1
Features
Supply-voltage Range: 2.7 V to 5.5 V
Single-ended Output, no Balun Required
Single-ended Input for RF and LO
Excellent Isolation Characteristics
Power-down Mode
IP3 and Compression Point Programmable
2.5-GHz Operating Frequency
Benefits
Reduced System Costs as only Few External Component (no Balun) are Required
Small Package
Very Low Current Consumption
Easy to Use
Electrostatic sensitive device.
Observe precautions for handling.
Description
The U2795B is a 2.5-GHz mixer for WLAN and RF telecommunications equipment,
e.g., DECT and PCN. The IC is manufactured using Atmel's advanced bipolar technol-
ogy. A double-balanced approach was chosen to assure good isolation characteristics
and a minimum of spurious products. The input and output are single-ended, and their
characteristics are programmable. No output transformer or balun is required.
Figure 1. Block Diagram
R1
Voltage
regulator
VH
R
V
VS
2
RFi
3
P
VH
7
LO i
6
GND
VS
1
4
8
R2
5 IF
PD
S
o
o
2.5-GHz
Double-
balanced
Mixer
U2795B
Rev. 4654ACELL01/03
2
U2795B
4654ACELL01/03
Pin Configuration
Figure 2. Pinning
1
2
3
4
5
6
7
8
V
S
RF
P
IF
O
LO
i
PU
GND
S
O
Pin Description
Pin
Symbol
Function
1
V
S
Supply voltage
2
RF
i
RF input
3
P
Progamming port IP3, CP
4
S
O
Output symmetry
5
IF
O
IF output
6
GND
Ground
7
LO
i
LO input
8
PU
Power-up
3
U2795B
4654ACELL01/03
Functional Description
Supply Voltage
The IC is designed for a supply-voltage range of 2.7 V to 5.5 V. As the IC is internally
stabilized, the performance of the circuit is nearly independent of the supply voltage.
Input Impedance
The input impedance, Z
RFi
, is about 700
W
with an additional capacitive component. This
condition provides the best noise figure in combination with a matching network.
3rd Order Intercept Point
(IP3)
The voltage divider, R
P
/R
1
, determinates both the input and output intercept point, IIP3
and OIP3. If the value of RP is infinite, the maximum value of IIP3 reachs about -4 dBm.
The IP3/R
P
characteristics are shown in Figure 3 and Figure 4.
Output Impedance and
Intercept Point
The output impedance is shown in Figure 11. Both low output impedance and a high
intercept point are defined to a high value of R
P
.
Current Consumption, I
S
Depending on the chosen input and output conditions of the IC, the current consump-
tion,I
S
, is between 4 mA and 10 mA. The current consumption in dependence of Rp is
shown in Figure 6.
Power-up
This feature provides extended battery lifetime. If this function is not used, Pin 8 has to
be connected to V
S
(Pin 1).
Output Symmetry
The symmetry of the load current can be matched and thus optimized for a given load
impedance.
Absolute Maximum Ratings
Parameters
Symbol
Value
Unit
Supply voltage
V
S
6
V
Input voltage
V
I
0 to V
S
V
Junction temperature
T
j
125
C
Storage-temperature range
T
stg
-40 to +125
C
Thermal Resistance
Parameters
Symbol
Value
Unit
Junction ambient SO8
R
thJA
175
K/W
Operating Range
Parameters
Symbol
Value
Unit
Supply-voltage range
V
S
2.7 to 5.5
V
Ambient-temperature range
T
amb
-40 to +85
C
4
U2795B
4654ACELL01/03
Electrical Characteristics
V
S
= 3 V, f
LOi
= 1 GHz, IF = 900 MHz, RF = 100 MHz, R
P
=
, system impedance Zo = 50
W
, T
amb
= 25
C, R
T
= 56
W
reference point Pin 6, unless otherwise specified
No.
Parameters
Test Conditions
Pin
Symbol
Min.
Typ.
Max.
Unit
Type*
1.1
Supply voltage range
1
V
S
2.7
5.5
V
A
1.2
Supply Current
VS = 2.7 V
1
1
I
S
I
S
9
3
13
6.2
mA
mA
A
A
1.3
Conversion Supply
Current
R
L
= 50
W
, R
T
=
R
L
=
50
W
, R
T
= 56
W
1
PG
C
PG
C
9
4
dB
dB
B
2
Operating Frequencies
2.1
RF
i
frequency
2
RF
i
10
2500
MHz
D
2.2
LO
i
frequency
7
f
LOi
50
2500
MHz
D
2.3
IF
o
frequency
5
f
IFo
50
2500
MHz
D
3
Isolation
3.1
LO spurious at R
Fi
P
iLO
= -10 to 0 dBm
7, 2
IS
LORF
-30
dBm
D
3.2
RF
i
to LO
i
P
iRF
= -25 dBm
2, 7
IS
RFLO
35
dB
D
3.3
LO spurious at IF
o
P
iLO
= -10 to 0 dBm
5, 7
IS
LOIF
-25
dBm
D
3.4
IF
o
to LO
i
5, 7
IS
IFLO
30
dB
D
4
Output (IF)
4.1
Output compression
point
5
CP
O
-10
dBm
D
5
Input (RF)
5.1
Input impedance
2
Z
RFi
700
||
0.8
W||
pF
D
5.2
Input compression point
2
CP
i
-14
dBm
D
5.3
3rd-order input
intercept point
2
IIP3
-4
dBm
D
6
Input (LO)
6.1
LO level
7
P
iLO
-6
dBm
D
7
Voltage Standing Wave Ratio (VSWR)
7.1
Input LO
7
VSWR
LOi
< 2
D
7.2
Output IF
4
VSWR
IFo
< 2
D
8
Noise Performance
8.1
Noise figure
P
iLO
= 0 dBm, R
T
=
NF
10
dB
D
9
Power-down Mode
9.1
Supply current
V
PU
< 0.5V
V
PU
= 0 V
1
I
SPU
< 5
30
A
A
B
B
10
Power-down Voltage
10.1
"Power ON"
V
S
= 3.5 to 5.5 V
V
S
= 2.7 to 3.5 V
8
V
PON
V
S
-0.5
V
S
V
S
+ 0.5
V
S
+ 0.5
V
V
D
D
10.2
"Power DOWN"
8
V
PDN
1
V
D
10.3
Power-down current
Power ON
Power DOWN
8
I
PON
I
PDN
0.15
< 5
0.22
mA
A
A
D
10.4
Settling time
5,8
t
sPD
< 30
s
D
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
5
U2795B
4654ACELL01/03
Figure 3. IIP3 versus Resistor R
p
, IF: 900 MHz
Figure 4. OIP3 versus Resistor R
p
, IF: 900 MHz
0
20
40
60
80
-10
-9
-8
-7
-6
-4
I
I
P
3
(
d
B
m
)
R
p
(k
W
)
100
-5
0
20
40
60
80
-25
-20
-15
-10
-5
0
O
I
P
3
(
d
B
m
)
R
p
(k
W
)
100
PDF 
ZIP