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ü
8-97
8
FRONT-ENDS
Preliminary
Product Description
Ordering Information
Typical Applications
Features
Functional Block Diagram
RF Micro Devices, Inc.
7628 Thorndike Road
Greensboro,NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
Optimum Technology Matching® Applied
Si BJT GaAs MESFETGaAs HBT
Si Bi-CMOS
SiGe HBT
Si CMOS
1LO IN
2GND2
3VCC
4GND1
8 IF+
7 IF-
6 GND3
5RFIN
RF2459
3V PCS DOWNCONVERTER
• CDMA/TDMA/DCS1900 PCS Systems
• PHS 1500/WLAN 2400 Systems
• General Purpose Downconverter
• Micro-Cell PCS Base Stations
• Portable Battery-Powered Equipment
The RF2459 is a monolithic integrated downconverter for
PCS, PHS, and WLAN applications. The IC contains all of
the required components to implement the RF functions
of the downconverter. It contains a double-balanced Gilbert cell mixer and a balanced IF output. The mixer’s high
third-order intercept point makes it ideal for digital cellular
applications. The IC is designed to operate from a single
3V power supply.
• Extremely High Dynamic Range
• Single 3V Power Supply
• 1500MHz to 2500MHz Operation
RF2459 3V PCS Downconverter
RF2459 PCBA Fully Assembled EvaluationBoard
8
Rev A2 010717
NOTES:
1. Shaded lead ispin 1.
2. All dimensions are exclusiveof
flash, protrusions or burrs.
3. Lead coplanarity: 0.002 with
respect to datum "A".
0.012
6° MAX
0° MIN
0.021
+0.004
0.006
+0.002
0.192
+ 0.008
0.0256
0.118
+0.004sq.
0.006
+0.003
0.034
-A-
Package Style: MSOP-8
Page 2
Preliminary
8-98
RF2459
Rev A2 010717
8
FRONT-ENDS
Absolute Maximum Ratings
Parameter Ratings Unit
Supply Voltage -0.5 to 7.0 V
DC
Input LO and RF Levels +6 dBm
Ambient Operating Temperature -40 to +85 °C
Storage Temperature -40 to +150 °C
Parameter
Specification
Unit Condition
Min. Typ. Max.
Overall
T=25°C, VCC=3.0V, RF=1960MHz,
LO =1750MHz@-2dBm
Usable RF Frequency Range 1500 2500 MHz
Typical RF Frequency Range 1930 to 1990 MHz
Usable LO Frequency Range 1200 2500 MHz
Typical LO Frequency Range 1430 to 1990 MHz
IF Frequency Range DC to 500 MHz
Noise Figure 14 dB
Input VSWR <2:1 Single-ended with external matching net-
work.
Input IP3 +5.0 +7.0 dBm
Gain 8 10 dB
Output Impedance 1000 Ω Single-ended with external matching net-
work.
Input P1dB -7.5 dBm
LO Input
LO Input Range -5 to +3 dBm
LO to RF (Mix In) Rejection 30 dB
LO to IF 40 dB
LO Input VS WR <2:1 Single-ended with external matching net-
work.
Power Supply
Voltage 2.7 3.0 3.6 V
Current Consumption 20 26 mA
Caution! ESD sensitive device.
RF Micro Devices believes thefurnished information is correct and accurate
at the time of this printing. However, RF Micro Devices reserves the right to
make changes to its products without notice. RF Micro Devices does not
assume responsibility for the use of the described product(s).
Page 3
Preliminary
8-99
RF2459
Rev A2 010717
8
FRONT-ENDS
Pin Function Description Interface Schematic
1LOIN
Mixer LO single-ended input. The pin is internally DC blocked. External
matching sets impedance.
2GND2
Ground for downconverter. Keep traces physically short and connect
directly to ground plane for best performance.
3VCC
Supply voltage for downconverter.External RF bypassing i s required.
The trace length between the bypass caps and the pin should be minimized. Connect ground sides of caps directly to ground.
4GND1
Same as pin 2.
5RFIN
Mixer RF single-ended input. The pin is internally DC blocked. External
matching sets input impedance.
6GND3
Same as pin 2.
7IF-
IF output pin. The output is balanced. A current combiner external network perfor ms a differential to single-ended conversion and sets the
output impedance. There must be a DC path from V
CC
to this pin. this
is normally achievedwith the current combiner network. A DC blocking
cap must be present if the IF filter input has a DC path to ground.
8IF+
Same as pin 7, except complementary output.
LO IN
RF IN
IF+ IF-
Page 4
Preliminary
8-100
RF2459
Rev A2 010717
8
FRONT-ENDS
Applicatio n Schematic
1
2
3
4
8
7
6
5
4.7 nH
1.5 pF
22 pF100 nF
1.5 pF
2.2 nH
R
L1
C1 C1
C2
L2
V
CC
V
CC
LO IN
RF IN
IF OUT
IF Filter
Output Interface Network
L1, C1 and R form a current combiner which performs
a differential to single-ended conversion at the IF frequency and sets the output impedance. In most cases,
the resonance frequency is independent of R and can
be set according to the following equation:
Where C
EQ
is the equivalent stray capacitance and
capacitancelookingintopins7and8.Anaverage
valuetouseforC
EQ
is 2.5pF .
R can then be used to set the output impedance
according to the following equation:
where R
OUT
is the desired output impedance and RPis
the parasitic equivalent parallel resistance of L1.
C1 should be chosen as high as possible, while main-
taining an R
P
of L1 that allows for the desired R
OUT
.
L2 and C2 serve dual purposes. L2 serves as an output bias choke, and C2 ser ves as a series DC block.
In addition, L2 and C2 may be chosen to form an
impedance matching network if the input impedance of
the IF filter is not equal to ROUT. Otherwise, L2 is chosen to be large (suggested 8.2nH) and C2 is chosen to
be large (suggested 22nF) if a DC path to ground is
present in the IF filter, or omitted if the filter is DC
blocked.
1
2
π
L1
2
(C1+CEQ)
fIF=
R=
1
4R
OUT
-
1
R
P
()
-1
Page 5
Preliminary
8-101
RF2459
Rev A2 010717
8
FRONT-ENDS
Evaluation Board Schematic
RF=1.959MHz, IF=210MHz
(Download Bill of Mater i als from www.rfmd.com.)
1
2
3
4
8
7
6
5
L1
4.7 nH
C1
1.5 pF
J1
LO IN
C3
22 pF
C2
100 nF
VCC
C4
1.5 pF
L2
2.2 nH
J2
RF IN
R1
16k Ω
L3
100 nH
C5
9pF
C6
9pF
C7
4pF
J3
IF OUT
L4
180 nH
VCC
50 Ωµstrip
50 Ωµstrip
50 Ωµstrip
VCC
GND
N/C
1
2
3
P1
CON3
NOTES:
1) R1, L3, C5, and C6 are chosen to produce an output impedance, R
OUT
, of 1000 Ω @ 210 MHz.
2) L4 and C7 are chosen to match the 1000 Ω output impedance to 50 Ω for testing purposes.
Page 6
Preliminary
8-102
RF2459
Rev A2 010717
8
FRONT-ENDS
Evaluation Board Layout 900MHz
Board Size 2.0" x 2.0"
Board Thickness 0.031”, Board Material FR-4
Page 7
Preliminary
8-103
RF2459
Rev A2 010717
8
FRONT-ENDS
MIXINVSWR versus V
CC
1.65
1.70
1.75
1.80
1.85
1.90
1.95
2.70 2.80 2.90 3.00 3.10 3.20 3.30 3.40 3.50 3.60
VCC(V)
MIX
IN
VSWR
MIXin,-30º
MIXin, 25º
MIXin, 85º
LOINVSWR versus V
CC
1.20
1.25
1.30
1.35
1.40
1.45
2.70 2.80 2.90 3.00 3.10 3.20 3.30 3.40 3.50 3.60
VCC(V)
LO
IN
Loin, -30º
Loin, 25º
Loin, 85º
NF versus V
CC
11.0
12.0
13.0
14.0
15.0
16.0
17.0
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC(V)
Noise Figure
NF,-30º
NF,25º
NF,85º
Gain versus V
CC
7.0
8.0
9.0
10.0
11.0
12.0
13.0
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC(V)
Gain (dB)
Gain, -30º
Gain, 25º
Gain, 85º
ICCversus V
CC
10.0
15.0
20.0
25.0
30.0
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC(V)
I
CC
(mA)
Icc, -30º
Icc, 25º
Icc, 85º
IIP3 versus V
CC
3.0
5.0
7.0
9.0
11.0
13.0
15.0
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC(V)
IIP3 (dBm)
IIP3, -30º
IIP3, 25º
IIP3, 85º
Page 8
Preliminary
8-104
RF2459
Rev A2 010717
8
FRONT-ENDS
IP1dB versus V
CC
-10.0
-9.0
-8.0
-7.0
-6.0
-5.0
-4.0
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC(V)
IP1dB (dBm)
IP1dB, -30º
IP1dB,25º
IP1dB,85º
Gain versus LO P
IN
VCC=3.0V
7.0
8.0
9.0
10.0
11.0
12.0
13.0
14.0
-6.0 -4.0 -2.0 0.0 2.0 4.0
LO PIN(dBm)
Gain (dB)
Gain, -30º
Gain, 25º
Gain, 85º
IIP3 versus LO P
IN
VCC=3.0V
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
-6.0 -4.0 -2.0 0.0 2.0 4.0
LO PIN(dBm)
IIP3 (dBm)
IIP3, -30º
IIP3,25º
IIP3,85º
IP1dB versus LO P
IN
VCC=3.0V
-12.0
-11.0
-10.0
-9.0
-8.0
-7.0
-6.0
-5.0
-6.0 -4.0 -2.0 0.0 2.0 4.0
LO PIN(dBm)
IP1dB (dBm)
IP1dB, -30º
IP1dB,25º
IP1dB,85º
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