Skyworks Solutions, Inc. Phone [781] 376-3000 Fax [781] 376-3100 sales@skyworksinc.com www.skyworksinc.com
200029B Skyworks Proprietary and Confidential Information Products and Product Information are Subject to Change Without Notice January 14, 2005
1
PRODUCT SUMMARY
SKY74691: Receiver for CDMA Mobile Handset Applications
Applications
Single mode CDMA handsets
Features
Three-step gain control, cellular LNA
External resistor to adjust LNA bias current
Buffered LO signal for transmit upconverter
VGA with 90 dB dynamic range
Integrated IF VCO and tank circuit
VCO_ON auto-tuning control
Battery cell operation (2.7 V < VCC < 3.3 V)
RFLGATM (48-pin, 7 x 7 mm) Pb-free package (MSL3, 260 C
per JEDEC-J-STD-020) with downset paddle
Description
The SKY74691 is a highly integrated, super-heterodyne receiver.
This single band receiver is intended for use in Code Division
Multiple Access (CDMA) phones in cellular CDMA mode.
Except for the Surface Acoustic Wave (SAW) filters and matching
components, the device incorporates all the components required
to implement the receiver chain, from the Low-Noise Amplifier
(LNA) to the In-Phase and Quadrature (I/Q) demodulator stages.
After RF LNA signal amplification and filtering from the antenna,
the received signal is downconverted from RF to the Intermediate
Frequency (IF).
The LO_IN signal (pin 39) provides a Local Oscillator (LO) port for
the RF mixer. The UHF Voltage Controlled Oscillator (VCO) is
buffered and amplified internally, and provides the LO to drive the
LO port of a transmitter upconverter (such as Skyworks
CX74002).
The Variable Gain Amplifier (VGA) has a minimum dynamic range
of 90 dB with a control voltage range of 0.2 to 2.7 V. A VHF
oscillator operates with an internal tank circuit to provide LO
frequencies for the I/Q demodulator.
The noise figure, gain, and third order Input Intercept Point (IIP3)
of each stage in the receiver are optimized to meet the system
requirements for CDMA according to TIA/EIA-98-B/C. The design
employs SiGe BiCMOS technology for low cost, high performance,
and a high level of integration.
The device package and pinout for the 48-pin RF Land Grid Array
(RFLGA) are shown in Figure 1 and a block diagram of the
SKY74691 is shown in Figure 2.
Skyworks offers lead (Pb)-free "environmentally
friendly" packaging that is RoHS compliant
(European Parliament for the Restriction of
Hazardous Substances).
1
14 15
16 17
18 19
20 21
22
23 24
48 47
46 45
44 43
42 41
40
39 38
2
3
4
5
6
7
8
9
10
11
13
12
37
36
35
34
33
32
31
30
29
28
27
25
26
S307
GND
CELL_LNA_IN
GND
N/C
GND
N/C
LNA_0
LNA_1
VCO_ON
VCO_DEC_CAP
VCO_TUNE
PLL
VCC_VCO
I+
I
Q+
Q
XTAL
SLEEP
VGACTRL
N/C
GND
CELL_LNA_OUT
N/C
N/C
GND
RF_BIAS_RES
N/C
CELL_MIX_IN
MIX_VCC
LO_IN
MODE_0
LO_OUT
MODE_1
LO_BUFF_VCC
N/C
N/C
CELL_IF+
CELL_IF
N/C
N/C
VGA_VCC
N/C
CDMA_VGA_IN+
CDMA_VGA_IN
VCC_RF_BIAS
LNA_BIAS_RES
BUFF_EN
Figure 1. SKY74691 Pinout 48-Pin RFLGA
(Top View)
PRODUCT SUMMARY SKY74691
Skyworks Solutions, Inc. Phone [781] 376-3000 Fax [781] 376-3100 sales@skyworksinc.com www.skyworksinc.com
2
January 14, 2005 Skyworks Proprietary and Confidential Information Products and Product Information are Subject to Change Without Notice 200029B
CELL_LNA_OUT
CELL_MIX_IN
LO_IN
AFC
VCO_TUNE
PLL
I+
I
Q+
Q
XTAL
CELL_LNA_IN
S308
90
o
2
2
4
CDMA_VGA_IN+
Cellular Mixer
CDMA, 800 MHz
Cellular LNA
CDMA, 800 MHz
CDMA_VGA_IN
LO_OUT
CELL_IF+
CELL_IF
2
Figure 2. SKY74691 Receiver Block Diagram
Ordering Information
Model Name
Manufacturing Part Number
Product Revision
SKY74691 CDMA Receiver
SKY74691-11
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