Datasheet AS2525 Datasheet (Austria Mikro Systeme International)

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Page 1

Preliminary AS2525

Austria Mikro Systeme International AG

CMOS Integrated Circuit

Single-Chip Handsfree Phone

Key Features

q q Line/speech handsfree circuit, LD/MF repertory

dialler, and tone ringer on one 44 pin CMOS chip

q q Operating range from 15 to 100 mA line current

(down to 5 mA with slightly reduced performance)

q q All significant parameters programmable with

external EEPROM

q q Volume control of receiver signal q q Handsfree function with enhanced voice switching q q Low noise (max. -72 dBmp) q q Unique EMC performance q q LD/MF switchable dialling with temporary MF

mode

q q Repertory dialling with last number redial and

memory dialling (8 x 2 direct and 10 indirect)

q q Call restriction with PIN code q q Serial interface for EEPROM and LCD driver q q 2-tone/3-tone ringer with ring frequency detection

General Description

The AS2525 is a CMOS mixed-mode integrated circuit for use in feature phones, answering machines and fax machines. It contains an analogue line interface and speech circuit for a/b terminals, loudhearing, handsfree, enhanced LD/MF dialler, tone ringer with dc/dc converter and serial interface to EEPROM and LCD-driver (AS2591), all in a 44 pin package. The circuit is fully line powered.

The AS2525 uses an external EEPROM for a 31 digit last number redial storage and memories for 26 numbers each containing up to 21 digits/data.

The device provides a volume control for the earpiece and the loudspeaker. The volume can be controlled by pressing the [V-]/[V+] keys.

The versatility of the circuit is provided by programming all parameters through an external EEPROM. This allows easy adaptation to various PTT requirements worldwide.

Package

Available in 44 pin TQFP.

Block Diagramme

Ω

300 Ω

BAL

STB

DM/HM

DPN

LED

HS HF

FCI

AS2525

–

DEBOUNCE

DI DO CLK CS1 CS2

LINE

SENSE

CPU

DIALLER

GND

SUPPLY

DTMF

MELODY

PEAK

DET.

PEAK

DET.

KEYBOARD (C1-4/R1-3)

FT2 CBN FT1

GND

–

NOISE

REF

DET.

VOICE

SWITCHING

OSCILLATORKEYSCANNING

3.58 MHz

–

DC/DC

CONVERTER

LO1

LO2

SSA

RECI RECV

Rev. 1.3 Page 1 May 1999

Page 2

Preliminary AS2525 Pin Description

Pin # Symbol Type Description

1 CS2 DO Chip Select 2

Chip select signal for external LCD driver circuit or 2 mA LED If signal is not activated, a pull down resistor ( 100 k

Ω ) is inserted.

2 DPn DO

3 HF DI

4 HS DI

5 FT1 AI Analogue input pin for connecting a capacitor for offset cancellation. 6 FT2 AI Analogue input pin for connecting a capacitor for offset cancellation. 7 M4 AI

8 M2 AI

9 M3 AI

10 M1 AI

Dial Pulse Output

Digital output which holds the line during off-hook operation or pulls low during break periods of pulse dialling and flash.

HandsFree Switch Input

This is an Schmitt-trigger input that is pulled high to enable handsfree operation.

HandSet Switch Input

This is an Schmitt-trigger input that is pulled high by the hook switch to enable handset or headset operation.

Microphone Input 4

Differential input for the handsfree microphone (electret).

Microphone Input 2

Differential input for the handset microphone (electret).

Microphone Input 3

Differential input for the handsfree microphone (electret).

Microphone Input 1

Differential input for the handset microphone (electret).

11 STB AI

12 CS AO

13 V

14 LI AI

15 RI AI

16 SS AO

17 LS AI

Supply

Side Tone Balance Input

Analogue input for side tone cancellation network.

Current Shunt Control Output

N-channel open drain output to control the external high power shunt transistor for synthesising ac- and dc-impedance, modulation of line voltage and shorting the line during make periods of pulse dialling.

Voltage Source Source

Negative Power Supply.

Line Input

Analogue input used for power extraction and line current sensing.

Receive Input

Analogue input for ac-separated receive signal.

Supply Source Control Output

N-channel open drain output to control the external high power source transistor for supplying (Vpp) the loudspeaker amplifier in off-hook loudspeaking/handsfree mode.

Line Current Sense Input

Analogue input for sensing the line current.

Rev. 1.3 Page 2 May 1999

Page 3

Preliminary AS2525

Pin # Symbol Type Description

18 CI AI

19 RECI AI RECeive Input

20 RECV AI RECeive Voice Switching Input

21 RO AO

22 V

23 A

24 CBN AI Analogue input pin for connecting a capacitor for background noise monitoring. 25 CM DO

26 V

GND

Supply

Supply Loudspeaker Power Supply

Complex Impedance Input

Analogue input pin for the capacitor to program a complex impedance.

Analogue input for the handsfree receive path. Should be connected to RO via a coupling capacitor.

Analogue input for receive voice switching path.

Receive Output to Handset

Output for driving a dynamic earpiece with an impedance from 150

Ω to 300 Ω.

Voltage Drain Drain

Positive Power Supply.

Analogue Ground

Special ground for the internal amplifiers.

Converter Make Output

This is an output for controlling the external switching converter. During ringing it converts the ring signal into a 4V supply voltage.

High power supply for the output driver stage.

27 28

29 V 30 DM/HM DI

31 FCI DI

32 LED DO

33 OSC

34 35 36

37 38 39 40

LO1 LO2

SSA

R1 R2 R3

C1 C2 C3 C4

Supply Power supply pin for LO1-LO2 output amplifier.

DI/O

Loudspeaker Outputs 1/2

Output pins for a 32 Ω ( 25 to 50 Ω ) loudspeaker.

Dial Mode/Headset Mode Switch Input

Digital input for choosing between LD and MF dialling or choosing handset and headset mode. See “Table 3: Parameter settings” for further details. This pin is scanned after manual off-hook only.

Frequency Comperator Input

This is a Schmitt-trigger input for ring frequency discrimination. Disabled during off-hook.

LED Output

Digital output for connecting 2 mA LED to indicate handsfree mode.

Oscillator Input

Input for ceramic resonator 3.58 MHz. Keyboard

(see Figure 4: Keyboard Layout).

Keyboard (see Figure 4: Keyboard Layout).

Rows

Columns

41 CLK DO

Rev. 1.3 Page 3 May 1999

Clock

Clock output for 3-wire bus. If signal is not activated, a pull down resistor (100 k

Ω) is inserted.

Page 4

Preliminary AS2525

CS 12 VSS 13

LI 14

RI 15

SS 16

LS 17

CI 18 RECI 19

RECV 20

RO 21 VDD 22

Pin # Symbol Type Description

42 DI DI

Data Input

Data input of 3-wire bus.

Ω) is inserted.

43 DO DO

If signal is not activated, a pull down resistor (100 k

Data Output

Data output of 3-wire bus.

Ω resistor connected from this pin to VSS enables key locking.

Ω) is inserted.

44 CS1 DO

A 100 k If signal is not activated, a pull down resistor (100 k

Chip Select 1

Chip select signal for external EEPROM. If signal is not activated, a pull down resistor (100 k

DI: Digital Input AI: Analogue Input DO: Digital Output AO: Analogue Output DI/O: Digital Input/Output AI/O: Analogue Input/output

Pin Configuration

Keyboard Layout

CS2 1

DPn 2

HF 3

HS 4 FT1 5 FT2 6

M4 7 M2 8 M3 9 M1 10

STB 11

YYWWAAA AS2525 Austria

33 OSC 32 LED 31 FCI 30 Head 29 VSSA 28 LS2 27 LS1 26 VPP 25 CM 24 CBN 23 AGND

2 3

MR R/P FL

V+ M1 M2 M3 M51M6

Maximum RON for key closure: 1 k

5 6 9

V-

Figure 4: Keyboard Layout

Ω) is inserted.

C4C3C2C1

7 8

∗∗

0 #

R1 R2

Ω

Minimum R

for open key: 1 MΩ

OFF

See “Table 1: Key definitions” for description of key functions.

Figure 3: Pin configuration

Basic Definitions

Password is set to 0123 and is used to access basic parameter settings (see Table 3: Parameter settings). The set-up programming is normally done in the factory during manufacturing of the telephone sets. The factory settings can be loaded into the EEPROM (see Figure 6: Memory allocation for external EEPROM).

PIN code is default set to 1111 and is used by the user to protect certain user settings (see Table 5: User programming with PIN code). The PIN code can be changed by the user.

Default settings are shown in bold. Program procedures are entered with the [PG] key. Pressing any invalid key or going on-hook during programming

will abort the program mode and no changes will be stored. Ending a program procedure by pressing the [PG] key will store the changes and exit the program mode.

Rev. 1.3 Page 4 May 1999

Page 5

Preliminary AS2525 Key Definitions and Procedures

Table 1: Key definitions

Key Condition Function Remark

[0] - [9],

∗]

[#], [

[∗]

Off-hook Digits Function depending on mode

LD mode Temporary MF select Providing mixed mode dialling (default LD

selected)

[PG] Speech mode Enter programme state To enter the programme state

Programme mode Exit programme state To terminate/exit programme state

[MT] Speech mode Enter mute state To enter mute state

Mute state Exit mute state To terminate/exit mute state Programme mode Enter blank To enter blank digit during programming

[R/P] Redial/Pause Allows re-signalling of the last dialled number and

insertion of pauses

Programme state Pause Each key pressure inserts a pause [FL] Flash function Invokes a timed loop break [V+] Speech mode Volume control To increase the receive gain

[V-] Speech mode Volume control To increase or decrease the receive gain

[MR] Memory redial key To access memory by key codes

[M1] - [M8] Memory dial Access keys to memories 1 to 8 and 9 to 16

[SH] Second function (shift) To access second function of keys

Table 2: Digits

Digit Key DTMF Mode

+ f

LOW

HIGH

)

Pulse Mode Programming Mode

([PG] + Digit)

Memory Location

([MR] + Digit) [0] 941 + 1336 Hz 10 pulses Memory 17 [1] 697 + 1209 Hz 1 pulse To enter PIN protected programming Memory 18 [2] 697 + 1336 Hz 2 pulses Select flash duration Memory 19 [3] 697 + 1477 Hz 3 pulses Select dialling mode Memory 20 [4] 770 + 1209 Hz 4 pulses Select pause duration Memory 21 [5] 770 + 1336 Hz 5 pulses Key lock toggle Memory 22 [6] 770 + 1477 Hz 6 pulses Ringer volume Memory 23 [7] 852 + 1209 Hz 7 pulses Ringer melody Memory 24 [8] 852 + 1336 Hz 8 pulses LCD contrast Memory 25 [9] 852 + 1477 Hz 9 pulses Ringer on/off Memory 26 [∗]

941 + 1209 Hz Temporary MF select -

[#] 941 + 1477 Hz - -

Rev. 1.3 Page 5 May 1999

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Preliminary AS2525

Table 3: Parameter settings

Parameter Symbol Procedure:

[PG] + [0] + (Password) + Inter-Digit Pause (LD) IDP MF Tone Duration TD MF Inter-Tone Pause ITP Flash 1 Duration FL1 Flash 2 Duration FL2 Pause 1 Duration P1 Pause 2 Duration P2 Pre-Digit Pause (LD) PDP Post Flash Pause PFP Tx Gain, Handset A Rx Gain, Handset A Tx Gain, Handsfree A Rx Gain, Loudspeaker A Line Loss

TX-HS

RX-HS

TX-HF

RX-HS

LLC [0] + [5] + [0] = off [1] = range 1: I

∗] + [1] + [HEX code]

[

∗] + [2] + [HEX code]

[

∗] + [3] + [HEX code]

[

∗] + [4] + [HEX code]

[

∗] + [5] + [HEX code]

[

∗] + [6] + [HEX code]

[

∗] + [7] + [HEX code]

[

∗] + [8] + [HEX code]

[

∗] + [9] + [HEX code]

[

[0] + [1] + [HEX code] 37 dB 30 to 45 dB (see Table 8)

[0] + [2] + [HEX code] 1 dB -6 to 9 dB (see Table 12)

[0] + [3] + [HEX code] 46 dB 39 to 54 dB (see Table 10)

[0] + [4] + [HEX code] 29 dB 22 to 37 dB (see Table 14)

Compensation DTMF Level (Low

[0] + [6] + [HEX code] -6 dBm -18 to -6 dBm in 1 dB steps

Group)

Default Options

840 ms 1.72 ms … 7.03 sec. (see Table 4) 82 ms 1.72 ms … 7.03 sec. (see Table 4) 82 ms 1.72 ms … 7.03 sec. (see Table 4) 101 ms 1.72 ms … 7.03 sec. (see Table 4) 285 ms 1.72 ms … 7.03 sec. (see Table 4) 1 second 1.72 ms … 7.03 sec. (see Table 4) 3 seconds 1.72 ms … 7.03 sec. (see Table 4) 33 ms 1.72 ms … 7.03 sec. (see Table 4) 274 ms 1.72 ms … 7.03 sec. (see Table 4)

= 20 - 50 mA

[2] = range 2: I

LINE

= 45 - 75 mA

LINE

(see Table 24) Tx Gain, Headset A Rx Gain, Headset A MF Comfort Tone, RO V

TX-HEAD

RX-HEAD

MF-CT/RO

[0] + [7] + [HEX code] 37 dB 30 to 45 dB (see Table 20) [0] + [8] + [HEX code] 1 dB -6 to 9 dB (see Table 21) [0] + [9] + [HEX code] -30 dBr -36 to -18 dBr in 6 dB steps

(see Table 30) MF Comfort Tone,

LO1/2 Make/Break Ratio

MF-CT/LO

[0] + [0] + [HEX code] -9 dBr -15 to 3 dBr in 6 dB steps

(see Table 30)

M/B [#] + [1] + [1] = 2 : 3 [0] = 1 : 2

(LD) Dial Rate (LD) DR [#] + [2] + [0] = 10 pps [1] = 20 pps DC Mask (LI Voltage) V Tx Soft Clip (Handset) [#] + [4] + [1] = on

Rx Soft Clip (Handset) [#] + [5] + [1] = on

[#] + [3] + [1] = 4.5 Volt [0] = 3.5 Volt

(2 V

(1 V

PEAK

)

[0] = off

Noise Monitoring (HF) [#] + [6] + [1] = on [0] = off Loudhearing Mode [#] + [7] + [1] = HF only [0] = LH and HF modes available Ringer Melody [#] + [8] + [1] = 3-Tone [0] = 2-Tone Key-in Tone (Beep) KT [#] + [9] + [1] = on [0] = off Reset PIN Code [#] + [0] + [1] = 1111 Selected by user

Rev. 1.3 Page 6 May 1999

Page 7

Preliminary AS2525

Parameter Symbol Procedure:

Default Options

[PG] + [0] + (Password) +

Flash 1 During LD

[#] + [

∗] +

[1] = on [0] = off Flash 2 During LD [#] + [#] + [0] = off [1] = on Extended LCD

[9] + [1] + [0] = off [1] = on

Symbols Tx Soft Clip,

[9] + [2] + [1] = on [0] = off

Handsfree Rx Soft Clip,

[9] + [3] + [1] = on [0] = off

Handsfree Voice Switching,

[9] + [4] + [1] = x 2 [0] = x 1; [2] = x 4; [3] = x 8

Speed Handset/Headset

Volume

[9] + [5] + [1] = reset by

on/off-hook

[0] = setting is maintained

LCD Test [9] + [6] Turns on all segments, pressing any further key

turns on all digits “1” and all symbols off. Temporary MF by ∗

[9] + [7] + [0] = off [1] = on

with tone Key Lock Function [9] + [8] + [1] =

[0] = not available

available Pin Select “DM/HM” DM/HM [9] + [9] + [1] = MF/LD [0] = Handset/Headset Ringer Off Function [9] + [0] + [1] =

[0] = not available

available Key Test Volume Control on

∗] +

[9] + [ [9] + [#] + [1] = enabled [0] = disabled

Any key pressure turns the LED on

Handset The above parameters are programmable using a password (0123) through external EEPROM. All procedures

must be terminated by pressing the [PG] key. Software for factory settings is available on request. The programming of timings is done by using a HEX data code as follows:

C4C3C2C1

1 2

(

M1)

(

M5)

4 5 6 9

(

M2)

(

M6)

7 8

(

M3)

(

M4)

Figure 5: Keys for HEX-code entry

Data = 4096 - (f

OSC

/(512

R1 R2

∗12) ∗ T

Table 4: Timing selection by HEX code

Parameter Default HEX Binary Data

Inter-digit pause 840 ms E17

Tone duration 82 ms FD0

Inter-tone pause 82 ms FD0

Flash 1 101 ms FC4

Flash 2 285 ms F5A Pause 1 1 sec DB9 Pause 2 3 sec 92C

Post-digit pause 33 ms FED

1111 0001 0111 1111 1101 0000 1111 1101 0000 1111 1100 0100 1111 0101 1010 1101 1011 1001 1001 0010 1100 1111 1110 1101

(T = Time; f

= 3.58 MHz)

OSC

Post-flash pause 274 F60

1111 0110 0000

Rev. 1.3 Page 7 May 1999

Page 8

Preliminary AS2525

Table 5: User programming with PIN code

Function Symbol Procedure Options Call Restriction 1 CR1 Call Restriction 2 CR2

[PG] + [1] + (PIN) + [ [PG] + [1] + (PIN) + [

∗] + [1] + ∗] + [2] +

Key in two digits, use [MT] for blank

Key in two digits, use [MT] for blank Key Lock [PG] + [1] + (PIN) + [#] + [6] + [0] = unlocked and [1] = locked Clear All Memories [PG] + [1] + (PIN) + [#] + [7] + Press [1] to clear Reset To Factory

[PG] + [1] + (PIN) + [#] + [8] + Press [1] to reset

Settings Change PIN Code PIN [PG] + [1] + (PIN) + [0] + Key in new PIN + new PIN

Press [PG] to store setting and terminate procedure

Table 6: Mode programming

Function Symbol Procedure Options Select Flash FL [PG] + [2] + [0] = Flash 1 and [1] = Flash 2 Select Dialling Mode DM [PG] + [3] + [0] = LD (pulse) and [1] = MF (DTMF) Select Pause Time P [PG] + [4] + [0] = Pause 1 and [1] = Pause 2 Easy Key Lock [PG] + [5] + [3] + [9] Toggles between locked and unlocked Ringer Volume [PG] + [6] + [1] = -16 dB, [2] = -7 dB, and [3] = 0 dB (maximum) Ringer Melody [PG] + [7] + [0], [1], [2], [3], or [4] LCD Contrast V

[PG] + [8] + [1], [2], or [3] (see also AS2591 data sheet)

Bell On/Off [PG] + [9] + [0] = Off and [1] = On

Press [PG] to store setting and terminate procedure

Memory Allocation

The EEPROM memory consists of three areas: A = factory settings; B = user settings; C = stored numbers

EEPROM

A) factory settings

programmed in factory

B) user settings

…write/read by AS2525

C) stored numbers

Figure 6: Memory allocation for external EEPROM

The AS2525 is writing and reading to and from area B and C during normal operation and user-code programming. Area A is protected during normal operation and contains a back-up copy of the factory settings. This back-up copy can be loaded into area B by the user with the user-code programming procedure "reset to factory settings". The only way to change the factory settings in area A is by set-up programming using password. After changing area A by set-up programming, the AS2525 automatically performs a "reset to factory settings" to load this changes also into area B.

Set-up programming

"reset to factory settings"

User-code programming

Rev. 1.3 Page 8 May 1999

Page 9

Preliminary AS2525

1008060402000

ILine

VLine

VLS

(V)

Functional Description

DC Conditions

The normal operating mode is from 15 mA to 100 mA. An operating mode with reduced performance is from 5 mA to 15 mA. In the line-hold range from 0 mA to 5 mA the device is in a power down mode.

The dc characteristic is determined by the voltage at LI pin and a 30 can be calculated by the following equation:

VLI can be programmed to be 3.5 V or 4.5 V.

Table 7: DC mask selection

[PG] + [0] + (Password) + [#] + [3] + (digit) + [PG]

Digit DC Mask (dc voltage at pin LI)

[0] Low dc mask, VLI = 3.5 Volt [1]

Ω resistor between pin LI and LS. It

VLS = VLI + I

LINE

∗ 30 Ω

High dc mask, VLI = 4.5 Volt

Side-Tone

A good side-tone cancellation can be achieved by using the following equation:

BAL/ZLINE

= 10

This is assuming that the side-tone reference resistor, R2 (between LI and STB) is 300

LINE

BAL

Ω and R1 is 30 Ω.

R1 = 30 ohm

R2 = 300 ohm

Figure 8: Side-tone balance

Transmit Path

The gain of the M1/M2 —> LS path is default set to 37 dB. This gain can be changed from 30 dB to 45 dB in 1 dB steps by set-up programming.

Table 8: Handset Tx gain setting

Figure 7: DC characteristic with low dc mask

2/4 Wire Conversion

AS2525 has a built-in dual Wheatstone bridge with one common ground. This provides a maximum of independence of ac impedance and side-tone from each other. One can adapt side-tone without changing the ac impedance.

AC Impedance

The ac impedance of AS2525 is set to 1000 Ω. A complex impedance can be adjusted by connecting an external capacitor to the CI pin. With an external resistor of approximately 1.5 k pin, it can be programmed to 600

= 33

AC(syn)

Ω connected to the LS

Ω.

∗ 30 Ω

[PG] + [0] + (Password) + [0] + [1] + (x) + [PG]

Key

(x)

Tx Gain (dB)

M1/2 to LS

Key

(x)

Tx Gain (dB)

M1/2 to LS

[0] 30 [8] 38 [1] 31 [9] 39 [2) 32 [M1] 40 [3] 33 [M2] 41 [4] 34 [M3] 42 [5] 35 [M4] 43 [6] 36 [M5] 44 [7]

[M6] 45

The input is differential with an impedance of 10 kΩ. The soft clip circuit limits the output voltage swing at pin LS to 2 V

when activated.

PEAK

Table 9: Handset Tx soft clipping selection

[PG] + [0] + (Password) + [#] + [4] + (digit) + [PG] Digit Handset Tx Soft Clipping

[0] Disabled [1] Enabled (2 V

PEAK

)

There is optional LLC for this path. The gain of the M3/M4 —> LS path is default set to

46 dB. This gain can be changed from 39 dB to 54 dB in 1 dB steps by set-up programming.

Rev. 1.3 Page 9 May 1999

Page 10

Preliminary AS2525

Table 10: Handsfree Tx gain setting

[PG] + [0] + (Password) + [0] + [3] + (x) + [PG]

Key

(x)

Tx Gain (dB)

M3/4 to LS

Key

(x)

Tx Gain (dB)

M3/4 to LS

[0] 39 [8] 47 [1] 40 [9] 48 [2] 41 [M1] 49 [3] 42 [M2] 50 [4] 43 [M3] 51 [5] 44 [M4] 52 [6] 45 [M5] 53 [7]

[M6] 54

The input is differential with an impedance of 10 kΩ. The soft clip circuit limits the output voltage swing at

pin LS to 2 V

when activated.

PEAK

Table 11: Handsfree Tx soft clipping selection

[PG] + [0] + (Password) + [9] + [2] + (digit) + [PG] Digit Handfree Tx Soft Clipping

[0] Disabled [1] Enabled (2 V

PEAK

)

There is no LLC option for this path.

Receive Path

The gain of the LS —> RO receive path is default set to 1 dB. This gain can be changed from -6 dB to 9 dB in 1 dB steps by set-up programming.

Table 12: Handset Rx gain setting

voltage at RO to 1 V

. It prevents harsh distortion

PEAK

and acoustic shock.

Table 13: Handset Rx soft clipping selection

[PG] + [0] + (Password) + [#] + [5] + (digit) + [PG] Digit Handset Rx Soft Clipping (Earpiece)

[0] Disabled [1]

Enabled

There is LLC option for this path. The gain of the LS —> LO1/LO2 receive path is set to

29 dB. This gain can be changed by set-up programming

from 22 dB to -37 dB in 1 dB steps.

Table 14: Loudspeaker gain setting

[PG] + [0] + (Password) + [0] + [4] + (x) + [PG]

Key

(x)

Rx Gain (dB)

LS to LO1/2

Key

(x)

Rx Gain (dB)

LS to LO1/2

[0] 22 [8] 30 [1] 23 [9] 31 [2] 24 [M1] 32 [3] 25 [M2] 33 [4] 26 [M3] 34 [5] 27 [M4] 35 [6] 28 [M5] 36 [7]

[M6] 37

The user can also change the gain using the [V+]/[V-] keys (see section "Handsfree"). The volume range is 15 dB (-7/+8 dB).

[PG] + [0] + (Password) + [0] + [2] + (x) + [PG]

Key

(x)

Rx Gain (dB)

LS to RO

Key

(x)

Rx Gain (dB)

LS to RO

[0] -6 [8] 2 [1] -5 [9] 3 [2] -4 [M1] 4 [3] -3 [M2] 5 [4] -2 [M3] 6 [5] -1 [M4] 7

The receive input is the differential signal of RI and STB. The soft clip circuit limits the output voltage swing at LO1/LO2 to 1 V

PEAK

Table 15: Loudspeaker soft clipping selection

[PG] + [0] + (Password) + [9] + [3] + (digit) + [PG] Digit Handfree Rx Soft Clipping (Loudspeaker)

[0] Disabled

[6] 0 [M5] 8 [7]

[M6] 9

The user can also change the gain within this range in

[1]

There is optional LLC for this path.

Enabled

4 dB steps via the [V+]/[V-] keys. The receive default gain in handset and headset mode must lie between position 5 and 9 for correct operation of the volume control. The receive input is the differential signal of RI and STB. The soft clip circuit limits the output

Line Loss Compensation (LLC)

The line loss compensation is set-up programmable and effects only the handset mode.

Rev. 1.3 Page 10 May 1999

Page 11

Preliminary AS2525

Gmax = +9dB

Table 16: Line loss compensation selection

[PG] + [0] + (Password) + [0] + [5] + (digit) + [PG] Digit LLC Range

[0] No LLC (gain independent of line current) [1] -1 dB/5 mA from 20 to 50 mA [2] -1 dB/5 mA from 45 to 75 mA

When it is activated, the transmit and receive gains for both channels are decreased by 6 dB at line currents from 20 mA to 50 mA or from 45 mA to 75 mA depending on selected range.

Handsfree

The handsfree function allows voice communication without using the handset (full 2-way speaker phone). Two voice controlled attenuators prevent acoustic coupling between the loudspeaker and the handsfree microphone.

The voice switching circuit has three states, namely idle, transmit or receive. In receive mode the attenuation of the receive path and the transmit path can be controlled by the volume keys between 0 dB and -15 dB. The following table (Table 18: Handsfree

attenuation scheme) shows how voice switching is controlled.

voice switching circuit

TX_atten

Voice

switching

speech

Backgnd

noise

monitor

Figure 9: Handsfree voice switching

A background monitoring circuit is incorporated. This circuit can be enabled/disabled as required.

Table 17: Background noise monitoring selection

[PG] + [0] + (Password) + [#] + [6] + (digit) + [PG]

Digit Background Noise Monitoring

[0] Disabled [1]

Enabled

LINE

+3dB

+14dB

+8dB

RECV

RECI

FT2

Offset comp

Compress Peak

CTXoffset

Compress Peak

Gmin = -21dB … -40dB (VOL)

detector

Voice

switching

detector

speech

CBN

CBckgnd

Gmax = -4dB … +16dB (VOL) Gmin = -33dB

Figure 10: Signal path of handsfree circuit

detector

CompressPeak

+23dB

Offset

comp

FT1

Cmicoffset

+12dB

Rev. 1.3 Page 11 May 1999

Page 12

Preliminary AS2525

Table 18: Handsfree attenuation scheme

Speech Mode RX-gain TX-gain Remark

RX > TX_atten X Receive 0 dB to -20 dB -50 dB to -30 dB adjustable with [V+]/[V-] keys in 8

steps

TX_atten > RX No Idle -25 dB -25 dB middle position

TX_atten > RX Yes Transmit -50 dB 0 dB independent of [V+]/[V-] keys

IDLE-mode

Vol minVol defaultVol max

Figure 11: Gain transition of voice switching

Loudhearing

A loudhearing mode can be enabled/disabled through the set-up programming.

Table 19: Loudhearing mode selection

[PG] + [0] + (Password) + [#] + [7] + (digit) + [PG] Digit Loudhearing

[0] Enabled (LH + HF provided) [1]

Disabled (only HF is provided)

Headset mode

0dB

-10dB

-20dB

-25dB

-30dB

-40dB

-50dB

TX-modeRX-mode

TX-gain

RX-gain

Table 20: Headset Tx gain setting

[PG] + [0] + (Password) + [0] + [7] + (x) + [PG]

Key

(x)

Tx Gain (dB)

M1/2 to LS

Key

(x)

[0] 30 [8] 38 [1] 31 [9] 39 [2] 32 [M1] 40 [3] 33 [M2] 41 [4] 34 [M3] 42 [5] 35 [M4] 43 [6] 36 [M5] 44 [7]

[M6] 45

Tx Gain (dB)

M1/2 to LS

Head set mode is selected by connecting pin "HEAD" to VDD and enabling the head function by service code programming (see also Table 3: Parameter settings).

Rev. 1.3 Page 12 May 1999

Page 13

Preliminary AS2525

Table 21: Headset Rx gain setting

[PG] + [0] + (Password) + [0] + [8] + (x) + [PG]

Key

(x) [0] -6 [8] 2

[1] -5 [9] 3 [2] -4 [M1] 4 [3] -3 [M2] 5 [4] -2 [M3] 6 [5] -1 [M4] 7 [6] 0 [M5] 8 [7]

If this mode is entered both hook inputs HS and HF act as electronic off-hook for handset operation. The gain in transmit and receive can be programmed by service code programming. The pin "HEAD" is only scanned once after off-hook and any change on this pin during one session will be ignored.

Rx Gain (dB)

LS to RO

Key

(x)

[M6] 9

Rx Gain (dB)

LS to RO

Ring Frequency Detection

The ring frequency detector assures that only signals with a frequency between 13 Hz and 70 Hz are regarded as valid ring signals.

When a valid ring signal is present for 100 ms continuously, the melody generator is activated and remains active as long as the ring signal is present.

Once the melody generator has been started, the ring signal is continuously monitored and the melody generator is instantly turned on or off according to the momentary presence of a valid or invalid ring signal respectively (until next POR or off-hook).

DC/DC converter

When a valid ring signal is detected, the dc/dc converter is started.

Rev. 1.3 Page 13 May 1999

Page 14

Preliminary AS2525 Dialling and Control Functions

Valid Keys

The key scanning is enabled in off-hook mode with

above V

keyboard by connecting the appropriate row to the column (R

m keyboard matrix with single contacts. Three diodes and a resistor are used to extend the number of rows (see Figure 4: Keyboard Layout).

PIN Code

A PIN code is available for protection various user settings. The default PIN code is set to 1111 and can be change as follows:

1. Press [PG] to enter programme mode

2. Press [1] + (PIN) + [0]

3. Key in new PIN code (valid digits: 0 - 9, #)

4. Key in new PIN code again

5. Press [PG] (= store and exit) or go on-

It is also possible to reset the PIN code through setup programming:

1. Press [PG] to enter programme mode

2. Press [0) + (Password) + [#] + [0]

3. Press [1] to reset

4. Press [PG] (= store and exit) or go on-

. A valid key is detected from the

REF

< 1 kΩ). This can be done using an n x

hook to abort

5. Press [PG] (= store and exit) or go onhook to abort.

Key Lock

A key lock function is provided to allow the user to protect the telephone from any mis-use. When this function is available through the set-up programming, it is possible to enable/disable the key lock using the user PIN code.

Enabling/disabling key lock:

1. Press [PG] to enter programme mode

2. Press [1] +(PIN) + [#] + [6]

3. Press [1] for enable or [0] for disable

4. Press [PG] (= store and exit) or go onhook to abort

Also an easy key lock function is provided. This function can be activated/disactivated when the key lock function is available through set-up programming and the previous mentioned key lock through PIN code is disabled.

Clear Memory Procedure

It is possible to clear all stored numbers by using the PIN code as follows:

1. Press [PG] to enter programme mode

2. Press [1) + (PIN) + [#] + [7]

3. Press [1] for clear

4. Press [PG] (= store and exit) or go onhook to abort

Call Restriction

Reset to Factory Settings

A call restriction function is accommodated. This function can be activated using the PIN code.

Storing digits for call restriction:

1. Press [PG] to enter programme mode

2. Press [1] + (PIN) + [

∗∗]

3. Press [1] for first call restriction and [2] for second call restriction

4. Key in digits for call restriction (2 digits, [MT] for blank)

Rev. 1.3 Page 14 May 1999

It is possible to reset all settings to the default factory settings with following procedure:

1. Press [PG] to enter programme mode

2. Press [1] + (PIN) + [#] + [8]

3. Press [1] for reset

4. Press [PG] (= store and exit) or go onhook to abort

Page 15

Preliminary AS2525

Dial Mode Selection

The default signalling mode (LD or MF) is selectable through following procedure:

1. Press [PG] to enter programme mode

2. Press [3] to enter dial select mode

3. Press [0] for LD and [1] for MF

4. Press [PG] (= store and exit) or go onhook to abort

When default LD mode is selected, a temporary change to MF can be invoked by pressing the [ key. Temporary MF select with tone on first key pressure can be selected as option (see also Table 3: Parameter settings). The circuit will revert to LD by pressing the [FL] key or by next on-hook.

Re-Dialling (Last Number Redial)

Re-dialling is a facility that allows re-signalling of the last dialled number without keying in all the digits again. Numbers dialled out from any memory will also be stored in the LNR memory. The re-dialling works in following manner:

• Any digit (including Flash, Pause, and MF select)

being dialled is storable in the LNR memory up to a total of 31 digits.

• If more than 31 digits are entered, re-dialling will

be inhibited.

• Pressing the [R/P] key as first entry after off-hook

(LNR cursor at first digit) will invoke dialling the content of the LNR memory.

• If the [R/P] key is pressed after entering one or

more digits, the key will function as a pause key and each pressure will insert a pause.

Pauses can also be inserted by pressing the [R/P] key in programme mode.

Flash Function

A flash, [FL] key, activation will invoke a timed loop break. The flash duration can be programmed through set-up (see Figure 5: Keys for HEX-code entry and Table 4: Timing selection by HEX code):

Table 22: Flash duration setting

[PG] + [0] + (Password) + [∗] + (digit) + (HEX) + [PG]

Digit Timing Flash Duration

[4] HEX code Flash 1 [5] HEX code Flash 2

One of two pre-programmed can be selected as follows:

1. Press [PG] to enter programme mode

2. Press [2] to enter flash select mode

∗]∗]

3. Press [0] for duration 1 and [1] for duration 2

4. Press [PG] (= store and exit) or go onhook to abort

A flash entered will be stored in the LNR memory together with entered digits. After a recall a 270 ms pause will automatically be executed.

Pauses

Pauses can be inserted if the [R/P] key is pressed after entering one or more digits. Also during programming, pauses can be inserted by pressing the [R/P] key. Default pause duration is 1 second (P1) and an alternative pause of 3 second (P2) can be selected. These pauses can be changed through the set-up programming (see Table 3: Parameter settings)

Memory Keys

The keys [M1] to [M8] are direct memory access keys, [SH] key is used to access second level of direct memories, and the [MR) key is used for keycode dialling. Up to 26 numbers can be stored in the on-chip RAM. Each number can contain up to 21 digits (including pauses).

During programming multiple pauses can be inserted by pressing the [RD] key.

Example (45678P123 is stored in M1, where P is a pause and 123 the extension number):

1. Off-hook, wait for dial tone

2. Press [M1]

• 45678 is dialled out

• Dialling halts (pauses)

• Dialling is resumed, 123 is dialled out.

Rev. 1.3 Page 15 May 1999

Page 16

Preliminary AS2525

Memory dialling is cascadable up to a the maximum of 31 digits/data.

Tone Generator

The tone generator incorporates the DTMF tones, 3 frequencies for the tone ringer and pacifier tones.

DTMF

The DTMF generator provides 7 frequencies.

Table 23: DTMF frequencies

Digit Frequency

Rows Low Group

1 - 2 - 3 697 Hz 4 - 5 - 6 770 Hz 7 - 8 - 9 852 Hz

* - 0 - # 941 Hz

Columns High Group

1 - 4 - 7 - * 1209 Hz 2 - 5 - 8 - 0 1336 Hz 3 - 6 - 9 - # 1477 Hz

The MF output level can be set through set-up programming. The range is from -18 dBm to -6 dBm in 1 dB steps.

Table 24: DTMF level settings

Table 25: Basic ringer melody selection

[PG] + [0] + (Password) + [#] + [8] + (digit) + [PG]

Digit Ringer Melody

[0] 2-tone [1]

The user can chose the following melodies as shown in below table.

Table 26: 3-tone melody programming

Procedure Digit Sequence Rate [PG] + [7] + [0] F1 F2 F3 F1 F2 F3 1

The chosen melody will be heard in the loudspeaker during programming. Pressing the [PG] key will end the procedure and the last selected melody will be stored.

3-tone

[1] F1 F2 F3 F1 F2 F3 2 [2] F1 F2 F3 F1 F2 F3 4 [3) F1 F2 F3 F1 F2 F3 6 [4] F1 F2 F3 F1 F2 F3 10

Press [PG] to store and terminate

[PG] + [0] + (Password) + [0] + [7] + (x) + [PG]

Key

(x) [0] -18 [7] -11

[1] -17 [8] -10 [2] -16 [9] -9 [3] -15 [M1] -8 [4] -14 [M2] -7 [5] -13 [M3] [6] -12

The pre-emphasis is 2.6 dB. The DTMF tones are according to CEPT recommendations.

Tone Ringer (Melody/Volume)

The tone ringer incorporates two basic selection, namely 2-tone or 3-tone melodies. The default set-up selection is the 3-tone ringer.

Level (dBm)

Low Group

Key

(x)

Level (dBm)

Low Group

-6

When 2-tone melody is selected through the set-up procedure, it is possible to chose the following melodies:

Table 27: 2-tone melody programming

Procedure Digit Sequence Rate [PG] + [7] + [0] F1 F2 F1 F2 F1 F2 2

[1] F1 F2 F1 F2 F1 F2 5 [2] F1 F3 F1 F3 F1 F3 2 [3) F1 F3 F1 F3 F1 F3 5 [4] F2 F3 F2 F3 F2 F3 2

Press [PG] to store and terminate

Repetition rate means that a sequence of 6 frequencies is repeated 1, 2, 4, 5, 6 or 10 times within 1 second.

Pacifier Tone

Any key entry is acknowledged by a pacifier tone (key-in tone) of 1333 Hz. The pacifier tone can be enabled/disabled through set-up programming.

Rev. 1.3 Page 16 May 1999

Page 17

Preliminary AS2525

Table 28: Pacifier tone selection

[PG] + [0] + (Password) + [#] + [9] + (digit) + [PG]

Digit Pacifier Tone (Key-in Tone)

[0] Disabled [1]

Table 29: Pacifier tones

Key Entry Frequency Duration Acknowledge 1333 Hz 40 ms Reject/Terminate 1333 Hz 4 x 40 ms

An invalid key entry will be indicated by a rejection tone of 4 times 40 ms.

By MF dialling the DTMF tones are provided to the earpiece as comfort tone. The level of the comfort is selected through the set-up programming.

Table 30: DTMF comfort tone level setting

Key

(y + x)

Enabled

[PG] + [0] + (Password) + [0] + (y + x) + [PG]

Level (dBr)

Earpiece

Key

(y + x)

Level (dBr)

Loudspeaker

Serial Bus

The AS2525 incorporates a serial bus (DO, DI, and CLK) with two chip select outputs (CS1 and CS2). The serial bus is used to:

• sending data to the LCD driver (AS2591) when a

key is pressed or a number is dialled out

• reading and writing to the external EEPROM

under following conditions:

Table 31: EEPROM read/write timings

ACTION DURATION After off-hook (debounced) 50 ms After on-hook (debounced) 200 ms After first rising edge at FCI 10 ms After PG is terminated 12…600 ms After pressing [V+]/[V-] 20 ms

See also AS2591 data sheet for further information.

LCD Control

The AS2525 is designed to work together with the LCD driver AS2591 (see also AS2591 data sheet).

[9] + [0] -36 [0] + [0] -15 [9] + [1] [9] + [2] -24 [0] + [2] -3 [9] + [3] -18 [0] + [3] 3

-30

[0] + [1]

-9

Rev. 1.3 Page 17 May 1999

Page 18

Preliminary AS2525 Electrical Characteristics

Absolute Maximum Ratings*

Supply Voltage ................................................................ ...............................................................-0.3 ≤ V

Input Current ................................................................................................ ..........................................+/- 25 mA

Input Voltage (LS).......................................................................................................................-0.3V

Input Voltage (LI, CS)................................................................................................................... -0.3V

≤ V

Input Voltage (STB, RI).........................................................................................................-2V

Digital Input Voltage..........................................................................................................-0.3V

Electrostatic Discharge...........................................................................................................................+/- 1000V

Storage Temperature Range........................................................................................................... -65 to +125°C

Total Power Dissipation ............................................................................................................................500mW

*Exceeding these figures may cause permanent damage. Functional operation under these conditions is not permitted.

Recommended Operating Range

Symbol Parameter Conditions Min. Typ.* Max. Units

≤ V

+0.3V

+ 0.3V

≤ 7V

≤ 12V

≤ 8V

AMB

OSC

Supply Voltage (internally generated) Speech mode 3.0 5.0 V Ambient Operating Temp. Range -25 +70 °C Oscillator Frequency Resonator: Murata CSA

3.58 MHz

3.58M G312AM

* Typical figures are at 25°C and are for design aid only; not guaranteed and not subject to production testing.

DC Characteristics

= 15 mA, recommended operating conditions unless otherwise specified)

LINE

Symbol Parameter Conditions Min. Typ. Max. Units

DD-EXT

DD0

Operating Supply Current Speech mode

Handsfree mode LD dialling, VDD = 2.5V Ring mode, VDD = 2.5V

Available Supply Current

Speech mode or MF dialling 2 mA

for Peripheral Circuits Idle Current Idle mode, VDD = 2 V, T Line Voltage, LIVolt = 0

13 mA< I

< 100 mA 3.2

LINE

Line Voltage, LIVolt = 1

13mAmA 200 300

= 25°C 2 µA

AMB

4.2

3.5

4.5

3.8

4.8VV

µA µA

Output Current, Sink

VOL = 0.4V 1 mA

Pin CS, SS

Input Low Voltage T Input High Voltage T

= 25°C V

AMB

= 25°C 0.7 V

AMB

0.3 VDDV V

Rev. 1.3 Page 18 May 1999

Page 19

Preliminary AS2525

AC Electrical Characteristics

= 15 mA; f = 800 Hz; ZAC = 1000ΩΩ; recommended operating conditions and default settings unless otherwise

LINE

specified.

Transmit

Symbol Parameter Conditions Min. Typ. Max. Units

Transmit Gain, default M1/M2 to LS

M3/M4 to LS

Variation with Frequency f = 500 Hz to 3.4 kHz +/- 0.8 dB THD Distortion VLS < 0.25 V V A t

DECAY

AGC

SCO

Soft Clip Level

Soft Clip Overdrive

Attack Time

Decay Time

Input Impedance; M1/M2

VLS = 2

Input Impedance; M3/M4 A

MUTE

Mute Attenuation Mute activated 60 dB

Noise Output Voltage T

= 25°C, handset mode

AMB

ATX = 37 dB

IN MAX

Input Voltage Range;

Differential +/- 1 V

M1/M2 and M3/M4

RMS

34.3

42.0

35.8

44.0

20 70

100

10 10

37.3

46.0dBdB

2 %

V dB µs/6dB ms/6dB

Ω

k kΩ

-72 dBmp

PEAK

Line Driver

Symbol Parameter Test Conditions Min. Typ. Max. Units

V V RL

∆Z

IN MAX

AC/TEMP

Input Voltage Range; LI +/- 2 V Dynamic Range; LI +/- 2 V Return Loss Temperature Variation

ZRL = 1000

Ω; T

= 25°C

AMB

0.5

PEAK

Ω/°C

Rev. 1.3 Page 19 May 1999

Page 20

Preliminary AS2525

Receive

Symbol Parameter Condition Min. Typ. Max. Units

∆A

RX-VOL

Receive Gain, Default LS to RO; volume reset

Volume Control Range 8 steps through [V-]/[V+] keys 15 dB Variation with Frequency f = 500 Hz to 3.4 kHz +/- 0.8 dB

THD Distortion, RO

Distortion, LO1/LO2 V A t

DECAY

V V

AGC

SCO

UFC

Soft Clip Level

Soft Clip Overdrive

Attack Time

Decay Time

Noise Output Voltage, RO

Unwanted Frequency

Components Z

IN-MAX RI

Input Impedance, RI 8

Input Voltage Range, RI +/- 2 V

LS to LO1/LO2; volume max.

VRO = 0.25 V V

= 0.25 V

LO1/2

RMS

VRO =

VRI > 0.8 V

= 25°C, ARX = 3 dB

AMB

RMS

50 Hz.........20 kHz

-2.0

25.0

-0.5

27.0

1 10 70

100

1.0

29.0dBdB

% V dB µs/6dB ms/6dB

-72

-60

dBmp dBmp

PEAK

Ω

PEAK

IN-MAX ST

Side Tone Cancellation VRI < 0.25 V

RMS

26 dB Input Impedance, STB 80 Input Voltage Range, STB +/- 2 V

Ω

PEAK

General Timings

Symbol Parameter Condition Min. Typ. Max. Units

t t t t

t t

HS-L

HS-H

PFP

Key Debounce Time 15 ms Low/High Debounce HS Input (going off-hook) 15 ms High/Low Debounce HS Input (going on-hook) 210 ms Flash Duration FL 1 (default)

FL 2 (default)

100 275 285

102

300msms Post Flash Pause 274 ms Access Pause P1 (default)

P2 (default)

0.9 1.0

3.0

1.1 sec. sec.

Rev. 1.3 Page 20 May 1999

Page 21

Preliminary AS2525

DTMF

Symbol Parameter Condition Min. Typ. Max. Units

DF Frequency Deviation Deviation of ceramic resonator is

not included

MF Tone Level at LS

Default -4.5 -5.5 -6.5 dBm

(Low Group)

MF-RANGE

MF Tone Level Range at

13 steps -18/-6 dBm

LS (Low Group)

∆V

L_H

Pre-emphasis, Low to High

UFC

Unwanted Frequency Components

300 Hz....4.3 kHz

4.3 kHz…7 kHz

7 kHz....10 kHz

10 kHz…14 kHz

14 kHz....28.5 kHz

28.5 kHz....40 kHz

ITP

Tone Duration, Minimum Default 80 82.3 85 ms Inter Tone Pause, Min. Default 80 82.3 85 ms Tone Rise Time Tone Fall Time

From 10% to 90% amplitude From 90% to 10% amplitude

1.2 %

2.0 2.6 3.2 dBr

- 40

-46

- 52

-58

- 70

- 80

dBm dBm dBm dBm dBm dBm

Comfort Tone Level, RO Relative to LS, 4 steps - 36

dBr

-18

LD Dialling

Symbol Parameter Condition Min. Typ. Max. Units

PDP

IDP

Dialling Rate Default

Option

Break Period Default

Option Option

Make Period Default

Option Option

9.53 10 20

57 61.2

66 33

38 40.8

16.5

10.5 pps pps

63 ms

ms ms

42 ms

ms ms

Pre-Digit Pause 35 ms Inter-Digit Pause 800 880 ms

Rev. 1.3 Page 21 May 1999

Page 22

Preliminary AS2525

Tone Ringer

Symbol Parameter Condition Min. Typ. Max. Units

F1 F2 F3 t

MIN

MAX

Frequency 1 Frequency 2 Frequency 3

770 1025 1280

800 1067 1333

830 1110 1385

Hz Hz

Hz Detection Time Initial 100 ms Min. Detection Frequency 12 13 14 Hz Max. Detection Frequency 68 70 75 Hz

Pacifier Tone

Symbol Parameter Condition Min. Typ. Max. Units

PARO

TBD

Tone Output Level, RO Tone Output Level, LO1/2

RL = 150 RL = 32 Ω

Ω

300

mV Frequency Key entry 1333 Hz Tone Burst Duration Key entry

Acknowledge, terminate PG

140

mode

P-P

Rejection, invalid key entry

ITP

Inter-Tone Pause 80 ms

4x40

Rev. 1.3 Page 22 May 1999

Page 23

Preliminary AS2525 Timing Diagrams

LD dialling

MUTE MASK

DPN

IDP

PDP

LD dialling with access pause

MUTE MASK

DPN

IDP

PDP

MF dialling

MUTE MASK

DPN

TONE

Flash

MUTE MASK

DPN

ITP

Flash1/2

PDP

IDP

ITP

Pause

PFP

Pause

Flash1/2

IDP

PDP

ITP

Figure 12: Timing diagrams

Rev. 1.3 Page 23 May 1999

Page 24

Preliminary AS2525

AS2525

Test Circuit

LINE

100 µ

600 ohm

327

10 V

327

30 ohm

300 ohm

22 µ

10 µ

6 k

1 µ

STB

CS Vss

GND

OSC

LO1

LO2

15 n

10 µ

3.58 MHz

10 µ

1 k

32 ohm

150 ohm

CS1

CLK

CS2

DPn

LED

DM/HM

FCI

Figure 13: Test circuit

RECI

RECV

FT1

FT2

CBN

R1 R2 R3

34 35 36

100 n

10 µ

10 k

10 µ

22 µ

Rev. 1.3 Page 24 May 1999

Page 25

Preliminary AS2525 Typical Application

Figure 14: Typical application

Rev. 1.3 Page 25 May 1999

Page 26

Preliminary AS2525

Package Outline

44 Pin TQFP

See Package Catalogue

Devices sold by Austria Mikro Systeme Int. AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. Austria Mikro Systeme Int. AG 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 Int. AG 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 Int. AG 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 Int. AG for each application.

Copyright © 1999, Austria Mikro Systeme International AG, 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.

Austria Mikro Systeme Int. AG reserves the right to change or discontinue this product without notice.

Rev. 1.3 Page 26 May 1999