Rev. 4654B–CELL–07/04
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
VS
2
RFi
3
P
VH
7
LOi
6
GND VS
1
4
8
R25IFo
PD
So
VH
VR
2.5-GHz
Double-
balanced
Mixer
U2795B
2U2795B
4654B–CELL–07/04
Pin Configuration
Figure 2. Pinning
1
2
3
45
6
7
8
VS
RFI
P
IFO
LOI
PU
GND
SO
Pin Description
Pin Symbol Function
1 VS Supply voltage
2RFIRF input
3 P Programming port IP3, CP
4 SO Output symmetry
5 IFO IF output
6 GND Ground
7 LOI LO input
8 PU Power-up
3
U2795B
4654B–CELL–07/04
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, ZRFi, is about 700 Ω 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, RP/R1, determinates both the input and output intercept point, IIP3
and OIP3. If the value of RP is infinite, the maximum value of IIP3 reach about -4 dBm.
The IP3/RP characteristics are shown in Figure 3 and Figure 4.
Output Impedance and
Intercept Point
The output impedance is shown in Figure 11 on page 8. Both low output impedance and
a high intercept point are defined to a high value of RP.
Current Consumption, ISDepending on the chosen input and output conditions of the IC, the current consump-
tion, IS, is between 4 mA and 10 mA. The current consumption in dependence of RP is
shown in Figure 6 on page 6.
Power-up This feature provides extended battery lifetime. If this function is not used, pin 8 has to
be connected to VS (pin 1).
Output Symmetry The symmetry of the load current can be matched and thus optimized for a given load
impedance.
Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Parameters Symbol Value Unit
Supply voltage VS6V
Input voltage VI0 to VSV
Junction temperature Tj125 °C
Storage-temperature range Tstg -40 to +125 °C
Thermal Resistance
Parameters Symbol Value Unit
Junction ambient SO8 RthJA 175 K/W
Operating Range
Parameters Symbol Value Unit
Supply-voltage range VS2.7 to 5.5 V
Ambient-temperature range Tamb -40 to +85 °C
4U2795B
4654B–CELL–07/04
Electrical Characteristics
VS = 3 V, fLOi = 1 GHz, IF = 900 MHz, RF = 100 MHz, RP = ∞, system impedance Zo = 50 Ω, Tamb = 25°C, RT = 56 Ω
reference point pin 6, unless otherwise specified
No. Parameters Test Conditions Pin Symbol Min. Typ. Max. Unit Type*
1.1 Supply voltage range 1 VS2.7 5.5 V A
1.2 Supply Current VS = 2.7 V, RP = 10 kΩ1I
S913mAA
VS = 3.0 V, RP = ∞1I
S36.2mAA
1.3 Conversion Power Gain RL = 50 Ω, RT = ∞
RL = 50 Ω, RT = 56 Ω1PGC
PGC
9
4
dB
dB B
2 Operating Frequencies
2.1 RFi frequency 2 RFi10 2500 MHz D
2.2 LOi frequency 7 fLOi 50 2500 MHz D
2.3 IFo frequency 5 fIFo 50 2500 MHz D
3Isolation
3.1 LO spurious at RFi PiLO = -10 to 0 dBm 7, 2 ISLO-RF -30 dBm D
3.2 RFi to LOiPiRF = -25 dBm 2, 7 ISRF-LO 35 dB D
3.3 LO spurious at IFoPiLO = -10 to 0 dBm 5, 7 ISLO-IF -25 dBm D
3.4 IFo to LOi5, 7 ISIF-LO 30 dB D
4 Output (IF)
4.1 Output compression point 5 CPO-10 dBm D
5 Input (RF)
5.1 Input impedance 2 ZRFi 700||0.8 Ω||pF D
5.2 Input compression point 2 CPi-14 dBm D
5.3 3rd-order input
intercept point 2IIP3 -4 dBmD
6 Input (LO)
6.1 LO level 7 PiLO -6 dBm D
7 Voltage Standing Wave Ratio (VSWR)
7.1 Input LO 7 VSWRLOi < 2 D
7.2 Output IF 4 VSWRIFo < 2 D
8 Noise Performance
8.1 Noise figure PiLO = 0 dBm, RT = ∞NF 10 dB D
9 Power-down Mode
9.1 Supply current VPU < 0.5V
VPU = 0 V 1I
SPU < 5
30 µA
µA
B
B
10 Power-down Voltage
10.1 “Power ON” VS = 3.5 to 5.5 V
VS = 2.7 to 3.5 V 8VPON
VS -0.5
VS
VS + 0.5
VS + 0.5
V
V
D
D
10.2 “Power DOWN” 8 VPDN 1VD
10.3 Power-down current Power ON
Power DOWN 8IPON
IPDN
0.15
< 5 0.22 mA
µA
A
D
10.4 Settling time 5,8 tsPD < 30 µs D
*) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter
5
U2795B
4654B–CELL–07/04
Figure 3. IIP3 versus Resistor Rp, IF: 900 MHz
Figure 4. OIP3 versus Resistor Rp, IF: 900 MHz
Figure 5. Gain versus Resistor Rp, LO: 1030 MHz, level -10 dBm; RF: 130 MHz,
-30 dBm, RT = 56 Ω
020406080
-10
-9
-8
-7
-6
-4
IIP3 (dBm)
RP (kΩ)
100
-5
020406080
-25
-20
-15
-10
-5
0
OIP3 (dBm)
RP (kΩ)
100
020406080
-13
-9
-5
-1
3
Gain (dB)
RP (kΩ)
100
6U2795B
4654B–CELL–07/04
Figure 6. Supply Current IS versus Resistor Rp
Figure 7. Gain versus IF Output Frequency, LO Level: -6 dBm, RF: 130 MHz, -35 dBm;
Parameter: RF Input Termination
Figure 8. IIP3 versus IF Output Frequency, LO Level: -6 dBm; RF: 130 MHz/
130.1 MHz, -35 dBm; Parameter: RF Input Termination
020406080
0
2
4
6
8
12
I
S
(mA)
RP (kΩ)
100
10
0 500 1000 1500 2000
-2
2
6
10
14
18
Gain (dB)
IF (MHz)
2500
with RF input matching
LS = 220 nH, CP = 4.7 pF
without RT
with RT = 56 Ω
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
0 500 1000 1500 2000 2500
IF (MHz)
IIP3 (dBm)
with RT = 56 Ω
with RF input matching
LS = 220 nH, CP = 4.7 pF
without RT
7
U2795B
4654B–CELL–07/04
Figure 9. Double Sideband Noise Figure versus IF Output Frequency; LO: 1000 MHz,
Level 0 dBm; no RF Input Matching, RT Left Out
Figure 10. Typical VSWR Frequency Response of the IF Output, RP = ∞
0 200 400 600 800
0
2
4
6
8
12
NF (dB)
IF (MHz)
10
100 280 460 640 820
1
2
3
4
5
VSWR
IF Frequency (MHz)
1000
8U2795B
4654B–CELL–07/04
Figure 11. Typical Impedance of the Output versus RP at Frequency fIFo = 900 MHz
Markers (from Left to Right): RP = ∞/22 kΩ/10 kΩ/8.2 kΩ/5.6 kΩ
Figure 12. Typical S11 Frequency Response of the IF Output, RP = ∞, IF Frequency
from 100 MHz to 1000 MHz, Marker: 900 MHz
-0.2j
-0.5j
-j
-2j
-5j
0
0.2j
0.5j
j
2j
5j
0.2 0.5 125∞
-0.2j
-0.5j
-j
-2j
-5j
0
0.2j
0.5j
j
2j
5j
0.2 0.5 1 2 5 ∞
9
U2795B
4654B–CELL–07/04
Figure 13. Typical S11 Frequency Response of the RF Input, RP = ∞, RT = ∞
RF Frequency from 100 MHz to 1000 MHz, Marker: 900 MHz
Figure 14. Typical S11 Frequency Response of the LO Input, RP = ∞, LO Frequency
from 100 MHz to 1000 MHz, Marker: 900 MHz
-0.2j
-0.5j
-j
-2j
-5j
0
0.2j
0.5j
j
2j
5j
0.2 0.5 1 2 5 ∞
-0.2j
-0.5j
-j
-2j
-5j
0
0.2j
0.5j
j
2j
5j
0.2 0.5 1 2 5 ∞
10 U2795B
4654B–CELL–07/04
Application
If the part-list values are used, the PU settling time is < 20 µs. Using other values, time
requirements in burst-mode applications have to be considered.
The values of RSO and RP depend on the input and output condition requirements. For
RSO, 68 Ω is recommended.
By means of the optional RI, the intercept and compression point can be slightly
increased; values between 500 Ω and 1 kΩ are suitable. Please note that such modifica-
tion will also increase the supply current.
Table 1. Part List
Part Value
C110 nF
C2, C3, C4, C5, C6, C7100 pF
*RP
50-Ω Microstrip
*RSO 68 Ω
— — — optional
RT56 Ω
1
2
3
4
U2795B
VS8
7
6
5
C2
RP
C1
C5
C4
PU
RT
C6
RSO
C3
RF
C7
LO
IF
RI
11
U2795B
4654B–CELL–07/04
Application Circuit (Evaluation Board)
12 U2795B
4654B–CELL–07/04
Package Information
Ordering Information
Extended Type Number Package Remarks
U2795B-MFP SO8 Tube
U2795B-MFPG3 SO8 Taped and reeled
technical drawings
according to DIN
specifications
Package SO8
Dimensions in mm 5.00
4.85
0.4
1.27
3.81
1.4
0.25
0.10
5.2
4.8
3.7
3.8
6.15
5.85
0.2
85
14
Printed on recycled paper.
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warranty which is detailed in Atmel’s Terms and Conditions located on the Company’s web site. The Company assumes no responsibility for any
errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and
does not make any commitment to update the information contained herein. No licenses to patents or other intellectual property of Atmel are
granted by the Company in connection with the sale of Atmel products, expressly or by implication. Atmel’s products are not authorized for use
as critical components in life support devices or systems.
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4654B–CELL–07/04
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