MT88E45BN1

MT88E45 4-Wire Calling Number Identification Circuit 2 (4-Wire CNIC2) Data Sheet Features • June 2006 Compatible with: Ordering Information • Bellcore GR-30-CORE, SR-TSV-002476, ANSI/TIA/EIA-716, TIA/EIA-777; • ETSI ETS 300 778-1 (FSK only variant) & -2; • BT (British Telecom) SIN227 & SIN242 • Bellcore ‘CPE Alerting Signal’ (CAS), ETSI ‘Dual Tone Alerting Signal’ (DT-AS), BT Idle State and Loop State ‘Tone Alert Signal’ detection • 1200 baud Bell 202 and CCITT V.23 FSK demodulation • Separate differential input amplifiers with adjustable gain for Tip/Ring and telephone hybrid or speech IC connections MT88E45BN MT88E45BS MT88E45BSR MT88E45BNR MT88E45BN1 MT88E45BNR1 MT88E45BS1 MT88E45BSR1 20 20 20 20 20 20 Pin Pin Pin Pin Pin Pin SSOP SOIC SOIC SSOP SSOP* SSOP* Tubes Tubes Tape & Reel Tape & Reel Tubes Tape & Reel, Bake & Drypack 20 Pin SOIC* Tubes, Bake & Drypack 20 Pin SOIC* Tubes, Bake & Drypack *Pb Free Matte Tin -40°C to +85°C Applications • Bellcore CID (Calling Identity Delivery) and CIDCW (Calling Identity Delivery on Call Waiting) telephones and adjuncts • ETSI, BT CLIP (Calling Line Identity Presentation) and CLIP with Call Waiting telephones and adjuncts • Selectable 3-wire FSK data interface (bit stream or 1 byte buffer) • Facility to monitor the stop bit for framing error check • FSK Carrier detect status output • Fax and answering machines • 3 to 5V +/- 10% supply voltage • Computer Telephony Integration (CTI) systems • Uses 3.579545 MHz crystal or ceramic resonator • Low power CMOS with power down MODE FSKen+Tip/Ring CASen + IN1- - Anti-Alias Filter PWDN GS1 + IN2- - Carrier Detector Hybrid CASen PWDN MODE Bias Generator PWDN FSKen OSC2 2130Hz Bandpass CASen Control Bit Decode Oscillator OSC1 DATA Data Timing Recovery DCLK FSKen CASen GS2 VREF FSK Demodulator PWDN PWDN IN2+ FSK Bandpass 2750Hz Bandpass CD DR STD Tone Detection Algorithm Mux IN1+ Guard Time CASen CB0 CB1 CB2 Figure 1 - Functional Block Diagram 1 Zarlink Semiconductor Inc. Zarlink, ZL and the Zarlink Semiconductor logo are trademarks of Zarlink Semiconductor Inc. Copyright 2001-2006, Zarlink Semiconductor Inc. All Rights Reserved. DR/STD ST/GT EST Vdd Vss MT88E45 Data Sheet Description The MT88E45B is a low power CMOS integrated circuit suitable for receiving the physical layer signals used in North American (Bellcore) Calling Identity Delivery on Call Waiting (CIDCW) and Calling Identity Delivery (CID) services. It is also suitable for ETSI and BT Calling Line Identity Presentation (CLIP) and CLIP with Call Waiting services. The MT88E45B contains a 1200 baud Bell 202/CCITT V.23 FSK demodulator and a CAS/DT-AS detector. Two input op-amps allow the MT88E45B to be connected to both Tip/Ring and the telephone hybrid or speech IC receive pair for optimal CIDCW telephone architectural implementation. FSK demodulation is always on Tip/Ring, while CAS detection can be on Tip/Ring or Hybrid Receive. Tip/Ring CAS detection is required for the Bellcore/TIA Multiple Extension Interworking (MEI) and BT’s on-hook CLIP. A selectable FSK data interface allows the data to be processed as a bit stream or extracted from a 1 byte on chip buffer. Power management has been incorporated to power down the FSK or CAS section when not required. Full chip power down is also available. The MT88E45B is suitable for applications using a fixed power source (with a +/-10% variation) between 3 and 5 V. 2 Zarlink Semiconductor Inc. MT88E45 VREF 1 IN1+ 2 IN1- Data Sheet 20 IN2+ 19 IN2- 3 18 GS2 GS1 4 17 CB2 Vss 5 16 CB1 OSC1 6 15 Vdd OSC2 7 14 CD CB0 8 13 ST/GT DCLK 9 12 EST DATA 10 11 DR/STD MT88E45B Figure 2 - Pin Connections Pin Description Pin # Name Description 1 VREF Voltage Reference (Output). Nominally Vdd/2. It is used to bias the Tip/Ring and Hybrid input opamps. 2 IN1+ Tip/Ring Op-amp Non-inverting (Input). 3 IN1- Tip/Ring Op-amp Inverting (Input). 4 GS1 Tip/Ring Gain Select (Output). This is the output of the Tip/Ring connection op-amp. The opamp should be used to connect the MT88E45B to Tip and Ring. The Tip/Ring signal can be amplified or attenuated at GS1 via selection of the feedback resistor between GS1 and IN1-. FSK demodulation (which is always on Tip/Ring) or CAS detection (for MEI or BT on-hook CLIP) of the GS1 signal is enabled via the CB1 and CB2 pins. See Tables 1 and 2. 5 Vss Power supply ground. 6 OSC1 Oscillator (Input). Crystal connection. This pin can also be driven directly from an external clock source. 7 OSC2 Oscillator (Output). Crystal connection. When OSC1 is driven by an external clock, this pin should be left open. 8 9 CB0 Control Bit 0 (CMOS Input). This pin is used primarily to select the 3-wire FSK data interface mode. When it is low, interface mode 0 is selected where the FSK bit stream is output directly. When it is high, interface mode 1 is selected where the FSK byte is stored in a 1 byte buffer which can be read serially by the application’s microcontroller. The FSK interface is consisted of the DATA, DCLK and DR/STD pins. See the 3 pin descriptions to understand how CB0 affects the FSK interface. When CB0 is high and CB1, CB2 are both low the MT88E45B is put into a power down state consuming minimal power supply current. See Tables 1 and 2. DCLK 3-wire FSK Interface Data Clock (Schmitt Input/CMOS Output). In mode 0 (when the CB0 pin is logic low) this is a CMOS output which denotes the nominal mid-point of a FSK data bit. In mode 1 (when the CB0 pin is logic high) this is a Schmitt trigger input used to shift the FSK data byte out to the DATA pin. 3 Zarlink Semiconductor Inc. MT88E45 Data Sheet Pin Description Pin # Name 10 11 12 13 DATA Description 3-wire FSK Interface Data (CMOS Output). Mark frequency corresponds to logical 1. Space frequency corresponds to logical 0. In mode 0 (when the CB0 pin is logic low) the FSK serial bit stream is output to the DATA pin directly. In mode 1 (when the CB0 pin is logic high) the start bit is stripped off, the data byte and the trailing stop bit are stored in a 9 bit buffer. At the end of each word signalled by the DR/STD pin, the microcontroller should shift the byte out onto the DATA pin by applying 8 read pulses to the DCLK pin. A 9th DCLK pulse will shift out the stop bit for framing error checking. DR/STD 3-wire FSK Interface Data Ready/CAS Detection Delayed Steering (CMOS Output). Active low. When FSK demodulation is enabled via the CB1 and CB2 pins this pin is the Data Ready output. It denotes the end of a word. In both FSK interface modes 0 and 1, it is normally hi and goes low for half a bit time at the end of a word. But in mode 1 if DCLK starts during DR low, the first rising edge of the DCLK input will return DR to high. This feature allows an interrupt requested by a low going DR to be cleared upon reading the first DATA bit. When CAS detection is enabled via the CB1 and CB2 pins this pin is the Delayed Steering output. It goes low to indicate that a time qualified CAS has been detected. EST CAS Detection Early Steering (CMOS Output). Active high. This pin is the raw CAS detection output. It goes high to indicate the presence of a signal meeting the CAS accept frequencies and signal level. It is used in conjunction with the ST/GT pin and external components to time qualify the detection to determine whether the signal is a real CAS. ST/GT CAS Detection Steering/Guard Time (CMOS Output/Analog Input). It is used in conjunction with the EST pin and external components to time qualify the detection to determine whether the signal is a real CAS. A voltage greater than VTGt at this pin causes the MT88E45B to indicate that a CAS has been detected by asserting the DR/STD pin low. A voltage less than VTGt frees up the MT88E45B to accept a new CAS and returns DR/STD to high. 14 CD Carrier Detect (CMOS Output). Active low. A logic low indicates that an FSK signal is present. A time hysteresis is provided to allow for momentary signal discontinuity. The demodulated FSK data is ignored by the MT88E45B until carrier detect has been activated. 15 Vdd Positive power supply. 16 CB1 Control Bit 1 (CMOS Input). Together with CB2 this pin selects the MT88E45B’s functionality between FSK demodulation, Tip/Ring CAS detection and Hybrid CAS detection. When CB0 is high and CB1, CB2 are both low the MT88E45B is put into a power down state consuming minimal power supply current. See Tables 1 and 2. 17 CB2 Control Bit 2 (CMOS Input). Together with CB1 this pin selects the MT88E45B’s functionality between FSK demodulation, Tip/Ring CAS detection and Hybrid CAS detection. When CB0 is high and CB1, CB2 are both low the MT88E45B is put into a power down state consuming minimal power supply current. See Tables 1 and 2. 18 GS2 Hybrid Gain Select (Output). This is the output of the hybrid receive connection op-amp. The opamp should be used to connect the MT88E45B to the telephone hybrid or speech IC receive pair. The hybrid receive signal can be amplified or attenuated at GS2 via selection of the feedback resistor between GS2 and IN2-. When the CPE is off-hook CAS detection of the GS2 signal should be enabled via the CB1 and CB2 pins. See Tables 1 and 2. 19 IN2- Hybrid Op-amp Inverting (Input). 20 IN2+ Hybrid Op-amp Non-Inverting (Input). 4 Zarlink Semiconductor Inc. MT88E45 CB0 CB1 CB2 FSK Interface Data Sheet Function 0/1 1 1 Set by CB0 FSK Demodulation. Tip/Ring input (GS1) selected. DR/STD is DR. 0/1 1 0 Set by CB0 Hybrid CAS Detection. Hybrid Receive input (GS2) selected. DR/STD is STD. 0/1 0 1 Set by CB0 Tip/Ring CAS Detection. Tip/Ring input (GS1) selected. DR/STD is STD. When the line is off-hook, a Bellcore/TIA Multiple Extension Interworking (MEI) compatible Type 2 CPE should be able to detect CAS from Tip/Ring while the CPE is on-hook because it may be the ACK sender. Tip/Ring CAS detection is also required for BT’s on-hook CLIP. 1 0 0 Mode 1 Power Down. The MT88E45B is disabled and draws virtually no power supply current. 0 0 0 Mode 0 Reserved for factory testing. Table 1 - CB0/1/2 Functionality The number of control bits (CB) required to interface the MT88E45B with the microcontroller depends on the functionality of the application, as shown in Table 2. Functionality Group Controls Description FSK (mode 0 or 1) and Hybrid CAS only (Non MEI compatible) CB2 CB0 is hardwired to Vdd or Vss to select the FSK interface. CB1 hardwired to Vdd. The microcontroller uses CB2 to select between the 2 functions. FSK (mode 0 or 1), Hybrid CAS, Tip/Ring CAS (MEI compatible or BT on-hook CLIP) CB1 CB2 CB0 is hardwired to Vdd or Vss to select the FSK interface. The microcontroller uses CB1 and CB2 to select between the 3 functions. FSK (mode 1), Hybrid CAS, Tip/Ring CAS, Power Down (MEI compatible or BT on-hook CLIP) CB1 CB2 CB0 is hardwired to Vdd to select FSK interface mode 1. The microcontroller uses CB1 and CB2 to select between the 4 functions. FSK (mode 0), Hybrid CAS, Tip/Ring CAS, Power Down (MEI compatible or BT on-hook CLIP) CB0 CB1 CB2 All 3 pins are required. Table 2 - Control Bit Functionality Groups Functional Overview The MT88E45B is compatible with FSK and FSK plus CAS (CPE Alerting Signal) based Caller ID services around the world. Caller ID is the generic name for a group of services offered by telephone operating companies whereby information about the calling party is delivered to the subscriber. In Europe and some other countries Caller ID is known as Calling Line Identity Presentation (CLIP). ETSI calls CAS ‘Dual Tone Alerting Signal’ (DT-AS), BT calls it ‘Tone Alert Signal’. Depending on the service, data delivery can occur when the line is in the on-hook or off-hook state. In most countries the data is modulated in either Bell 202 or CCITT V.23 FSK format and transmitted at 1200 baud from the serving end office to the subscriber’s terminal. Additionally in off-hook signalling, the special dual tone CAS is used 5 Zarlink Semiconductor Inc. MT88E45 Data Sheet to alert the terminal before FSK data transmission. BT uses CAS to alert the terminal prior to FSK in both on-hook (Idle State) and off-hook (Loop State) signalling. In North America, Caller ID uses the voiceband data transmission interface defined in the Bellcore document GR30-CORE. The terminal or CPE (Customer Premises Equipment) requirements are defined in Bellcore document SR-TSV-002476. Typical services are CND (Calling Number Delivery), CNAM (Calling Name Delivery), VMWI (Visual Message Waiting Indicator) and CIDCW (Calling Identity Delivery on Call Waiting). In Europe, Caller ID requirements are defined by ETSI. The CPE documents are ETS 300 778-1 for on-hook, ETS 300 778-2 for off-hook. The end office requirements are ETS 300 659-1 (on-hook) and ETS 300 659-2 (off-hook). ETSI has defined services such as CLIP and CLIP with Call Waiting which are similar to those of Bellcore. Some European countries produce their own national specifications. For example, in the UK BT’s standards are SIN227 and SIN242, the UK CCA (Cable Communications Association) standard is TW/P&E/312. In on-hook Caller ID, such as CND, CNAM and CLIP, the information is typically transmitted (in FSK) from the end office before the subscriber picks up the phone. There are various methods such as between the first and second rings (North America), between an abbreviated ring and the first true ring (Japan, France and Germany). On-hook Caller ID can also occur without ringing for services such as VMWI. In BT’s on-hook CLIP, the signalling begins with a line polarity reversal, followed by CAS and then FSK. Bellcore calls an on-hook capable Caller ID CPE a ‘Type 1 CPE’. In off-hook Caller ID, such as CIDCW and CLIP with Call Waiting, information about a new calling party is sent to the subscriber who is already engaged in a call. Bellcore’s method uses CAS to alert the CPE. When the CPE detects CAS and there are no off-hook extensions, the CPE should mute its transmission path and send an acknowledgment to the end office via a DTMF digit called ACK. Upon receiving ACK, the end office will send the FSK data. Bellcore calls an off-hook capable CPE a ‘Type 2 CPE’. A Type 2 CPE is capable of off-hook and Type 1 functionalities and should ACK with a DTMF ‘D’. The ETSI and BT off-hook signalling protocols are similar to Bellcore’s but with timing and signal parametric differences. ETSI has no requirement for off-hook extension checking before ACK. One factor affecting the quality of the CIDCW service is the CPE’s CAS speech immunity. Although the end office has muted the far end party before and after it sends CAS, the near end (the end which is to receive the information) user may be still talking. Therefore the CPE must be able to detect CAS successfully in the presence of near end speech. This is called the talkdown immunity. The CPE must also be immune to imitation of CAS by speech from both ends of the connection because the CAS detector is continuously exposed to speech throughout the call. This is called the talkoff immunity. If the CPE is a telephone, one way to achieve good CAS speech immunity is to put CAS detection on the telephone hybrid or speech IC receive pair instead of on Tip and Ring. Talkdown immunity improves because the near end speech has been attenuated while the CAS level is the same as on Tip/Ring, resulting in improved signal to speech ratio. Talkoff immunity is also improved because the near end speech has been attenuated. In the Bellcore SR-TSV-002476 Issue 1 off-hook protocol, the CPE should not ACK if it detected an off-hook extension. The FSK will not be sent and the customer will not receive the Call Waiting ID. Bellcore, together with the TIA (Telecommunications Industry Association) TR41.3.1 working group, has defined a CPE capability called Multiple Extension Interworking (MEI) which overcomes this problem. In the MEI scheme, all MEI compatible CPEs must be capable of detecting CAS when the line is off-hook, even though the CPE itself may be on-hook. This is because under some conditions an on-hook CPE may become the ACK sender. Another reason for the on-hook CPE to detect CAS is to maintain synchronous call logs between on and off-hook CPEs. When CAS is received and all off-hook CPEs are MEI compatible, one of the CPEs will ACK and all compatible CPEs will receive FSK. A problem arises in a CPE where the CAS detector is connected only to the hybrid or speech IC receive pair: it cannot detect CAS when it is on-hook. The reason is that when the CPE is on-hook either the hybrid/speech IC is non functional or the signal level is severely attenuated. Therefore an on-hook Type 2 CPE must be capable of 6 Zarlink Semiconductor Inc. MT88E45 Data Sheet detecting CAS from Tip/Ring, in addition to detecting CAS from the hybrid/speech IC receive signal when it is offhook. The MT88E45B offers an optimal solution which combines good speech immunity and MEI compatibility. Two input op-amps allow the MT88E45B to be connected both to Tip/Ring and to the hybrid/speech IC receive pair. Both connections can be differential or single ended. FSK demodulation is always on the Tip/Ring signal. CAS detection can be from the Tip/Ring or hybrid/speech IC receive signal. Being able to detect CAS on Tip/Ring also makes the MT88E45B suitable for BT on-hook CLIP applications. For applications such as those in most European countries where Tip/Ring CAS detection is not needed, then the Tip/Ring and Hybrid op-amp gains can be tailored independently to meet country specific FSK and CAS signal level requirements respectively. Note that since the Hybrid op-amp is for CAS detection only, its gain can always be tailored specifically for the CAS signal level. The FSK demodulator is compatible with Bellcore, ETSI and BT standards. The demodulated FSK data is either output directly (bit stream mode) or stored in a one byte buffer (buffer mode). In the buffer mode, the stop bit immediately following a byte is also stored and can be shifted out after the data byte. This facility allows for framing error checking required in Type 2 CPEs. In the bit stream mode, two timing signals are provided. One indicates the bit sampling instants of the data byte, the other the end of byte. A carrier detector indicates presence of signal and shuts off the data stream when there is no signal. The entire chip can be put into a virtually zero current power down mode. The input op-amps, FSK demodulator, CAS detector and the oscillator are all shut off. Furthermore, power management has been incorporated to minimize operating current. When FSK is selected the CAS detector is powered down. When CAS is selected the FSK demodulator is powered down. Functional Description 3 to 5 V Operation The MT88E45B’s FSK and CAS reject levels are proportional to Vdd. When operated at Vdd equal 3 V +/- 10%, to keep the FSK and CAS reject levels as at 5 V (nominal) the Tip/Ring and Hybrid op-amp gains should be reduced from those of 5 V. Gains for nominal Vdd (with a +/- 10% variation) other than 3 or 5 V can be chosen as interpolation between the 3 and 5 V settings. Input Configuration The MT88E45B provides an input arrangement comprised of two op-amps and a bias source (VREF). VREF is a low impedance voltage source which is used to bias the op-amp inputs at Vdd/2. The Tip/Ring op-amp (IN1+, IN1-, GS1 pins) is for connecting to Tip and Ring. The Hybrid op-amp (IN2+, IN2-, GS2 pins) is for connecting to the telephone hybrid or speech IC receive pair. Either FSK or CAS detection can be selected for the Tip/Ring connection, while the hybrid connection is for CAS detection only. Phrased in another way, FSK demodulation is always on Tip/Ring, while CAS detection can be on Tip/Ring or Hybrid Receive. Tip/Ring CAS detection is required for MEI and BT on-hook CLIP, while Hybrid CAS detection is needed for optimal CAS speech immunity. The feedback resistor connected between GS1 and IN1- can be used to adjust the Tip/Ring signal gain. The feedback resistor connected between GS2 and IN2- can be used to adjust the hybrid receive signal gain. When the Tip/Ring op-amp is selected, the GS2 signal is ignored. When the Hybrid op-amp is selected, the GS1 signal is ignored. Either or both op-amps can be configured in the single ended input configuration shown in Figure 33, or in the differential input configuration shown in Figure 44. 7 Zarlink Semiconductor Inc. MT88E45 Data Sheet IN+ C IN- RIN Voltage Gain (AV) = RF / RIN Highpass Corner Frequency f-3dB = 1/(2πRINC) GS RF VREF Figure 3 - Single Ended Input Configuration C1 R1 IN+ IN- C2 R4 R5 GS R2 R3 VREF Differential Input Amplifier C1 = C2 R1 = R4 (For unity gain R5= R4) R3 = (R2R5) / (R2 + R5) Voltage Gain Highpass Corner Frequency (AVdiff) = R5/R1 f-3dB = 1/(2πR1C1) Input Impedance (ZINdiff) = 2 R12 + (1/ωC)2 Figure 4 - Differential Input Configuration CAS Detection In North America, CAS is used in off-hook signalling only. In Europe (ETSI) it is used in off-hook signalling, and by BT in both on and off-hook signalling. ETSI calls it the Dual Tone Alerting Signal (DT-AS). Although the ETSI onhook standard contains a DT-AS specification, BT is the only administration known to employ CAS in on-hook signalling. (BT calls it Tone Alert Signal.) The CAS/DT-AS characteristics are summarized in Table 3. BTc (Off-hook = ‘Loop State’) (On-hook = ‘Idle State’) Bellcorea (Off-hook only) ETSIb (Off-hook) +/-0.5% +/-0.5% Off-hook: +/-0.6% On-hook: +/-1.1% Signal Level (per tone) -14 to -32 dBmd -9.78 to -32.78 dBm (-12 to -35 dBVe) +0.22 to -37.78 dBm (-2 to -40 dBV) Reject Level (per tone) -45 dBm Maximum Twist (V2130Hz/V2750Hz) +/-6 dB 2130 Hz and 2750 Hz CAS/DT-AS Characteristics Frequency Tolerance On-hook: -43.78 dBm (-46 dBV) +/-6 dB 8 Zarlink Semiconductor Inc. +/-7 dB MT88E45 2130 Hz and 2750 Hz CAS/DT-AS Characteristics Duration Data Sheet Bellcorea (Off-hook only) ETSIb (Off-hook) 75 to 85 ms 75 to 85 ms Reject Duration Signal to Noise Ratio BTc (Off-hook = ‘Loop State’) (On-hook = ‘Idle State’) Off-hook: 80 to 85 ms On-hook: 88 to 110 ms Off-hook: