MX105ADW

DATA BULLETIN MX105A • • • • • • • FEATURES Operates in High Noise Conditions ≥36 dB Signal Input Range High Sensitivity Low Power Operation 2.7 V to 5.5 V Adjustable Bandwidth Adjustable Frequency • • Tone Detector PRELIMINARY INFORMATION APPLICATIONS Single and Multitone System Applications C4 R2 4 2 Tone In C5 R3 3 Input Amp - 1 VDD 16 VDD/2 C6 + C3A C2A 7 8 Loop Filter -+ Detect Filter Timing Logic -+ 5 6 C2B C3B 11 R4 12 13 VCO 15 14 Detect Counter MX105A 9 10 C1B R1 C1A RL Detect Out The MX105A is a monolithic CMOS tone detector for tone decoding in single and multitone signaling systems. Using phase locked loop (PLL) decoding techniques, the MX105A recognizes tones in the presence of high noise levels and strong adjacent channel tones. Detection frequency and bandwidth can each be independently adjusted. The design is immune to high levels of harmonic and sub-harmonic noise. It also maintains excellent noise immunity and constant bandwidth over a wide range of input signal levels. The MX105A requires a voltage supply of 2.7V to 5.5V and is available in the following package styles: 16-pin SOIC (MX105ADW), 16-pin PDIP (MX105AP), and 24-pin PLCC (MX105ALH). © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 2 MX105A PRELIMINARY INFORMATION CONTENTS Section.......................................................................................................................... Page 1. Block Diagram ................................................................................................................3 2. Signal List .......................................................................................................................4 3. External Components ....................................................................................................5 4. General Description .......................................................................................................6 5. Application ......................................................................................................................7 5.1 Method for Calculating External Component Values...............................................................7 5.2 Define f0 ..................................................................................................................................7 5.3 Calculate Minimum Usable Bandwidth....................................................................................7 5.4 Calculate The Recommended Operating Bandwidth ..............................................................7 5.5 Select R4 for Operating BW ....................................................................................................8 5.6 Calculate R2×C2A ...................................................................................................................8 5.7 Define Maximum Allowed Response Time..............................................................................8 5.8 Calculate R3×C3A ...................................................................................................................8 5.9 Calculate Maximum De-response Time ..................................................................................9 5.10 Calculate Signal to Noise Performance...............................................................................10 5.11 Calculate C4 for 30° Phase Shift.........................................................................................10 6. Performance Specification ..........................................................................................11 6.1 Electrical Performance ..........................................................................................................11 6.1.1 Absolute Maximum Ratings ..........................................................................................................11 6.1.2 Operating Limits............................................................................................................................11 6.1.3 Operating Characteristics .............................................................................................................12 6.2 Packaging..............................................................................................................................13 MX•COM, Inc. reserves the right to change specifications at any time and without notice. © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 3 MX105A PRELIMINARY INFORMATION 1. Block Diagram C4 R2 4 2 Tone In C5 R3 3 Input Amp + 1 VDD 16 VDD/2 C6 C2A 7 8 Loop Filter -+ Detect Filter Timing Logic -+ 5 6 C3A C2B C3B 11 R4 12 13 VCO 15 14 Detect Counter MX105A 9 10 C1B R1 C1A RL Detect Out Figure 1: Block Diagram © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 4 MX105A PRELIMINARY INFORMATION 2. Signal List Pin No. DW/P 1 2 3 4 Pin No. LH 1 3 5 6 INPUT AMP IN INPUT AMP OUT R3 R2 input output input input AC couple to this input. Nominal input impedance is 200 kΩ. Nominal output impedance is 1 kΩ. Detect filter resistor pin. PLL loop filter resistor pin. For improved performance C4 may be chosen to provide 30° of phase shift at the loop filter input. Detect filter capacitor pin A Detect filter capacitor pin B Loop filter capacitor pin A Loop filter capacitor pin B PMOS open drain output - active on detect. Ground. Bandwidth control resistor pin A Bandwidth control resistor pin B VCO capacitor B VCO capacitor A VCO discharge resistor. When potentiometer tuning is required, a series resistor is recommend to prevent possible shorting to ground. Power supply. Name Type Description 5 6 7 8 9 10 11 12 13 14 15 7 8 10 11 13 14 16 17 19 20 22 C3A C3B C2A C2B DETECT OUT VSS R4A R4B C1B C1A R1 output output output output output power input input output output input 16 24 VDD power © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 5 MX105A PRELIMINARY INFORMATION 3. External Components C5 Signal Input 1 2 R3 3 R2 4 C4 C3A C3B 7 C2A 8 C2B Detect Out Figure 2: Recommended External Components R1F R1V R2 R3 R4 RL C1A C1B See Section 5.2 See Section 5.2 See Section 5.6 See Section 5.8 See Section 5.5 Note 4 See Section 5.2 Note 2 See Section 5.2 Note 2 20kΩ ±20% 300kΩ 100kΩ C2A C2B C3A C3B C4 C5 C6 D1 See Section 5.9 Note 3 See section 5.6 Note 2 See Section 5.6 Note 2 See Section 5.8 Note 2 See Section 5.8 Note 2 See Section 5.11 Note 1, 2 0.27µF 0.1µF ±20% ±20% VDD 16 R1F 15 C1A 14 C1B 13 R1V C6 MX105A 5 D1 6 11 10 9 12 R4 VSS RL small signal diode (1N914) External Components Notes: 1. For improved performance, C4 may be chosen to provide 30° phase shift at the VCO loop filter input. 2. For compatibility with the MX105; capacitors (C1 - C4) may be connected to VDD instead of VSS. 3. For improved de-response time, a diode (D1) may be added. 4. Any value load resistance (RL) may be used, providing the maximum load current does not exceed the value given in ‘Maximum Ratings Specifications’. © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 6 MX105A PRELIMINARY INFORMATION 4. General Description The MX105A implements a frequency detector with a phase locked loop (PLL) and a lock detector. The voltage controlled oscillator (VCO) center frequency, detection bandwidth, loop filter, and detect filter are all independently controlled by external components. The MX105A provides a pair of pseudo-sinewave multipliers for splitting the input signal into approximately orthogonal components. These multipliers are implemented with commutating filters (cyclically sampling filters) which translate an in band AC input signal to DC. The commutating loop filter is used as the phase detector of the PLL while the commutating detect filter provides for lock detection. Each pseudo-sinewave has a cyclic form (1 1 0 -1 -1 0) to eliminate low order harmonic responses. The loop filter produces an error signal, which when applied to the VCO input allows frequency locking. A limiter between the loop filter output and the VCO input provides tunable control of the detection bandwidth (BW). Once lock is achieved the detect filter produces a DC value proportional to the input tone amplitude. An internally generated reference is compared to the detect filter output to determine whether the PLL is locked to an input tone. Once lock is determined the internal reference is reduced by 50% to minimize output chatter with marginal input signals. The sampling clocks of the detect filter lag those of the loop filter by 60°. To improve performance, a capacitor (C4) can be used to phase shift the input to the loop filter by 30°. This shifts all sampling clocks an additional 30° relative to the input tone to phase align the detect filter sampling clocks with the amplitude peaks of the input tone. Figure 3 shows the sampling clocks relative to an in band input tone; this figure represents the steady state ‘locked’ condition without C4. Internal Clock Segment 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 Input Tone Logic 1 indicates sampling period C2B C2A C3A C3B Figure 3: Sampling Clocks of Commutating Filters © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 7 MX105A PRELIMINARY INFORMATION 5. Application The external components shown in Figure 2 are used to adjust the various performance parameters of the MX105A. The signal-to-noise performance, response time and signal bandwidth are all interrelated factors which should be optimized to meet the requirements of the application. By selecting component values in accordance with the following formulas, optimum circuit performance is obtained for any given application. First define the following application parameters: A. The center frequency to be detected (f0). B. The MX105A Minimum Usable Bandwidth (MUBW). This is obtained by taking into account the worst case tolerances on the input tone frequency and variations in the MX105A f 0 due to supply voltage and any temperature effect of the MX105A and its supporting components. C. The maximum permissible MX105A response time. D. The minimum input signal amplitude. Note: Using this information the appropriate component values can be calculated, and the signal-to-noise performance can be read from a chart. Do not add large safety margins for response time and minimum signal amplitude; reasonable margins are already included in the formulas. Excessive margins may result in reduced noise immunity. 5.1 Method for Calculating External Component Values The examples on the following pages demonstrate the calculation of component values for any given application. For the purpose of the examples, the values below are used: A. f0 = 2800 Hz B. ∆TEMP = 100 °C, ∆ VDD = 1V, ∆fIN = 0.5% C. Maximum allowed response time = 50ms D. Minimum input signal amplitude = 200 mVRMS. 5.2 Define f0 The components R1, C1A and C1B set the free running frequency of the VCO and therefore the f0 of the MX105A. As shown below, the frequency of 2800 Hz corresponds to a capacitor value of 220pF and a resistor value of 385 kΩ. This resistance can be achieved with a 300 kΩ fixed resistor for R1F and for R1V a 100 kΩ potentiometer. The capacitance of C1A and C1B should include 10-20pF parasitic capacitance due to the device and its package plus any board parasitic capacitance. f0 = 1 1 ⇒ R1 × C1A = K ⋅ R1(C1A + C1B ) 2Kf 0 where : K R1 = = 2.1 ± 5% (R1F + R1V) 5.3 Calculate Minimum Usable Bandwidth Minimum Usable Bandwidth (MUBW) is the TOTAL bandwidth required for the following: A. Input signal frequency tolerance B. MX105A f0 temperature coefficient (TC = 100 ppm/°C) C. MX105A f0 supply voltage coefficient (VC = 5000 ppm/V) Note: Add A, B and C and express as TOTAL bandwidth, not as a ± percentage (%) value. MUBW = ∆f 0 + T C ∆TEMP + V C ∆V MUBW = 0.5 + 0.01 × 100 + 0.5 × 1 = 2% 5.4 Calculate The Recommended Operating Bandwidth BW = 10 + MUBW 10 + 2 = = 6% 2 2 © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 8 MX105A PRELIMINARY INFORMATION 5.5 Select R4 for Operating BW R4 = 4.8 × BW 4.8 × 6 = ≈ 6.8kΩ 10.35 − BW 10.35 − 6 The exact bandwidth given by any value of R4 will vary slightly. In applications where an exact bandwidth is required, R4 should be a variable resistor to permit adjustment. 5.6 Calculate R2×C2A R2 × C2 A ≈ 100 3 × f0 × BW For a frequency of 2800 Hz, a bandwidth of 6%, and a choice of C2 A = 0.01µF ⇒ R V = 200kΩ . Note: Use nearest preferred values. 5.7 Define Maximum Allowed Response Time The maximum response time (TON) is the sum of the VCO lock time (TLOCK) and the DETECT integration time (TDETECT). The MX105A’s TON must not exceed the maximum time allowed for the application, but a value lying near the maximum gives the best S/N performance. A. Calculate TLOCK TLOCK = 150 f0 × BW Using the formula above, for a frequency of 2800 Hz and a bandwidth of 6% the approximate Lock time (TLOCK) will be 9 ms. Since the maximum response time is 50 ms, a DETECT time of 41 ms is allowed. Note: TLOCK may vary from near zero to the value given, causing corresponding variations in actual T ON. B. Calculate Maximum Allowable TDETECT TDETECT = TON MAX − TLOCK C. Define Minimum Expected Signal Amplitude VINMIN This is used in calculating TDETECT components. ( ) 5.8 Calculate R3×C3A R3 × C3 A ≈ TDETECT   V −3 × ln 1 − TH   VINMIN    where: VTH is the detect filter sensitivity. Note: 1. For a signal amplitude of 200 mVRMS, a resistor value R3 of 510 kΩ with a 0.1µF capacitor for C3A and C3B will yield a TDETECT time of 20ms. This in turn yields a response time of 9ms + 20 ms = 29ms. 2. Use nearest preferred values. © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 9 MX105A PRELIMINARY INFORMATION 5.9 Calculate Maximum De-response Time  VTH TOFF ≈ −3 × ln V  INMAX   R3 × C3 A   where: VTH is the detect filter sensitivity. For improved de-response time, a diode (1N914 or similar) can be placed between pins 5 and 6, as shown in Figure 3. The formula and figure below show the approximate time the MX105A will take to turn off after an in-band signal has been removed. The effect of this diode is to greatly reduce the turn-off time with signal input amplitudes greater than 300 mVRMS. This graph is for VDD = 5V; for lower VDD KDT increases. TOFF ≈ K DT × R3 × C3 A 3.8 KDT = Number of RC Time Constants for De-response with Diode 3.6 3.4 3.2 3.0 2.8 2.6 2.4 2.2 0 80 160 240 320 400 480 560 640 720 Input Signal Level (mVRMS) Figure 4: KDT Factor for TOFF vs. Signal Input Amplitude © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 10 MX105A PRELIMINARY INFORMATION 5.10 Calculate Signal to Noise Performance Worst-case S/N calculations depend on calculation of a value “M” using the formula shown below: M= substituting example values, R3 × C3 A 3 × R2 × C2 A M= 510 × 0.1 = 8.5 3 × 200 × 0.01 By substituting this value for M in Figure 5, the minimum required S/N of an in band tone with respect to an adjacent interfering tone can be found. This then has to be increased depending on the input tone amplitude. -28 -24 -20 -16 M=∞ M=1 M = 0.33 M = 0.1 -12 -8 -4 0 6 8 10 12 4 Number of Bandwidths Separation Figure 5: S/N vs. BW Separation The following formula expresses the reduction in noise immunity as the input signal approaches the detect filter sensitivity VTH. required   VIN S S = 20log + N N Figure 5  VIN − VTH  If this S/N is better than required for the application, R3×C3A can be reduced, or the operating bandwidth can be increased to obtain a faster tone detection time. If the S/N performance is not adequate, the operating bandwidth can be reduced toward the MUBW, or R3C3A can be increased to improve S/N performance at the expense of slower response time. 5.11 Calculate C4 for 30° Phase Shift Capacitor C4 is used to phase shift the input to the VCO commutating filter by 30°, thereby shifting the sampling clocks by the same amount. This enables the Detect sampling filter to sample and integrate at the maximum and minimum of the input tone. C4 = tan(30° ) 0.092 ≈ ≈ 164pF 2π × f 0 × R V f 0 × R V © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 11 MX105A PRELIMINARY INFORMATION 6. Performance Specification 6.1 Electrical Performance 6.1.1 Absolute Maximum Ratings Exceeding these maximum ratings can result in damage to the device. General Supply (VDD - VSS) Voltage on any pin (wrt VSS) Current VDD VSS Any other pins Max. Output Switch Load Current P/LH/DW Package Device Dissipation at TAMB = 25°C Derating above 25°C Storage Temperature Operating Temperature 6.1.2 Operating Limits Correct operation of the device outside these limits is not implied. Notes Supply (VDD - VSS) Operating Temperature Min. 2.7 -30 Typ. 3.3/5.0 Max. 5.5 85 Units V °C -40 -30 800 13 85 85 mW mW/°C above 25°C °C °C -30 -30 -20 30 30 20 10 mA mA mA mA Min. -0.3 -0.3 Max. 7.0 VDD + 0.3 Units V V © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 12 MX105A PRELIMINARY INFORMATION 6.1.3 Operating Characteristics For the following conditions unless otherwise specified: VDD = 5.0 V @ TAMB = 25°C Load resistance on decoder output = 20kΩ. Notes Static Parameters IDD Amplifier Input Impedance Digital Output Impedance Analog Output Impedance Dynamic Parameters Input Signal Frequency Lowest Must Detect Level Highest Will Not Detect Level Highest Will Not Detect f0/2 Highest Will Not Detect 5(f0) VCO Frequency Frequency Stability BW Limiter BW Range Amplifier Open Loop Gain GBWP Closed Loop Gain Detect Commutating Filter Sensitivity (VTH) Operating Characteristics Notes: 1. Multiply by VDD /5V for other supply values. 2. The reference level is VTH. The following formula converts dB to mVRMS. 1 25 mVRMS 60 1.0 0 dB MHz dB 2 10 %f0 3 120 100 5000 120,000 Hz ppm/°C ppm/V 1 1 1, 2 1, 2 40 30 20 30 790 20 250 20,000 Hz mVRMS mVRMS dB mVRMS dB mVRMS 160 1.0 200 500 1000 1000 1200 mA kΩ Ω Ω Min. Typ. Max. Units mVRMS = 10 (dB/20) × VTH 3. Observing pins 13, 14, or 15 (DW/J package) will cause a frequency shift due to additional loading. If tuning center frequency by observing oscillator, design in a buffer amplifier between pin 15 and probe/calibration point and tune with no input signal. Otherwise, tune by observing detect output band edges while sweeping input signal. VCO center frequency is 6(f0) at pin 15 while it is 3(f0) at pins 13 and 14. © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 13 MX105A PRELIMINARY INFORMATION 6.2 Packaging Package Tolerances A Z B E W L PIN 1 X Y C H J P K T DIM. A B C E H J K L P T W X Y Z MIN. TYP. MAX. 0.395 (10.03) 0.413 (10.49) 0.286 (7.26) 0.299 (7.59) 0.093 (2.36) 0.105 (2.67) 0.390 (9.90) 0.419 (10.64) 0.003 (0.08) 0.020 (0.51) 0.013 (0.33) 0.020 (0.51) 0.041 (1.04) 0.016 (0.41) 0.050 (1.27) 0.050 (1.27) 0.009 (0.23) 0.0125 (0.32) 45° 0° 10° 7° 5° 5° ALTERNATIVE PIN LOCATION MARKING NOTE : All dimensions in inches (mm.) Angles are in degrees Figure 6: 16-pin SOIC Mechanical Outline: Order as part no. MX105ADW Package Tolerances DIM. A B C E E1 H J J1 K L P T Y MIN. TYP. MAX. 0.740 (18.80) 0.810 (20.57) 0.240 (6.10) 0.262 (6.63) 0.200 (5.06) 0.135 (3.43) 0.300 (7.62) 0.390 (9.91). 0.290 (7.37) 0.325 (8.26) 0.015 (0.38) 0.070 (1.77) 0.014 (0.35) 0.023 (0.58) 0.040 (1.02) 0.065 (1.65) 0.056 (1.42) 0.064 (1.63) 0.121 (3.07) 0.150 (3.81) 0.100 (2.54) 0.008 (0.20) 0.015 (0.38) 7e NOTE : All dimensions in inches (mm.) Angles are in degrees Figure 7: 16-pin PDIP Mechanical Outline: Order as part no. MX105AP © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. Tone Detector 14 MX105A PRELIMINARY INFORMATION E B Y DA W C K J W T H Package Tolerances DIM. A B C D E F G H J K P T W Y MIN. TYP. MAX. 0.380 (9.61) 0.409 (10.40) 0.380 (9.61) 0.409 (10.40) 0.128 (3.25) 0.146 (3.70) 0.417 (10.60) 0.435 (11.05) 0.417 (10.60) 0.435 (11.05) 0.250 (6.35) 0.250 (6.35) 0.023 (0.58) 0.018 (0.45) 0.022 (0.55) 0.047 (1.19) 0.048 (1.22) 0.049 (1.24) 0.051 (1.30) 0.006 (0.152) 0.009 (0.22) 45° 30° 6° PIN 1 P G F NOTE : All dimensions in inches (mm.) Angles are in degrees Figure 8: 24-pin PLCC Mechanical Outline: Order as part no. MX105ALH © 1997 MX•COM, INC. www.mxcom.com Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054 Doc.# 20480133.003 4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies. CML Microcircuits COMMUNICATION SEMICONDUCTORS CML Product Data In the process of creating a more global image, the three standard product semiconductor companies of CML Microsystems Plc (Consumer Microcircuits Limited (UK), MX-COM, Inc (USA) and CML Microcircuits (Singapore) Pte Ltd) have undergone name changes and, whilst maintaining their separate new names (CML Microcircuits (UK) Ltd, CML Microcircuits (USA) Inc and CML Microcircuits (Singapore) Pte Ltd), now operate under the single title CML Microcircuits. These companies are all 100% owned operating companies of the CML Microsystems Plc Group and these changes are purely changes of name and do not change any underlying legal entities and hence will have no effect on any agreements or contacts currently in force. CML Microcircuits Product Prefix Codes Until the latter part of 1996, the differentiator between products manufactured and sold from MXCOM, Inc. and Consumer Microcircuits Limited were denoted by the prefixes MX and FX respectively. These products use the same silicon etc. and today still carry the same prefixes. In the latter part of 1996, both companies adopted the common prefix: CMX. This notification is relevant product information to which it is attached. CML Microcircuits (USA) [formerly MX-COM, Inc.] Product Textual Marking On CML Microcircuits (USA) products, the ‘MX-COM’ textual logo is being replaced by a ‘CML’ textual logo. Company contact information is as below: CML Microcircuits (UK)Ltd COMMUNICATION SEMICONDUCTORS CML Microcircuits (USA) Inc. COMMUNICATION SEMICONDUCTORS CML Microcircuits (Singapore)PteLtd COMMUNICATION SEMICONDUCTORS Oval Park, Langford, Maldon, Essex, CM9 6WG, England Tel: +44 (0)1621 875500 Fax: +44 (0)1621 875600 uk.sales@cmlmicro.com www.cmlmicro.com 4800 Bethania Station Road, Winston-Salem, NC 27105, USA Tel: +1 336 744 5050, 0800 638 5577 Fax: +1 336 744 5054 us.sales@cmlmicro.com www.cmlmicro.com No 2 Kallang Pudding Road, 09-05/ 06 Mactech Industrial Building, Singapore 349307 Tel: +65 7450426 Fax: +65 7452917 sg.sales@cmlmicro.com www.cmlmicro.com D/CML (D)/2 May 2002