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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.
DIODE CATHODE GYRATOR C2 GYRATOR C1 INPUT VCC (VCCI)
1 2 3 4 5 6 7 8
16 15 14 13
DIODE ANODE 1ST STAGE DECOUPLE INPUT VEE (VEEI) OUTPUT VEE (VEEO) REGULATOR INPUT (VREGIN) STRETCH OUTPUT STRETCH INPUT OUTPUT
FEATURES s Fast Acting AGC Improves Operation In Noisy Environments
SL486
2ND STAGE DECOUPLE 4TH STAGE DECOUPLE OUTPUT VCC (VCCO) AGC DECOUPLE
12 11 10 9
s Differential Inputs Reduce Noise Pick-up and Improve
Stability
s Gyrator Circuit Allows Operation in Environments with
High Brightness Background Light Levels
DP16 MP16
s Output Pulse Stretcher for use with Microprocessor
Decoders
Fig. 1 Pin connections - top view
s On-chip Regulator allows Operation from Wide Range
of Power Supplies
ABSOLUTE MAXIMUM RATINGS
Supply voltage, VCCI Supply voltage, VCCO Regulator input voltage, VREGIN Output current Stretch output current Operating temperature range Storage temperature 110V wrt VEEI 110V wrt VEEO 220V wrt VCCO 5mA 5mA 0°C to 170°C 255°C to1150°C
s Low Noise Output
ORDERING INFORMATION
SL486 NA DP SL486 NA MP
GYRATOR C1 C2
3 2
VCCI
4
2ND STAGE DECOUPLE
5
4TH STAGE DECOUPLE
6
VCCO
7
11
GYRATOR
PULSE STRETCH
STRETCH OUTPUT STRETCH INPUT
10
DIODE 1 CATHODE DIFFERENTIAL DIODE 16 INPUT STAGE ANODE
15k BUFFER 5·4k AGC PEAK DETECTOR VREG* REGULATOR 2·4k
9
OUTPUT
14
15
8
13
12
VEEI
1ST STAGE DECOUPLE
AGC DECOUPLE
VEEO
*When regulator is used (see Application Notes).
REGULATOR INPUT (VREGIN)
Fig. 2 SL486 block diagram
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 Supply current (see note 1) Pin Min. 4,7 4 4,7 4,7 4,7 13 4,7 1,16 Minimum sensitivity of differential input 1,16 Common mode rejection Maximum signal input AGC range Output and Stretch output internal pull-up resistance Stretch output pulse width, tP 9, 11 11 1,16 3·0 9·0 74·0 168·0 35 4·0 68·0 55·0 2·4 3·513ID 4·5 8·4 5·9 6·2 Value Typ. 6·5 4·213ID 8·5 Max. 9·0 513ID 10 9·5 18 6·5 1·5 1·1 2·3 18·5 42·0 mA mA mA V V V V V nA nA nA dB mA (pk) dB kΩ ms 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) ISINK = 0·2mA max. ISOURCE = 5µA ISINK = 1·6mA max. ISOURCE = 5µA, output open circuit Ripple amplitude at 100Hz, VREGIN = 0V Ripple amplitude at 100Hz, VEEO and VEEI = 0V VEEI = VEEO = VREG (see Figs. 4 & 6) VCCO1VREGIN = 116V TAMB = 170°C ID = 1·0µA ID = 100µA ID = 0·5mA VCC = 5·0V, ID = 1·0µA VCC = 4·5V, ID<1·5mA VCC = 18V, ID = 1·0µA, VREGIN = 0V Units Conditions
Low voltage supply wrt VEEI &VEEO High voltage supply wrt VREGIN Int. regulated voltage, VREG, wrt VCCO
|VCCI2VCCO|
0·7 Temperature coefficient of RX Output low voltage Output high voltage Stretch output low voltage Stretch output high voltage VCCI supply rejection 0·8
NOTE 1. ID = IR diode forward current
%/°C VEEO10·35 V V VEEO10·5 V V
9 9 11 11 4 VCCO20·1 1·5 VCCO20·5
V (pk) V (pk)
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.