CML Semiconductor Products PRODUCT INFORMATION Duplex Frequency Inverter for Cordless Telephones FX118 Publication D/118/3 July 1994 Features/Applications Frequency Inversion Scrambling Low Power Requirement (3.0 Volt Minimum) Full-Duplex Operation High Baseband and Carrier Rejection Cordless Telephones Base and Handheld Applications Audio Lowpass and Bandpass Filtering On-Chip Input Gain Adjustment Plastic DIL and S.O.I.C. Package Styles Xtal Oscillator Stabilty C1 AMP OUT LPF(1) OUT B MOD(1) IN LPF(1) BAL MOD (1) BPF(1) C1 IN C1 OUT +0.5dB INPUT AMP -4.0dB CHANNEL 1 (C1) +4.0dB V BIAS V DD XTAL/CLOCK CLOCKS CARRIER 3.3kHz and XTAL V BIAS LOGIC FILTER CLOCKS 111kHz V BIAS INPUT AMP V SS FX118 -4.0dB CHANNEL 2 (C2) C2 OUT C2 IN +0.5dB +4.0dB LPF(2) C2 AMP OUT BAL MOD (2) LPF(2) OUT BPF(2) B MOD(2) IN Fig.1 FX118 Duplex Frequency Inverter Brief Description The FX118 is a low-power, full-duplex frequency inverter available to provide voice privacy for cordless telephone systems by mixing the incoming audio with an internally produced carrier frequency (3.3kHz). The frequency stability of the FX118 is achieved by an on-chip oscillator employing an external 4.433619MHz Xtal or clock input to produce the common carrier frequency and the sampling clocks for the switched capacitor low and bandpass filters. This chip contains two completely separate audio channels (C1 and C2) each comprising a “componentadjustable” input amplifier, a 10th-order lowpass filter, a balanced modulator and a 14th-order bandpass filter output. This microcircuit has a low power requirement of 3.0 volts (min.) and is encapsulated in either 16-pin DIL or small outline SMD (S.O.I.C.) plastic packages both of which are of a physical size suitable for either base or handset type telephone instruments as well as batteryportable and mobile communications systems. The on-chip modulation process has the properties of high baseband and carrier frequency rejection which when combined with high-order output filtering, produces a high-quality recovered voiceband audio. 1 Pin Number Function FX118DW FX118P 1 Xtal: Output of clock oscillator inverter. 2 No Internal Connection: It is recommended that, to improve noise conditions, this pin is connected to VSS. 3 LPF(1) Out: The output of the Channel 1 Lowpass Filter. It is to be coupled to “B Mod(1) In” via a 1.0µF capacitor – see Figure 2. 4 B Mod(1) In: The input to Channel 1 balanced modulator. Internally biased at VDD/2 it is to be coupled to “LPF(1)” via a 1.0µF capacitor – see Figure 2. 5 VSS: Negative supply (GND). 6 C1 Out: The analogue output of Channel 1. 7 C1 Amp Output: Channel 1 amplifier with external components (see Figure 2) can be used to provide gain in the signal path. 8 C1 In: The negative input of Channel 1 Amplifier. Recommended external components are shown in Figure 2. 9 C2 In: The negative input of Channel 2 Amplifier. Recommended external components are shown in Figure 2. 10 C2 Amp Output: Channel 2 amplifier with external components (see Figure 2) can be used to provide gain in the signal path. 11 C2 Out: The analogue output of Channel 2. 12 VBIAS: The internal analogue bias line at VDD/2. It should be decoupled to VSS via a 1.0µF or greater capacitor. See Figure 2. 13 B Mod(2) In: The input to Channel 2 balanced modulator. Internally biased at VDD/2 it is to be coupled to “LPF(2)” via a 1.0µF capacitor – see Figure 2. 14 LPF(2) Out: The output of the Channel 2 Lowpass Filter. It is to be coupled to “B Mod(2) In” via a 1.0µF capacitor – see Figure 2. 15 VDD: The positive supply rail. A single positive supply voltage (3.0v – 5.0v) is required. Levels and voltages within the Duplex Frequency Inverter are dependent upon this supply. 16 Xtal/Clock: 4.433619 MHz Xtal or externally derived clock is injected at this pin. See Figure 2. Operation of the FX118 without a Xtal or clock input may cause device damage. 2 Application Information V DD C2 C3 X1 C1 R1 XTAL LPF(1) OUT C4 B MOD(1) IN 15 3 14 4 13 XTAL/CLOCK V DD LPF(2) OUT VBIAS 12 C VSS C2 OUT 11 6 C8 B MOD(2) IN C1 AMP OUT 10 7 C1 IN 8 7 CHANNEL 2 OUTPUT R5 C2 AMP OUT CHANNEL 1 INPUT C5 2 5 C1 OUT R3 16 FX118 VSS CHANNEL 1 OUTPUT 1 CHANNEL 2 INPUT C2 IN 9 R2 R4 C6 VSS Component R1 R2 R3 C5 R4 R5 C6 C1 NOTES Value = 1.0MΩ See Note See Note 47pF C2 C3 C4 = 33pF 0.47µF 1.0µF C7 C8 X1 = 1.0µF 1.0µF 4.433619MHz Tolerances C = ±20% R = ±10% 1. Configurations R2, R3, C5 and R4, R5, C6 should be chosen with respect to the specific application. 2. Operation of any CML microcircuit without a Xtal or clock input may cause device damage. To minimise damage in the event of a Xtal/drive failure, it is recommended that the power rail (VDD) is fitted with a current limiting device (resistor or fast-reaction fuse). Fig.2 Recommended External Components Rx Channel RF AMP IF AMP BASE UNIT DETECTION FX118 DE-EMPHASIS AF AMP FM CHANNEL 1 (C1) RF AMP MODULATION HYBRID TRANSFORMER PREEMPHASIS TELEPHONE LINE AF AMP CHANNEL 2 (C2) FM Tx Channel Rx Channel RF AMP IF AMP DETECTION FX118 DE-EMPHASIS FM CHANNEL 1 (C1) RF AMP MODULATION PREEMPHASIS AF AMP CHANNEL 2 (C2) FM Tx Channel HANDHELD UNIT Fig.3 Example of the FX118 Employed in a Cordless Telephone Application 3 AF AMP Application Information ...... Gain dB +5 0 -3 Audio Input Level = 275mVrms -10 VDD = 3.75V -20 -30 -40 0.1 0.2 0.3 0.5 1.0 2.0 3.0 7.0 Frequency kHz Fig.4 Typical Audio Frequency Response of a Single Scrambled or De-scrambled Channel System Gains When calculating the external components for the operation of the FX118 the following points should be considered: (a) The Input Lowpass Filter has a (typical) gain of 0.5dB. (b) The Balanced Modulator has a (typical) attenuation of 4.0dB. (c) The Output Bandpass Filter has a (typical) gain of 4.5dB. How the Inverter Works Carrier Frequency minus Input Voice Frequency equals Scrambled Voice Frequency (1) B (2) A Lowpass Filtered Voiceband for Input to Balanced Modulator Input Voiceband Frequencies Speech Band 0 1000Hz Carrier Frequency (3300Hz) Generated On-Chip for Input to Balanced Modulator 1000 2000 2000Hz D 3000Hz B (4) (3) 0 C C A D Bandpass Filtered Voiceband Presented at the Ouput after Mixing with the Carrier Frequency in the Balanced Modulator 0 3000 3300 Fig.5 A Pictorial Explanation of the FX118 “Scramble Operation” 4 1000 2000 3000 Specification Absolute Maximum Ratings Exceeding the maximum rating can result in device damage. Operation of the device outside the operating limits is not implied. Supply voltage Input voltage at any pin (ref VSS = 0V) Sink/source current (supply pins) (other pins) Total device dissipation @ TAMB 25°C Derating -0.3 to 7.0V -0.3 to (VDD + 0.3V) +/- 30mA +/- 20mA 800mW Max. 10mW/°C Operating temperature range: FX118DW/P -40°C to +85°C Storage temperature range: FX118DW/P -40°C to +85°C Operating Limits All device characteristics are measured under the following conditions unless otherwise specified: VDD = 3.75V. TAMB = 25°C. Xtal/Clock f0 = 4.433619MHz. Audio level 0dB ref: = 388mV rms @ 1.0kHz. Characteristics See Note Static Values Supply Voltage Supply Current Input Impedance (Amplifiers) Output Impedance (LP Filters) Output Impedance (C1, C2 ) Output Impedance (C1, C2 Amps) On-Chip Xtal Oscillator RIN ROUT Inverter Gain Gain/Bandwidth Product Dynamic Values Analogue Signal Input Levels SINAD 6 Unwanted Modulation Products 1, 2 Carrier Breakthrough 1, 2 Baseband Breakthrough 1, 2 Carrier Frequency Analogue Output Noise 3 Analogue Output Noise 5 Filters Input Lowpass Filter 1 Cut-Off Frequency (-3dB) Passband Ripple (300Hz - 3kHz) Attenuation at 3.3kHz Attenuation at 3.6kHz Passband Gain Output Bandpass Filter 1, 4 Passband Frequencies Passband Ripple Low Freq. Roll-Off <200Hz High Freq. – Attenuation at 3.4kHz Passband Gain Overall Modulated and De-Modulated Channel Response Passband Frequencies (Tx and Rx Channel) Passband Ripple Low Freq. Roll-Off <250Hz High Freq. – Attenuation at 3.4kHz Passband Gain 4 Distortion 1 Min. Typ. Max. Unit 3.0 – 1.0 – – – 3.75 4.0 10.0 2.0 200 10.0 5.5 6.0 – – – – V mA MΩ kΩ Ω kΩ 10.0 – – – – 10.0 10.0 10.0 – – – – MΩ kΩ V/V MHz -16.0 – – – – – – – – 30.0 -40.0 -55.0 -40.0 3299 -42.0 -46.0 4.0 – – – – – – – dB dB dB dB dB Hz dB dBp – – – – – 3100 ±1.0 30.0 45.0 0.5 – – – – – Hz dB dB dB dB 300 – 12.0 – 3.5 – ±1.0 – 48.0 4.5 3000 – – – 5.5 Hz dB dB/oct. dB dB 300 -3.0 18.0 – – – – – – 48.0 0.5 3.0 3000 2.0 – – – – Hz dB dB/oct. dB dB % Notes: 1. 2. 3. 4. 5. 6. Measured with an audio input level of -3.0dB. With respect to a single modulated (scrambling) channel. Measured with a short circuit input, at any analogue output, in a 30.0kHz bandwidth. With Input Amplifier gain at 0dB. Measured psophometrically weighted, at any analogue output. Measured in a 30kHz bandwidth. 5 Package Outlines Handling Precautions The FX118 is available in the package styles outlined below. Mechanical package diagrams and specifications are detailed in Section 10 of this document. Pin 1 identification marking is shown on the relevant diagram and pins on all package styles number anti-clockwise when viewed from the top. The FX118 is a CMOS LSI circuit which includes input protection. However precautions should be taken to prevent static discharges which may cause damage. FX118DW 16-pin S.O.I.C. FX118P (D4) 16-pin plastic DIL (P3) NOT TO SCALE NOT TO SCALE Max. Body Length Max. Body Width Max. Body Length Max. Body Width 10.49mm 7.59mm Ordering Information FX118DW 16-pin S.O.I.C. (D4) FX118P 16-pin plastic DIL (P3) CML does not assume any responsibility for the use of any circuitry described. No circuit patent licences are implied and CML reserves the right at any time without notice to change the said circuitry. 6 20.57mm 6.60mm 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. Company contact information is as below: CML Microcircuits (UK)Ltd CML Microcircuits (USA) Inc. CML Microcircuits (Singapore)PteLtd COMMUNICATION SEMICONDUCTORS COMMUNICATION SEMICONDUCTORS COMMUNICATION SEMICONDUCTORS Oval Park, Langford, Maldon, Essex, CM9 6WG, England Tel: +44 (0)1621 875500 Fax: +44 (0)1621 875600 [email protected] 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 [email protected] www.cmlmicro.com No 2 Kallang Pudding Road, 09-05/ 06 Mactech Industrial Building, Singapore 349307 Tel: +65 7450426 Fax: +65 7452917 [email protected] www.cmlmicro.com D/CML (D)/1 February 2002