AM336-1

IC FOR OPTO DETECTOR FEATURES • 2 Operation Modes (Proximity and Barrier) • External Synchronisation in the Barrier Mode • Ambient Light Rejection • Adjustable Threshold and Hysteresis • Normally Open and Normally Closed Outputs • Driver for PNP Output Transistors with Short Circuit Protection • LED Output 8 mA (Source and Sink) • Adjustable Detection Distance and Hysteresis • Dirt Indication in the Barrier Mode • Internal Zener Diode for Voltage Stabilisation (optional) • Maximum Supply Voltage only Depending on External Elements AM 336 GENERAL DESCRIPTION The AM 336 is a bipolar monolithic integrated circuit designed for optical detection applications. By adding an external photodiode, an IR LED, two PNP power transistors and a minimum of other parts, the AM 336 will be a complete optoelectronic interface (proximity and barrier) for a reflective optical proximity switch or for a light barrier with external synchronisation. APPLICATIONS • Miniaturised One Way Light Barrier • Miniaturised Reflection Light Barrier • Frame Light Barrier BLOCK DIAGRAM IRD FO P/B oscillator T :128 T1 VCC VZ zener diode T2 CSC short circuit pulse regulation current regulation SC SC L H H H LED T1 L T2 H RS :4 T1 IND OUTA ALR INA GND SYNC B A T2 B X L H H amplifier signal detection A X L L H QC output driver QO LED LED driver RH RD Figure 1: Block diagram of AM336 analog microelectronics Analog Microelectronics GmbH An der Fahrt 13, D – 55124 Mainz Internet: www.analogmicro.de Phone: Fax: Email: +49 (0)6131/91 073 – 0 +49 (0)6131/91 073 – 30 info@analogmicro.de February 2005 1/12 Rev. 1.1 IC FOR OPTO DETECTOR ABSOLUTE MAXIMUM RATINGS DC Supply Voltage VCC Current Zener Diode IZD Junction Temperature TJ Storage Temperature Range Tst Operating Temperature Range Tamb 6,7V 10mA 150°C – 25...125°C 0...85°C AM 336 ELECTRICAL SPECIFICATIONS Tamb = 25°C, VCC = 6.5V, RO = 560kΩ, CO = 4.7nF (unless otherwise noted) Parameter Supply Voltage Supply Current Oscillator Output current (low) Output current (high) Discharging resistor Proximity (P/B = low): Emission pulse width Emission frequency Barrier (P/B = high): Frequency oscillator freerun Synchronisation pulse width Synchronisation frequency Amplifier Low frequency impedance Signal detection stage Threshold comparator A Threshold comparator B Hysteresis comparator A Filter resistor VTA VTA VTB VTB VHA VHA RIN RD = 30kΩ RD = 180kΩ RD = 30kΩ RD = 180kΩ RH = 200kΩ, RD = 30kΩ RH = 200kΩ, RD =180kΩ internal 15 900 25 1350 25 45 2 19 24 mV mV mV mV mV mV kΩ RB internal 8 10 12.5 kΩ fOB TSYNC fSYNC 1.25 / (RO × CO), RO >> RE 0.6 × RE × CO, RO >> RE 1.2 × fOB < fSYNC < fOP 25 600 900 475 Hz µs Hz TIRD fOP 0.4 × RE × CO 2.5 / (RO × CO), RO >> RE 11 950 µs Hz IIRD low IIRD high RE VIRD = 0.8V VIRD = 6.5V internal 4.4 380 5.9 7.4 8.0 mA µA kΩ Symbol VCC ICC Conditions Min. 5.5 6.0 Typ. 6.5 8.0 Max. 6.7 Unit V mA analog microelectronics February 2005 2/12 IC FOR OPTO DETECTOR Parameter Output stages Output current (on) Output current (off) Current limitation threshold LED driver LED current (low) LED current (high) Short circuit frequency IND window frequency Zener diode Zener voltage VZ IZ=100µA 6.7 6.9 7.1 ILED low ILED high T1 T2 IQ on IQ off VS UQ = VCC–1.5V UQ = VCC–1.5V internal (Ro=580k, Co ≈ 4.7nF) at VLED = 0.8V at VLED = VCC–1.8V fOP / 128 fSYNC / 128, fSYNC = 768Hz fOP / 512 7.4 6.0 1.8 8.0 –8.0 1.2 –0.7 440 Symbol Conditions Min. Typ. Max. AM 336 Unit mA mA mV mA mA Hz Hz Hz V Tabelle 1: Electrical Specifications BOUNDARY CONDITIONS Parameter Oscillator pull up Amplifier DC input current Distance resistor Hysteresis resistor Symbol RTD IINA RD RH Min. 0.7 0 30 22 Max. 10 200 200 Unit kΩ µA kΩ kΩ Tabelle 2: Boundary Conditions analog microelectronics February 2005 3/12 IC FOR OPTO DETECTOR FUNCTIONAL DIAGRAM + Rtd1 Rtd2 + IRD PROXIMITY + Ro Co FO + + D BARRIER T :128 T1 :4 T2 C + short circuit pulse generatation VCC VZ CSC Csc AM 336 + + current regulation RS Rs + VS Re QC P/B IND Cin + Rin OUTA Ra Ca INA Rb VR ALR I(Rd,Rh) VTA Rta Rtb VTB B A FFA D Q A + QO FFB DQ B + T1 SC A B + A X L L H T2 B X L H H SC LED L T1 H L H T2 H H + LED GN RH RD Rd Rh + Figure 1: Functional circuit FUNCTIONAL DESCRIPTION GENERAL: The AM 336 is designed for proximity and barrier applications with the possibility of external synchronisation (mode selection by Pin P/B). The circuit contains different functional modules. Oscillator: Oscillator thresholds refer to VCC/2, driver output for IR–LED, emitting–pulse length and duty cycle adjusted by external components RO and CO. Amplifier: Current to voltage converter, ambient light rejection. analog microelectronics February 2005 4/12 IC FOR OPTO DETECTOR AM 336 Signal detection stage: Triggered window comparator, trigger at the end of emitting–pulse, "one pulse system" (no signal filtering). Output stages: Two antivalent outputs for external PNP Darlington transistors, short circuit protection with external resistor, periodically shutdown with a duty cycle of 1%. LED driver: Push–pull output, indicates state of the output stages. Z–diode: For supply voltage stabilisation with an external transistor, so the maximum system operating voltage depends only on external elements (wide voltage range possible). Signal emission: Emission pulses for applications with internal synchronisation are generated by the oscillator. Signal detection: Photodiode current at pin INA is converted by the amplifier. Amplifier output (pin OUTA) is connected via a capacitor (CIN) to the signal detection input (pin IND). The signal is applied to the comparators A and B. At the end of the emitting pulse the output state of the comparators is taken over to the flip–flop A and B. Flip–flop A controls the output stages QO and QC. External synchronisation: A valid recepted light pulse synchronises the at low frequency running oscillator, pulse length and period have to be appropriate. OSCILLATOR: The frequency fO of the on-chip oscillator is set by external resistor RO and capacitor CO (pin FO). CO is charged via RO and discharged via RE (RO >> RE) controlled by internal thresholds. The oscillator frequency varies with the two operating modes by switching oscillator thresholds. IRD drives an IR–LED via an external PNP transistor. If no external transistor is used, a pull–up resistor has to be connected. Proximity mode (P/B = low): When the ramp at pin FO reaches the upper threshold of comparator C, an emission pulse at pin IRD and the discharging of capacitor CO is triggered. This negative pulse is dermined by the discharging time of capacitor CO. Comparator D is not affected (output stays at high level) because its thresholds are closer to the limits of the operating voltage than the thresholds of comparator C. Barrier mode (P/B = high): By setting the Pin A/B = high, the comparator C is disabled and the oscillator runs by means of comparator D at a lower frequency. If there is no light pulse or it is too low, the capacitor CO is discharged when the upper threshold of comparator D is reached. A valid recepted light pulse starts the discharge of CO earlier thus synchronising the oscillator. The synchronisation frequency has as an upper (proximity–frequency: fOP) and a lower (barrier–frequency: 1.2 × fOB) limit. If the analog microelectronics February 2005 5/12 IC FOR OPTO DETECTOR AM 336 frequency it to high the signal detection is not triggered. In case of a too low frequency a pulsed signal could occur at the output stages. Connection pins: FO, IRD, P/B AMPLIFIER: The input stage for the photo current is a transimpedance–amplifier. His impedance depends on the input frequency to reject ambient light. The input current, coming from pin INA, appears multiplied by the impedance between INA and OUTA at pin OUTA. For low frequencies this impedance is approximately RB (internal resistor) and for high frequencies RA (external resistor). Connection pins: INA, OUTA, ALR. SIGNAL DETECTION STAGE: The signal of the input stage is connected via a high–pass filter (CIN between OUTA and IND, RIN internal) to the inputs of comparator A and B (window comparator). The threshold voltages VTA and VTB and the hysteresis voltages VHA and VHB are generated by a constant current across the resistors RTA and RTB (RTA = 2 × RTB). The hysteresis is switched by the output signals of the D– flip–flops. Threshold and hysteresis levels are determined by external resistors (RD RH) and temperature compensated by an internal voltage reference (VR). The resistors have to be located as I ND VTB VTB- VHA VTA+VHA VTA I RD VTB=1.5 * VTA VHB=1.5* VHA QO LED t Figure 2: Functional diagram analog microelectronics February 2005 6/12 IC FOR OPTO DETECTOR AM 336 close as possible to the pin to prevent noise. Also, in case of high emission-currents, blocking capacitors against VCC are useful. The comparator signals are taken over into the flip–flops with the positive slope of the IRD–signal. Connections pins: IND, RD, RH OUTPUT STAGES: There are two antivalent output drivers for external PNP Darlington transistors with a current limitation and periodical shut down in case of overload (short circuit protection). The output signal of the internal flip-flop A (depending on VTA) controls the output drivers. They consist of current sources which are attached to an internal pull-up resistor. The voltage drop at the resistor RS, produced by the loading current, is compared with an internal voltage and is used to limit the loading current. When limitation occurs, the external capacitor CSC is discharged and by reaching the internal threshold both output drivers are switched off. After loading the capacitor CSC is discharged and by reaching the threshold both output drivers are switched off. After charging the capacitor CSC to the upper threshold the output stages are enabled again. Unused outputs have to be attached to VCC. External PNP Darlington transistors have to be used so that the necessary potential (VCC–2 × VBE) is available at the outputs in order to limit the loading current. Connection pins : QO, QC, RS, CSC LED DRIVER: The push–pull driver for the LED indicates the different ranges of the window–comparator or short circuit of the output stages. Following conditions are possible: A X L L H B X L H H SC L H H H LED T1 L T2 H short circuit, input voltage at IND has no effect input voltage at IND is higher than VTA and VTB input voltage is higher than VTA, but smaller than VTB input voltage is smaller than VTA and VTB Tabelle 3: LED indications Blinking frequencies for LED: T1: oscillator frequency for devided by 128 T2: oscillator frequency for devided by 512 Connection pin: LED analog microelectronics February 2005 7/12 IC FOR OPTO DETECTOR PADOUT PAD 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 NAME LED RD VZ RS QO QC VCC RH FO IND GND INA ALR OUTA IRD P/B CSC DESIGNATION LED driver output Detection distance adjustment Zener diode Sense input for current regulation and short circuit Output for PNP–Darlington, normally open Output for PNP–Darlington, normally close Supply voltage Hysteresis of the detection distance Oscillator input Detection input Ground Amplifier input Ambient light rejection Amplifier output Output for PNP, IR–LED driver Mode selection: low = proximity, high = barrier Short circuit capacitor AM 336 Tabelle 4: Padout analog microelectronics February 2005 8/12 IC FOR OPTO DETECTOR AVAILABLE PINOUTS LED RD VZ RS QO QC VCC RH 1 2 3 4 5 6 7 8 AM336-1 16 15 14 13 12 11 10 9 CSC I RD OUTA ALR INA GND I ND FO CSC LED RD RS QO QC VCC RH 1 2 3 4 5 6 7 8 AM336-2 AM 336 16 15 14 13 12 11 10 9 P/B I RD OUTA ALR INA GND I ND FO Figure 3: Internal synchronisation only [Z–Diode (pin VZ) available] Figure 4: Internal/external synchronisation [mode selection (pin P/B) available] 15 14 13 12 11 10 9 16 1 .9 3 m m 17 8 1 2 3 4 3 .0 6 m m 5 6 7 Figure 5: Chip Dimensions DELIVERY • SO16–packaging (standard) • DIL16–package only for engineering samples • dice on 5“ blue foil analog microelectronics February 2005 9/12 IC FOR OPTO DETECTOR APPLICATION EXAMPLES AM 336 Vcc = 8.5V - 40V Rts 10 Tt BSS60 Rtd1 820 Rt 68 Rh 100k Crh 22n Co 4n7 8 RH 9 7 2 RD Ro Crd 560k 22n Rd 33k Rled 1k LED Dz Rs 1R5 4 5 6 Tout BSS60 + Rtd2 560 15 10 Cs 10µ Ct 10µ 1 LED RS Cin 10n Ra 1M Ca 4n7 Dt GL360 14 13 12 Dph PD480 IRD IND OUTA ALR INA GND 11 FO VCC AM 336-1 CSC 16 Csc 10n VZ 3 Ts Rzd QO QC OUT A - Figure 7: Proximity application Vcc = 5.5V - 6.7V + Cs 10µ Rtd 10k Rh 100k Co 4n7 15 10 IRD IND 14 OUTA 13 12 ALR INA GND 11 16 P/B 8 RH 9 FO 3 7 2 VCC RD LED RS Rled 1k Rs 1R5 Ro 560k Rd 33k Dz Cin 10n Ra 1M Ca 4n7 AM 336-2 CSC 1 Csc 10n QC QO Tout BSS60 OUT A Dph PD480 - Figure 8: Barrier application (without voltage stabilisation) analog microelectronics February 2005 10/12 IC FOR OPTO DETECTOR AM 336 EXTERNAL VOLTAGE STABILISATION AND USE OF BOTH OUTPUTS Vcc = 8.5V - 40V + VCC RS Tout Rs Dz Dz AM336 QO OUT O Tout QC GND Dzd OUT Rzd Ts Figure 9: External Voltage Stabilisation General application hints: The nearness of the emission stage with a powerful pulsed current source and the sensitive photoamplifier require a careful breadboarding (and layout) of the circuit. • Connections to Vcc and GND should be as short as possible. • Photodiode Dph should be located closely to the amplifier (Pin: INA) or a shielded line should be provided. • Resistors Rd and Rh should be located closely to the chip and should be blocked against Vcc with a appropriate ceramic capacitor. • By use of the voltage stabilisation, the maximum supply voltage is only depending of the breakthrough-voltage of the external elements: Tout, Ts, Dz. analog microelectronics February 2005 11/12 IC FOR OPTO DETECTOR TYPICAL VALUES Symbol DT DPH CT, CS RT RTS RTD RTD1 RTD2 RO CO CA CIN CSC Crh,Crd RLED RZD RS Tt TOUT TS DZ DZD RD, RH BST60; Philips BST60; Philips BCX51–16; Philips Zy47: ITT ZPD 6.8; ITT Threshold approximation: VTA [V] =800 / (Rd [kΩ])2 VTB VHB RA =1.5 VTA =1.5 × VHA VHA [V] =(10 × VTA[V] / Rh [kΩ]) depends on photodiode–pulse–current, RA [min] = VTA / Ipulse [max] depending on used supply voltage, IZD max. = 10 mA Blocking Capacitor against Perturbation, Noise 10–100nF 1 Description SFH40x; SFH41x; SFH48x; Siemens or GL 360; Sharp SHF21x ; SFH22x ; Siemens or PD 480; Sharp typical; depending on noise caused by emission current AM 336 Value Unit 10 68 10 10 820 560 560 4.7 4.7 10 10 µF Ω Ω kΩ Ω Ω kΩ nF nF nF nF kΩ kΩ kΩ 4.7 1.5 analog microelectronics February 2005 12/12