파트넘버.co.kr TA0003 데이터시트 PDF


TA0003 반도체 회로 부품 판매점

HBT Technology Adds Power to CDMA Chip Set



RF Micro Devices 로고
RF Micro Devices
TA0003 데이터시트, 핀배열, 회로

TA0003
TA0003
HBT Technology Adds Power to CDMA Chip Set
    
          
        

   
Efficient bandwidth utilization and low operating power
characterize code-division-multiple-access (CDMA)
transmissions, capturing the interest of several major
telephone carriers in the technology. In support of
future CDMA and dual-mode (analog/CDMA) handset
designs, the engineers at RF Micro Devices (Greens-
boro, NC), in cooperation with CDMA-developer Qual-
comm, Inc.(San Diego, CA) and device foundry TRW
(Redondo Beach, CA), have created an RF chip set
with the performance levels required by CDMA system
designers.
The chip set is based on the low-power GaAs hetero-
junction-bipolar-transistor (HBT) device technology
from TRW. The CDMA chips perform all the RF front-
end functions in a handset (Fig. 1), including frequency
translation, RF and intermediate-frequency (IF) amplifi-
cation, and automatic gain control (AGC).
The chip set consists of the RF9906 low-noise ampli-
fier (LNA)/mixer, the RF9908 upconverter integrated
circuits (ICs), and the RF9907 and RF9909 AGC
amplifier ICs. These ICs can be used in a handset
design prior to second-stage frequency conversion.
The RF9906 integrates a low-noise preamplifier, dou-
ble-balanced mixer, two switched variable-gain IF
amplifiers, and a switched local-oscillator (LO) output
buffer amplifier (Fig. 2). The IC is housed in a QSOP-
24 surface-mount package and is designed to provide
high dynamic range from a single +3.6 VDC supply
without additional external matching networks or bias
circuitry.
The RF9906 is optimized for 850 to 900 MHz assum-
ing 2.5 to 3.0 dB external image filter loss, although the
wideband circuits provide similar performance from
500 to 1500 MHz. The 1 dB IF bandwidth is 110 MHz
to either output port.
The overall gain of the RF9906 is 26 dB to the differen-
tial (IF1) port or 16 dB to the single-ended (IF2) port at
the nominal gain setting. The gain can be tuned by (4.5
dB by adjusting a control voltage between 0.5 and 2.5
V. The IF output impedance is 1kfor IF1 and 750
for IF2 ports. The overall noise figure is 2.8 dB and the
input third-order intercept point is -8 dBm at the nomi-
nal gain setting. The RF and LO input-port VSWRs are
less than 1.50:1, while the LO output-port VSWR is
less than 2.00:1. The LO-to-RF isolation is more than
50 dB in addition to image filter rejection.
The RF9906’s LNA employs a combination of series
and shunt feedback around a common-emitter ampli-
fier to achieve excellent port impedance match without
reactive elements. The gain is 16 dB, with more than
22 dB reverse isolation at 880 MHz (Fig. 3). The noise
figure is less than 1.5 dB at frequencies below 1.2 GHz
(Fig. 4). The input third-order intercept point is -3 dBm.
The DC current drain is 7 mA.
Power Amp & Driver
RF Micro Devices
RF9908
Upconverter
RF Micro Devices
RF9909
Tx AGC Amp
DUPLEXER
UHF
Synth
VCTCXO
Synth
Qualcomm BB2
Baseband Analog ASIC
DAC
DAC
VCO/
SYNTH
VCO
ADC
ADC
Qualcomm MSM 2
Mobile Station
MODEM ASIC
MODULATOR
INTERLEAVER
CONTROL
PROCESSOR
VOCODER
VITERBI
DECODER
CDMA
DEMOD
KEYPAD
RINGER
LCD &
DRIVER
AUDIO
CODEC
RF Micro Devices
RF9906
LNA/Mixer
RF Micro Devices
RF9907
Rx AGC Amp
ADC
ADC
FM
DEMOD
Figure 1: The CDMA chips provide the basic front-end functions required by a handset design.
Speaker
Mic
Car Kit
13
13-25


TA0003 데이터시트, 핀배열, 회로
TA0003
Vcc
100 nF
1 nF
RF IN
1F2 OUT
FM IF
Filter
L2
C2
IF SELECT
IF 1 OUT
+
IF 1 OUT
-
CDMA IF Filter
V CC
C1
C1
100 nF
L1
1 nF
22 pF
1
2
3
4
5
6
7 SELECT
LOGIC
8
9
10
L1
22 pF
11 IF GAIN
ADJUST
12
24
23
22
21
1 nF
20
19
1 nF
18
17
16
15
1 nF
14
1 nF
13
RF IMAGE
FILTER, 50
LO BUFFER OUT
LO BUFFER ENABLE
LO
IN
GAIN ADJUST
(0.2 - 2.9 V)
10 k
Figure 2: The RF9906 integrates an LNA, mixer, two switched variable-gain IF ampli-
fiers, and a switched local-oscillator (LO) output buffer.
13
The RF9906’s double-balanced mixer is a series-con-
nected differential RF amplifier with a cross-coupled
active LO switch (Gilbert cell). Series feedback sets
the third-order intercept point. The mixer draws 9 mA
and features measured double-sideband noise figure
of 9 dB and an input third-order intercept point of +6
dBm. The 50 device can achieve an input third-order
intercept point of +10 dBm at +4.8 VDC with no
increase in noise figure. The mixer’s gain is reduced by
only 0.4 dB when the LO power is reduced to -9 dBm.
Two variable-gain IF amplifiers follow the mixer,
selected by logic-level signals. The gain-control circuit
uses a phase-cancellation technique. The mixer noise
figure and input third-order intercept point are affected
by less than 1 dB by the IF output selection at the nom-
inal gain setting. The mixer’s gain at the IF1 port is
13.5 ± 4.5 dB while gain at the IF2 port is 3.5 ± 4.5 dB.
Current drains for the IF1 and IF2 selections, including
bias and logic circuits, are 14 and 6 mA, respectively.
The switched LO output buffer provides 0-dB gain into
a 50 load over the LO input-power range of -6 to -3
dBm. The isolation to the LO port is 20 dB. The on/off
output ratio is also 20 dB. The buffer, with an AC-cou-
pled output port, is switched on with greater than 3.1 V
on pin 15. DC current drain is dependent upon the LO
13-26
drive, being 2.7 mA with -6-dBm LO power and 4.3 mA
with 0 dBm LO power.
The RF9908 upconverter IC is housed in an eight-pin
SOIC package. It contains a Gilbert-cell mixer with dif-
ferential IF inputs and differential LO ports (for single-
ended LO operation, one port is connected to an AC
ground). The mixer is followed by a Class B push-pull
output buffer amplifier. The IC operates at +3.6 VDC
with 0 dB conversion gain and +13 dBm output third-
order intercept point. The gain and intercept-point per-
formances are not affected by changing the LO level.
The mixer is made of a differential pair amplifier and a
four-quadrant multiplier. The lower differential part of
the mixer pair is the IF amplifier, which has emitter-
degeneration resistors to reduce the IF gain. By keep-
ing the IF level small and well below the LO level,
mixer linearity improves. The upper portion of the
mixer incorporates switching transistors. Large LO sig-
nals (ideally square waves) are applied to the bases of
the two cross-coupled transistors to alternately turn the




PDF 파일 내의 페이지 : 총 5 페이지

제조업체: RF Micro Devices

( rfmd )

TA0003 data

데이터시트 다운로드
:

[ TA0003.PDF ]

[ TA0003 다른 제조사 검색 ]




국내 전력반도체 판매점


상호 : 아이지 인터내셔날

전화번호 : 051-319-2877

[ 홈페이지 ]

IGBT, TR 모듈, SCR, 다이오드모듈, 각종 전력 휴즈

( IYXS, Powerex, Toshiba, Fuji, Bussmann, Eaton )

전력반도체 문의 : 010-3582-2743



일반적인 전자부품 판매점


디바이스마트

IC114

엘레파츠

ICbanQ

Mouser Electronics

DigiKey Electronics

Element14


관련 데이터시트


TA0003

HBT Technology Adds Power to CDMA Chip Set - RF Micro Devices