SM8224B Dual-Tone Receiver IC NIPPON PRECISION CIRCUITS INC. OVERVIEW The SM8224B is a receiver and decoder that supports the Bellcore TR-NWT-000030 and SR-TSV-002476 standards calling number identification (caller ID) and call waiting dual-tone signals. It has separate caller ID signal and call waiting signal inputs, which allows the gain for each input to be adjusted independently. It is fabricated in CMOS and features a power-down function, realizing low power dissipation operation. FEATURES ■ ■ ■ ■ ■ ■ ■ ■ TR-NWT-000030 and SR-TSV-002476 standards (Bellcore) Call waiting FSK decoder High input sensitivity Independent input gain adjustment for caller ID signal and call waiting signal inputs Power-down mode Crystal oscillator circuit built-in Single supply operation:4.5 to 5.5V Molybdenum-gate CMOS process ■ ■ ■ ■ AGND 1 TIP RING TRQ GND OSCIN APPLICATIONS ■ (Top view) OSCOUT Telephones, fax machines and modems that support pre- and mid-conversation information services Adapters for pre- and mid-conversation information service functions Telephone answering machines Facsimile machines Computer peripheral equipment 20 SM8224B ■ PINOUT DT2 DTQ S0 S1 VDD CDET CR MODE TEST DOUT DT1 DTDET 10 11 STR ORDERING INFORMATION D e vice P ackag e SM8224BM 20-pin SSOP SM8224BS 20-pin SOP NIPPON PRECISION CIRCUITS—1 SM8224B PACKAGE DIMENSIONS (Unit: mm) 20-pin SSOP 1.30 ± 0.10 0.6 ± 0.15 7.90 ± 0.20 5.30 ± 0.05 0.10 ± 0.10 1.80 ± 0.10 2.10 max 0.20 ± 0.05 0.62 typ 7.40 max 7.20 ± 0.05 0 to 8 0.65 0.68 ± 0.12 0.10 0.30 ± 0.10 0.13 M 20-pin SOP 0.275 ± 0.045 0.76 ± 0.25 0.51 ± 0.2 45 10.31 ± 0.20 7.50 ± 0.10 12.75 ± 0.10 0.41 ± 0.05 2.34 ± 0.10 1.27 0.20 ± 0.10 0 to 8 NIPPON PRECISION CIRCUITS—2 SM8224B BLOCK DIAGRAM TIP Filter RING FSK Demodulator Output Circuit DOUT TRQ Carrier Detector DT1 CDET DT2 Filter (2130Hz) DTQ Detector Circuit (2130Hz) Level Detector Filter Time-constant Circuit AGND Bias Circuit Filter (2750Hz) Detector Circuit (2750Hz) STR CR DTDET Level Detector Crystal Oscillator Circuit OSCIN OSCOUT Power-down Circuit MODE S1 S0 VDD GND NIPPON PRECISION CIRCUITS—3 SM8224B PIN DESCRIPTION Number Name I/O Function 1 AG N D O Analog ground output. Internal reference voltage (V D D /2) output level 2 TIP I Tip input. Connected to the telephone line through a protection circuit 3 RING I Ring input. Connected to the telephone line through a protection circuit 4 TRQ O Input-stage amplifier gain-select output. Used to adjust the gain of the input-stage amplifier. 5 GND – Ground. Connected to the system ground potential. 6 OSCIN I Cr ystal oscillator input. The crystal oscillator element is connected between this pin and OSCOUT. 7 OSCOUT O Cr ystal oscillator output. The crystal oscillator element is connected between this pin and OSCIN. 8 MODE I When MODE is HIGH, and S1 and S0 are both LOW , the device is in pow er-down state. See table 2. 9 TEST – TEST pin. Set OPEN when nor mal using. 10 DOUT O Data output. Demodulated FSK signal output. HIGH level output when C D E T goes HIGH. 11 STR O Dual-tone confirmation output. Function is selected by S0 and S1. See table 2. Dual-tone confirmation: Active-LOW output when dual tone detection signal passes through RC time constant delay circuit. 12 DTDET O Dual-tone detector output. HIGH-level output when dual tone is detected. 13 CR I/O Dual tone RC time constant circuit connection. The dual tone detection signal passes through the RC network to generate the S T R signal. 14 CDET O FSK signal carrier detector output. LOW -level when active carrier is detected. 15 VDD – Supply 16 S1 I Function select bit 1. Selects the device mode in combination with S0 and MODE. See table 2. 17 S0 I Function select bit 1. Selects the device mode in combination with S1 and MODE. See table 2. 18 DTQ O Dual-tone signal input-stage amplifier output. Used to adjust the gain of the input-stage amplifier. 19 DT2 I Dual-tone signal input-stage operational amplifier inverting input 20 DT1 I Dual-tone signal input-stage operational amplifier non-inverting input NIPPON PRECISION CIRCUITS—4 SM8224B SPECIFICATIONS Absolute Maximum Ratings GND = 0V P arameter Symbol Condition Rating Unit Supply voltage range VDD − 0.5 to 7.0 V Input voltage range V IN − 0.3 to V D D + 0.3 V Pow er dissipation PD 44 mW Storage temperature range T stg −40 to 125 °C Recommended Operating Conditions GND = 0V Rating P arameter Symbol Condition Unit min typ max Supply voltage VDD 4.5 – 5.5 V Clock frequency fC L K – 3.579545 – MHz Clock frequency accuracy ∆f C −0.1 – +0.1 % Operating temperature T opr −20 – 85 °C Electrical Characteristics VDD = 5.0V ± 0.5V, GND = 0V, fCLK = 3.579545MHz, Ta = −20 to 85°C unless otherwise noted. Rating P arameter Symbol Condition Unit min typ max Supply current consumption ID D No analog signal input, no output load, S1 = 0V, S0 = V D D , MODE = 0V – – 8.0 mA Pow er-down current ID P D No analog signal input, other inputs = V D D or 0V, no output load, S1 = 0V, S0 = 0V, MODE = V D D – – 15 µA MODE, S0, S1 LOW -level input voltage V IL1 – – 0.3V D D V MODE, S0, S1 HIGH-level input voltage V IH1 0.7V D D – – V O S C I N L OW -level input voltage V IL2 – – 0.3V D D V OSCIN HIGH-level input voltage V IH2 0.7V D D – – V D O U T, S T R , DTDET, CR, C D E T L O W -level output current IO L 2 – – mA D O U T, S T R , DTDET, CR, C D E T HIGH-level output current IO H – – −0.8 mA TIP, RING, DT1, DT2, MODE, S1, S0 input leakage current IIN −1 – 1 µA NIPPON PRECISION CIRCUITS—5 SM8224B AC Electrical Characteristics Measurement conditions: R1 = 430kΩ, R2 = 34kΩ, R3 = 390kΩ, C1= 0.22µF FSK decoder VDD = 5.0V ± 0.5V, GND = 0V, fCLK = 3.579545MHz, Ta = −20 to 85°C unless otherwise noted. Rating P arameter Symbol Condition Unit min typ max – −43 CDON dBm FSKSNR 20 – – dB Carrier detection sensitivity CDON – −43 −37.78 dBm Carrier non-detection sensitivity C DOFF −50 −46 – dBm fC L K typ − 0.1% 3.579545 typ + 0.1% MHz Input sensitivity S/N ratio 1 Oscillator frequency 1. M a r k signal and SPA CE signal are same level. Noise: Random noise from 200Hz to 3400Hz. Dual tone detector VDD = 5.0V ± 0.5V, GND = 0V, fCLK = 3.579545MHz, Ta = −20 to 85°C unless otherwise noted. Rating P arameter Symbol Condition Unit min typ max Frequency (low frequency) fL – 2130 – Hz Frequency (high frequency) fH – 2750 – Hz Detection frequency deviation 1.1 – – % Non-detection frequency deviation 3.5 – – % −37.78 – – dBm Non-detection sensitivity – – −43.78 dBm Signal level deviation – – 6 dB Detection sensitivity Note: (S0, S1, MODE) = (V D D , 0V, 0V) Input-stage amplifier Characteristics VDD = 5.0V ± 0.5V, GND = 0V, fCLK = 3.579545MHz, Ta = −20 to 85°C unless otherwise noted. Rating P arameter Symbol Condition Unit min typ max IIN – – 1 µA G OL 30 – – dB Unity gain frequency fC 80 – – kHz Load capacitance CL – – 100 pF Load resistance RL 50 – – kΩ Input leakage current DC open-loop voltage gain NIPPON PRECISION CIRCUITS—6 SM8224B Timing Characteristics FSK decoder VDD = 5.0V ± 0.5V, GND = 0V, fCLK = 3.579545MHz, Ta = −20 to 85°C unless otherwise noted. Rating P arameter Symbol Condition Unit min typ max Pow er-down release to start-up time tD O S C – 5 – ms Carrier detection ON time tD A Q 2.5 – 10 ms Final data to carrier detection OFF time tD C H 3 – 15 ms Output timing) VDD = 5.0V ± 0.5V, GND = 0V, fCLK = 3.579545MHz, Ta = −20 to 85°C, FSK input data = 1200 ± 12 baud unless otherwise noted. Rating P arameter Symbol Condition Unit min typ max S T R , DOUT rise time tr0 – – 200 ns S T R , DOUT fall time tf0 – – 200 ns – – 5 ms 1188 1200 1212 baud Input/output delay DOUT data rate tI D D Input to DOUT NIPPON PRECISION CIRCUITS—7 SM8224B TIMING DIAGRAMS FSK demodulator timing 1st Ring 2nd Ring L1/L2 101010... 1 Data PDWN CDET tDCH tDAQ DOUT 101010...1 Data OSCOUT tDOSC P D WN is an internal signal (set by S0, S1, MODE) Output timing DOUT 90% DOUT 10% tr0 tf0 STR 90% STR 10% tf0 tr0 STOP START STOP START Data timing TIP/RING b6 b7 1 0 b0 b1 b2 b3 b4 b5 b6 b7 1 0 b0 b1 b2 b3 b4 b5 b6 tIDD START DOUT b4 b5 b6 b7 b0 b1 b2 b3 b4 b5 b6 b7 b0 b1 b2 b3 b4 STOP NIPPON PRECISION CIRCUITS—8 SM8224B FUNCTIONAL DESCRIPTION The SM8224B receiver with caller ID service conforms to the Bellcore standards. It incorporates FSK demodulator and dual-tone detection functions in a single chip. It has a dedicated dual-tone signal input so that the FSK signal input amplification and dual- tone signal input amplification can be set independently. This allows systems can be easily constructed that provide pre- and mid-conversation information services. FSK Demodulator Calling number identification service is sent as an FSK signal, and the SM8224B FSK demodulator processes this signal. The FSK signal conforms to the following Bellcore standard. Table 1. FSK signal P arameter Modulation type Description Continuous-phase binar y frequency-shiftkeying Logic “1” data (mark) 1200 ± 12 Hz Logic “0” data (space) 2200 ± 22 Hz Signal level (mark) −32 to −1 2 d B m Signal level (space) −36 to −1 2 d B m Data transfer rate 1200 ± 12 baud Table 2. Function select S1 S0 MODE Function STR LOW LOW HIGH Pow er-dow n HIGH LOW LOW Dual-tone detection from DT1/DT2 1 L O W (dual tone confirmation) L O W (dual tone confirmation) HIGH LOW HIGH LOW FSK and dual-tone detection from TIP/RING HIGH HIGH LOW FSK detection from TIP/RING LOW LOW LOW Test HIGH mode 2 1. DT1, DT2, DTQ are active in this mode only. 2. Test mode should not be used. Note: S1, S0, MODE setting should be used from above combination except Test mode. Dual Tone Detector When using mid-conversation information services, 2 mixed signals of 2130Hz and 2750Hz are sent on lines L1 and L2. The SM8224B detects the 2 signals from the background noise. It uses 2 separate highorder filters with center frequencies of 2130Hz and 2750Hz to detect the presence of the signal frequencies. In series with the filters are level detectors. When the input level exceeds the preset rating, the signal is detected. When the input level is below the rating, the signal is not detected. If both the 2130Hz and 2750Hz signals are simultaneously detected, DTDET goes HIGH and starts charging the time constant circuit comprised by an external capacitor and external resistor. When the time constant circuit voltage rises above a fixed voltage level, STR signal goes LOW to indicate dual tone detection. NIPPON PRECISION CIRCUITS—9 SM8224B TYPICAL APPLICATION CIRCUIT Speech Network Circuit R6 1% C2 5% C2 5% R6 1% R8 1% R9 1% VDD Protection Circuit R1 1% R2 1% R4 1% L1 C1 5% VDD R5 1% R3 1% L2 C1 5% R1 1% R2 1% AGND DT1 TIP DT2 RING DTQ TRQ S0 GND S1 OSCIN 0.1µF 20% R7 1% VDD VDD OSCOUT CDET MODE TEST DOUT CR DTDET 0.1µF 20% STR Note : Please set this capacitor nearby IC pin. Symbol Rating 1 Unit R1 330 kΩ R2 27 kΩ R3 220 kΩ C1 0.001 µF R4 47.5 kΩ R5 60.4 kΩ R6 430 + 34 kΩ R7 390 kΩ C2 0.22 µF R8 52.3 kΩ R9 60.4 kΩ 1. Circuit values are preliminary. NIPPON PRECISION CIRCUITS—10 SM8224B NIPPON PRECISION CIRCUITS INC. reserves the right to make changes to the products described in this data sheet in order to improve the design or performance and to supply the best possible products. Nippon Precision Circuits Inc. assumes no responsibility fo r the use of any circuits shown in this data sheet, conveys no license under any patent or other rights, and makes no claim that the circuits are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Nippon Precision Circuits Inc. makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification. The products described in this data sheet are not intended to use for the apparatus which influence human lives due to the failure or malfunction of the products. Customers are requested to comply with applicable laws and regulations in effect now and hereinafter, including compliance with expor t controls on the distribution or dissemination of the products. Customers shall not expor t, directly or indirectly, any products without first obtaining required licenses and approvals from appropriate government agencies. NIPPON PRECISION CIRCUITS INC. NIPPON PRECISION CIRCUITS INC. 4-3, Fukuzumi 2-chome Koto-ku, Tokyo 135-8430, Japan Telephone: 03-3642-6661 Facsimile: 03-3642-6698 NC9910AE 2000.02 NIPPON PRECISION CIRCUITS—11