SAA3027

SAA3027 PHILIPS

Document overview

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Technical content

Features

© Transmitter for 32 x 64 commands © One transmitter controls 32 systems. © Very low current consumption © For infrared transmission link ® Transmission by biphase technique © Short transmission times; speed-up of system reaction time © LC oscillator; no crystal required © Input protection © Test mode facility QUICK REFERENCE DATA Supply voltage range Vpp 4,75 to 12.6. v Input voltage range vy —0,5 to (Vpp+0,5) V* Input current Ean max. 10 mA Output voltage range Vo -0,5 to (Vpp+0,5) V* Output current lo max. 10 mA Operating ambient temperature range Tamb —25 to +85 oc * Vpp + 0,5 V not to exceed 15 V. PACKAGE OUTLINE 28-lead DIL; plastic (SOT117). July 1983 519

osci }18 SAA3027

1 TEST RESET

SSM MODE 2" z2|5 )| zi fa 7] zol3 | x6 KEYBOARD xa x2 Command [ef on: xT SYSTEM [, 15[ on2 xo] ADDRESS xeyeoaro [5 13] ona oriver [a2f ora PARALLEL DRE. ouTPUT TO SERIAL [3] oR? DATA MDATA ss, Yoo 7290148 Fig. 1 Block diagram.

520 July 1983

Infrared remote control transmitter (RC-5) SAA3027 PINNING

14 Vsg negative supply (ground)

28 Vpp positive supply

220=&X1 sow x6 23 (x2 20 (| [25] xs a 6 keyboard command inputs with a [a] xe XS P-channel pull-up transistors 27 «X6 2 x3 2 1 x7 z3 [oe] x2 3 20 moata [7] x1 4 21 keyboard system inputs with SAA3027 5 22 P-channel pull-up transistors oata [a] xo 6 23 on? [a] [20] osco 2 SSM system mode selection input one [ia] fia] 1 19 «1P test pin ' ' 18 SCI oscillator input ons [nf tg] osc 20. 0SCO oscillator output ore 77] ono 17 DRO

16 DRI

one [a p=) 15 DR2 \\ss [a] oRz 13 DR3 scan driver outputs with open

12 DR4 drain N-channel transistors

Fig. 2. Pinning diagram. a) DR?

7 MDATA | remote signal outputs

8 DATA | (3-state outputs)

( 7 Ke xo eNOS ' | eke Retehehy ye al | RERERERRE RRS ae]? OF) RRS SeRRS SRS ae” _RERERERERORG Rae | RE RORE RT RO ROR ar | SAA3027 | ARBRE ROR RER EKG . LeEbRULL vod ROSERERE REINER 2)” | SRERERERO RR RE] Te SANA NN SNS < 2 888 8 23 28 8 g Trsones Ce yD @ a ot (1) Programming inputs for operating modes, test mode and reset. (2) Remote signal outputs. (3) Keyboard command code matrix 8 x 8, (4) Keyboard system code matrix 4 x 8, Fig. 3. Keyboard interconnection.

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Infrared remote control transmitter (RC-5) u SAA3027 if FUNCTIONAL DECRIPTION Combined system mode (SSM = LOW) The X and Z-lines are active HIGH in the quiescent state. Legal key operation e'ther in the X-DR or Z-DR matrix starts the debounce cycle. When the contact is made for two bit times without interruption, the oscillator-enable signal is latched and the key may be released. Interruption within the two bit times resets the internal action, At the end of the debounce time, the DR-outputs are switched off and two scan cycles are started, switching on the DR-outputs one by one. When a Z or X-input senses a LOW level, a latch-enable signal is fed to the system address or command latches, depending on whether sensing was found in the Z or X-input matrix. After latching a system address number, the device will generate the last command (i.e. all command bits ‘1’) in the chosen system as long as the key is pressed. Latching of a command number causes the device to generate this command together with the system address number stored in the system address latch. Releasing the key will reset the internal action if no data is ‘transmitted at that time. Once the transmission is started, the signal will be finished completely. Single system mode (SSM = HIGH) The X-lines are active HIGH in the quiescent state; the pull-up transistors of the Z-lines are switched off and the inputs are disabled. Only legal key operation in the X-DR matrix starts the debounce cycle. When the contact is made for two bit times without interruption, the oscillator-enable signal is latched and the key may be released. Interruption within the two bit times resets the internal action. At the end of the debounce time, the pull-up transistors in the X-lines are switched off, those in the Z-lines are switched on during the first scan cycle. The wired connection in the Z-matrix is then translated into a system address number and stored in the system address latch. At the end of the first scan cycle the pull-up transistors in the Z-lines are switched off and the inputs are disabled again, while the transistors in the X-lines are switched on. The second scan cycle produces the command number which, after latching, is transmitted together with the system address number. Inputs The command inputs XO to X7 carry a logical ‘1’ in the quiescent state by means of an internal pull-up transistor. When SSM is LOW, the system inputs ZO to Z3 also carry a logical ‘1’ in the quiescent state by means of an internal pull-up transistor. When SSM is HIGH, the transistors are switched off and no current flows via the wired connection in the Z-DR matrix. Oscillator OSCI and OSCO are the input/output respectively of a two-pin oscillator. The oscillator is formed externally by one inductor and two capacitors and operates at 72 kHz (typical). Key-release detection An extra control bit is added which will be complemented after key-release. In this way the decoder gets an indication that shows if the next code is to be considered as a new command. This is very important for multi-digit entry (e.g. by channel numbers or Teletext/Viewdata pages). The control bit will only be complemented after finishing at least one code transmission. The scan cycles are repeated before every code transmission, so that, even by ‘take-over’ of key operation during code transmission, the correct system and command numbers are generated. July 1983 523

FUNCTIONAL DESCRIPTION (continued) Outputs The output DATA carries the generated information according to the format given in Fig. 4 and Tables 1 and 2. The code is transmitted in biphase; definitions of logical ‘1’ and ‘0’ are given in Fig. 5. The code consists of four parts: © Start part formed by 2 bits (two times a logical ‘1’); © Control part formed by 1 bit; © System part formed by 5 bits; ‘© Command part formed by 6 bits. The output MDATA carries the same information as output DATA but is modulated on a carrier frequency of half the oscillator frequency, so that each bit is presented as a burst of 32 oscillator periods. To reduce power consumption, the carrier frequency has a 25% duty cycle. In the quiescent state, both outputs are non-conducting (3-state outputs). The scan drivers DRO to DR7 are of the open drain N-channel type and are conducting in the quiescent state of the circuit. After a legal key operation, a scanning procedure is started so that they are switched into the conducting state one after the other. Reset action The circuit will be reset immediately when a key release occurs during: @ debounce time; ‘© between two codes. When a key release occurs during scanning of the matrix, a reset action will be accomplished if: @ the key is released while one of the driver outputs is in the low-ohmic ‘0’ state; © the key is released before detection of that key; @ there is no wired connection in the Z-DR matrix while SSM is HIGH. Test pin The test pin TP is an input which can be used for testing purposes. When LOW, the circuit operates normally. When HIGH, all pull-up transistors are switched off, the control bit is set to zero and the output data is 2° times faster than normal. When Z2 = Z3 = LOW, the counter will be reset to zero. KEY ACTIVITIES Every connection of one X-input and one DR-output is recognized as a legal keyboard operation and causes the device to generate the corresponding code. Activating more than one X-input at a time is an illegal keyboard operation and no circuit action is taken (oscillator does not start). When SSM is LOW, every connection of one Z-input and one DR-output is recognized as a legal keyboard operation and causes the device to generate the corresponding code. Activating two or more Z-inputs, or Z-inputs and X-inputs, at one time is an illegal keyboard operation and no circuit action is taken. When SSM is HIGH, a wired connection must be made between a Z-input and a DR-output. If no connection is made, the code is not generated. When one X or Z-input is connected to more than one DR-output, the last scan signal is considered legal. The maximum allowable value of the contact series resistance of the keyboard switches is 10 k&. 22 or Z3 must be connected to Vpp to avoid unwanted supply current.

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Infrared remote control transmitter (RC-5) SAA3027 debounce 1 CODE er nse tse MsB use =| le conrornit el | scan time |e ta word time 14 bite

2 CODES SUCCESSIVELY

Z it [ r= 200147 Fig. 4. DATA output format (RC-5). Gita cigar Fig. 5 Biphase transmission code; 1 bit time = 2” x Togc = 1,778 ms (typical), where Toc is the oscillator period time. July 1983 525

Table 1 Command matrix X-OR X-lines DRelines command bits 01234567/01234567/543210 o je . 000000 1 |e . 000001 2 |e . 000010 3 |e ° 000011 4 |e . 000100 5 |e . 000101 | 6 |e ° 000110) 7 |e efooor1dd. 8 ° . 001000 9 . ° 001001 10 . . oo101d)0) W . ° 001011) 12 . . 001100} 13 . . porto | 14 . . 0011104} 15 . eloorriaia!l 16 . ° 010000 | 17 . . 010001) 18 ° . 010010) 19 . . 010011 20 . . 010100 21 . . 010101 22 . . 0101104 23 ° elotro1rdd | 24 . . 011000 25 . | . o11001 26 . . 011010 | a7 . . 011011 28 e e 011100 29 . . 011101 30 . ° 011110 31 . eforradad4 526 say 1909) (

Infrared remote control transmitter (RC-5) SAA3027 code X-lines DR-lines command bits 01234567/01234567/543210 32 . 100000 33 . 100001 34 ° 100010 35 ° 100011 36 . 100100 a7 . 100101 38 | . 100110 39 . 100111 40 . 101000 a1 . 101001 | 42 . 101010 43 . 101011 44 . 101100 45 . 101101 | 46 . 101110 | 47 . 101111 48 . 110000 | 49 . 110001 | 50 . 110010 81 . 110011 52 . 110100 583 . 110101 54 . 110110 | 55 . 110111 | 56 e 1171000 57 e 111001 | 58 . 111010 59 . 114071 60 . 117100 61 e 1111401 62 . 117110 63 ° ,14atd.4 July 1983 527

SAA3027 | Table 2 System matrix Z-DR system Zslines DR-lines system bits o 12 3/0 123 45 67/4 3210 0 . ° 00000 1 . ° 00001 2 . . 'o0 001 0 3 . e }o 001414 4 e . ; 0 0 1 0 0 5 e . | oo 101 6 . . 0 0110 7 . e/oo11 1 | 8 ° ° 0 1 0 0 0) 9 . . }o 1 0 0 1) 10 . . !o 1 01 0) " . . o 1014 4) 12 . . o 1 1 0 0, 13 . ° o 4110 1) 14 . ° 011 10 15 . e/o4 1 4 16 ° . | 1 0000 7 ° . /1 0001 18 ° ° / 1 00 1 0 19 ° . 10011 20 ° . 1 0 1 0 0 21 . . 10101 22 . ° 1014 10 23 ° ef} 10414 4 24 ele 51 10 0 0 25 . . j 1 1.0 014 26 ° . 110 10 27 ° . 11091 28 . . 11100 29 . ° 14101 30 . . 1 14°40 31 . ef toa 444

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Infrared remote control transmitter (RC-5) SAA3027 RATINGS Limiting values in accordance with the Absolute Maximum System (IEC 134) Supply voltage range with respect to Vsg Vpp = -0,5 to +15 v Input voltage range vy -0,5 to (Vpp+0,5) V* Input current ty max. 10 mA Output voltage range Vo -0,5 to (Vpp + 0,5) V* Output current tlo max. 10 mA Power dissipation output OSCO Po max. 50 mW Power dissipation per output (all other outputs) Po max. 100 mw Total power dissipation per package Prot: max. 200 mw Operating ambient temperature range Tamb —25 to +85 °c Storage temperature range Tstg —55 to +150 °C HANDLING Inputs and outputs are protected against electrostatic charge in normal handling. However, to be totally safe, it is desirable to take normal precautions appropriate to handling MOS devices (see “Handling MOS Devices”). * Vpp +0,5 V not to exceed 15 V. July 1983 529

Vsg = 0 V; Tamb = 25 to 85 °C unless otherwise specified Supply voltage - Vop |4.75 12,6 v Supply current at Iq = 0 mA for all outputs; XO to X7 and Z3 at Vpp; | all other inputs at Vpp or Vgg; excluding leakage current from open drain N-channel outputs; Tamb = 25 °C 12,6 Ipod |- 10 HAY Inputs Keyboard inputs X and Z with P-channel pull-up transistors | Input current (each input) at Vj = 0 V; TP = SSM = LOW 4,75 to 12,6} -l) | 10 300 HA Input voltage HIGH 4,75 to 12,6| Vin |0,7x Vop Vpp v Input voltage LOW 4,75t012,6/Vi_ | 0 0,3xVpp| V Input leakage current at Tamp = 25 °C; TP = HIGH; | Vi, =12,6V 12,6 in |- 1 BA Vj=OV 12,6 -lin |- 1 BA SSM, TP and OSCI inputs Input voltage HIGH 4,75 0 12,6/ Vin |0,7x Vop Vpo =| Vv | Input voltage LOW 4,75 10126) Vi_ | 03xVpp| V | Input leakage current at Tamp = 25 °C; | Vy, =12,6V 12.6 tra f= 1 uA Vj=0V |126 —lin |- 1 HA Outputs | DATA, MDATA outputs | Output voltage HIGH at -I9H = 0,8 mA 4,75 to 12.6|VoH |Vpp—06 - v Output voltage LOW at Io, = 0,8 mA 4,75 t012,6| Vo. |- 04 v Output leakage current at: Vo = 12,6 V 12.6 lor |- 10 BA Vo=0V 12,6 -lor |- 20 BA Tamb = 25 °C; Vo = 12,6V 126 lor |- 1 uA Vo=0V 126 -lor |- 2 HA

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i if Infrared remote control transmitter (RC-5) u SAA3027 parameter Vop(V)_ [symbol | min. | typ. | max. [unit | DRO to DR7 outputs Output voltage LOW : | at Io. = 0,35 mA 4,750 12,6 |Vo. |~ - | 04 v Output leakage current at Vo = 12,6 V 12,6 lor |- - | 10 HA at Vo = 12,6 V; Tamb = 25 °C 12,6 for |- |- | 1 BA OSCO output | | Output voltage HIGH | at lon = 0,2 mA; | OSCI= Vs | 4.76t0126 \\VoH |Vop-06|~ | ~ v Output voltage LOW | at lol = 0,45 mA; | OSCI=Vpp | 47540126 \\VoL |- ~ | 05 v Oscillator | Maximum oscillator frequency at C= 40 pF (Figs 6 and 7) | 4,75 foscl |75 72 | = kHz le fosci | 120 72 | - kHz | 12,6 fosci | 300 72 | - kHz Yoo sa 2 7282857 ose! 28 2 DATA Pic HE 18 8 normaized PT TTT treaverey [TAT TTT TTT | x0} WEEN | [ono] 3 TEN ” | 1S. o_o CAE % ss oLLL IT TTT TTT) Yss ° 50 c (pF) 100 200145 Fig.6 Typical normalized input Fig. 7 Test circuit for measure- frequency as a function of the ment of maximum oscillator load (keyboard) capacitance. frequency. | July 1983 531