMG-SM101 Inductive Proximity Sensor IC Table of Contents 1.Functional Description of the AMG-SM101............................................................................ 1 2.Features................................................................................................................................. 1 3.Application............................................................................................................................. 1 3.1.Example Application ................................................................................................................ 2 3.2.Application Notes..................................................................................................................... 2 4.Block Diagram....................................................................................................................... 4 5.Block Descriptions................................................................................................................. 4 5.1.LC Oscillator............................................................................................................................. 4 5.2.Oscillation Detector.................................................................................................................. 4 5.3.Normally Open/Normally Closed (NO/NC) Block.....................................................................5 5.4.Reference Voltage and Current Generator.............................................................................. 5 5.5.Linear Voltage Regulator.......................................................................................................... 5 5.6.Output and LED Drivers........................................................................................................... 5 5.7.Overload Protection Circuits.....................................................................................................6 5.8.Output NPN Transistor............................................................................................................. 6 6.Pinning................................................................................................................................... 6 7.Absolute Maximum Ratings................................................................................................... 8 8.Electrical Characteristics........................................................................................................ 9 8.1.Operational Range................................................................................................................... 9 8.2.DC Characteristics................................................................................................................. 10 8.3.AC Characteristics.................................................................................................................. 11 9.Application........................................................................................................................... 12 9.1.Example Application Circuit.................................................................................................... 12 9.2.Application Notes................................................................................................................... 12 9.3.Thermal Considerations.........................................................................................................13 9.4.Surge Protection..................................................................................................................... 13 10.Ordering Information.......................................................................................................... 13 11.IC-Package........................................................................................................................ 14 12.IC-Marking......................................................................................................................... 15 13.Notes and Cautions........................................................................................................... 15 13.1.ESD Protection..................................................................................................................... 15 13.2.Storage conditions................................................................................................................ 15 14.Disclaimer.......................................................................................................................... 15 15.Contact Information............................................................................................................ 17 AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 3 of 17 AMG-SM101 Inductive Proximity Sensor IC 4. Block Diagram Vlin 4,5V Vcc 4,5V OscOut D_LED OscIn A P_LED Y B S0 Rh OUTN NO/NC Rcl Monoflop Vref 300mV 1,2V Ccl Figure 2: Block Diagram 5. Block Descriptions 5.1. LC Oscillator The LC oscillator utilises the operational amplifier OA featuring a high gain-bandwidth product. The positive feedback of this operational amplifier produces negative resistance at Pin OSCin to compensate for energy losses in an external LC tank. The LC oscillator generates a sinusoidal 100kHz…1MHz signal as long as no metallic object is present within the sensing range of the sensor. As soon as a metallic object is placed in close proximity of the external inductor (called proximity transducer in proximity detection applications) its Q factor drops due to eddy currents induced in the object. This leads to higher energy losses in the LC tank, and if the distance between the transducer and the object is small enough, the oscillations are broken. 5.2. Oscillation Detector This block, consisted of a peak detector, low-pass filter and comparator with hysteresis, determines whether the oscillator oscillates or not. It also implements a hysteresis function. The output of the detector is used to drive, through the NO/NC multiplexer, the output drivers of the chip. The detector features a dedicated pin Cdet to connect an external capacitor controlling the cut-off frequency of the low-pass filter. This low pass filter eliminates malfunction of the sensor in the presence of short interfering signals which might be received by the magnetic field-sensitive inductive transducer. Therefore, if the IC is expected to work in a ‘harsh’ environment it is advised that the value of C F be increased at the expense of reaction time of the IC. AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 4 of 17 AMG-SM101 Inductive Proximity Sensor IC 5.3. Normally Open/Normally Closed (NO/NC) Block The NO/NC block and its NO/NC pin are responsible for the output logic of the IC: the output logic can either be normally open (the output is off if no object is detected) or normally closed (the output is on if no object is detected). State of the output and Object detected NO/NC NO Not connected OFF NO GND ON YES Not connected ON YES GND OFF detect LED 5.4. Reference Voltage and Current Generator This block provides the IC with a single reference voltage of about 1.2V and a set of reference currents, which are used to bias all building blocks of the IC. 5.5. Linear Voltage Regulator Since the level of external supply voltage of the IC is expected to vary considerably, an internal voltage regulator has been used to improve the immunity of the LC Oscillator and Oscillation Detector against variations thereof. In this way the influence of supply voltage on the sensing distance of the sensor has been minimised. This voltage regulator can supply external circuitry within the current limits given in section 8.2 5.6. Output and LED Drivers This block senses the output of the NO/NC Block and uses this information to drive the NPN output transistor. Additionally, it provides a bias current for two external LEDs: the Power LED and the Detect LED. AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 5 of 17 AMG-SM101 Inductive Proximity Sensor IC 5.7. Overload Protection Circuits The function of this block is to protect the output transistor against destruction resulting from attempting to sink excessive current into the IC or shorting the output of the IC directly to the supply rail. The overload/overcurrent state of the IC is detected by comparing an internal reference voltage with the voltage drop over an external current limiting resistor connected in series with the emitter of the output transistor. The voltage threshold over the shunt resistor necessary to switch the protection circuit is given in section 8.2. If the overload/overcurrent state is detected (threshold exceeded), the state of the output is periodically sampled as long as the overload/overcurrent condition persists. In this state the average overload current flowing through the load is much lower than its guaranteed value in the normal operation mode, and the value of this overload current is given in Section 8.2. Apart from protecting the output transistor the Overload Protection block is also responsible for deactivating the output transistor shortly after the supply voltage was applied to the sensor. In this way undesired transient behaviour of the IC output is suppressed. 5.8. Output NPN Transistor The output NPN transistor is capable of sinking at least 150mA of constant output current. In the overload mode the transistor delivers short current pulses used to test the state of the output and to provide a small charge (or overload) current for capacitive loads. 6. Pinning PIN# Symbol 1 Description D_LED Detect LED (1.2mA) 2,3 OutN NPN output (open drain) 4,5 RCL Current limiting resistor of NPN output transistor 6 7 n. c. NO/NC 8 Normally open / normally closed switch n.c. 9 CDET Oscillation detector capacitor (CDET to GND) 10 RREF Reference resistor 11 CCL Current limiter sampling capacitor 12 13 n.c. GND 14 Ground n.c. 15 Vlin Regulator blocking capacitor 16 VCC Supply voltage 17 OSCin Oscillator input (LC tank) AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 6 of 17 AMG-SM101 Inductive Proximity Sensor IC PIN# Symbol 18 Description OSCout Oscillator output 19 n.c. 20 RH Hysteresis adjustment 21 Vref Reference voltage output (connect C to GND) 22 PGND Power Ground 23 P_LED Power LED (1.2mA) 24 n.c. Rh Vref PGND P_LED n.c. n.c. 1 19 OSCout OutN OSCin SM101 YYWW xxxxxxx D_LED OutN RCL Vcc Vlin RCL n.c. n.c. GND n.c. CCL RREF CDET n.c. 13 NO/NC Center Pad = GND 7 Top View Fig.3: QFN24 Pinout AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 7 of 17 AMG-SM101 Inductive Proximity Sensor IC 7. Absolute Maximum Ratings The Absolute Maximum Ratings may not be exceeded under any circumstances. # Symbol Parameter Min Max Unit 1 VCC Supply voltage -0.3 40 V 2 VMAX Voltages at pins NO/NC, L1, Rh, Rf, Cdet, Rref, Vref, Vlin, Covl -0.3 Vlin + 0.3 V 3 VESD ESD test voltage*1) -1 1 kV 4 TSTG Storage temperature range -55 150 °C 5 TSOLD Soldering temperature 300 °C 6 TJ Junction temperature *2) 150 °C Note: *1) Human Body Model *2) TJ = TA + PTOT·RTHJ-A, where TA is ambient temperature, PTOT is total power dissipation and RTHJ-A is thermal resistance junctionambient AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 8 of 17 AMG-SM101 Inductive Proximity Sensor IC 8. Electrical Characteristics 8.1. Operational Range # Symbol Parameter Min Max Unit 7 35 V 1 VCC,AVG Average supply voltage at pin VCC*1) 2 VCC,DC DC supply voltage*2)*3) 5.5 38 V 3 TA Ambient temperature range -25 90 °C 4 TJ Junction temperature -25 120 °C 5 PTOT Total power dissipation 1 W 6 RTHJ-A, Thermal resistance junction-ambient 42 K/W Note: *1) amplitude of allowable low-frequency ripple (100-120Hz) is not higher than +/-10% *2) for supply voltages below 6.5V, it is mandatory to use low ESR blocking caps *3) for supply voltages below 6.5V, it is mandatory that the supply is stable AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 9 of 17 AMG-SM101 Inductive Proximity Sensor IC 8.2. DC Characteristics The typical values are given for VCC =24V, Tj = 25°C unless otherwise specified. # Symbol Parameter Min Typ Max Unit 1 IVCC,OFF Supply current of pin VCC (Output off) 3.8 4.8 mA 2 IVCC,ON Supply current of pin VCC (Output on) 8.5 12 mA 3 VSAT,OUT Output saturation voltage (Iout = 150mA) 0.50 0.70 V 4 ILED LED current 1.0 1.2 1.6 mA 5 IOVL Average overload current 5 8 14 mA 6 ILKG Output leackage current 5 μA 7 VTH,OVL Overload threshold voltage*4) 250 290 330 mV 8 Vlin Output of linear regulator *5) 4.1 4.45 4.8 V 9 Ilin External load for lin. regulator 5 mA 10 Vdrop Min. dropout of lin. regulator 1.9 V 11 Vref Voltage reference 12 Iref External load for reference 1.5 1.7 1.2 V 100 μA Note: *4) overload threshold voltage is the level of the voltage across the current limiting resistor which triggers the overload protection circuit; for more information on this refer to Section 5.7. *5) for supply voltages below 6.5V, Vlin will follow Vcc less the dropout voltage AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 10 of 17 AMG-SM101 Inductive Proximity Sensor IC 8.3. AC Characteristics The typical values are given for VCC =24V, Tj = 25°C unless otherwise specified. # Symbol Parameter Min 1 fOSC Operating frequency (set by ext. LC tank) 2 RN Negative resistance at pin L1 3 fcutoff 4 Typ Max Unit 0.1 1.0 MHz -200 -2 kΩ Detector filter frequency 2 7 kHz HW Hysteresis width (set by Rhys) 0 15 % 5 tR Output rise time (@ 1kΩ load) 6 tF Output fall time (@ 1kΩ load) *2) 7 TS,OVL 8 TSTARTUP 9 CMAX 10 CIN Input capacitance d Sensing distance vs. Vcc 11 Δ sense <1.5 μs <1 μs Sampling period in overload mode (set by COVL) 50 120 250 ms Startup time*3) 50 120 250 ms 10 nF 8.5 13 pF 1 2 % Maximum output capacitance for regular loads*4) 6 Note: *2) fall time right after start-up depends on the load used and can be as long as 10ms *3) this is the maximum start-up time of the IC itself; this parameter does not reflect performance of a sensor; during start-up the output is inactive (off) regardless of the state of the NO/NC pin *4) for more information on capacitive loads refer to Overload Explanation in Section 5.7. AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 11 of 17 AMG-SM101 Inductive Proximity Sensor IC 9. Application Inductive Proximity 9.1. Example Application Circuit Figure 3: Example Application Circuit 9.2. Application Notes AMG-AN-SM101 AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 12 of 17 AMG-SM101 Inductive Proximity Sensor IC 9.3. Thermal Considerations The SM101's QFN24 package has limited power dissipation capabilities. In case the ambient temperature is rising above 78°C, the package requires extra cooling to prevent the junction temperature to rise above specified limits. Such cooling can be achieved by having a GND layer in the PCB and connecting that with vias to the center pad of the QFN24. Such cooling can be calculated, but as a rule of thumb, a 150mm² GND area under the IC, connecting to the center pad with 16 vias will provide for sufficient cooling. If 150mm² cooling area cannot be achieved, one should try to create star type traces originating from the center pad location to the rim of the PCB. This will work as heat pipes. 9.4. Surge Protection Depending on the necessary surge protection class, surge protection diodes and low pass filter schemes might be necessary to protect the Vcc and OutN pins. For more information please refer to AMG-AN-SM101. 10. Ordering Information AMG-SM101-IQN24R AMG-SM101 Revision: B (QFN24 06.11.12 shipment in tape & reel) © All rights reserved Page 13 of 17 AMG-SM101 Inductive Proximity Sensor IC 11. IC-Package QFN24 SYMBOL AMG-SM101 Dimensions in mm, angles in deg MIN NOM MAX A 0.80 0.85 0.90 A1 0 0.010 0.030 A3 - 0.20 - b 0.18 0.23 0.28 D 3.95 4.00 4.03 D1 - 2.60 - E 3.95 4.00 4.03 E1 - 2.60 - e - 0.50 - L 0.35 0.4 0.45 Θ -12 - 0 ccc - 0.08 - M - - 0.05 Revision: B 06.11.12 © All rights reserved Page 14 of 17 AMG-SM101 Inductive Proximity Sensor IC 12. IC-Marking Top Marking by Laser SM101 yyww ******* Date Code Lot Number 13. Notes and Cautions 13.1. ESD Protection The Requirements for Handling Electrostatic Discharge Sensitive Devices are described in the JEDEC standard JESD625-A. Please note the following recommendations: When handling the device, operators must be grounded by wearing a for the purpose designed grounded wrist strap with at least 1MΩ resistance and direct skin contact. Operators must at all times wear ESD protective shoes or the area should be surrounded by for ESD protection intended floor mats. Opening of the protective ESD package that the device is delivered in must only occur at a properly equipped ESD workbench. The tape with which the package is held together must be cut with a sharp cutting tool, never pulled or ripped off. Any unnecessary contact with the device or any unprotected conductive points should be avoided. Work only with qualified and grounded tools, measuring equipment, casing and workbenches. Outside properly protected ESD-areas the device or any electronic assembly that it may be part of should always be transported in EGB/ESD shielded packaging. 13.2. Storage conditions The AMG-SM101 corresponds to moisture sensitivity classification ML2, according to JEDEC standard J-STD-020, and should be handled and stored according to J-STD-033. 14. Disclaimer Information given in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed for the consequences of its use nor for any infringement of patents or other rights of third parties that may result from its use. alpha microelectronics gmbh does not authorize or warrant any of its products for use in life support system equipment. The values stated in Absolute Maximum Ratings may under no circumstances be exceeded. No warranty is given for use in life support systems or medical equipment without the specific written consent of alpha microelectronics gmbh. For questions regarding the application please contact the publisher. The declared data are only a description of the product. They are not guaranteed properties as defined by law. Examples are given without obligations and cannot give rise to any liability. AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 15 of 17 AMG-SM101 Inductive Proximity Sensor IC Reprinting of this data sheet – or any part of it – is not allowed without the license of the publisher. Data sheets are subject to change without any notice. AMG-SM101 Revision: B 06.11.12 © All rights reserved Page 16 of 17 AMG-SM101 Inductive Proximity Sensor IC 15. Contact Information This data sheet is published by alpha microelectronics gmbh. To order samples or inquire information please contact: alpha microelectronics gmbh Im Technologiepark 1 15236 Frankfurt (Oder) Germany [email protected] www.alpha-microelectronics.de +49-335-557-1750 (telephone) +49-335-557-1759 (fax) © All rights reserved. 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