RFMD RF2449

RF2449
Preliminary
8
CDMA/FM LOW NOISE AMPLIFIER/MIXER
900MHZ DOWNCONVERTER
Typical Applications
• CDMA/FM Cellular Systems
• General Purpose Downconverter
• Supports Dual-Mode CDMA/AMPS
• Commercial and Consumer Systems
• Supports Dual-Mode CDMA/TACS
• Portable Battery-Powered Equipment
Product Description
0.157
0.150
The RF2449 is a receiver front-end designed for the
receive section of dual-mode CDMA/FM cellular applications. It is designed to amplify and downconvert RF signals, while providing 30dB of stepped gain control range.
Features include digital control of LNA gain, mixer gain,
LNA IIP3, and power down mode. Another feature of the
chip is adjustable IIP3 of the LNA and mixer using an offchip current setting resistor. The LNA IIP3 can be digitally
controlled between two levels to reduce current draw in
CDMA standby and other conditions where high IIP3 is
not required. Noise Figure, IP3, and other specs are
designed to be compatible with the IS-98 specification for
CDMA cellular communications. The IC is manufactured
on an advanced Silicon Bipolar process and packaged in
an SSOP-24.
1
!Si Bi-CMOS
GaAs HBT
GaAs MESFET
SiGe HBT
Si CMOS
0.012
0.008
0.344
0.337
0.025
0.0688
0.0532
0.2440
0.2284
8
0.050
0.016
0.0098
0.0075
Package Style: SSOP-24
Features
ENABLE 1
24 LO IN
• Complete Receiver Front-End
IP SET 2
23 GND2
• Stepped LNA/Mixer Gain Control
IF SEL 3
22 GND2
LNA GAIN 4
21 VCC2
MIX GAIN 5
20 IF2+
LNA IN 6
19 IF2-
VCC1 7
18 BYPASS
GND1B 8
17 IF1-
GND1A 9
16 IF1+
LNA OUT 10
15 GND3A
11
14 MIX IN
12
13 GND3B
Functional Block Diagram
Rev A4 001016
FRONT-ENDS
8°MAX
0°MIN
Optimum Technology Matching® Applied
Si BJT
0.0098
0.0040
• Adjustable LNA/Mixer Bias Current
• Adjustable LNA/Mixer IIP3
• Digital LNA IIP3 Control
• Meets IS-98 IMD and Single Tone
Ordering Information
RF2449
RF2449 PCBA
CDMA/FM Low Noise Amplifier/Mixer 900MHz
Downconverter
Fully Assembled Evaluation Board
RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
8-75
RF2449
Preliminary
Absolute Maximum Ratings
Parameter
Supply Voltage
Input LO and RF Levels
Operating Ambient Temperature
Storage Temperature
Parameter
Rating
Unit
-0.5 to +5.0
+6
-40 to +85
-40 to +150
VDC
dBm
°C
°C
Specification
Min.
Typ.
Max.
Caution! ESD sensitive device.
RF Micro Devices believes the furnished 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).
Unit
Condition
T = 25°C, VCC =2.75V, RF=880MHz,
LO=990MHz@0dBm, IF = 110MHz,
VIPSET <1.0V
Overall
RF Frequency Range
LO Frequency Range
IF Frequency Range
869 to 894
760 to 1010
0.1 to 250
MHz
MHz
MHz
LNA - High Gain Mode
Gain
Noise Figure
IIP3
LNA Out to Mixer in Isolation
Current
FRONT-ENDS
8
14
15
2.3
+6
40
3.5
2.5
dB
dB
dBm
dB
mA
IIP3 is adjustable.
LNA Bypass
Gain
Noise Figure
IIP3
Current
-6.3
6.3
20
0
dB
dB
dBm
mA
13
6.5
+3
dB
dB
dBm
dB
mA
Mixer - High Gain Mode
Gain
Noise Figure
IIP3
RF to IF Isolation
Current
3kΩ balanced load.
12
+2
29
7.5
21
Mixer - Low Gain Mode
Gain
Noise Figure
IIP3
RF to IF Isolation
Current
IIP3 is adjustable - See Data Plots.
3kΩ balanced load.
3
+12
35.5
4
13
+13
14
16
dB
dB
dBm
dB
mA
IIP3 is adjustable - See Data Plots.
Local Oscillator Input
Input Level
LO to IF Isolation
LO to RF Isolation
LO to LNA Input Isolation
-10
40
40
35
-3
24
25
2.9
-9
0
dBm
dB
dB
dB
Cascade (Mode 1)
Gain
Noise Figure
IIP3
-10
27
dB
dB
dBm
Cascade (Mode 2)
Gain
Noise Figure
IIP3
8-76
16.0
4.7
0
dB
dB
dBm
Any gain state.
(LNA Gain High, Mix Gain High)
With -3dB image rejection filter.
3kΩ balanced IF load.
Single sideband.
(LNA Gain High, Mix Gain Low)
With -3dB image rejection filter.
3kΩ balanced IF load.
Single sideband.
Rev A4 001016
RF2449
Preliminary
Parameter
Specification
Min.
Typ.
Max.
Unit
Cascade (Mode 3)
Gain
Noise Figure
IIP3
3.5
16
+11.8
dB
dB
dBm
Cascade (Mode 4)
Gain
Noise Figure
IIP3
+16.0
-5
22.5
+18.0
2.65
2.75
dB
dB
dBm
Condition
(LNA Gain Low, Mix Gain High)
With -3dB image rejection filter.
3kΩ balanced IF load.
Single sideband.
(LNA Gain Low, Mix Gain Low)
With -3dB image rejection filter.
3kΩ balanced IF load.
Single sideband.
Power Supply
Voltage
Power Down Current
3.9
10
V
µA
Enable<1.0V
FRONT-ENDS
8
Rev A4 001016
8-77
RF2449
Pin
1
2
3
4
5
6
Function
ENABLE
IP SET
IF SEL
LNA GAIN
MIX GAIN
LNA IN
Preliminary
Description
This pin is used to enable or disable the RF2449. A logic high (>2.0V)
enables the circuitry. A logic low (<1.0V) disables the circuitry.
Interface Schematic
ENABLE
Controls the setting of the LNA current. A logic low (<1.0V) selects the
internal resistance (49.5kΩ), resulting in an LNA current of 3.5mA. A
logic high (>2.0V) selects the external resistance at pin 12.
IP SET
Determines which IF port is active. A logic low (<1.0V) activates IF1
and deactivates IF2. A logic high (>2.0V) activates IF2 and deactivates
IF1.
IF SEL
Controls the bypass feature of the LNA. A logic low (<1.0V) selects the
bypass mode. A logic high (>2.0V) turns on the LNA.
LNA GAIN
Controls the bypass feature of the mixer pre-amp. A logic low (<1.0V)
selects the bypass mode. A logic high (>2.0V) turns on the pre-amp.
MIX GAIN
LNA input pin.
LNA OUT
MIX GAIN
FRONT-ENDS
8
GND1B
7
8
9
10
11
VCC1
GND1B
GND1A
LNA OUT
ISET2
12
ISET1
13
GND3B
VCC pin for all circuits except the LO.
LNA ground pin.
See pin 6.
Package ground pin.
LNA output pin.
See pin 6.
An external resistor connected to this pin sets the current of the preamp and the mixer.
An external resistor connected to this pin sets the current of the LNA
when IP SET is high (see pin 2).
Ground pin for pre-amp circuit.
VCC2
MIX IN
GND3B
14
15
16
8-78
MIX IN
GND3A
IF1+
Mixer pre-amp input pin.
See pin 13.
Ground pin for the mixer circuits.
First differential output pin for the first mixer.
IF1-
IF1+
Rev A4 001016
RF2449
Preliminary
Pin
17
18
19
Function
IF1BYPASS
IF2+
20
21
22
23
24
IF2VCC2
GND2
GND2
LO IN
Description
Interface Schematic
Second differential output pin for the first mixer.
See pin 16.
Bypass pin for the LO bias reference.
First differential output pin for the second mixer.
Second differential output pin for the second mixer.
IF2-
IF2+
See pin 20.
VCC pin for the LO circuits.
Ground pin for the LO circuits.
Ground pin for the LO circuits.
Local oscillator input pin.
LO IN
FRONT-ENDS
8
Rev A4 001016
8-79
RF2449
Preliminary
Application Schematic
VCC
100 pF
LO IN
56 Ω
1 nF
L2
C2
L1
ENABLE
C1
IP SET
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
IF SEL
C1
Filter
IF2+
IF2-
L
R
LNA GAIN
MIX GAIN
30 nH
RF IN
6.8 nH
VCC
1 nF
33 nF
6.8 nH
510 Ω
100 pF
100 pF
*
3.0 pF
8
C1
L1
22 kΩ
33 kΩ
FRONT-ENDS
R
C2
L
Filter
IF+
1.5 nH 33 nF
C1
IF-
L2
VCC
RF SAW Filter
1 nF
22 nH
*NOTE:
Microstrip Inductor, ZO = 50 Ω, L = 100 mils
Suggested component values for 85.38 MHz IF and
ROUT = 1 kΩ:
L1 = 470 nH
C1 = 10 pF
R = 7.5 kΩ
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:
1
f IF = ----------------------------------------------L1
2π ------ ( C1 + C EQ )
2
Where CEQ is the equivalent stray capacitance and
capacitance looking into pins 16 and 17. An average
value to use for CEQ is 2.5pF.
R may then be used to set the output impedance
according to the following equation:
8-80
1 –1
1
R =  --------------------- – ------ 
 4 ⋅ R OUT R P 
where ROUT is the desired output impedance and RP is
the parasitic equivalent parallel resistance of L1.
C1 should be chosen as high as possible, while maintaining an RP of L1 that allows for the desired ROUT.
L2 and C2 serve dual purposes. L2 serves as an output bias choke, and C2 serves 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 and C2 is chosen to be large if a DC
path to ground is present in the IF filter, or omitted if the
filter is DC blocked.
Rev A4 001016
RF2449
Preliminary
Evaluation Board Schematic
(Download Bill of Materials from www.rfmd.com.)
313 ps Electrical Delay @ 880 MHz
0.09 dB Line Loss
P2
P1
P1-3
1
IP SET
1
LNA GAIN
2
3
GND
2
GND
ENABLE P2-3
3
IF SEL
P2-1
CON3
P3-3
C20
22 pF
CON3
1
NC
2
GND
3
MIX GAIN
P4-1
P4-3
CON3
1
VCC1
2
GND
3
VCC2
J6
LO IN
VCC2
50 Ω µstrip
R6
56 Ω
C19
100 pF
VCC1
L8
220 nH
C12
100 pF
C13
1 nF
50 Ω µstrip
CON3
ENABLE
IP SET
1
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
50 Ω µstrip
C14
8 pF
50 Ω µstrip
268 ps Electrical Delay @ 110 MHz
0.025 dB Line Loss
IF SEL
50 Ω µstrip
LNA GAIN
50 Ω µstrip
MIX GAIN
L1
6.8 nH
440 ps Electrical Delay @ 880 MHz
0.14 dB Line Loss
J1
LNA IN
J5
IF2 OUT
50 Ω µstrip
L2
30 nH
C1
33 nF
C3
100 pF
VCC1
50 Ω µstrip
J2
LNA OUT
C6
3.0 pF
C4
1 nF
C5
100 pF
*
R1
510 Ω
R2
22 kΩ
R3
33 kΩ
C7
5 pF
50 Ω µstrip
2449400A
L7
470 nH
50 Ω µstrip
R4
5.6 kΩ
C8
5 pF
50 Ω µstrip
C9
8 pF
268 ps Electrical Delay @ 110 MHz
0.025 dB Line Loss
50 Ω µstrip
L4
1.5 nH
50 Ω µstrip
L6
220 nH
50 Ω µstrip
C10
100 pF
C11
1 nF
VCC1
50 Ω µstrip
C17
33 nF
Rev A4 001016
J4
IF1 OUT
50 Ω µstrip
NOTE: LE
Microstrip Inductor, ZO = 50 Ω, L = 100 mils
For IF Freq. = 85 MHz
C14, C15, C5, C6 = 8 pF
L6 and L8 = 470 nH
C7 and C13 = 15 pF
C16
5 pF
C18
100 pF
50 Ω µstrip
L3
6.8 nH
VCC2
R5
5.6 kΩ
50 Ω µstrip
C2
1 nF
410 ps Electrical Delay @ 880 MHz
0.13 dB Line Loss
L9
470 nH
50 Ω µstrip
50 Ω µstrip
C15
5 pF
50 Ω µstrip
L5
22 nH
50 Ω µstrip
J3
MIXER IN
290 ps Electrical Delay @ 880 MHz
0.07 dB Line Loss
8-81
8
FRONT-ENDS
P1-1
P4
P3
RF2449
Preliminary
Evaluation Board Layout
Board Size 2.0" x 2.0"
Board Thickness 0.040”, Board Material FR-4, Multi-Layer
Assembly
Top
FRONT-ENDS
8
Inner 1
8-82
Inner 2
Rev A4 001016
RF2449
Preliminary
Back
FRONT-ENDS
8
Rev A4 001016
8-83
RF2449
Preliminary
LNA - IIP3
(Low Gain Mode)
25.0
LNA - IIP3
(High Gain/Low IP Mode)
9.0
8.0
20.0
7.0
IIP3 (dBm)
IIP3 (dBm)
6.0
15.0
IIP3, -30º
IIP3, 25º
IIP3, 85º
10.0
5.0
IIP3, -30º
IIP3, 25º
IIP3, 85º
4.0
3.0
2.0
5.0
1.0
0.0
0.0
2.7
2.8
2.9
3
3.1
3.2
3.3
2.7
2.8
2.9
VCC (V)
LNA - IIP3
(High Gain/High IP Mode)
8.0
-6.1
6.0
-6.2
5.0
-6.3
S21 (dB)
IIP3 (dBm)
3.1
3.2
3.3
LNA - S21
(Low Gain Mode)
-6.0
7.0
4.0
IIP3, -30º
IIP3, 25º
3.0
-6.4
S21, -30º
S21, 25º
S21, 85º
-6.5
IIP3, 85º
2.0
-6.6
1.0
-6.7
0.0
-6.8
2.7
2.8
2.9
3.0
3.1
3.2
3.3
2.7
2.8
2.9
VCC (V)
3.0
3.1
3.2
3.3
VCC (V)
LNA - S21
(High Gain/Low IP Mode)
15.0
LNA - S21
(High Gain/High IP Mode)
15.4
15.3
14.9
15.2
14.8
15.1
14.7
S21 (dB)
15.0
S21 (dB)
FRONT-ENDS
8
3
VCC (V)
14.6
14.5
S21, -30º
S21, -30º
14.8
S21, 25º
14.4
14.9
S21, 25º
S21, 85º
14.7
14.3
14.6
14.2
14.5
14.1
14.4
2.7
2.8
2.9
3.0
VCC (V)
8-84
S21, 85º
3.1
3.2
3.3
2.7
2.8
2.9
3.0
3.1
3.2
3.3
VCC (V)
Rev A4 001016
RF2449
Preliminary
LNA - Noise Figure
(Low Gain Mode)
8.0
LNA - Noise Figure
(High Gain/Low IP Mode)
3.0
7.0
2.5
6.0
2.0
NF (dB)
NF (dB)
5.0
4.0
3.0
1.5
NF, -30º
NF, -30º
1.0
NF, 25º
NF, 25º
NF, 85º
NF, 85º
2.0
0.5
1.0
0.0
0.0
2.7
2.8
2.9
3.0
3.1
3.2
3.3
VCC (V)
2.7
2.8
2.9
3.0
3.1
3.2
3.3
VCC (V)
LNA - Noise Figure
(High Gain/High IP Mode)
3.0
2.5
8
FRONT-ENDS
NF (dB)
2.0
1.5
NF, -30º
NF, 25º
1.0
NF, 85º
0.5
0.0
2.7
2.8
2.9
3.0
3.1
3.2
3.3
VCC (V)
Rev A4 001016
8-85
RF2449
Preliminary
Mixer - IIP3
(Low Gain Mode)
16.0
Mixer - IIP3
(High Gain Mode)
6.0
14.0
5.0
12.0
4.0
IIP3 (dB)
IIP3 (dBm)
10.0
8.0
6.0
3.0
IIP3, -30º
IIP3, -30º
2.0
IIP3, 25º
4.0
IIP3, 25º
IIP3, 85º
IIP3, 85º
1.0
2.0
0.0
0.0
2.7
2.8
2.9
3.0
3.1
3.2
2.7
3.3
2.8
2.9
VCC (V)
Mixer - RF to IF1 Isolation
(Low Gain Mode)
36.8
Isolation, -30º
RF to IF1 Isolation (dB)
RF to IF1 Isolation (dB)
3.3
29.6
Isolation, -30º
36.2
Isolation, 25º
36.0
Isolation, 85º
35.8
35.6
35.4
35.2
29.4
Isolation, 25º
Isolation, 85º
29.2
29.0
28.8
28.6
28.4
35.0
28.2
34.8
34.6
28.0
2.7
2.8
2.9
3.0
3.1
3.2
2.7
3.3
2.8
2.9
VCC (V)
3.0
3.1
3.2
3.3
VCC (V)
Mixer - LO to IF1 Isolation
(Low Gain Mode)
43.0
Mixer - LO to IF1 Isolation
(High Gain Mode)
44.2
42.8
44.0
42.6
43.8
LO to IF1 Isolation (dB)
LO to IF1 Isolation (dB)
FRONT-ENDS
3.2
29.8
36.4
42.4
42.2
42.0
Isolation, -30º
41.8
Isolation, 25º
43.6
43.4
Isolation, -30º
Isolation, 25º
Isolation, 85º
43.2
43.0
Isolation, 85º
41.6
42.8
41.4
41.2
42.6
2.7
2.8
2.9
3.0
VCC (V)
8-86
3.1
Mixer - RF to IF1 Isolation
(High Gain Mode)
30.0
36.6
8
3.0
VCC (V)
3.1
3.2
3.3
2.7
2.8
2.9
3.0
3.1
3.2
3.3
VCC (V)
Rev A4 001016
RF2449
Preliminary
Mixer - LO to RF Isolation
(Low Gain Mode)
46.5
46.0
49.0
45.5
48.5
Isolation, -30º
45.0
LO to RF Isolation (dB)
LO to RF Isolation (dB)
Mixer - LO to RF Isolation
(High Gain Mode)
49.5
Isolation, 25º
Isolation, 85º
44.5
44.0
43.5
48.0
47.5
47.0
46.5
Isolation, -30º
Isolation, 25º
43.0
46.0
42.5
45.5
42.0
Isolation, 85º
45.0
2.8
2.9
3.0
3.1
3.2
3.3
2.7
2.8
2.9
VCC (V)
Mixer - Noise Figure
(Low Gain Mode)
3.1
3.2
3.3
Mixer - Noise Figure
(High Gain Mode)
8.0
14.0
7.0
12.0
6.0
10.0
5.0
NF (dB)
NF (dB)
16.0
3.0
VCC (V)
8.0
6.0
8
4.0
NF, -30º
3.0
NF, 25º
NF, -30º
4.0
FRONT-ENDS
2.7
NF, 85º
2.0
NF, 25º
NF, 85º
2.0
1.0
0.0
0.0
2.7
2.8
2.9
3.0
VCC (V)
Rev A4 001016
3.1
3.2
3.3
2.7
2.8
2.9
3.0
3.1
3.2
3.3
VCC (V)
8-87
RF2449
Preliminary
FRONT-ENDS
8
8-88
Rev A4 001016