AS2574BP

Data Sheet AS2574B 20 NUMBER ONE TOUCH DIALLER WITH SERIAL BUS FOR DISPLAY DRIVER ® Austria Mikro Systeme International Key Features u u u u u u u u u u u u u u u u u Low operating voltage (2.5V to 5.5V) Low current consumption (typ. 200 µA in LD mode) Oscillator using ceramic resonator (681 kHz) MF level independent of supply voltage Direct ´wake-up´ from keyboard Automatic Call Progress by direct memory key Data protection with 8 digit FIFO Sliding cursor protocol with comparison Diode options for different PTT requirements Automatic pause generation after access code Temporary MF select via keyboard 36 digit LNR (Last Number Redial) 20 memories addressable with direct keys and the 2nd key or indirect with a MEM key Notepad Serial interface to display driver AS2590 Consistent, simple and useable procedures Input for dial tone recognizer General Description The AS2574B is an integrated CMOS device for feature telephones. It is a very versatile LD/MF dialler with serial interface to a display driver. The device is designed to be used in a wide variety of applications together with the companion display driver, AS2590. The on chip RAM can contain up to 20 memories (each with maximum 18 digits), a 36 digit Last Number Redial (LNR) and an 18 digit notepad. Access to the 20 memories is either with direct keys, abbreviated dial code or a combination of both. The AS2574B provides a unique feature, Automatic Call Progress (ACP), on all memory keys, i.e. the circuit automatically seizes the line and waits for the dial tone and dials the number just by pressing any of the memory keys (including LNR). The circuit features 2 different access code procedures to allow easy use under a PABX. A dial tone input enables the use of a dial tone recognizer. Application High feature telephone sets. La Package Available in 28 pin DIP and PLCC. Direct wake-up is an AMS patented solution providing line seizing with a telephone, that is entirely powered from the telephone line, by pressing a key in a key matrix connected to a dialler/controller that is constantly connected to the line by means of a line voltage limiter and yet maintaining a high dc isolation resistance in idle state (on-hook). The wake-up feature allows the user to go off-hook by pressing a direct memory key or a loudspeaker key, so-called onhook dialling or call progress monitoring, and thereby seize the line. Lb E Flash ER Ground Loop DP DIALLER/CONTROLLER 1 4 7 2 5 8 0 LNR 3 6 9 # M9 ENTER M 1 M5 M6 M7 M8 R1 R2 R3 R4 R5 C6 C5 C4 C3 C2 C1 VDD HS MASK TONE 681kHz OSC1 OSC2 TB SPEECH LOUDHEARING HANDSFREE TONE RINGER R 2ND M2 M3 * LS MODE ACP M/B MS MUTE M 4 MEM M10 AS2574BCD Vss SCL SDA MT MR LS VDD SDA SCL MS 32.768kHz X1 X2 BIAS VLCD Vss V23 V13 DISPLAY AS2590 Rev. 1 1 Jan. 1995 Data Sheet Pin Description Pin # 1 2 3 4 5 - 10 11 - 15 16 17 18 Pin Node OSC2 OSC1 SCL SDA C1 - 6 R1 - 5 LS MASK CD Description Oscillator pins for ceramic resonator (681 kHz) The SCL output is used to clock all data into the display driver The SDA output is used to transfer data into the display driver Keyboard columns Keyboard rows Output for controlling loudhearing and handsfree facilities, active high (see hook state diagramme) AS2574B Mask output, active high during pulsing (make and break period, see timing diagrammes). Chip disable input, active low. When CD is low, the circiut is disabled. If this pin is pulled to VSS during Off-hook (indicating a disconnect) for more than 2 sec., the circuit is reset*. If the pin is pulled to VSS for less than 2 sec., the line break is ignored. * If in ACP or monitor state, reset also means return to idle state. 19 20 21 22 MR MT ER DT Mute output, active high during signalling (see timing diagrammes). Transmit mute output, active high when MR is high and when the Mute key has been activated (see timing diagrammes). Earth recall input/output, active high during ER but when forced to VDD, the flash is enabled. Dial tone input. This input is scanned when invoking ACP or a pause is read in a digit string: DT pin Open Low High Function Pause duration 4.1 sec If a high is not detected within 8 sec., the circuit is reset * If the pin is high for > 1.15 sec., the pause is terminated and the dialling continued. Noise immunity > 8 ms * Reset means that dialling is stopped and the circuit returns to standby. If the circuit was in ACP state, the reset will also return the circuit to idle state. 23 DP Hook switch control, dial pulse and flash output; low during Idle and break periods and high during off-hook (see timing diagrammes). Continues… Rev. 1 2 Jan. 1995 Data Sheet Pin Description Continued Pin # 24 25 26 Pin Node HS Vss TB Description AS2574B Hook switch input; active high with internal pull-down resistor. Debounce 25 ms. Negative terminal of power supply. Tone burst output: LS high MT high MT+LS high 80 ms burst, 8 sec pause 80 ms burst, 2 sec pause 80 ms burst, 2 sec pause Only in speech mode 27 TONE MF tone output. An on chip reference voltage provides tone levels independent of the supply voltage. A dc path from TONE output is needed to accommodate an external voltage divider for setting the appropriate tone level. Frequencies: Frequency (Hz) 697 770 852 941 1209 1336 1477 1633 Key Matrix (Hz) row 1 row 2 row 3 row 4 col. 1 col. 2 col. 3 see p. 7 Error (%) ≤ ± 0.7% 28 Vdd Positive terminal of power supply Keyboard Layout COLUMN 1 1 2 ROWS 2 3 4 ENTER RECALL 5 6 1 4 7 2 5 8 0 LNR 3 6 9 # M9 M1 M2 M3 M4 M10 M5 M6 M7 M8 In off-hook state all keys are enabled (CD = high) Enabled only when off-hook 3 4 5 2ND MUTE MEM * LS Enabled also when ACP is active (diode 5 inserted) The keyboard is arranged in a 5 x 6 contact matrix with single pole single throw contacts (SPST). Keyboard resistance: Ron < 5 kΩ; Roff > 5 MΩ. Enabled when CD = high Rev. 1 3 Jan. 1995 Data Sheet Power On Reset The on chip analogue power on reset circuit monitors the supply voltage (VDD). As long as VDD remains below the internal reference voltage, VREF (typically 1.2V), the oscillator is inhibited. When VDD rises above VREF, a reset signal is generated to assure correct start-up, and the oscillator is enabled. The correct start-up/reset condition of the circuit is guaranteed regardless of the absolute and chronological rise time of VDD, CD and HS inputs. AS2574B following procedures revert it to default LD mode: - pressing R key (all subsequently entered digits are buffered in FIFO), - by next On-hook. Last Number Redial LNR is a facility that allows resignalling of the last manually dialled number without keying in all the digits again. The LNR is repeatable. A manually entered number is automatically stored in the LNR RAM. The capacity of the RAM is 36 digits. If a number greater than 36 digits is entered, the LNR facility will be inhibited (until new entries < 37 digits) and further entries will be buffered in FIFO. If more than 18 digits are entered, the display will show the digit 19 and onwards. Postdialled digits, i.e. digits manually entered after LNR has been invoked, are not stored in RAM but buffered in FIFO. The current contents of the LNR RAM are overwritten by new entries. Line Supervision In off-hook condition the device performs supervision of the line current disconnects in the following manner: Line disconnects (CD low) of less than 2 sec. are ignored and the device continues operation. Line disconnects of more than 2 sec. cause stop of dialling and the circuit is switched to standby mode if HS is high, otherwise the circuit will return to idle mode. Valid Keys A valid key is detected from the keyboard by connecting the appropriate row to the column. This can be done using an n x m keyboard matrix with single contacts. Positive and negative edges of each contact are debounced. The debounce time is 15 ms. In idle state (on-hook) only the LS key is always valid independent of the CD pin. When diode 5 is connected, also the LNR, MEM, and M1 - 9 keys are valid entries invoking ACP (automatic call progress). Memory Dial An on chip RAM enables the dialler to store up to 20 numbers, each containing a maximum 18 digits/data. The first 10 memories are accessible with 10 Direct dial keys (M1 to M10) and another 10 memories (11 - 20) are accessible by pressing the 2nd key before one of the Direct dial keys or by pressing the MEM key and a digit 0 - 9 (abbreviated dialling). Basic store procedure: 1 Press Enter key 2 Key in digits, including access code, pauses and recall as appropriate (number is stored in LNR RAM) 3 Select location by keeping Enter key depressed while entering the desired location ( M1 … M10, 2 nd M1…M10, or MEM 0…9) 4 Release Enter key to finish 5 Continue with 1, 2, 3 and 4 for storing further numbers. Only the first 18 digits/data will be stored when copying more than 18 digits/data in a memory. Mute Key Depressing the Mute key activates and deactivates (toggle switch) the MT output, when internal mute is inactive, i.e. when no data is being read from the RAM or FIFO. A change of the hook state will release the mute. Mode Selection The default mode (LD or MF) can be selected by the diode option mode (diode 6). When default LD mode is selected, a temporary change to MF mode can be invoked by pressing the * key. When the circuit is in temporary MF mode, each of the Rev. 1 4 Jan. 1995 Data Sheet Recall Function A recall activation will invoke a flash (timed loop break) or an earth recall (ER) depending on the ER pin. When the ER pin is forced to VDD, a flash is executed; and when ER is open (> 50 kΩ}, an earth recall is executed. If R is the first entry in a digit string, it will be stored in LNR RAM. If the R key is depressed after a digit string has been dialled out, the recall will not be stored, and subsequently entered digits will be buffered in the FIFO. A recall will automatically generate a pause when a recall is read from a memory and therecall has been stored as an access code. A manual invoked earth recall will pull ER high for minimum 500 ms, but the ER pin is maintained high as long as the key is depressed. During auto dial an earth recall is executed with a duration of 500 ms. AS2574B Pause Generation Pause introduces a delay in signalling digits strings to accommodate second and subsequent dial tones. Automatic pauses are generated: - during dialling out from memories when the first digit(s) in the digit string equal the stored access code(s) (pause depends on DT input). - when going Off-hook by pressing LNR, MEM, or M1 9 (ACP). Any pause can be terminated (shortened) prior to time out by pressing the LNR key or a high level on the DT input. During ACP a pause time out, i.e. DT kept low for > 8 sec., will return the device to idle state. Pauses are storable as digits within a string of any of the memories by pressing 2nd # during programming. Multiple pause entries can be stored up to the maximum length of the digit string (18 digits/data). A pause is not accepted in location 1 of a digit string. If more pauses have been stored in succession, they can all be terminated by one depression of the LNR key or a high level on the DT pin for ≥ 1.15 sec. Access Codes Different access codes (totally up to 18 digit/data including spaces) can be stored in one string. Spaces between the different access codes are entered by pressing the 2nd # during programming. Each access code can contain up to 4 digits. If one or more access codes are stored, the first entered digit(s) in a digit string read from the RAM will be compared with the access code(s) and if equal, a pause is generated. Sliding Cursor Procedure To accommodate redialling (LNR) behind a PABX without using automatic pause generation (storing access codes), a sliding cursor protocol is implemented. If new entries match the previous LNR RAM contents, pressing the LNR key will dial out the remaining digits. If there is an error in matching, the LNR will be inhibited until next On-hook, and the LNR RAM will contain the new number. Example on programming access codes: ENTER, 9 , 2nd #, 50 Keep ENTER depressed while pressing 0 Release both The first access code in this example is 9 and the second 50. Rev. 1 5 Jan. 1995 Data Sheet Serial Interface The AS2574B supports a serial bus. The protocol defines device that sends data onto the bus as a transmitter, and the receiving device as the receiver. The AS2574B is controlling the transfer and hence the master. The display driver, AS2590, being controlled is the slave. Clock and Data Conventions Data states on the SDA line can change only during SCL SDA SCL START BIT BIT 0 BIT 1 … … BIT 4 STOP BIT AS2574B low. SDA state changes during SCL high are reserved for indicating start and stop conditions (see figure 1). Start Condition All commands are preceded by the start condition, which is a high to low transition of SDA when SCL is high. Stop Condition All communications are terminated by a stop condition, which is low to high transition of SDA when SCL is high. WORD GAP Figure 1: Data Transmission No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Symbol/command 0 1 2 3 4 5 6 7 8 9 a b c d * # Pause Temporary MF select Recall LS on LS off MT on MT off 2nd on 2nd off Set Clock Start Start copy Start FIFO Start timer Blank all Test mode MSB 1 0 0 0 1 1 1 0 0 0 0 1 0 1 1 1 1 1 0 0 0 1 0 0 1 0 0 0 1 1 1 1 B3 1 0 0 0 0 0 0 1 1 1 0 0 1 1 1 1 1 1 0 0 0 0 1 0 1 1 1 1 0 0 1 0 B2 1 0 1 0 0 1 0 0 1 0 1 1 1 1 0 0 0 0 0 1 0 0 0 1 1 0 1 1 0 1 1 1 B1 0 0 0 1 0 0 1 0 0 1 1 1 1 1 0 1 1 0 0 0 1 0 0 1 1 1 0 1 1 0 0 1 LSB 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 HEX 1C 00 04 02 10 14 12 08 0C 0A 06 16 0E 1E 18 1A 1B 19 01 05 03 11 09 07 1F 0B 0D 0F 13 15 1D 17 Rev. 1 6 Jan. 1995 Data Sheet Key Combinations Key/Key Combination ENTER R MEM MUTE LS LNR Function Programming Flash or ground loop Abbreviated dialling Privacy mute Monitor/Handsfree Last Number Redial Code no 22/23 Code no 20/21 Code no 19 Remarks AS2574B During execution of a pause the LNR key is used to terminate the pause. M1 - 10 2nd 2nd, 1 2nd, 2 2nd, 3 2nd, 4 2nd, * 2nd, # 2nd, M1 - 10 MEM, 0 - 9 ENTER, Address* ENTER/Address* ENTER/# 2nd, 5 - 9 2nd, 0 2nd, R 2nd, MUTE ENTER/LNR ENTER, ENTER Direct memory keys Second functions a b c d Enter FIFO Pause Memories 11 - 20 Memories 11 - 20 Displaying content of Memo Programming Setting clock 5-9 0 RECALL Privacy MUTE Clearing LNR Displaying Access code Code no 28 when both keys are released Code no 26 Code no 6 - 10 Code no 1 Code no 19 Code no 22/23 Code no 27 Code no 27 Code no 24 Code no 11 Code no 12 Code no 13 Code no 14 Code no 29 Code no 17 *) Address means M1 - 10 keys or 2nd, M1 - 10 or MEM, 0 -9 key combinations. Rev. 1 7 Jan. 1995 Data Sheet Diode Options Option NoP Column 1 Function Number of Pulses Digit 1 2 3 4 5 6 7 8 9 0 FT MS M/B ACP MODE 2 3 4 5 6 Flash Time Memory Size Make/Break Ratio Automatic Call Progress Default Signalling Mode No diode Standard 1 2 3 4 5 6 7 8 9 10 101.2 ms 10 33/66 ms no MF diode NZ 9 8 7 6 5 4 3 2 1 10 600 ms 20 40/60 ms yes LD AS2574B Columns 1 2 3 4 5 6 The diode options are scanned by POR and low to high transition on HS. Row 5 NoP FT MS M/B ACP MODE System Considerations The device is intended to be used in telephone instruments, that are permanently on-line, i.e. also when onhook the circuit is connected to the telephone line, but in standby mode (idle) and hence only drawing a small leakage current from the line. This implementation offers new features like electronic hook switch and call progress monitoring (on-hook dialling). Call progress monitoring (CPM) means pressing the LS key will switch the telephone on from standby (direct ´wake-up´from keyboard) and will present the dialling tones via a loudspeaker without lifting the handset. Furthermore, it is also possible to invoke the CPM by pressing the LNR, MEM or M1 - 9 when the ACP (Automatic Call Progress) is activated (diode 5). Procedure Principles The procedures for utilizing the features of the device are optimized out of consideration for the human factor in order to: - meet the user´s expectations - be easy to learn and relearn - not invoke any automatic functions which the user doesn’t expect - protect the user from committing critical errors, e.g. dialling wrong numbers, deleting stored numbers, etc. - be consistent, simple and usable. Rev. 1 8 Jan. 1995 Data Sheet Symbols Idle Idle Standby state, no keys activated AS2574B Off-hook Lifting handset (HS = High) or pressing LS key On-hook Replacing handset (HS = Low) or repressing LS key Manual Dial Idle Idle Off-hook Key in digits Entries stored in LNR RAM Entries are dialled out Speech mode On-hook Idle The last manually dialled number is automatically stored in the LNR RAM. In LD mode * invokes temporary MF mode and # are ignored. In MF mode * and # are automatically stored in LNR RAM. Rev. 1 9 Jan. 1995 Data Sheet Programming/Notepad Speech mode Speech mode or idle AS2574B During programming the dial out is inhibited. Enter correction Key in an address no change Content of selected memory is displayed Key in number Digits are entered in LNR RAM Enter Enter keep Enter depressed Direct dial (M1 - 10) 2nd MEM Digit 0 (access codes) Direct dial (M11 - 20) Digit 0-9 (M11 - 20) Access code(s) are displayed release Enter Code no 28 stored The content of the LNR RAM is stored in the selected memory. Speech mode Speech mode or idle 10 Direct dial keys, a MEM and a 2nd key are available for addressing up to 20 numbers. Each number can contain up to 18 digits, including recall and pauses. Programming a new number will automatically clear the previous. 2nd, # has to be pressed between the different access codes. Rev. 1 10 Jan. 1995 Data Sheet Direct Dial/Abbreviated Dial/Last Number Redial Idle Y HS = High AS2574B N Off-hook D Y D Diode 3? N MEM 2nd D Digit 0 - 9 (M11 - 20) D Direct dial (M11 - 20) D Direct dial (M1 - 10) D LNR D Terminate pause Reset timer Y N DT high ≥ 1.15 sec H Pause 4 sec Hi-Z DT pin L Executing pause Starting timer Y DIALLING Pause N All digits dialled ? N Y Speech mode Timer overflow Y N Postdialling available Rev. 1 11 Jan. 1995 Data Sheet Automatic Call Progress (ACP) D Y Diode 3? N Idle (Diode 5 inserted) AS2574B MEM D Direct dial (M1 - 9) D LNR D Off-hook Off-hook Start timer Start timer Y Off-hook Off-hook Start timer Start timer Off-hook Off-hook Start timer Start timer Time-out 8 sec N Digit 0 - 9 (M11 - 20) D Time-out 8 sec N Y Terminate pause Reset timer Y N DT high ≥ 1.15 sec H Pause 4 sec Hi-Z DT pin L Executing pause Starting timer Y Reset timer Dialling Pause N All digits dialled ? N Y Speech mode Timer overflow Y Rev. 1 N Postdialling available 12 Jan. 1995 Data Sheet Privacy Mute AS2574B MT output will go low. (code 23) Speech mode Dialling Change of hook state Mute key (code 22) Speech mode MT high Mute key (code 23) MT output will go low. Speech mode Rev. 1 13 Jan. 1995 Data Sheet Temporary MF Select Speech mode LD default AS2574B * Speech mode MF selected Key in digits All further entries are NOT stored in LNR RAM but buffered in FIFO. The LNR RAM will contain the number entered before pressing the * key and the mode change code. Recall On-hook LD default Idle Key in digits Off-hook LD default Speech mode LD default Rev. 1 14 Jan. 1995 Data Sheet Setting Clock (in display driver) AS2574B Speech mode Speech mode or idle keep Enter Enter depressed keep Enter keep Enter depressed depressed Press # __:__ release Enter Key in hours (2 digits) 18:__ keep Enter Enter depressed Key in min. (2 digits) 18:31 Speech mode Speech mode or idle or idle Rev. 1 15 Jan. 1995 Data Sheet Hook States AS2574B 1) Idle N Diode 5? Y LS On-hook LS Monitor or Handsfree 5) M Off-hook POT 2) () Automatic Call Progress (ACP) LS POT + Monitor Dialling finished LS Y N 1) 2) 3) 4) 5) Pressing any unvalid key doesn´t have any effect in Idle state. POT means Plain Ordinary Telephone. Lift handset means HS going high. Replace handset means HS going low. Lifting the handset during ACP will change the hook state to POT, however, the dialling will continue uneffected. Rev. 1 16 Jan. 1995 Data Sheet Timing Diagrammes The timing diagrammes do not show the correct scaling only the sequence. P.O.T. < 2 sec. CD HS 2 sec. AS2574B DP Whole keyboard enabled Diode scanning Monitor State < 2 sec. CD LS key 2 sec. ιι ιι DP Whole keyboard enabled ιι < 2 sec. 2 sec. CD LS key ιι ιι DP ιι Rev. 1 17 Jan. 1995 Data Sheet LD Dialling AS2574B Osc Key entry MT MR Mask DP Tidp Tb Tb Tpre Tm Tpo Tidp Tb Tpre Tpo Tho 2 1 = depending on Mute key (high when Mute key has been activated, otherwise low) MF Dialling Osc Key entry MT MR Mask Tone 2 3 1 DP Tmo Tho Ttd Titp Tmo Tho = depending Mute key (high when Mute key has been activated, otherwise low) Rev. 1 18 Jan. 1995 Data Sheet Flash AS2574B Osc Key entry MT MR Mask DP GL Pause Tpre Tfd Tpo R Tho = depending on Mute key (high when Mute key has been activated, otherwise low) Ground Loop (GL) Osc Key entry MT MR Mask DP GL Tgl R Tho Pause Tpre Tpo = depending on Mute key (high when Mute key has been activated, otherwise low) Rev. 1 19 Jan. 1995 Data Sheet Automatic Dialling LD (content of LNR is GL, 2, 1 and GL is stored as access code) Osc Key entry MT MR Mask DP GL Pause Tap Tpo = depending on Mute key (high when Mute key has been activated, otherwise low) Tidp Tho AS2574B LNR Automatic Dialling MF (content of LNR is Flash, 1, 2, 3, and Flash is stored as access code) Osc Key entry MT MR Mask DP GL Tone Pause Tap Tpo = depending on Mute key (high when Mute key has been activated, otherwise low) Tmo LNR Rev. 1 20 Jan. 1995 Data Sheet Electrical Data Absolute Maximum Ratings AS2574B Positive Supply Voltage ...................................................................................................................-0.3V ≤ VLS ≤ 7V Input Voltage .......................................................................................................................-0.3V ≤ VIN ≤ VDD + 0.3V Input Current ................................................................................................................................................ ± 25 mA Storage Temperature ......................................................................................................................-65°C to +125°C Electrostatic Discharge (HBM) ...................................................................................................................... ±1000V Recommended Operating Range Parameter Operating Temperatur Operating Voltage Retention Voltage Oscillator Frequency Symbol Top VDD VDD Fosc Min - 25 2.5 1.8 681 3.0 Typ Max 70 5.5 5.5 Unit °C V V kHz Condition DC Characteristics Default conditions: Recommended Operating Range; VDD = 3.0V. Parameter Supply Current Operating except MF Operating MF Data Retention Input Voltage Low High Input Current Low High Output Current Sink Source Pull-down Resistor HS Input CD Input Scanning Current DT Sink Source Isl Ish 20 20 150 150 µA µA Vil Vih Iil Iih Iol Ioh Rhs Rcd 1.5 1 1 1 VSS 0.7xVDD 0.3xVDD VDD 1 1 V V µA µA mA mA MΩ MΩ During Pause Vol = 0.4V Voh = VDD - 0.4V Symbol IDD 200 0.75 1 2 250 1 2 4 Min Typ Max Unit µA mA µA µA VDD=1.8V; note1 Note 1 Condition Outputs unloaded Note 1: Circuit in Idle state (HS = Low and no key activated). Rev. 1 21 Jan. 1995 Data Sheet Signalling Characteristics Defaults conditions: Recommended Operating Range Parameter Clock Startup Time Key Debounce Time HS Debounce Time CD Reset Delay Time DTMF Tone Level, High Group Preemphasis Distortion Tone Duration Inter Tone Pause Tone Rise/Fall Time LD Dial Rate Make/Break Period (diode option) Inter Digit Pause Pre Digit Pause Post Digit Pause Flash Duration Symbol Ts Td Ths Tr Vol - 12.4 2 80 80 14 21 2 - 10.9 2.5 82.3 82.3 - 9.4 2.8 - 26 85 85 5 Min Typ Max 5 18 26 Unit ms ms ms sec dBm dBm dBr ms ms ms pps ms ms ms ms ms ms ms AS2574B Condition RL = 15 kΩ RL = 15 kΩ RL = 15 kΩ, note 3 Note 1 Note 1 Note 2 ± 5% ± 5% ± 5% Ttd Titp Ttr Tm/Tb Tidp Tpre Tpo Tfd 753 55 55 100 600 10 33/66 40/60 785 57 57 101.2 103 620 No diode 2 With diode 2 Earth Recall Duration Automatic Access Pause Short Long Termination Mute Overhang MR/MT Hold Over Tone Burst Frequency Output Level Tone Duration Inter Tone Pause (LS) Inter Tone Pause (Mute) Time-out Tg 500 Tap 4 7.9 1.15 Tmo Tho Fb Vtb Ttb Titb1 Titp2 Tto 182 18 700 -13 80 7 1.8 7.7 4.1 8 1.2 200 4.2 8.1 1.25 223 27 800 -9 85 9 2.2 8.2 sec sec sec ms ms Hz dBm ms sec sec sec DT = Hi-Z DT = Low DT = High 510 ms -11 8 2 8 Note 1: The values are valid during automatic dialling and are minimum values during manual dialling, i.e. the tones will continue as long as the key is depressed. Note 2: The rise time is the time from valid key detection (key has been debounced) till the tone amplitude has reached 90 % of its final value. Note 3: Relative to high group. Rev. 1 22 Jan. 1995 Data Sheet Pin Configuration 28 Pin DIP 28 Pin SOIC AS2574B OSC2 OSC1 SCL SDA C1 C2 C3 C4 C5 C6 R1 R2 R3 R4 1 28 Vdd TONE TB Vss HS DP DT ER MT MR CD MASK LS OSC2 OSC1 SCL SDA C1 C2 C3 C4 C5 C6 R1 R2 R3 R4 1 28 Vdd TONE TB Vss HS DP DT ER MT MR CD MASK 14 15 LS R5 14 15 R5 28 Pin PLCC TONE OSC1 OSC2 SDA SCL Vdd Ordering Information Part number AS2574B P AS2574B N Vss HS DP DT ER MT MR Package 28 pin DIL 28 pin PLCC C1 C2 C3 C4 C5 C6 R1 MASK R2 R3 CD R4 R5 LS TB Rev. 1 23 Jan. 1995 Data Sheet AS2574B Devices sold by Austria Mikro Systeme are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. Austria Mikro Systeme makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Austria Mikro Systeme reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with Austria Mikro Systeme for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by Austria Mikro Systeme for each application. Copyright © 1995, Austria Mikro Systeme International, Schloss Premstätten, 8141 Unterpremstätten, Austria. Trademarks Registered®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. Rev. 1 24 Jan. 1995