HYBRID CIRCUIT FOR PROXIMITY DETECTORS AMS8176 PNP Open Collector GENERAL DESCRIPTION The AMS8176 is a hybrid circuit (2.9mm × 20mm) dedicated to tubular inductive proximity detectors, especially for 4mm to 6.5mm diameter hollow stud constructions. The module consists of a proximity detector IC with a PNP output buffer for NC and NO applications. A part of the multiple protection functions and the status indicator (LED) are realised with discrete elements. All these components are assembled by using hybrid thickfilm technology (ASICon-Hybrid) combined with surface mounted devices. By adding a coil with a potcore and a distance resistor the AMS8176 works as a complete proximity switch. FEATURES • • • • • • • • • • • Normally Open, AMS8176-1 or Normally Closed, AMS8176-2 option capability Switching distance adjustable by discrete resistor trimming Wide voltage supply range 7 to 35V Output current up to 100mA; PNP open collector LED for function control (LED = ON when detection occurs) Protection against short-circuit and overload (scanning) Protection against open ground Protection against reverse polarity Protection of output transistor against transients by a zener diode (350mW) Protection against supply voltage overloads by a zener diode (350mW) Protection against repetitive fast electrical transients on supply voltage leads by RC-filtering • Power-on delay and level BLOCK DIAGRAM AMS8176 oszillator stabilisation and regulation of supply voltage rectifier distance and hysteresis adjustment AMSYS GmbH & Co. KG An der Fahrt 13, D – 55124 Mainz Internet: http://www.amsys.de comparator output driver function control LED short circuit protection reverse polarity protection and filter reverse polarity protection and filter reverse polarity protection and filter Phone: Fax: E-mail: +49 (0)6131/469875 – 0 +49 (0)6131/469875 – 66 [email protected] May 2002 1/5 Rev. 2.1 HYBRID CIRCUIT FOR PROXIMITY DETECTORS AMS8176 PNP Open Collector FUNCTIONAL DESCRIPTION The proximity detector AMS8176 is specially designed for mounting of ∅ 4mm tubes or M6. The proximity detector consists of an oscillator, rectifier, comparator as well as a suitability for industry protecting wiring with PNP open collector output. The detection distance is given by the resistor Rd. This trimmable resistor has to be defined and to be mounted on the hybrid as chip-resistor by the customer. Hysteresis and TK is determined in thickfilm-resistors (Rh and Rk), by laser trimming of producer of hysteresis > 10% and TK typical 0.2%/°C. The bipolar coil has to be mounted on the capacitor Cosc and after applying the positive supply voltage to the hybrid the AMS8176 is able to work as a proximity detector. The AMS8176 has an integrated short circuit protection whose scanning duty cycle is pre-adjusted. ABSOLUTE MAXIMUM RATINGS DC supply voltage Output voltage Output transistor dissipation Junction temperature of the output transistor Storage temperature Operating temperature range V+ Vout Ptr Tj Tst TS 35V 35V 330mW 150°C – 45 to 100°C – 40 to 85°C PERFORMANCES Oscillator frequency (see oscillator recommendations) typ. 833kHz Operating (switching) distance (see mounting recommendations) depending on magnetic environment and used materials 1.0mm Differential travel (% of operating distance, hysteresis in switching distance), depending on magnetic environment typ. 10% Maximum operating frequency (according to EN 50010), with recommended potcore and coil in brass tube typ. 2.5kHz Switching distance temperature drift, depending on magnetic environment typ. 0.2%/°C May 2002 2/5 HYBRID CIRCUIT FOR PROXIMITY DETECTORS AMS8176 PNP Open Collector ELECTRICAL SPECIFICATIONS V+ = 7 to 35V, T = 25°C, unless otherwise indicated with Rd = 5kΩ, Rh = 50kΩ, Rk = 30Ω encapsulated (see mounting recommendations) Parameter Supply current NO Detector Symbol I+ NC Detector I+ Current limit for Iout short circuit protection Output voltage drop Vdrop Power on delay Tabt Scanning duty cycle Ton Toff Conditions TS = –25 to 75°C Output stage "OFF" (25V) Output stage "OFF" (35V) Output stage "ON“ Output stage "OFF" Output stage "ON" TS = –25°C TS = 25°C TS = 75°C Iout = 10mA Iout = 100mA TS = –25 to 75°C min typ. max. Unit 1.0 1.6 3.5 3.5 1.0 7.0 7.0 2.0 180 150 120 2.5 3.0 10.0 10.0 3.5 mA mA1) mA mA mA mA mA mA V V 120 100 250 0.9 1.9 350 5.5 380 Output overload or short circuit µs µs µs 1) not tested but guaranteed by design CIRCUIT DIAGRAM V+ Rm LED V ref 14 7 Z2 3 11 Rk 2 1 10 AM 313 Rh 15 16 C osc L Rd 9 6 5 4 8 Q T D1 C Z1 Rs OUT Q D2 R GND May 2002 3/5 HYBRID CIRCUIT FOR PROXIMITY DETECTORS AMS8176 PNP Open Collector EXTERNAL COMPONENTS Symbol Value Description Rd LC depended ( ≈ 5kΩ) Operating distance adjust (SMD resistor 0805) Rh 50kΩ typical Differential hysteresis adjust Rk 30Ω typical Oscillator temperature drift adjust Cosc 1nF NPO Oscillator capacitor Rm 1.05Ω typical Maximum output current limitation resistor Rs 300Ω typical Output transistor base current adjust D1, D2 BAS 28 Protection against reverse polarity Z1 BZX 84 C 39 V Protection against supply overloads Z2 BZX 84 C 39 V Protection against transients R 100Ω typical Voltage supply filter C 22nF X7R Voltage supply filter T BCW 68G (0.33W) Discrete output power transistor LED LYS 260 Function control display (yellow) L Application depended External coil (see recommendations) OUTLINE AND CONNECTIONS Rk, R, Rm and Rs are thickfilm screen printed resistors. Rd has to be trimmed and/or assembled according to customer’s specifications. Coil connections are located on each extremity of Cosc. NC (normally closed) is identified with a red dot. GND Rm R OUT D1 C D2 Z1 Z2 2.9 ± 0.2 mm V+ Rh LED Rk Rd AM313 T Cosc L Rs 20 ± 0.2 mm Order No: AMS8176 NO (normally open) AMS8176 NC (normally closed) 8176-1 8176-2 May 2002 4/5 HYBRID CIRCUIT FOR PROXIMITY DETECTORS AMS8176 PNP Open Collector MOUNTING RECOMMENDATIONS If a protective cap is mounted on the coil, it should be as thin as possible, because its thickness forms part of the operating distance. The stud wall should not extend beyond the potcore. The exact value of the operating distance with its tolerance is determined by: • the values of the adjustment resistors (Rd, Rh, Rk) • the oscillator coil • the metal of the actuator and the material and shape of the housing Handle with care to avoid electrostatic discharge. OSCILLATOR RECOMMENDATIONS Potcore SIFFERIT (Siemens) ∅ 3.3mm, K1 material Coil N = 80 Thermofix S (Isolawerke) ∅ Cu 0.063mm Coil L = 36.5µH embedded in NiCr steel tube SOLDERING RECOMMENDATIONS To solder the external connection pads it is necessary to preheat the substrate to 120...150°C and use solder type Sn-Pb-Ag 62-36-2 (2% silver). POTTING RECOMMENDATIONS First cover the hybrid circuit with about 0.5mm of silicone coating, let it harden and with the parts inserted in the housing, fill with epoxy resin. There might be some problems of starting up cold if the quality coefficient of the coil is not sufficient. The information provided herein is believed to be reliable; however, AMSYS assumes no responsibility for inaccuracies or omissions. AMSYS assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user's own risk. Prices and specifications are subject to change without notice. No patent rights or licences to any of the circuits described herein are implied or granted to any third party. AMSYS does not authorise or warrant any AMSYS product use in life support devices and/or systems. May 2002 5/5