IC FOR OPTO DETECTOR AM 336 FEATURES GENERAL DESCRIPTION • 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 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 zener diode FO P/B IND oscillator T T1 :128 SYNC signal detection amplifier B A INA GND short circuit pulse regulation T2 :4 T1 OUTA ALR CSC VZ VCC A X L L H T2 B X L H H RS current regulation SC SC L H H H LED T1 L T2 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 [email protected] February 2005 1/12 Rev. 1.1 IC FOR OPTO DETECTOR AM 336 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 ELECTRICAL SPECIFICATIONS Tamb = 25°C, VCC = 6.5V, RO = 560kΩ, CO = 4.7nF (unless otherwise noted) Parameter Symbol Supply Voltage Supply Current Conditions Min. Typ. Max. Unit VCC 5.5 6.5 6.7 V ICC 6.0 8.0 mA Oscillator Output current (low) IIRD low VIRD = 0.8V 8.0 Output current (high) IIRD high VIRD = 6.5V Discharging resistor RE internal Emission pulse width TIRD 0.4 × RE × CO 11 µs Emission frequency fOP 2.5 / (RO × CO), RO >> RE 950 Hz Frequency oscillator freerun fOB 1.25 / (RO × CO), RO >> RE 475 Hz Synchronisation pulse width TSYNC 0.6 × RE × CO, RO >> RE 25 Synchronisation frequency fSYNC 1.2 × fOB < fSYNC < fOP 600 RB internal VTA RD = 30kΩ 900 mV VTA RD = 180kΩ 25 mV VTB RD = 30kΩ 1350 mV VTB RD = 180kΩ 25 mV VHA 380 4.4 5.9 mA µA 7.4 kΩ Proximity (P/B = low): Barrier (P/B = high): µs 900 Hz 12.5 kΩ Amplifier Low frequency impedance 8 10 Signal detection stage Threshold comparator A Threshold comparator B Hysteresis comparator A Filter resistor RH = 200kΩ, RD = 30kΩ 45 mV VHA RH = 200kΩ, RD =180kΩ 2 mV RIN internal analog microelectronics 15 19 24 kΩ February 2005 2/12 IC FOR OPTO DETECTOR Parameter AM 336 Symbol Conditions Min. Typ. Max. Unit Output current (on) IQ on UQ = VCC–1.5V 1.2 mA Output current (off) IQ off UQ = VCC–1.5V –0.7 mA Current limitation threshold VS internal 440 mV Output stages (Ro=580k, Co ≈ 4.7nF) LED driver LED current (low) ILED low at VLED = 0.8V 8.0 mA LED current (high) ILED high at VLED = VCC–1.8V –8.0 mA Short circuit frequency T1 fOP / 128 7.4 Hz fSYNC / 128, fSYNC = 768Hz 6.0 Hz T2 fOP / 512 1.8 Hz VZ IZ=100µA IND window frequency Zener diode Zener voltage 6.7 6.9 7.1 V Tabelle 1: Electrical Specifications BOUNDARY CONDITIONS Parameter Symbol Min. Max. Unit Oscillator pull up RTD 0.7 10 kΩ Amplifier DC input current IINA 0 200 µA Distance resistor RD 30 200 kΩ Hysteresis resistor RH 22 kΩ Tabelle 2: Boundary Conditions analog microelectronics February 2005 3/12 IC FOR OPTO DETECTOR AM 336 FUNCTIONAL DIAGRAM + Rtd1 Rtd2 IRD + VCC CSC + short circuit pulse generatation C + Ro VZ + PROXIMITY Co Csc + VS + current regulation RS Rs Re FO + + D T BARRIER :128 T1 :4 QC T2 P/B FFA IND VTA + Cin A D + A QO Rta Rin FFB Rtb OUTA Ra Q VR B VTB D Q B + ALR Ca T1 I(Rd,Rh) INA Rb SC A B GN A X L L H T2 B X L H H + SC LED L T1 H L H T2 H H LED + 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 VTB=1.5 * VTA VHB=1.5* VHA VTA+VHA VTA I RD 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 B SC LED X X L T1 short circuit, input voltage at IND has no effect L L H L input voltage at IND is higher than VTA and VTB L H H T2 input voltage is higher than VTA, but smaller than VTB H H H H 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 AM 336 PADOUT PAD NAME DESIGNATION 1 LED LED driver output 2 RD Detection distance adjustment 3 VZ Zener diode 4 RS Sense input for current regulation and short circuit 5 QO Output for PNP–Darlington, normally open 6 QC Output for PNP–Darlington, normally close 7 VCC Supply voltage 8 RH Hysteresis of the detection distance 9 FO Oscillator input 10 IND Detection input 11 GND Ground 12 INA Amplifier input 13 ALR Ambient light rejection 14 OUTA Amplifier output 15 IRD Output for PNP, IR–LED driver 16 P/B Mode selection: low = proximity, high = barrier 17 CSC Short circuit capacitor Tabelle 4: Padout analog microelectronics February 2005 8/12 IC FOR OPTO DETECTOR AM 336 AVAILABLE PINOUTS LED 1 16 CSC CSC 1 16 P/B RD 2 15 I RD LED 2 15 I RD VZ 3 14 OUTA RD 3 14 OUTA RS 4 13 ALR RS 4 13 ALR QO 5 12 INA QO 5 12 INA QC 6 11 GND QC 6 11 GND VCC 7 10 I ND VCC 7 10 I ND RH 8 9 FO RH 8 9 FO AM336-1 AM336-2 Figure 3: Internal synchronisation only [Z–Diode (pin VZ) available] 15 Figure 4: Internal/external synchronisation [mode selection (pin P/B) available] 14 13 12 11 10 9 16 1 .9 3 m m 17 8 1 2 3 4 5 6 7 3 .0 6 m m 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 AM 336 APPLICATION EXAMPLES Vcc = 8.5V - 40V Rts 10 Crh 22n Rh 100k Tt BSS60 Ct 10µ Rtd2 560 10 Cin 10n Ra 1M 14 Ca 15 8 IRD IND RH INA Dph PD480 Rd 33k LED Co 4n7 9 7 2 FO VCC RD Rs 1R5 1 LED RS AM 336-1 ALR 12 4n7 Dt GL360 Ro Crd 560k 22n Dz Cs 10µ OUTA 13 + Rled 1k Rt 68 Rtd1 820 QO QC GND 11 CSC 16 VZ 3 Csc 10n 4 5 6 Tout OUT A BSS60 Rzd Ts - Figure 7: Proximity application Vcc = 5.5V - 6.7V + Cs 10µ Rtd 10k Rh 100k Ro 560k Rd 33k Dz Co 4n7 Cin 10n Ra 1M Ca 4n7 15 10 IRD IND 14 OUTA 13 12 ALR INA Dph PD480 GND 11 16 P/B 8 RH 9 FO 3 7 2 VCC RD LED Rled 1k Rs 1R5 RS AM 336-2 QC QO CSC 1 Csc 10n Tout BSS60 OUT A - 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 + Rs VCC RS Dz Dz Tout 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 AM 336 TYPICAL VALUES Symbol Description Value Unit 10 µF RT 68 Ω RTS 10 Ω RTD 10 kΩ RTD1 820 Ω RTD2 560 Ω RO 560 kΩ CO 4.7 nF CA 4.7 nF CIN 10 nF CSC 10 nF 1 kΩ 4.7 kΩ 1.5 kΩ DT SFH40x; SFH41x; SFH48x; Siemens or GL 360; Sharp DPH SHF21x ; SFH22x ; Siemens or PD 480; Sharp CT, CS Crh,Crd typical; depending on noise caused by emission current Blocking Capacitor against Perturbation, Noise 10–100nF RLED RZD depending on used supply voltage, IZD max. = 10 mA RS Tt BST60; Philips TOUT BST60; Philips TS BCX51–16; Philips DZ Zy47: ITT DZD ZPD 6.8; ITT RD, RH Threshold approximation: VTA [V] =800 / (Rd [kΩ])2 VTB =1.5 VTA VHA [V] =(10 × VTA[V] / Rh [kΩ]) VHB RA =1.5 × VHA depends on photodiode–pulse–current, RA [min] = VTA / Ipulse [max] analog microelectronics February 2005 12/12