CMX991/CMX9920 pages

CML Microcircuits
COMMUNICA
TION SEMICONDUCTORS

CMX991/CMX992
RF Quadrature Transmitter and
RF Quadrature/Low IF Receiver

D/991_992/20 February 2015

Provisional Issue

This document describes two separate, high performance, RF ICs covering the range: 100MHz1 to 1GHz.
The CMX991 is an RF Quadrature Transceiver and the CMX992 is an RF Quadrature Receiver.

Features

Applications

1

Rx (CMX991 and CMX992)
o RF mixer with output select
o 1st IF input select
o Selectable low IF outputs
(450kHz/455kHz)
o 1st IF Variable Gain Amplifier (VGA)
o 1st IF Signal Level Indicator (SLI)
o Two-mode demodulator
o I/Q Zero-IF with differential outputs
Tx (CMX991 only)
o I/Q modulator to IF
o Image-reject up-converter
o IF and RF outputs
IF (CMX991 and CMX992)
o IF LO synthesiser
o IF VCO negative resistance amplifier
3.3V low power operation

Analogue/digital multimode radio
Software Defined Radio (SDR)
Portable, mobile and base station terminals
Data telemetry modems
TETRA (CMX992)
ETSI: EN 300 113, EN 301 166, EN 302 561,
EN 300 220, TS 102 361 (DMR)
Automatic Identification System (AIS)
transponders
Constant envelope and linear modulation
Compatible with CMX998 (CMX992 only)
Narrowband: e.g. 25kHz, 12.5kHz, 6.25kHz
Wideband: up to 2MHz
APCO Project 25 (P25) Phase 1 and Phase 2
TDMA: TIA-102.CAAB
Satellite communications

Brief Description

The CMX991 is a single-chip, high performance, RF transceiver that provides the core functions required
to implement a full-featured radio transmitter and receiver. It operates from 100MHz to 1GHz and its I/Q
architecture supports multiple modulation types and bandwidths with a single radio design. The half-duplex
CMX991 integrates Tx modulators, Rx demodulators, IF PLL and IF VCO subsystems to minimise the
external circuits needed when implementing a complete transceiver. User-selected modes suit different
application requirements.
The Tx path includes an I/Q modulator to accurately generate modulation at the IF frequency, which may
then be translated to the final RF frequency by an integrated image-reject up-converter system. The I/Q
modulator IF output is also made available for conversion to RF via external circuits, if desired.
st

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The Rx path includes an integrated 1 Rx mixer having two outputs to support two external 1 IF filter
choices, then an integrated 2:1 input mux followed by VGA and wideband signal level measurement
st
functions, to support AGC implementation. The 1 IF signal is then either I/Q demodulated to Zero-IF or
mixed to a Low IF output. The CMX991 provides differential and single-ended Rx output options and
differential amplifiers for flexible signal conditioning.
The CMX992 is a single-chip, high performance, RF receiver that includes the core RF and IF receive
functions of the CMX991 above and can be used in a wide range of narrowband and wideband wireless
products, including multi-mode analogue/digital terminals.
The CMX992 can be used where highly linear modulations are being used, e.g. for applications such as
TETRA, where a typical transmitter solution would include the CMX998 Cartesian Feedback Transmitter.
Both devices operate from a single 3.3V supply over a temperature range of -40°C to +85°C and are
available in 48-pin VQFN (Q3) packages.
1 The CMX991/CMX992 may be used at lower frequencies by using appropriate external components. Use below 100MHz is
covered in a separate application note available from the CML website.

2015 CML Microsystems Plc