CML FX118DW Duplex frequency inverter for cordless telephone Datasheet

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
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