austriamicrosystems Telephone Line Interface and Speakerphone Circuit AS2523, AS2524, AS2524B Key Features - Line/Speakerphone circuit on a 28-pin CMOS-IC, simple inventory: same die for AS2523/24 and AS2523/24B Serial I/F on AS2523, parallel I/F on AS2524 Enhanced voice switching Background noise monitoring Tx- and Rx-gain programmable on AS2523 only Digital volume control of Rx signals on AS2523 only DC characteristic programmable on AS2523 only Dual softclipping in handset mode on AS2523 only Dual softclipping in handsfree mode on AS2523 only Loudspeaker amplifier for loudhearing and handsfree Supply voltage generation for external circuitry Automatic line loss compensation on AS2523 / 24B only Real and complex impedance selectable by external components Side tone adaptation selectable by external components Unique EMC performance Operating range from 15mA to 100mA (down to 5mA with reduced performance) Few external components DATA SHEET General Description AS2523/24 is a CMOS integrated circuit that incorporates DC and AC line adaptation (DC-mask and synthesized ACimpedance of 1000Ω) as well as a speech circuit with softclipping, line loss compensation and Rx-volume control for handset and handsfree operation. It shall act as an a/bline powered device, which is controlled by a CPU via a serial interface on AS2523 or a standard dialler via a parallel interface on AS2524 and AS2524B. Applications Enhanced handsfree feature phones with CallerID and extended displays. The AS2524 and AS2524B are developed to interface with common Taiwanese dialers. Package Available in 28-pin SOIC or die Block Diagram Revision 1.13 Page 1 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Pin description Pin # Symbol 15 LS Function L ine Current S ense Input Analog input for sensing the line current 12 LI L ine I nput Analog input used for power extraction and line current sensing 13 RI R eceive I nput Analog input for ac-separated receive signal 9 STB S ide T one B alance Input Analog input for side tone cancellation network 10 CS C urrent S hunt Control Output N-channel open drain output to control the external high power shunt transistor for synthesizing AC- and DC-impedance, modulation of line voltage and shorting the line during make periods of pulse dialing 16 CI C omplex I mpedance Input Analog input pin for the capacitor to program a complex impedance 14 SS S upply S ource 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 11 VSS V oltage S ource S ource Negative Analog Power Supply 18 VDD V oltage D rain D rain Positive Analog Power Supply 19 AGND A nalog G round Special ground for the internal amplifiers 8 M1 M icrophone Input 1 Differential input for the handset microphone (electret) 6 M2 M icrophone Input 2 Differential input for the handset microphone (electret) 7 M3 M icrophone Input 3 Differential input for the handsfree microphone (electret) 5 M4 M icrophone Input 4 Differential input for the handsfree microphone (electret) 17 RO R eceive O utput to H andset Output for driving a dynamic earpiece with an impedance from 150Ω to 300Ω Revision 1.13 Page 2 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Pin # Symbol 25 xCS Function C hip S elect on AS2523 Chip select input of the serial interface. Internal pull-up resistor ( 100kOhm ) /xMUTE 26 DI Mute transmit-, receive- path and activate tone path on AS2524 and AS2524B D ata I nput on AS2523 Data input of the serial interface. Internal pull-up resistor ( 100kOhm ) 27 /xPD Power down mode for AS2524 and AS2524B (On-hook) CLK Cl oc k on AS2523 Clock input of the serial interface. Internal pull-up resistor ( 100kOhm ) /HFE Handsfree mode operation on AS2524 and AS2524B 23 LO L oudspeaker O utput. Output pin is for a 25Ω 2 FT1 Analog input pin for connecting a capacitor for offset cancellation. 3 TXO Analog output of the transmit signal 4 TXV Analog input for the transmit signal in the voice switching path 1 CBN Analog input pin for connecting a capacitor for background noise monitoring. 20 RECI Analog input for the handsfree receive path. Should be connected to RO via coupling capacitor. 21 RECV Analog input for receive voice switching path. 24 VSSA Power supply pin for LO output amplifier. 22 VPP Power supply pin for LO output amplifier. 28 TONEIN Revision 1.13 loudspeaker Analog input for DTMF-signals. Page 3 of 19 Data Sheet AS2523, AS2524, AS2524B austriamicrosystems Detailed Block Diagram Revision 1.13 Page 4 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B The gain of the M3/M4 → LS is set to +46dB. This gain can be changed by programming from +39dB to +54dB in 1dB steps on AS2523. The input is differential Functional Description DC conditions with an impedance of 10kΩ. The soft clip circuit limits the output voltage at LS to 2V p . There is no LLC for this path. The normal operating mode is from 15mA to 100mA. An operating mode with reduced performance is from 5mA to 15mA. In the line hold range from 0mA to 5mA the device is in a power down mode. Receive path The gain of the LS → RO receive path is set to +7.5dB. This gain can be changed by programming from –7.5dB to +7.5dB in 1dB steps (Register Rxgain). The receive input is the differential signal of RI and STB. The soft clip circuit limits the output voltage at RO to 1V p. It prevents harsh distortion and acoustic shock. There is LLC for this path. The DC characteristic is determined by the voltage at LIpin and a 30Ω resistor between LI- and LS-pin. It can be calculated by the following equation: V LS = V LI + I Line * 30Ω. V LI can be programmed to be 3.5V or 4.5V. 2/4 wire conversion AC-impedance The gain of the LS → LO receive path is set to +32dB. This gain can be changed by programming from +19dB to 34dB in 1dB steps. The user can also change the gain via Register Handsfree receive end gain (See section "Handsfree"). The receive input is the differential signal of RI and STB. The soft clip circuit limits the output voltage at LO to 1.1V p. It prevents harsh distortion and acoustic shock. There is optional LLC for this path. The AC-impedance of AS2523/24 is set to t.m. 1000Ω. With the external capacitor at CI-pin it can be programmed Line Loss Compensation (AS2523, AS2524B) complex. With an external resistor of approx. 1.5kΩ - AS2523/24 has built in two Wheatstone bridges 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 ACimpedance. programmable on AS2523 not activated at AS2524 permanently activated at AS2524B When it is activated, the transmit and receive gains for both I/O’s are decreased by 6dB at line currents from 20mA to 50mA or from 45mA to 75mA. connected to the LS-pin it can be programmed to 600Ω. Side Tone A good side tone cancellation can be achieved by using the following equation: Z BAL /Z LINE = 10 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 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 Register Handsfree receive end gain between 0dB and -20dB. The following table shows how voice switching is controlled Transmit path The gain of the M1/M2 → LS is set to +37dB. This gain can be changed by programming on AS2523 from +30dB to +45dB in 1dB steps (Register Txgain), on AS2524 / 24B it is set to +37dB per default. The input is differential with an impedance of 10kΩ. The soft clip circuit limits the output voltage at LS to 2V p. There is LLC for this path. voice switching circuit TX_atten RX Revision 1.13 Voice switching speech Backgnd noise monitor Page 5 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Gmax = +9dB Gmin = -21dB … -40dB (Vol) LINE +23dB +14dB +8dB ~ +17dB Compress +3dB TXO speech Peak detector Voice switching TXV RO Compress Compress Offset comp FT1 0mV ~ 100mV Peak detector Peak detector CBN Cmicoffset CBckgnd RECV RECI Gmax = -4dB … +16dB (Vol) Gmin = -33dB +9dB Speech Mode Rx-gain Tx-gain Remark Rx > Tx_atten X Receive 0db to -20dB -50dB to -30dB adjustable with VOL-setting Tx_atten > Rx NO Idle -25 -25 middle position Tx_atten > Rx YES Transmit -50dB 0dB independent of VOL-setting IDLE-mode RX-mode TX-mode 0dB -10dB TX-gain -20dB Vol max Vol default Vol min -25dB -30dB -40dB RX-gain -50dB Revision 1.13 Page 6 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Typical Characteristics of Line Loss Compensation (AS2523, AS2524B only) The line-loss-compensation is programmable at the AS2523, not activated at the AS2524 and LLC high (45mA-75mA) activated at the AS2524B. (dB) 35 34 33 32 31 30 29 Tx Gain No LLC (AS2523, AS2524) LLC high (AS2523,AS2524B) LLC low (AS2523) f = 800 Hz Z LINE = 600Ω V LS = -10 dBm 20 DC Line Current 30 40 50 60 70 80 (mA) Figure 1 Typical Tx Gain Characteristics Line Loss Compensation (dB) +4 +3 +2 +1 0 -1 -2 Rx Gain No LLC (AS2523, AS2524) LLC low (AS2523) LLC high (AS2523,AS2524B) f = 800 Hz Z LINE = 600Ω V LS = -10 dBm VOL = 0 dB (neutral) 20 30 DC Line Current 40 50 60 70 80 (mA) Figure 2 Typical Rx Gain Characteristics Line Loss Compensation Revision 1.13 Page 7 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Serial Interface on AS2523 Registers The settings of the AS2523 are stored in 16 registers. Each register has 4 bit data width. Timing The data format for writing to a register has the following form: xCS CLK A3 DI Note: A2 A1 A0 D3 D2 D1 D0 The pins xCS,CLK,DI have internal pull-up resistors. Parameter Symbol MIN CLK Pulse width HIGH T6 100ns CLK Pulse width LOW T5 100ns xCS to first falling CLKedge setup time T1 50ns DIN to CLK setup time T3 50ns DIN to CLK hold time T4 50ns t5 t1 t3 TYP MAX t6 t4 xCS CLK DIN Revision 1.13 Page 8 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Serial interface Registers The following table shows the content of the 16 control registers. Address Data A A A A 3 2 1 0 D D D D 3 2 1 0 0 0 0 0 0 Nop na na na na 0111 na na na na 0111 0001 0001 1000 1000 0101 1100 1111 1011 0000 1100 16 gains Hfs1 HFs0: Speed of voice switching 0 0 max speed 0 1 1 0 1 1 min speed Transmit gain [16], 16 steps, 1dB stepsize 0111 0111 16 gains Data HS-mode HF-mode 0x0 30dB 39dB : : : 0xF 45dB 54dB Receive gain [16], 16 steps, 1dB stepsize 1111 1111 0100 1000 0100 0101 0000 0001 na na x x x Llc0 x Llc1 0 1 0 1 0 for AS2524 LH bond option Liv 0 0 1 1 0 for AS2523, AS2524HF Conf 0 0 0 0 1 Default value after reset Control registers AS2523 0... No Conf Tone 1... Conf Tone Conf-Tone: 0...3.5V, 1...4.5V LIV: Voltage at pin LI LLC1 LLC0: Line loss compensation setting 0 0 20mA-50mA 0 1 NO Line loss compensation 1 0 45-75mA 1 1 NO Line loss compensation CT0 x Softclip-settings, Tx_comp_gain settings Bit1 Bit0 :Tx_comp_gain 0 0 +8dB 0 1 +11dB 1 0 +14dB 1 1 +17dB 0...OFF, SOFTRX: Softclip RX 0...OFF, SOFTTX: Softclip TX Bnon Delay_10ms Rxoffset Bit0 Rxoffset Bit1 0 1 1 1 1 0 0 0 0...OFF, 1...ON BURS: Analog tone at RO 0...OFF, 1...ON BURL: Analog tone at LS CT1 CT0: @RO @LS 0 0 -36dB -15dB TONE-confidence level 0 1 -30dB -9dB rel. to pin LS 1 0 -24dB -3dB 1 1 -18dB +3dB Soft-TX CT1 x Soft-RX Burl x tx_comp_gain Bit0 x tx_comp_gain Bit 1 0 1 1 0 Burs 0 1 0 1 16 gains Bit1 Bit0: Rx-offset setting 0 0 0mV 0 1 12mV 1 0 40mV 1 1 100mV 0... no delay Delay_10ms 0... BGN off Bnon Handsfree receive endgain Data 0x0 : 0xF 1 0 0 1 x x x 1...ON 1...ON RXgain -20dB : +0dB TXgain -30dB 1... 10ms delay 1... BGN on Min. receive volume -50dB Max. receive volume x 1 0 1 0 1 0 1 1 Hfs0 Hfs1 off0 off1 off1 off0: BGN-offset 0 0 120mV 0 1 180mV 1 0 240mV 1 1 300mV Data 0x0 : 0xF Tone x x x 1 1 1 1 x x HP_on : rec_on : Mute : Tone : Mask, Lh, Hf, Hook Mask: 0... 0... 0... 0... Switch 0... His 0 1 1 1 1 Hook functions Power down Handset not allowed Handsfree Loudhearing HF x 0 0 1 1 LH: x 0 1 0 1 fg=200Hz Rxcomp=AGND No mute Tx-signal path 1... 1... 1... 1... fg=2000Hz Rxcomp=RECV Tx-path muted Ton in signal path No mask 1... Mask acitivated slow_rec LH Mute x HF-mode 19dB : 34dB Test2 Hf Rec_on x His x Mask x Krat5 1 1 1 0 x Test3 1 1 0 1 HP_on 1 1 0 0 HS-mode -6dB : +9dB slow_rec: fast change to TX, slow change to RX, no IDLE Krat5,Test3,Test2: For factory test only ! x x Reset to defaults For a detailed description of the commands see Application note AN523/24. Revision 1.13 Page 9 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Programming Guidelines for the AS2523 Additional settings in Handsfree mode The AS2523 is programmed by means of a serial 8-bit shift register. MSB is clocked in first, LSB last. The first four bits (7,6,5,4) are the addresses of the registers, the last four bits (3,2,1,0) are the data bits. Note: change the default settings only if necessary: Each register has a default setting (see data sheet), which is set after power-up of the chip. b) Change the Tx comparator preamplifier gain in register 6 Default = 14dB The internal registers are RAM-cells. When the AS2523 loses VDD (as in on-hook state) it also loses the register contents. c) Change the Receive DC offset and Background noise monitoring in Register 7 default = 0mV offset (higher val. puts more weight on Rx) switching delay default = on Background Noise Monitoring = on It is therefore necessary to re-write the affected registers after each hook event. The register contents cannot be read, they can only be written. d) Set the speaker amplifier volume in register 8 Default = 0B Registers need to be re-written after each power-up and after each hook event (handset / handsfree / on-hook). It is recommended to always initialize the chip with a “reset to defaults command” (Fx) first and then write the appropriate registers that need to be changed from the default setting. Alternatively, all registers (4 to 16) may be re-written in a bulk at each power-up and hook event (handset / handsfree / on-hook). This guarantees safe operation in case of unexpected loss of power during normal operation. Re-writing all registers also eases later software updates, as only register contents need to be changed, but no additional command lines need to be inserted. Example of a typical power-up sequence A typical power-up sequence will require the following programming. a) determine the cause of power-up (handset / handsfree mode) and set register D accordingly. Default = handset mode b) Set the LI voltage to 3.5V or 4.5V (default = 4.5V) and Line Loss Compensation (default = off) in register 4 c) Set the Confidence Tone level (e.g. the DTMF level which is audible in the handset) and path in register 5 Default = off d) Set the required Tx and Rx gains in Registers A and B Default = 37dB Tx gain, 1dB Rx gain Revision 1.13 a) A click-free startup can be achieved by starting up in handset mode (=default) and then switching to handsfree, once the chip has stabilized. e) Set the handsfree voice switching speed and Background Noise monitoring offset in register 9: default voice switching speed = 1ms/6dB (fastest) default BGN monitoring offset = 240mV (determines the Tx level required to switch from idle to Transmit) Additional settings during Flash During a Flash, the AS2523 should be powered down to avoid discharge of VDD: Set the MASK bit (bit3 in register D) to 1 After the line current is restored, the MASK bit must be cleared again. Other settings do not need to be re-written, as VDD has not discharged. As a safety margin however, it is recommended to re-write all registers after a flash Additional settings during line breaks If a line-break-detection (brief interruption of the line while in off-hook state) is implemented, the same rules apply as for a Flash: set the MASK bit to 1 to avoid discharge of VDD. It is recommended to re-write all registers after a line-break, as a line break may take long enough to discharge VDD, even when the MASK bit was set. General Rules The serial interface may be programmed at any time, it does not affect the speech quality, e.g. if a register is overwritten with the same value. It is also possible to re-write all registers periodically. The register is static, therefore it can be clocked at any speed up to 5MHz. However, electromagnetic pulses on the clock and data lines may cause unwanted programming of the chip. It is therefore recommended to keep these lines short, filter them by a discrete lowpass filter and reduce the clock speed accordingly. Page 10 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Parallel Interface on AS2524 and AS2524B Input Signal on Pin XPD xMute HF 0 0 0 Power down Mode 0 0 1 Power down 0 1 0 Power down 0 1 1 Power down 1 0 0 Tone mode 1 0 1 Tone mode 1 1 0 Handset mode 1 1 1 Handsfree mode Power down mode For low power consumption the analog part is turned off during activated power down mode. The Power down mode is used during Flash and Pulse dialing and for On-hook operation. Handset mode Speech mode is Handset mode (M1-M2, RO active; LO deactivated) Parameter AS2524 AS2524B 4.5V 4.5V LLC No LLC LLC high (45mA to 75mA) TX-Gain +37dB +43dB RX-Gain +7.5dB +7.5dB Rx-Softclip Off Off Tx-Softclip Off Off Tone Off Off LI Voltage Handsfree mode Speech mode is Handsfree mode (M3-M4, RO active; LO active) Parameter AS2524 AS2524B 4.5V 4.5V LLC No LLC LLC high (45mA to 75mA) HF TX-Gain +46dB +52dB HF RX-Gain +34dB +34dB Rx-Softclip Off Off Tx-Softclip Off Off Tone Off Off BNM On On LI Voltage Revision 1.13 Page 11 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Tone mode This mode is used to send DTMF and FSK data to the line. Speech mode is Tone mode (M1-M2;M3-M4 muted, Rx path muted, RO and LO active) Parameter AS2524 AS2524B 4.5V 4.5V LLC No LLC LLC high (45mA to 75mA) Tone TX-Gain +14dB +14dB -36dB@Ro –15dB@Lo relative to Pin LS -36dB@Ro –15dB@Lo relative to Pin LS LI Voltage Confidence tone level Loudhearing AS2524 and AS2524B (feature only available as DIE) Speech mode is Loudhearing (M3-M4, RO active; LO activated). Loudhearing can be activated via a bond-option (see document “AS2523/24 Delivery as Dice”). Parameter AS2524 AS2524B 4.5V 4.5V LLC No LLC LLC high (45mA to 75mA) TX-Gain +37dB +43dB RX-Gain +7.5dB +7.5dB Tone Off Off Slow_rec On On RECV pin Deactivated Deactivated Highpass 2000kHz (10nF from TXO->TXV) 2000kHz (10nF from TXO->TXV) 120ms/6dB 120ms/6dB 300mV 300mV LI Voltage Voice switching speed RX-Offset Electrical characteristics Electrical characteristics are measured with the Test Circuit application. Typical mean values will not be tested. Absolute maximum ratings Positive Supply Voltage Input Current Input Voltage (LS) Input Voltage (LI, CS) Input Voltage (STB, RI) Digital Input Voltage Electrostatic Discharge (HBM 1.5kΩ-100pF) Storage Temperature -0.3V <= V DD <= 7V +/- 25mA -0.3V <= V in <= 12V -0.3V <= V in <= 8V -2V <= V in <= V DD +0.3V -0.3V <= V in <= V DD +0.3V +/- 1000V -65°C to +125°C Recommended operating conditions Supply Voltage (generated internally) Operating Temperature Revision 1.13 3V <= V DD <= 5V -25°C to +70°C Page 12 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B DC characteristics I Line =15mA w/o operation of any additional external circuitry, unless other specified Symbol Parameter Conditions Min Type Max Units Test I DDS Operating Current Speech Mode 3 6 mA Y I DDH Operating Current Handsfree Mode 7 10 mA Y V LI Line Voltage LIVolt=0 Line Voltage LIVolt=1 15mA<=ILINE<=100mA 3.5 4.5 3.8 4.8 V V Y Y I OL Output Current, Sink CS,SS mA N 3.2 4.2 VOL=0.4V 1 Transmit characteristics I Line =15mA f=800Hz, default settings unless other specified Symbol A M1/2TX A M3/4TX A tone TX Parameter Conditions Transmit Gain M1/M2 → LS AS2524 AS2524B Z AC(syn)= 1000Ω Transmit Gain M3/M4 → LS AS2524 AS2524B Z AC(syn) =1000Ω Transmit Gain Z AC(syn) =1000Ω Min Type Max Units Test 35 39 +36.5 +42.5 38 44 dB dB Y Y 43 49 +45.0 +51 47 53 dB dB Y Y 12 +14dB 16 dB Y Tone → LS Δ A TX Variation with frequency f = 500Hz … 3.4kHz ±0.8 dB N A VRM12 Control range 16 steps -7/+8 dBr N 16 steps -7/+8 dBr N % Y 2 VP N 2 VP N M1/M2 → LS A VRM34 Control range M2/M4 → LS THD Distortion V AGC1 Soft Clip Level 2 V LS =0.25VRMS M1/M2 → LS at LS V AGC2 Soft Clip Level M3/M4 → LS at LS A SCO Soft Clip Overdrive M1/M2 - M3/M4 20 dB N t attack Attack time 70 us/6dB N t decay Decay time 100 ms/6dB N Revision 1.13 Page 13 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Symbol Parameter Conditions Min Type Max Units Test Z IN-M1/2 Input Impedance M1/M2 10 kΩ N Z IN-M3/4 Input Impedance M3/M4 10 kΩ N V INmax Input Voltage Range M1/2 - M3/4 differential ±1 Vp N V NO Noise Output Voltage LS T AMP =25°C dBmp dBmp N Y dB Y A MUTE Mute Attenuation Handset mode Gain = 36.5dB Gain = 42.5dB -72 -66 Mute activated 60 Receive characteristics I Line =15mA f=800Hz, default settings unless other specified Symbol A RO A LO12 Parameter Conditions Receive Gain Z AC(syn) =1000Ω LS → RO Vol default Receive Gain Z AC(syn) =1000Ω Min Type Max Units Test 6 +7.5 9 dB Y +32.0 +34 +36.0 dB Y LS → LO Vol maximum Δ A RX Variation with frequency f=500Hz to 3.4kHz ±0.8 dB N A VRRO Control range 16 steps -7/+8 dBr N 16 steps -7/+8 dBr N LS → RO A VRLS Control range LS → LO THD LS Distortion LO V LS =0.25VRMS 5 % Y THD RO Distortion RO V LS =0.25VRMS 2 % Y V UFC Unwanted Freq. Cmp. f = 200 … 20kHz -60 dBm Y 1 VP N V AGCRO Soft Clip Level RO V AGCLS Soft Clip Level LO 1.1 VP N A SCLS Soft Clip Overdrive LO 10 dB N T attack Attack time 70 us/6dB N T decay Decay time 100 ms/6dB N Revision 1.13 Page 14 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Symbol Parameter Conditions Noise Output Voltage RO V NO Min Type T AMP =25°C Max Units Test -68 dBmp Y Gain = 7.5dB Z IN-RI V INmax Input Imp. RI Input Voltage Range RI 8 ±2 kΩ Vp N Z IN-STB V INmax Input Imp. STB Input Volt. Range STB 80 ±2 kΩ Vp N ST Side tone V RI <=0.25VRMS 26 dB Y RL Δ Z AC/°C Return Loss Temp. Variation Z AC(syn) =1000Ω 18 dB Y 0.5 Ω/°C Test circuit U2 15 C1 100uF C2 I1 13 12 D1 10V R1 300R R1 600R Idc 10uF R1 30R VSS TONE IN RI M3 LI M4 C2 1uF 9 VSS Vac LS R1 6k 10 VSS 16 VSS Q1 BC327 11 24 VSS M1 28 C6 100nF 7 C6 100nF 5 C6 Vac 100nF 8 C6 100nF 6 C6 Vac 100nF STB M2 CS RO CI AS2523/24 VSS VSSA RECI RECV Vac V3 17 C2 10uF 20 C4 100nF 21 C6 VSS R3 R4 10k Q1 14 22 C2 47uF SS LO xCS / xMUTE DI / xPD CLK / HFI VPP 25 26 27 100uF R2 VSS 32R R5 10k VSS 3 2 1 1 C2 1uF TXV TXO FT 1 VD D C7 VSS 4 3 1uF2 C2 22uF 19 C2 18 100uF C2 D1 5V1 AGND CBN VSS 23 VSS 100nF VSS BC327 150R C3 1n VSS Revision 1.13 Page 15 of 19 Data Sheet AS2523, AS2524, AS2524B austriamicrosystems Typical application AS2523 Revision 1.13 Page 16 of 19 Data Sheet AS2523, AS2524, AS2524B austriamicrosystems Typical application AS2524 and AS2524B Revision 1.13 Page 17 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Packaging 28-pin plastic SOIC For exact mechanical package dimensions please see austriamicrosystems AG packaging information. Pin-out, Marking CBN 1 28 TONE IN FT 1 2 27 CLK / HFI TXO 3 26 DI / xPD TXV 4 25 xCS/ xMUTE M2 6 M3 7 M1 8 ST B 9 24 VS SA YYWWAAA AS252X M4 5 23 LO 22 VP P 21 RECV 20 RECI 19 AGND CS 10 18 VDD VSS 11 LI 12 17 RO RI 13 16 CI SS 14 15 LS YY WW AAA year of production calendar week of production austriamicrosystems AG assembly ID X 3 … AS2523 Version 4 … AS2524 Version 4B .. AS2524B Version Ordering Information Number Package Description AS2523 T SOIC28 plastic surface mounted package – 28 leads AS2524 T SOIC28 Plastic surface mounted package – 28 leads AS2524B T SOIC28 Plastic surface mounted package – 28 leads AS2523 F DOF Dice-on-Foil AS2524 F DOF Dice-on-Foil AS2524B F DOF Dice-on-Foil Revision 1.13 Page 18 of 19 austriamicrosystems Data Sheet AS2523, AS2524, AS2524B Copyright Copyright © 2002-2007, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria-Europe. 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. All products and companies mentioned are trademarks of their respective companies. Disclaimer Devices sold by austriamicrosystems AG are covered by the warranty and patent identification provisions appearing in its Term of Sale. austriamicrosystems 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. austriamicrosystems 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 austriamicrosystems 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 austriamicrosystems AG for each application. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. Contact Information Headquarters: austriamicrosystems AG Business Unit Communications A 8141 Schloss Premstätten, Austria T. +43 (0) 3136 500 0 F. +43 (0) 3136 5692 [email protected] For Sales Offices, Distributors and Representatives, please visit: www.austriamicrosystems.com austriamicrosystems Revision 1.13 – a leap ahead Page 19 of 19