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Data Sheet
AS2574B
20 NUMBER ONE TOUCH DIALLER WITH SERIAL BUS FOR DISPLAY DRIVER (R)
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 A 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 k; Roff > 5 M.
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, 2nd 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 k}, 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-upfrom 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 users 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 doesnt 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.

DP Whole keyboard enabled
< 2 sec. 2 sec. CD LS key

DP
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 ......................................................................................................................-65C to +125C 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 A A Vil Vih Iil Iih Iol Ioh Rhs Rcd 1.5 1 1 1 VSS 0.7xVDD 0.3xVDD VDD 1 1 V V A A mA mA M M During Pause Vol = 0.4V Voh = VDD - 0.4V Symbol IDD 200 0.75 1 2 250 1 2 4 Min Typ Max Unit A mA A A 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 k RL = 15 k RL = 15 k, 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 (c) 1995, Austria Mikro Systeme International, Schloss Premstatten, 8141 Unterpremstatten, Austria. Trademarks Registered(R). 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

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