THIS DOCUMENT IS FOR MAINTENANCE PURPOSES ONLY AND IS NOT RECOMMENDED FOR NEW DESIGNS 3055-2.2 SL486 INFRA RED REMOTE CONTROL PREAMPLIFIER (Supersedes version in April 1994 Consumer IC Handbook, HB3120 - 2.0) The SL486 is a high gain preamplifier designed to form an interface between an infra-red receiving diode and the digital input of remote control receiving circuits. The device contains two other circuit elements, one to provide a stretched output pulse facility and a voltage regulator to allow operation from a wide range of supplies. FEATURES ■ Fast Acting AGC Improves Operation In Noisy Environments ■ Differential Inputs Reduce Noise Pick-up and Improve Stability DIODE CATHODE 1 16 DIODE ANODE GYRATOR C2 2 15 1ST STAGE DECOUPLE GYRATOR C1 3 14 INPUT VEE (VEEI) INPUT VCC (VCCI) 4 13 OUTPUT VEE (VEEO) 12 REGULATOR INPUT (VREGIN) SL486 2ND STAGE DECOUPLE 5 4TH STAGE DECOUPLE 6 11 STRETCH OUTPUT OUTPUT VCC (VCCO) 7 10 STRETCH INPUT AGC DECOUPLE 8 9 OUTPUT DP16 MP16 ■ Gyrator Circuit Allows Operation in Environments with High Brightness Background Light Levels Fig. 1 Pin connections - top view ■ Output Pulse Stretcher for use with Microprocessor Decoders ■ On-chip Regulator allows Operation from Wide Range ABSOLUTE MAXIMUM RATINGS of Power Supplies Supply voltage, VCCI Supply voltage, VCCO Regulator input voltage, VREGIN Output current Stretch output current Operating temperature range Storage temperature ■ Low Noise Output ORDERING INFORMATION SL486 NA DP SL486 NA MP GYRATOR C1 C2 VCCI 4 3 2ND STAGE DECOUPLE 2 4TH STAGE DECOUPLE 5 VCCO 6 7 PULSE STRETCH GYRATOR DIODE 1 CATHODE DIFFERENTIAL DIODE 16 INPUT STAGE ANODE 110V wrt VEEI 110V wrt VEEO 220V wrt VCCO 5mA 5mA 0°C to 170°C 255°C to1150°C 11 STRETCH OUTPUT 10 STRETCH INPUT 9 15k BUFFER 2·4k 5·4k AGC PEAK DETECTOR REGULATOR VREG* 14 VEEI 15 8 1ST STAGE DECOUPLE AGC DECOUPLE 13 12 VEEO Fig. 2 SL486 block diagram *When regulator is used (see Application Notes). REGULATOR INPUT (VREGIN) OUTPUT SL486 ELECTRICAL CHARACTERISTICS These characteristics are guaranteed over the following conditions (unless otherwise stated): TAMB = 125°C, VCCI = VCCO = VCC = 14·5V to 17·0V, VEEI = VEEO = VEE = 0V Characteristic Value Pin Units Conditions 9·0 513ID 10 mA mA mA VCC = 5·0V, ID = 1·0µA VCC = 4·5V, ID<1·5mA VCC = 18V, ID = 1·0µA, VREGIN = 0V 4·5 9·5 V 4,7 8·4 18 V VEEI = VEEO = VREG (see Figs. 4 & 6) 13 5·9 6·5 V VCCO1VREGIN = 116V 1·5 1·1 V V TAMB = 170°C 2·3 18·5 42·0 nA nA nA ID = 1·0µA ID = 100µA ID = 0·5mA Min. Typ. Max. 4,7 4 4,7 3·513ID 6·5 4·213ID 8·5 Low voltage supply wrt VEEI &VEEO 4,7 High voltage supply wrt VREGIN Int. regulated voltage, VREG, wrt VCCO Supply current (see note 1) |VCCI2VCCO| 4,7 1,16 Minimum sensitivity of differential input 9·0 74·0 168·0 35 dB 4·0 mA (pk) 68·0 dB 9, 11 55·0 kΩ 11 2·4 ms 0·7 %/°C 1,16 Common mode rejection 1,16 3·0 Maximum signal input AGC range Output and Stretch output internal pull-up resistance 6·2 Stretch output pulse width, tP Capacitance pin 9 to pin 10 (C8 on Figs. 4 and 8) = 10nF; 1·5 tP ≈ 2RX C8 loge ms VCC where RX = 200kΩ 625% and RX = internal resistance) Temperature coefficient of RX Output low voltage Output high voltage Stretch output low voltage Stretch output high voltage VEEO10·35 9 9 VCCO20·5 VEEO10·5 11 11 4 VCCO20·1 V ISINK = 0·2mA max. V ISOURCE = 5µA V ISINK = 1·6mA max. V ISOURCE = 5µA, output open circuit 1·5 V (pk) Ripple amplitude at 100Hz, VREGIN = 0V 0·8 V (pk) Ripple amplitude at 100Hz, VEEO and VEEI = 0V VCCI supply rejection NOTE 1. ID = IR diode forward current 2 SL486 APPLICATION NOTES - REFER TO FIG. 4 Diode Anode and Cathode (Pins 1 and 16) The infra-red receiving diode is connected between pins 1 and 16. The input circuit is configured so as to reject signals common to both pins. This improves the stability of the device, and greatly reduces the sensitivity to radiated electrical noise, The diode is reverse biased by a nominal 0·65V Gyrator C2 and C1 (Pins 2 and 3) The decoupling, provided by gyrator C2 and C1, rolls off the gain of the feedback loop which balances the DC component of the infra-red diode current. The values of C2 and C1 are chosen to produce a low frequency cut-off characteristic below a nominal 2kHz. Hence, the gyrator produces approximately 20dB rejection at 100Hz. The gyrator consists of two feedback loops operating in tandem. Only one feedback path is functional when the DC component of the diode current is less than 200µA. This loop is decoupled by gyrator C2. For diode currents between 200µA and 1·5mA the second control loop is operative, and this is decoupled by gyrator C1. The decoupling capacitors, gyrator C2 and C1, must be connected between pins 2 and 3, to pin 4. The series impedance of C2 and C1 should be kept to a minimum. First Stage Decouple (Pin 15) The capacitor on pin 15 decouples the signal from the non-inverting input of the first difference amplifier (see also Fig. 2). The capacitance of 15nF is chosen to produce a 2kHz low frequency roll-off. The capacitor must be connected between pins 15 and 14 (the input ground). Second Stage Decouple (Pin 5) The capacitor on pin 5 decouples the signal from the non-inverting input of the second difference amplifier. The capacifance of 33nF is chosen to produce a 2kHz low frequency roll-off. The capacitor must be connected between pins 5 and 4 (the input VCC). Fourth Stage Decouple (Pin 6) The capacitor on pin 6 decouples the signal from the non-inverting input of the fourth difference amplifier. The capacitance of 4.7nF is chosen to produce a 2kHz low frequency roll-off. The capacitor must be connected between pins 6 and 7 (the output VCC). AGC Decouple/Delay Adjust (Pin 8) The output of the fourth difference amplifier is followed by a peak detector, which is used to provide an AGC control level. This produces a current source which is limited to 10mA at pin 8. The AGC decoupling capacitor (C5 normally 150nF) filters the pulsed input, and the resultant level controls the gain of the first three difference amplifiers. The AGC control level exhibits a fast attack/slow decay characteristic. Immediately infra-red pulses are detected, the gain will be reduced, so that any weaker noise pulses that are also received will not be seen at the output. Thus, provided the infra-red pulses are the most intense, it is possible to receive data in noisy environments. The slow decay keeps the AGC level intact during data reception, and produces a delay before any received noise may become present at the output, when transmission ceases. Output (Pin 9) The output will be low, pulsing high with a source impedance of a nominal 55kΩ , for a received infrared pulse. It is a linear amplification of the input and swings between output ground and output VCC. Stretch Input and Stretch Output (Pins 10 and 11) A typical infra-red PPM system transmits very narrow pulses. The duration of these pulses is typically 15µs, so in order to use a microprocessor-based decoder system it is necessary to lengthen the received pulse. This stretched output can be obtained from pin 11 when a capacitor is connected between pins 9 and 10 (C8 in Fig. 4). The width of the pulse is determined by the value of this coupling capacitor and is defined in the Electrical Characteristics. The stretch output is normally high, pulsing low for a received infra-red pulse and swings between VCCO and VEEO. It must be noted that the stretch output logic sense is inverse to that of the output on pin 9 so must be re-inverted for microprocessor applications. Regulator Input, VREGIN (Pin 12) The device can be operated with supplies of between 4·5V and 9·0V connected between input/output ground (pins 14 and 13) and input and output VCC (pins 4 and 7) as shown in Fig. 3. The device can also be operated with supplies in excess of 9·0V by using the on-chip regulator. In this case connections are made between VCCO (pin 7) and the regulator input VREGIN(pin 12) as shown in Fig. 4. A supply voltage of between 9·0V and 18V will then cause VEEO (pin 13) to be regulated at a level nominally 6·4V below VCCO(pin 7). The regulator will, however, lose control with a potential difference of less than 9·0V. Below this level the voltage on pin 13 will track nominally 1·5V above the level of pin 12. When the regulator is not used (low voltage operation), pin 12 must be connected to VEEO (pin 13). OPERATING NOTES - REFER TO FIGS. 3 AND 4 Gyrator C1 (Pin 3) If the environment in which the device is operating limits the background light such that the DC component of the diode current has a maximum of 200µA, it may be desirable to omit (as in Fig. 3) the more bulky and costly 68µF capacitor (gyrator C1 shown in Fig. 4). In this case pin 3 can be left open circuit. The resultant application will then have a characteristic of greatly reduced gain when the ambient light causes the DC current to rise above this threshold. Alternatively,the 68µF capacitor can be replaced by a resistor. The outcome of this is to further reduce the gain in ambient light levels above the 200µA threshold. Below this threshold the overall gain is slightly enhanced as the light level approaches the threshold value. If chosen, this resistance should lie between 10kΩ and 200kΩ . Noise Immunity The stretch output can also be used as a means of improving performance relating to a receiver system, over and above its main purpose of providing a microprocessor interface. Including C8 (Fig. 4) causes the output pulses (from pin 9) to be subjected to the stretch input threshold. Thus any noise pulses from pin 9 that are below this threshold will not be seen at the stretch output (pin 11). A further improvement can be made, using this stretch input threshold, by including some additional filtering of the output (C10 in Fig. 4). This can be adjusted in value (typically 100pF) to reduce some of the noise pulses that otherwise cross the threshold, to a level below the threshold. Screening Use of screening for the device, and associated components, improves the performance and immunity to externally radiated noise. The screening method used must protect the sensitive front-end of the device; provided that the diode, pin 1-pin 16, C2 (pin 2) and the first stage decoupling (pin 15) are screened, it may be found that for the application considered, the remalning circuitry need not be so protected. In applications where externally radiated noise is minimal, it may be possible to reduce any screening to pins 1 and 16 and the diode connections only. Screening may not be necessary in some instances, but this largely depends on the level of radiated noise, the decoupling/filtering employed and the receiver’s decoding technique. Decoupling Typical decoupling arrangements for use with or without the regulator are given in Figs. 4 and 3, respectively. When using the regulator, further improvements in high frequency supply rejection are possible by the inclusion of R2. The value can be chosen so as to keep the pin 12 end of R2 within the 29·0 to 218V (wrt pin 7) specified voltage range. For example, if the SL486 is used in a system with a supply of 16V, a typical value tor R2 would be 200Ω. Note that the regulator is a low impedance point between pins 12 and 13. C7 thus maintains a low impedance path between pins 4 and 12 at high frequencies. 3 SL486 I-R RECEIVER DIODE 6·8µ 33n 1 16 2 15 3 14 4 13 5 4·7n SL486 I-R RECEIVER DIODE C2 6·8µ C9 15n C1* 68µ 6 11 7 10 8 9 C7* 0·33µ R1* 50 3 14 C9 15n 13 SL486 12 6 11 7 10 8 9 C8† C10* C6* 22µ R2* † SEE APPLICATION NOTES CAN BE OMITTED IF ALREADY IN APPLICATION CIRCUIT * SEE OPERATING NOTES 0V OUTPUT Fig. 3 Circuit diagram of minimum component application (low voltage operation) COPPER SIDE 15 C5 150n 150n VCC 2 5 C4 4·7n 22µ 16 4 C3 33n 12 1 VCC OUTPUT Fig. 4 SL486 application diagram showing all optional components (Note: supply decoupling and connections for use of voltage regulator, also pulse stretch output) COMPONENT SIDE I-R RECEIVER DIODE 1 C2 C9 C3 SL486 C1 C4 C5 C7 R1 C6 C8 (OPTIONAL) SELECTABLE OUTPUT VIA WIRE LINK WIRE LINK, REMOVED FOR USE WITH REGULATOR R2 OR WIRE LINK OUTPUT SL486 684LS VCC 0V Fig. 5 PCB track (actual size)and component layout for the circuit of Fig. 4, using SL486 in DP16 package 4 0V SL486 116V 6·8µ 68µ 1 16 2 15 3 14 13 4 22n 5 4·7n SL486 16V SYSTEM 12 6 11 7 10 8 9 PPM 150n 0·33µ 50 15n 22µ 200 0V Fig. 6 SL486 application showing the use of the on-chip regulator 15V 6·8µ 68µ 1 16 2 15 3 14 13 4 22n 5 4·7n 15n SL486 12 6 11 7 10 8 9 STRETCHED PPM MICROPROCESSOR C8* 150n 0·33µ 0V 50 *SEE TEXT AND 22µ ELECTRICAL CHARACTERISTICS Fig. 7 Microprocessor interface, using the SL486 pulse stretching facility 5 SL486 PACKAGE DETAILS Dimensions are shown thus: mm (in) 1 PIN 1 REF NOTCH 7·11 (0·28) MAX 7·62 (0·3) NOM CTRS 16 1·14/1·65 (0·045/0·065) 0·23/0·41 (0·009/0·016) 20·32 (0·800) MAX SEATING PLANE 0·51 (0·02) 3·05 (0·120) MIN MIN 5·08/(0·20) MAX 0·38/0·61 (0·015/0·24) 16 LEADS AT 2·54 (0·10) NOM. SPACING NOTES 1. Controlling dimensions are inches. 2. This package outline diagram is for guidance only. Please contact your GPS Customer Service Centre for further information. 16-LEAD PLASTIC DIL – DP16 9·80/10·01 (0·386/0·394) 0·19/0·25 (0·007/0·010) 16 SPOT REF. 5·80/6·20 3·80/4·00 (0·150/0·157) (0·228/0·244) 0·37 (0·015) 345° CHAMFER REF. PIN 1 0-8° 0·35/0·49 (0·014/0·019) 0·41/1·27 (0·016/0·050) 0·69 (0·027) MAX 16 LEADS AT 1·27 (0·050) NOM SPACING 0·10/0·25 1·35/1·91 (0·004/0·010) (0·053/0·075) NOTES 1. Controlling dimensions are millimetres. 2. This package outline diagram is for guidance only. Please contact your GPS Customer Service Centre for further information. 16-LEAD MINIATURE PLASTIC DIL - MP16 HEADQUARTERS OPERATIONS GEC PLESSEY SEMICONDUCTORS Cheney Manor, Swindon, Wiltshire SN2 2QW, United Kingdom. Tel: (0793) 518000 Fax: (0793) 518411 GEC PLESSEY SEMICONDUCTORS P.O. Box 660017 1500 Green Hills Road, Scotts Valley, CA95067-0017 United States of America. 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No warranty or guarantee express or implied is made regarding the capability, performance or suitability of any product or service. The Company reserves the right to alter without prior knowledge the specification, design or price of any product or service. Information concerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific piece of equipment. It is the user's responsibility to fully determine the performance and suitability of any equipment using such information and to ensure that any publication or data used is up to date and has not been superseded. These products are not suitable for use in any medical products whose failure to perform may result in significant injury or death to the user. All products and materials are sold and services provided subject to the Company's conditions of sale, which are available on request. 6