U2761B
Preliminary Information
TEMIC Semiconductor
Rev. A4, 10-Mar-98
1 (11)
DECT RF / IF IC
Description
The U2761B is an integrated circuit manufactured in
TEMIC's UHF5S technology, designed for DECT
application. It contains rejection mixer, IF amplifier,
FM demodulator, baseband filter, RSSI, TX preamplifier
and power-ramping generator for power amplifier.
Features
D Supply-voltage range 2.7 to 5.5 V
D Low current consumption
D Few external components
D On-chip baseband filter
D LO switch and TX preamplifier
D Ramp-signal generator for power amplifier
Block Diagram
MIXER_IN1
MIXER_IN2
IF amp 1
IF amp 2
IF_TANK1
IF_IN1
IF_IN2
IR mixer
IF_TANK2
Demodulator
T/R switch
Bandgap
QUAD_TANK1
QUAD_TANK2
DEMOD_OUT
VS1
VS2
TX driver
MIXER_OUT1
MIXER_OUT2
Ramp
generator
RAMP_SET
RAMP_OUT
LO_IN1
LO_IN2
Control
logic
TX_ON
RX_ON
OpAmp
+
OP_N
OP_P
TX_RF_OUT
OP_OUT
14657
Figure 1. Block diagram
Ordering Information
Extended Type Number
Package
Remarks
U2761B
SSO28
U2761B
TEMIC Semiconductor
Rev. A4, 10-Mar-98
Preliminary Information
2 (11)
Pin Description
1
2
3
4
5
6
7
8
10
9
27
22
21
20
18
19
17
12
11
28
25
26
23
24
16
15
14
13
14808
MIXER_OUT1
TX_ON
VS2
OP_OUT
OP_P
OP_N
RX_ON
DEMOD_OUT
MIXER_OUT2
QUAD_TANK2
LO_IN1
LO_IN2
GND3
QUAD_TANK1
GND2
MIXER_IN1
VS1
IF_TANK1
TX_RF_OUT
IF_TANK2
IF_IN2
IF_IN1
PU
RSSI
GND1
MIXER_IN2
RAMP_OUT
RAMP_SET
Figure 2. Pinning
Pin
Symbol
Function
1
RSSI
Received signal strength
indicator output
2
PU
Hardware power-up input
3
IF_TANK1
IF tank circuit Pin 1
4
IF_TANK2
IF tank circuit Pin 2
5
GND1
Ground
6
MIXER_IN1
Mixer RF differential
input 1
7
MIXER_IN2
Mixer RF differential
input 2
8
GND2
Ground
9
TX_RF_OUT
Output of TX driver
amplifier
10
VS1
Supply voltage input 1
11
IF_IN1
IF amplifier differential
input 1
12
IF_IN2
IF amplifier differential
input 2
13
RAMP_OUT
Ramp-signal output for PA
14
RAMP_SET
Slew-rate setting of ramp
signal
15
RX_ON
RX control input
16
TX_ON
TX control input
17
MIXER_OUT1
Mixer IF differential
output 1
18
MIXER_OUT2
Mixer IF differential
output 2
19
VS2
Supply voltage input 2
20
LO_IN1
Local oscillator input 1
21
LO_IN2
Local oscillator input 2
22
GND3
Ground
23
QUAD_TANK1
Quadrature tank circuit 1
24
QUAD_TANK2
Quadrature tank circuit 2
25
DEMOD_OUT
Output of demodulator
26
OP_N
OP Input inverting
27
OP_P
OP Input non-inverting
28
OP_OUT
OP Output
U2761B
Preliminary Information
TEMIC Semiconductor
Rev. A4, 10-Mar-98
3 (11)
Absolute Maximum Ratings
All voltages are referred to GND (Pins 5, 8 and 22)
Parameters
Symbol
Value
Unit
Supply voltage
Pins 10 and 19
V
S
6
V
Junction temperature
T
j
150
C
Storage temperature
T
stg
40 to +125
C
Thermal Resistance
Parameters
Symbol
Value
Unit
Junction ambient
R
thJA
130
K/W
Operating Range
All voltages are referred to GND (Pins 5, 8 and 22)
Parameters
Symbol
Min.
Typ.
Max.
Unit
Supply voltage
Pins 10 and 19
V
S
2.7
3.0
5.5
V
Ambient temperature
T
amb
25
+25
+85
C
Electrical Characteristics
Test conditions: V
S
= 3.0 V, T
amb
= 25
C, unless otherwise specified
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Power supply
Total supply current
TX
30
mA
pp y
RX
I
50
mA
RX (RSSI only)
I
S
47
mA
Standby, PU = GND
1
10
mA
IR mixer
Pins 6, 7, 17 and 18
Image-rejection ratio
Pins 17 and 18
IRR
20
dB
DSB noise figure
Pins 17 and 18
NFDSB=
NFSSB
10
dB
Conversion gain
R
load
= 200
W
G
conv
12
dB
Output interception point
Pins 17 and 18
OIP3
10
dBm
Input impedance
Pins 6 and 7
Z
in
50
W
Input matching
Pins 6 and 7
VSWR
in
<2:1
LO switch and TX driver
Pin 9, 20 and 21
Power gain (high)
@ P
in
= 40 dBm
G
p
30
dB
Input impedance
Pin 20 or Pin 21 to GND
Z
in
50
W
Input matching
Pins 20 and 21
VSWR
in
<2:1
Isolation LO-TX
RX mode: LO Pin 20 or
Pin 21 to Pin 9
Isol
37
dB
Output impedance
Pin 9
Z
out
100
W
Maximum output power
Pin 9
P
max
3
dBm
Gain compression
@ TX_RF_OUT
Pin 9
P
1dB
1
dBm
Output interception point
Pin 9
OIP3
10
dBm
U2761B
TEMIC Semiconductor
Rev. A4, 10-Mar-98
Preliminary Information
4 (11)
Electrical Characteristics (continued)
Test conditions: V
S
= 3.0 V, T
amb
= 25
C, unless otherwise specified
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
IF amplifier
Pins 3, 4, 11 and 12
Input impedance
Pins 11 and 12
Z
in
200
400
W
Lower cut-off frequency
fl
3dB
90
MHz
Upper cut-off frequency
fu
3dB
130
MHz
Power gain
G
p
85
dB
Bandwidth of external tank
circuit
Pins 3 and 4
BW
3dB
10
MHz
Noise figure
NF
9
dB
RSSI
Pins 1, 6 and 7
RSSI sensitivity
At IF_IN1, IF_IN2
P
min
20
dB
mV
RSSI compression
_
,
_
Pins 6 and 7
P
max
100
dB
mV
RSSI dynamic range
DR
80
dB
RSSI resolution
Slope of the RSSI has to be
steady
Acc
2
dB
RSSI rise time
P
in
= 30 dB
mV to
100 dB
mV
Pin 1
t
r
1
ms
RSSI fall time
P
in
= 100 dB
mV to
30 dB
mV
Pin 1
t
f
1
ms
Quiescent output current
@ P
in
< 20 dB
mV at
IF_IN1, IF_IN2
Pin 1
I
out
30
mA
Max. output current
@ P
in
= 100 dB
mV at
IF_IN1, IF_IN2
Pin 1
I
out
150
mA
FM demodulator
Pins 23, 24 and 25
Co-channel rejection ratio
@ P
in
= 75 dBm at
IR-mixer input
CCRR
10
dB
Sensitivity
Quality factor of external
tank circuit approx. 20
S
0.5
V/MHz
Amplitude of recovered
signal
Nominal deviation of
signal
288 kHz
A
288
mVss
Output-voltage DC range
Pin 25
FMout
DC
0.4
V
S
0.4
V
Output impedance
Pin 25
Z
out
13
k
W
AM rejection ratio
Pin 25
AMRR
tbd
dB
OpAmp
Pins 26, 27 and 28
Power gain bandwidth
PGBW
10
MHz
Excess phase
R
load
= 1 k
W, C
load
= 15 pF
d
80
Input offset voltage
Pins 26 and 27
V
offs
1
mV
Open loop gain
g
70
dB
Output voltage range
Pin 28
V
out
0.3
V
S
0.3
V
Common mode input
voltage
Pins 26 and 27
V
in
0.3
V
S
0.3
V
Common mode rejection
ratio
Pin 28
CMRR
tbd
dB
Total harmonic distortion
Pin 28
THD
tbd
%
U2761B
Preliminary Information
TEMIC Semiconductor
Rev. A4, 10-Mar-98
5 (11)
Electrical Characteristics (continued)
Test conditions: V
S
= 3.0 V, T
amb
= 25
C, unless otherwise specified
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Ramp generator
Pins 13 and 14
Min. output voltage
Accord. to PA RAMP input
V
min
0.2
V
Max. output voltage
Accord. to PA RAMP input
V
max
1.95
V
Rise time
C
RAMP
= 270 pF at Pin 14
t
r
5
s
Fall time
C
RAMP
= 270 pF at Pin 14
t
f
5
s
Logic input levels (RX_ON, TX_ON)
Pins 15 and 16
High input level
= `1'
V
iH
1.5
V
Low input level
= `0'
V
iL
0.5
V
High input current
= `1'
I
iH
5
5
A
Low input current
= `0'
IiL
5
5
A
Power / standby
Pin 2
Power-up high input level
PU = `1'
V
PU
2.0
V
Standby low input level
PU = `0'
V
PU,OFF
0.7
V
Power-up high input current
PU = `1'
V
PU
= 3
V,
V
PU
= 5.5 V
I
PU
20
60
30
80
40
100
A
Standby low input current
PU = `0'
V
PU
= 0 V,
V
PU
= 0.5 V
I
PU,OFF
0.1
1
A
Settling time
VS = 0 > active operation
Switched
VS = 0 to VS = 3 V
t
soa
< 10
s
Settling time
standby > active operation
Switched
PU = 0 to PU = 1
t
ssa
< 10
s
Settling time
active operation > standby
Switched
VS = 3 V to VS = 0
t
sas
< 2
s
Active Blocks Corresponding to RX / TX
Logic
Active Parts
PU
RX_ON
TX_ON
OP
Demo-
dulator
IF amplifiers
IR mixer
RSSI
RX switch
TX switch
TX driver
Ramp
generator
TX mode
1
0
1
off
off
off
off
off
off
on
on
on
RX mode
1
1
0
on
on
on
on
on
on
off
off
off
RSSI
1
1
1
off
off
on
on
on
on
off
off
off
Standby
0
X
X
off
off
off
off
off
off
off
off
off
1
0
0
off
off
off
off
off
off
on
off
off
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