Datenblatt-pdf.com


RF2861PCBA-410 Schematic ( PDF Datasheet ) - RF Micro Devices

Teilenummer RF2861PCBA-410
Beschreibung CDMA LOW NOISE AMPLIFIER/MIXER 900MHz DOWNCONVERTER
Hersteller RF Micro Devices
Logo RF Micro Devices Logo 




Gesamt 14 Seiten
RF2861PCBA-410 Datasheet, Funktion
0
Typical Applications
• CDMA/JCDMA Cellular Systems
• CDMA450 Handsets/Data Cards
• AMPS Cellular Systems
RF2861
CDMA LOW NOISE AMPLIFIER/MIXER
900MHz DOWNCONVERTER
• General Purpose LNA and Downconverter
• Commercial and Consumer Systems
• Portable Battery-Powered Equipment
Product Description
The RF2861 is a receiver front-end for CDMA cellular
applications, including JCDMA and CDMA450. It is
designed to amplify and downconvert RF signals, using a
three gain state LNA to obtain 17dB of stepped gain con-
trol. Features include digital control of LNA gain and
power down mode, along with an integrated TX LO buffer
amplifier. Another feature of the chip is adjustable IIP3 of
the LNA and mixer using off-chip current setting resistors
to allow for minimum DC current consumption. Noise fig-
ure, IIP3, and other specs are designed to be compatible
with the TIA/EIA 98D standard for CDMA cellular commu-
nications. The IC is manufactured on an advanced Silicon
Germanium Bi-CMOS process and is in a 3mmx3mm,
16-pin, QFN.
Optimum Technology Matching® Applied
Si BJT
GaAs HBT
GaAs MESFET
Si Bi-CMOS
InGaP/HBT
SiGe HBT
Si CMOS
9GaN HEMT
SiGe Bi-CMOS
16 15 14 13
G2 1
12 LO IN
LNA IN 2
11 GND
LNA EMITTER 3
10 IF OUT-
LNA OUT 4
9 IF OUT+
5678
Functional Block Diagram
0.10 C A
-A-
3.00
2 PLCS
1.50 TYP
2 PLCS
0.10 C B
0.70
0.65
0.05 C
0.90
0.85
0.05
0.00
3.00
2 PLCS
0.10 C B
2 PLCS
0.10 C A
2.75 SQ
-B-
1.37 TYP
0.60
0.24
TYP
NOTES:
1. Shaded lead is pin 1.
2 Dimension applies to plated terminal: to be measured
between 0.20 mm and 0.25 mm from terminal end.
12°
MAX
Dimensions in mm.
SEATING
-C- PLANE
0.10 M C A B
0.30
0.18 2
PIN 1 ID
R.20
1.65
1.35
SQ.
0.50
0.30
0.50
Package Style: QFN, 16-Pin, 3x3
Features
• 3mmx3mm LNA/Mixer Solution
• Adjustable LNA and Mixer Current/IIP3
• Meets IMD Tests with Three Gain
States/Two Logic Control Pins
• Integrated TX LO Buffer Amplifier
• Full ESD Protection on all Pins
Ordering Information
RF2861
CDMA Low Noise Amplifier/Mixer 900MHz Down-
converter
RF2861 PCBA-410 Fully Assembled Evaluation Board
RF Micro Devices, Inc.
7628 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
Rev A2 040107
8-1






RF2861PCBA-410 Datasheet, Funktion
RF2861
Pin Function Type Description
1 G2 DI Gain control logic input. See logic control table.
Interface Schematic
G2
2
LNA IN
AI Cellular LNA input.
LNA IN
VCC
LNA OUT
LNA EMITTER
3
LNA
AO Cellular LNA emitter. A small inductor connects this pin to
See pin 2.
EMITTER
ground. Cellular LNA gain can be adjusted by the inductance.
4 LNA OUT AO Cellular LNA output. Simple external L-C components
required for matching and VCC supply.
See pin 2.
5
ISET2
AO An external resistor connected to this pin sets the current of
the mixer. Increasing resistance decreases current.
6
ISET1
AO An external resistor connected to this pin sets the current of
the LNA. Increasing resistance decreases current.
7 G1 DI Gain control logic input. See logic control table.
G1
8
MIX IN
AI Cellular mixer RF single-end input.
MIX IN
9
IF OUT+
AO CDMA IF output. Open collector.
IF OUT+
IF OUT-
10
IF OUT-
AO CDMA IF output. Open collector.
11 GND P Ground.
12
LO IN
AI LO single-end input. Matched to 50.
See pin 9.
LO IN
70
13 VCC P LO amplifier VCC external bypass capacitor may be required.
14
LO OUT
AO LO output. Internal DC block. Drives 50.
15
TX BUFF
DI Logic input. High enables TX LO output buffer amplifiers.
ENABLE
TX BUFF ENABLE
16
ENABLE
DI Logic input. Low level powers down the IC.
ENABLE
Pkg
Base
Legend:
GND
8-6
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
P=VCC or GND
AO=Analog Output
Rev A2 040107

6 Page









RF2861PCBA-410 pdf, datenblatt
RF2861
Single-End IF Matching
IF Output Interface Network
IF+ 10
IF- 9
4
5
IF Saw
C3
VCC
33 nF
L2 L1
R
C1
IF+
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:
fIF
=
-----------------------------1------------------------------
2π L--2--1--(C1 + 2C2 + CEQ)
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:
R
=
-4-------R--1--O----U---T-
-R-1--P--
–1
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 main-
tain 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.
8-12
Rev A2 040107

12 Page





SeitenGesamt 14 Seiten
PDF Download[ RF2861PCBA-410 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
RF2861PCBA-410CDMA LOW NOISE AMPLIFIER/MIXER 900MHz DOWNCONVERTERRF Micro Devices
RF Micro Devices

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche