Philips Semiconductors
Product specification
DECT receiver
FEATURES
•
Single-chip RF plus IF
•
Integrated channel filter
•
Low component count
•
No production trimming
•
High dynamic range
•
Low power
•
3.2 V operation
•
Built-in power-down mode.
QUICK REFERENCE DATA
V
CC
= 3.2 V; T
amb
= 25
°C;
unless otherwise specified.
SYMBOL
V
CC
I
CC
I
CC(pd)
T
amb
PARAMETER
supply voltage
supply current
power-down mode supply current
ambient temperature
CONDITIONS
over T
amb
MIN.
3.0
−
−
−10
GENERAL DESCRIPTION
UAA3540TS
The UAA3540TS is a low-power, highly integrated circuit,
for Digital Enhanced Cordless Telecommunication (DECT)
applications.
It features a fully integrated channel selection filter, an
analog Received Signal Strength Indicator (RSSI) and a
switched demodulator output to interface to Philips
Semiconductors ABC baseband chip. The circuit can be
fully powered down during the idle locked state.
TYP.
3.2
34
10
−
MAX.
3.6
45
50
+60
UNIT
V
mA
µA
°C
ORDERING INFORMATION
TYPE
NUMBER
UAA3540TS
PACKAGE
NAME
SSOP20
DESCRIPTION
plastic shrink small outline package; 20 leads; body width 4.4 mm
VERSION
SOT266-1
2000 Feb 15
2
Philips Semiconductors
Product specification
DECT receiver
PINNING
SYMBOL
GND
(LO)
PD
V
CC(RF)
GND
(RF)
RFA
RFB
GND
(IF)
RSET
TEST1
SLCCTR
DATA−
TEST2
DATA+
TEST3
RSSI
V
CC(IF)
LOA
LOB
V
CC(LO)
TEST4
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
DESCRIPTION
local oscillator ground
power-down control input (logic 1
disables the chip)
RF positive supply voltage
RF ground
RF balanced input A
RF balanced input B
IF ground
set filter (connect to external
resistor)
test 1 (connect to GND)
slicer threshold switch control input
(logic 1 closes the switch)
switched demodulator output
test 2 (connect to GND)
demodulator digital signal output
test 3 (connect to V
CC
)
received signal strength intensity
voltage output
IF positive supply
local oscillator balanced input A
local oscillator balanced input B
local oscillator positive supply
test 4 (connect to GND)
VCC(RF) 3
GND(RF) 4
RFA 5
handbook, halfpage
UAA3540TS
GND(LO) 1
PD 2
20 TEST4
19 VCC(LO)
18 LOB
17 LOA
16 VCC(IF)
15 RSSI
14 TEST3
13 DATA
+
12 TEST2
11 DATA
−
FCA039
UAA3540TS
RFB 6
GND(IF) 7
RSET 8
TEST1 9
SLCCTR 10
Fig.2 Pin configuration.
2000 Feb 15
4
Philips Semiconductors
Product specification
DECT receiver
FUNCTIONAL DESCRIPTION
General
The UAA3540TS is a fully integrated RF plus IF strip and
demodulator for DECT applications. It provides all the
required channel filtering over the DECT band and
generates analog RSSI and a data output for the
baseband chip. Very few off-chip components are required
and should not require trimming in normal applications.
The chip is designed to operate from a power supply
voltage which can fall to 3.0 V, and features full
power-down capabilities.
The inputs are an RF antenna signal and a Local
Oscillator (LO) signal. The RF antenna signal is from a
band filter or antenna switch. The higher frequency
LO signal is from an external Voltage Controlled
Oscillator (VCO).
The outputs are an RSSI voltage, representing the
instantaneous signal strength, and DATA− and DATA+
which are two high-level demodulator output signals.
DATA− is switched by SLCCTR to generate a threshold
voltage for the internal slicer, and DATA+ is the
comparator digital output.
Filter
The integrated filter provides all the channel selectivity
required for the DECT receiver. An external resistor of
18 kΩ must be connected to RSET (pin 8).
Limiter and RSSI
UAA3540TS
The main purpose of the limiter circuit is to reduce the
dynamic range of the signals presented to the
demodulator; these have a dynamic range greater than
60 dB.
The limiter also provides the RSSI output voltage.
The RSSI output has very little filtering applied, and it is
assumed that external circuits will be used to provide the
time constant and peak holding required by the DECT
specification.
Demodulator
The demodulator produces an output voltage directly
proportional to the instantaneous frequency of the
received signal. The output stage of the demodulator
contains a data filter to remove high frequencies from the
signal, prior to data slicing.
The demodulator provides a continuous output timing
signal that is applied to an internal data slicer. The same
signal is also switched to generate the threshold voltage of
the slicer during the initial DECT bit sequence.
Power-down
The power-down control input (pin 2) allows the current
consumption of the chip to be reduced to a very low level
when it is connected to V
CC
. In this state, some voltages in
the chip become indeterminate requiring time for the
receiver to stabilize after power-up.
2000 Feb 15
5
Power technology
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