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RF2890
0
Typical Applications * CDMA Cellular/GPS Applications * JCDMA/GPS Applications * AMPS/GPS Applications Product Description
-A4.00 SQ 2.00 TYP
DUAL-BAND CDMA CELLULAR/GPS LOW NOISE AMPLIFIER/MIXER
* CDMA Modem/Data Cards * Commercial and Consumer Systems * Portable Battery-Powered Equipment
0.15 C A 2 PLCS 0.15 C B 2 PLCS
The RF2890 is a high performance dual band CDMA Cellular and GPS LNA/mixer. An integrated optional LO prescaler allows VCO flexibility. The device is designed to exceed all sensitivity, intermodulation and single-tone requirements. The RF2890 is designed for three state gain control solutions (17.5dB of gain control) for cellular band IMD testing. The device offers a dedicated low current (15.5mA) GPS LNA/mixer with 32.5dB gain. An integrated TX LO buffer is also included. The design is flexible, in that the bias currents may be set using off-chip current reference resistors for the mixer and LNA blocks. Noise figure, IIP3, and other specifications are designed to be compatible with the TIA/EIA 98D standard for CDMA cellular communications. The device is packaged in a plastic, 4mmx4mm QFN. Optimum Technology Matching(R) Applied
Si BJT Si Bi-CMOS InGaP/HBT
ENABLE
3
2 PLCS 0.15 C B
1.87 TYP 0.15 C A 2 PLCS 0.90 0.85 0.70 0.65 0.05 C 3.75 SQ
Top View
-B-
0.10 M C A B 0.05 0.00 0.60 0.24 TYP 0.30 2 0.18
PIN 1 ID 0.20 R
Dimensions in mm
2.49 SQ. 2.19
12 MAX
0.50 0.30 TYP
-CNOTES: 1 Shaded lead is pin 1.
2 3
SEATING PLANE
0.50
Bottom View
Dimension applies to plated terminal: to be measured between 0.20 mm and 0.25 mm from terminal end. Pin 1 identifier must exist on top surface of package by identification mark or feature on the package body.
Package Style: QFN, 24-Pin, 4x4
GaAs HBT SiGe HBT GaN HEMT
DIV SEL CELL MIX IN
GaAs MESFET Si CMOS SiGe Bi-CMOS
Features * Optional Divide-by-Two LO Prescaler allows VCO Flexibility * Three Gain State Cellular LNA
24 CELL 1 LNA OUT CELL 2 LNA EMITTER CELL 3 LNA IN GPS 4 LNA IN VG1 5 GPS 6 LNA OUT 7 GPS MIX IN
23
22
21
20
ISET1
NC
19 18 GPS IF+
ISET2
* High IIP3 (8.5dBm) Cellular Mixer * Full ESD Protection on all Pins * 15.5mA GPS LNA/Mixer Solution
17 GPS IF-
16 CDMA IF+
/2
15 CDMA IFTX BUFF ENAB
14
Ordering Information
RF2890 RF2890PCBA-410 Dual-Band CDMA Cellular/GPS Low Noise Amplifier/Mixer Fully Assembled Evaluation Board Tel (336) 664 1233 Fax (336) 664 0454 http://www.rfmd.com
13 LO OUT 8 VG2 9 BAND SEL 10 VCC1 11 LO IN 12 VCC2
Functional Block Diagram
RF Micro Devices, Inc. 7628 Thorndike Road Greensboro, NC 27409, USA
Rev A4 040421
8-409
RF2890
Absolute Maximum Ratings Parameter
Supply Voltage Input LO and RF Levels Operating Ambient Temperature Storage Temperature
Rating
-0.5 to +5.0 +6 -40 to +85 -40 to +150
Unit
VDC dBm C C
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).
Parameter
Overall
RF Frequency Range IF Frequency Range
Specification Min. Typ. Max.
800 to 900 1575.42 183.6 2.75
Unit
MHz MHz MHz V V V A
Condition
T = 25C, VCC =2.75V Cellular band GPS band
0.1 2.65 1.8
400 3.15 0.4 10
Power Supply
Supply Voltage Logic High Logic Low Power Down Current
Cellular Band
JCDMA Band
ENABLE=0 Freq=869MHz to 894MHz Freq=832MHz to 870MHz LNA 50 match
LNA (High Gain)
Gain Noise Figure Input IP3 Current Isolation 13.0 +9.0 14.5 1.0 +11.0 7.0 19 5.5 +9.0 7.0 2.5 +12.0 4.0 -3.0 3.0 +23.0 0 8.5 2.8 16.0 1.3 dB dB dBm mA dB
IIP3 can be increased further by decreasing the value of ISET1.
LNA (Mid Gain)
Gain Noise Figure Input IP3 Current dB dB dBm mA dB dB dBm mA
LNA 50 match
LNA (Low Gain)
Gain Noise Figure Input IP3 Current -4.0 +20.0 -1.5 4.0
Mixer - CDMA/JCDMA
Gain Noise Figure Input IP3 Current LO Frequency Range 10.0 +6.5 600 2105.2-2155.2 183.6 11.5 7.5 +8.5 13.5 13.0 8.0 dB dB dBm mA MHz MHz MHz
LO IN=-4dBm See Notes 1, 2 and 3.
2300
IF Frequency Range
0.1
400
High and Low Side LO Injection. See note 3 and 4. /2 enabled, 183.6MHz IF Typical IF frequencies: 111.85MHz, 183.6MHz LO/2 enabled, TX LO Buffer enabled
Cellular Mode (High Gain)
Total Current 27.5 37.0 mA
8-410
Rev A4 040421
RF2890
Parameter GPS Band
LNA (High Gain)
Gain Noise Figure Input IP3 Current Isolation 15.0 +3.5 16.5 1.4 +6.0 7.0 20 18.0 1.7 dB dB dBm mA dB LO IN=-4dBm See note 1. 16.0 -5.5 1300 125 17.5 7.0 -3.0 8.0 183.6 15.5 19.0 7.5 dB dB dBm mA MHz MHz mA pF BAND SEL, VG1, VG2, ENABLE, DIV SEL, TX BUFF ENAB
Specification Min. Typ. Max.
Unit
Condition
Freq=1575.42MHz LNA 50 match
Mixer
Gain Noise Figure Input IP3 Current LO Frequency Range IF Frequency Range
1450 275 20.0 1
Mixer/LO Input Amps Low Side LO Injection Typical IF frequency: 183.6MHz
GPS Mode
Total Current
Control Lines
Input Capacitance
Local Oscillator Input
Cellular - CDMA/FM/JCDMA Input Power GPS Input Power -10 -10 -4 -4 0 0 dBm dBm
TX (Local Oscillator) Buffer
Cellular - CDMA/FM/JCDMA Output Power Output Frequency Current Consumption -7.0 600 -4.5 2 -2.0 1078 dBm MHz mA Single-ended 50 load See note 3. High and Low Side LO Injection.
NOTE 1. Mixer performance can be changed with external IF load/tuning. NOTE 2. Specifications apply for conditions of LO Divider enabled or disabled. NOTE 3. Mixer performance applies to both high and low side LO injection.
Rev A4 040421
8-411
RF2890
Evaluation Board Current Measurement
BAND SEL ENABLE CDMA Cellular High Gain Mode, TX Buffer Off, /2 Off Mid Gain Mode, TX Buffer Off, /2 Off Low Gain Mode, TX Buffer Off, /2 Off Alternate Low Gain Mode, TX Buffer Off, /2 Off GPS GPS Mode 0 0 0 0 1 1 1 1 VG1 0 1 1 0 VG2 0 0 1 1 TX BUFF ENAB 0 0 0 0 DIV SEL 1 1 1 1 IDC (mA) ISET2=7.5k 23.5 20.5 16.5 16.5
1
1
X
X
X
1
ISET2=7.5k 15.5
NOTES: All IDC current numbers include bias circuitry current of 1.5mA to 2.0mA (dependent on mode). TX Buffer On (=1): Add 2mA to total current. DIV SEL On (=0): Add 2mA to total current. "X" denotes setting does not impact current. Cascaded Performance (Typical Values for VCC =2.75V) NOTE: All total current numbers include bias circuitry current of 1.5mA to 2.0mA (dependent on mode).
Parameter HIGH GAIN Cascaded: Gain (dB) Noise Figure (dB) Input IP3 (dBm) 23.5 2.0 -3.7 CELL CDMA MID GAIN 16.0 5.5 +3.4 LOW GAIN 6.0 13.0 +13.5
Total Current (mA) 23.5 20.5 16.5 NOTE: Assumes 2.5dB image filter insertion loss. The TX Buffer is off (TX BUFF ENAB=0). DIV SEL function is off (=1). Parameter GPS Cascaded: Gain (dB) 32.5 Noise Figure (dB) 1.8 Input IP3 (dBm) -18.0 Total Current (mA) 15.5 NOTE: Assumes 1.5dB image filter insertion loss.
8-412
Rev A4 040421
RF2890
Operation Mode Control Table
Mode Cellular CDMA GPS BAND SEL 0 1
Gain Control Logic Table
Gain Setting VG1 0 1 1 0 VG2 0 0 1 1 Cellular LNA High Gain Mid Gain Low Gain Low Gain Resulting Gain State GPS Comments LNA High Gain Cellular CDMA IMD Test 1 and 2 High Gain Cellular CDMA IMD Test 3 and 4 High Gain Cellular CDMA IMD Test 5 and 6 High Gain Cellular CDMA IMD Test 5 and 6
VCO Options and Divider Logic Table
Dual-Band Application Dual VCO Configuration 2GHz CDMA VCO 1.4GHz GPS VCO DIV SEL pin tied to BAND SEL
MODE
CDMA Cellular GPS
CONTROL PINS
DIV SELECT 0 1 BAND SEL 0 1
ON-CHIP LO PRESCALER RESULT
Divide-by-2 ON OFF
Dual-Band Application Dual VCO Configuration 1GHz CDMA VCO 1.4GHz GPS VCO DIV SEL pin tied to VCC
MODE
CDMA Cellular GPS
CONTROL PINS
DIV SELECT 1 1 BAND SEL 0 1
ON-CHIP LO PRESCALER RESULT
Divide-by-2 OFF OFF
Rev A4 040421
8-413
RF2890
Pin 1 2 3 Function CELL LNA OUT CELL LNA EMITTER CELL LNA IN Type Description AO Cellular LNA output. Simple external L-C components
required for matching and VCC supply.
Interface Schematic
See pin 3. See pin 3.
AO AI
Cellular LNA emitter. A small inductor connects this pin to ground. Cellular LNA gain can be adjusted by the inductance. Cellular LNA input.
VCC CELL LNA OUT CELL LNA IN
CELL LNA EMITTER
4
GPS LNA IN
AI
GPS LNA input. For best performance, simple external matching required.
GPS LNA IN
VCC GPS LNA OUT
5
VG1
DI
Logic input. See Gain Control Logic table.
VG1
6 7
GPS LNA OUT GPS MIX IN
AO AI
GPS LNA output. Simple external L-C components required for matching and VCC supply. GPS mixer RF single-end input. Externally matched to 50.
See pin 4.
GPS MIX IN
8
VG2
DI
Logic input. See Gain Control Logic table.
VG2
9
BAND SEL
DI
Logic input. High level selects GPS band; low level selects cellular band.
BAND SEL
10 11
VCC1 LO IN
P AI
VCC connection with internal RF bypass capacitor. External bypass capacitor between 1nF and 47nF recommended. LO single-end input. Matched to 50.
LO IN 70
12 13 14
VCC2 LO OUT TX BUFF ENAB
DI AO DI
VCC connection with internal RF Bypass capacitor. External bypass capacitor between 1nF and 47nF recommended. LO output. Internal DC block. Logic input. High enables TX LO output buffer amplifiers.
TX BUFF ENAB
8-414
Rev A4 040421
RF2890
Pin 15 16 Function CDMA IFCDMA IF+ Type Description AO CDMA IF output. Open collector. AO CDMA IF output. Open collector. Interface Schematic
See pin 16.
CDMA IF+ CDMA IF-
17 18
GPS IFGPS IF+
AO AO
GPS IF output. Open collector. GPS IF output. Open collector.
See pin 18.
GPS IF+ GPS IF-
19 20 21
ISET2 ISET1 CELL MIX IN
AO AO AI
Resistor to ground sets mixer currents in both bands. Higher resistance results in lower currents. Resistor to ground sets the LNA current in boost mode (both LNAs). Higher resistance results in lower current. Cellular mixer RF single-end input. Externally matched to 50.
CELL MIX IN
22 23
NC DIV SEL
No connection.
DI
Logic input. Logic low enables LO divide-by-2 in cellular mode, DIV SEL must be set high in GPS mode. See VCO options table. Logic input. Low level powers down the IC.
DIV SEL
24
ENABLE
DI
ENABLE
Pkg Base
Legend:
GND
P
Ground connection. The backside of the package should be soldered to a top side ground pad which is connected to the ground plane with multiple vias.
DI=Digital Input from Baseband Chip AI=Analog Input AO=Analog Output P=VCC or GND
Rev A4 040421
8-415
RF2890
Application Schematic Differential Configuration
CELL RF SAW
33 nH
33 nH VCC VCC 33 nF 33 nF 10 nH 6.2 pF DIV ENABLE SEL C4 24 0 0 1 23 22 21 20 19 18 L1
(0603 Wire-wound Coilcraft)
16 k 7.5 k
L4
(0603 Wire-wound Coilcraft)
L5
(0603 Wire-wound Coilcraft)
R2
C5
L6
(0603 Wire-wound Coilcraft)
GPS IF (IFSAW2) SAW
GPS
VCC
C6 L2
(0603 Wire-wound Coilcraft)
2 33 nH CELL LNA IN 1.8 nH GPS LNA IN 1.2 pF DNI 5 G1 6 7 8 9 10 11 12 33 nF 4 /2 33 nF 3
17
16 C1 15 R1
C2
L3
(0603 Wire-wound Coilcraft)
CDMA IF (IFSAW1) SAW
CDMA
C3 14 TX BUFF ENAB LO OUT 33 nF 5.6 nH
13
22 nH
4.7 nH
33 nF
30
10 pF
15 nH
8.2 nH
33 nF VCC
GPS RF SAW
VCC1 *Note 3 G2 BAND SEL LO IN
VCC2
CDMA IF OUTPUT IF Frequency 184 MHz 85 MHz C1 1.8 pF 22 pF R1 DNI DNI L1 68 nH 68 nH L2 C2 C3 L3 47 nH 270 nH IF SAW1 EPCOS B4955 LG 0085G2 68 nH 5.6 pF 5.6 pF 68 nH 7.5 pF 7.5 pF
GPS IF OUTPUT for use with SAW FILTER IF Frequency 184 MHz C4 DNI C5 C6 L4 180 nH L5 180 nH L6 47 nH R2 10 k IF SAW2 Murata SAFCC183MCA1 5.6 pF 5.6 pF
Note 1: L1, L2, and L3 may be substituted with 0402 wire-wound inductors of the same value. Note 2: For single-ended configurations, C3 and C6 are removed.
Note 3: If system specifications allow the removal of the GPS RF SAW Filter, see diagram below for pin 6 and pin 7 connections. 6 7
22 nH
4.7 nH
33 nF
30
10 pF
15 nH
8.2 nH
33 nF VCC
8-416
Rev A4 040421
RF2890
Application Schematic GPS LC Filter CDMA IF SAW Filter
CELL RF SAW
33 nH
33 nH VCC VCC 33 nF 33 nF 10 nH 6.2 pF DIV ENABLE SEL C1 24 0 0 1 23 22 21 20 19 18 L5
(0603 Wire-wound Coilcraft)
16 k
7.5 k
L2
(0603 Wire-wound Coilcraft)
C4 C2 L3
(0603 Wire-wound Coilcraft)
C6 GPS L4
(0603 Wire-wound Coilcraft)
L1 R1
(0603 Wire-wound Coilcraft)
C3
C5
VCC L6
(0603 Wire-wound Coilcraft)
2 33 nH CELL LNA IN 1.8 nH GPS LNA IN 1.2 pF DNI 5 G1 6 7 8 9 10 11 12 33 nF 4 /2 33 nF 3
17
16 C7 15 R1
C8
L7
(0603 Wire-wound Coilcraft)
CDMA IF (IFSAW1) SAW
CDMA
C9 14 TX BUFF ENAB LO OUT 33 nF 5.6 nH
13
22 nH
4.7 nH
33 nF
30
10 pF
15 nH
8.2 nH
33 nF VCC
GPS RF SAW
VCC1 *Note 4 G2 BAND SEL LO IN
VCC2
CDMA IF OUTPUT IF Frequency C7 184 MHz 1.8 pF 85 MHz 22 pF R1 DNI DNI L5 68 nH 68 nH L6 C8 C9 68 nH 5.6 pF 5.6 pF 68 nH 7.5 pF 7.5 pF L7 47 nH 270 nH IF SAW 1 EPCOS B4955 LG LG0085G2
IF Frequency 184 MHz
C1 DNI
R1 10 k
L1 330 nH
GPS IF OUTPUT L2 C2 C3 220 nH 5.6 pF 9 pF
L3 82 nH
C4 10 nF
C5 9 pF
L4 82 nH
C6 1 nF
Note 1: L3, L4, L5, L6, and L7 may be substituted with 0402 wire-wound inductors of the same value. Note 2: For single-ended configurations, C3 and C6 are removed. Note 3: L1 and L2 must be 0603 wire-wound inductors to achieve datasheet performance.
Note 4: If system specifications allow the removal of the GPS RF SAW Filter, see diagram below for pin 6 and pin 7 connections. 6 7
22 nH
4.7 nH
33 nF
30
10 pF
15 nH
8.2 nH
33 nF VCC
Rev A4 040421
8-417
RF2890
Evaluation Board Schematic IF Freq=183.6MHz (Cellular and GPS IF)
(Download Bill of Materials from www.rfmd.com.)
ENABLE VCC DIV SEL L66 27 nH VCC C24 33 nF L11 150 nH 50 strip J14 CELL MIXER IN
C1 33 nF C14 3.3 pF L1 8.2 nH
C16 33 nF
C17 33 nF
L6 39 nH
R5 7.5 k
J1 CELL LNA OUT
50 strip
C4 33 nF
R4 16 k C19 2.0 pF 18 C20 2.0 pF
C26 4.3 pF R6 22 k
50 strip
J12 GPS
24 0 0 1
23
22
21
20
19
L12 270 nH
J2 CELL LNA IN J5 GPS LNA IN
50 strip C2 33 nF C29 1.2 pF
C15 24 pF L16 1.8 nH DNI L4 5.6 nH
2
17
3 50 strip
16
C18 2.7 pF
R3 7.5 k
L3 220 nH
C11 6.8 pF
50 strip
4 C32 33 nF 5
/2
15 C8 2.7 pF C10 33 nF VCC L2 110 nH
J11 CDMA
14
VG1 C34 33 nF 6 7 8 9 10 11 12 13 C43 33 nF
50 strip L22 2.2 nH
TX BUF ENAB J9 LO OUT
L19 22 nH R8 30 C33 33 nF VCC C35 10 pF
L20 4.7 nH L21 15 nH L9 8.2 nH
C36 33 nF C38 33 nF C40 33 nF C41 33 nF
50 strip
VCC2 J8 LO IN
J6 GPS LNA OUT J7 GPS MIXER IN
50 strip
VCC1 BAND SEL
50 strip VG2
8-418
Rev A4 040421
RF2890
IF Output Interface Network
Single-End IF Matching
C3 IF+ IF10 9 4 5
C1
IF+
VCC IF Saw 100 pF
L2
L1
R
C2
IF-
C1
L1, C1, C2, 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 2 ----- ( C 1 + 2C 2 + C EQ ) 2
Where CEQ is the equivalent stray capacitance and capacitance looking into pins 9 and 10. An average value to use for CEQ is 2.5pF. R can then be used to set the output impedance according to the following equation:
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. C2 should first be set to 0 and C1 should be chosen as high as possible (not greater than 39pF), while maintaining an RP of L1 that allows for the desired ROUT. If the self-resonant frequencies of the selected C1 produce unsatisfactory linearity performance, their values may be reduced and compensated for by including C2 capacitor with a value chosen to maintain the desired FIF frequency. L2 and C3 serve dual purposes. L2 serves as an output bias choke, and C3 serves as a series DC block. In addition, L2 and C3 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 120nH) and C3 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.
Rev A4 040421
8-419
RF2890
Differential IF Matching
C2 IF Saw VCC IF+ IF10 9 4 5
IF+
L1
R
C1
IF-
L2 100 pF C2 L1
L1 and C1 are chosen to resonate at the desired IF frequency. C1 can be omitted and the value of L1 increased and utilized solely as a choke to provide VCC to the open-collector outputs, but it is strongly recommended that at least some small-valued C1 (a few pF) be retained for better mixer linearity performance. R is normally selected to match the input impedance of the IF filter. However, mixer performance can be modified by selecting an R value that is different from the IF filter input impedance, and inserting a conjugate matching network between the Resistive Output Network and the IF filter. C2 serve dual purposes. C2 serves as a series DC block when a DC path to ground is present in the IF filter. In addition, C2 may be chosen to improve the combine performance of the mixer and IF filter. L2 should choose to resonate with the internal capacitance of the SAW filter. Usually, SAW filter has some capacitance. Otherwise, L2 could be eliminated. A practical approach to obtain the differential matching is to tune the mixer to the correct load point for gain, IIP3, and NF using the single-end current combiner method. Second, use the component values found in the single-end approach as starting point for the differential matching. The two-shunt capacitors in the single-end could be converted in a parallel capacitor and the parallel inductor in the single-end need to be converted in two-choke inductor. Third, set the DC block capacitors (C2) in the differential-end matching to a high value (i.e., 100pF) and retune the resonate circuit (C1 & L1) and the resistor (R) for optimal performance. After optimal performance is achieved and if performance is not satisfactory, decrease the series capacitors until optimal performance is achieved.
8-420
Rev A4 040421
RF2890
PCB Design Requirements
PCB Surface Finish The PCB surface finish used for RFMD's qualification process is electroless nickel, immersion gold. Typical thickness is 3inch to 8inch gold over 180inch nickel. PCB Land Pattern Recommendation PCB land patterns are based on IPC-SM-782 standards when possible. The pad pattern shown has been developed and tested for optimized assembly at RFMD; however, it may require some modifications to address company specific assembly processes. The PCB land pattern has been developed to accommodate lead and package tolerances. PCB Metal Land Pattern
A = 0.64 x 0.28 (mm) Typ. B = 0.28 x 0.64 (mm) Typ. C = 2.50 (mm) Sq. 2.50 Typ. 0.50 Typ.
Pin 24 Pin 1 Dimensions in mm.
B A
B
B
B
B
B A A
Pin 18
0.50 Typ.
A A A A A C
1.25 2.50 Typ.
A A A A
0.55 Typ. B 0.55 Typ. 1.25 B B B B B
Pin 12
Figure 1. PCB Metal Land Pattern (Top View)
Rev A4 040421
8-421
RF2890
8-422
Rev A4 040421

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