RFMD RF2958PCBA

RF2958
0
2.4GHz SPREAD-SPECTRUM TRANSCEIVER
Typical Applications
• IEEE 802.11b WLANs
• High Speed Digital Links
• Wireless Residential Gateways
• Wireless Security
• Secure Communication Links
• Digital Cordless Telephones
Product Description
The RF2958 is a single-chip transceiver specifically
designed for IEEE 802.11b applications. The part
includes all required transceiver functions. The receiver
includes: an LNA and downconverter; complete synthesizers and VCO’s; direct conversion from IF receiver with
variable gain control; quadrature demodulator; I/Q baseband amplifiers; and, on-chip baseband filters. For the
transmit side, a QPSK modulator and upconverter are
provided along with the synthesizer, VCO, and PA driver.
A minimum number of external components are required,
resulting in an ultra-compact low-cost radio design. Twocell or regulated three-cell (3.6V maximum) battery applications are supported by the part. The RF2958 is also
part of a 2.4GHz chipset along with our high-efficiency
GaAs HBT PA and the RF3002 Baseband Processor.
Optimum Technology Matching® Applied
TX Q
GaN HEMT
Q BYP
InGaP/HBT
I BYP
Si CMOS
TX I
SiGe HBT
VCC BB
Si Bi-CMOS
RX Q
GaAs MESFET
RX I
GaAs HBT
RX VGC
Si BJT
32
31
30
29
28
27
26
25
3rd Order
Bes LPF
3rd Order
Bes LPF
3rd Order
Bes LPF
IF IN+ 1
9SiGe Bi-CMOS
0.900
± 0.070
5.000
± 0.050
Shaded lead is pin 1.
Dimensions in mm.
3.400
0.400
± 0.050 TYP
-C-
SEATING
PLANE
3.400
SCALE:
NONE
0.025
± 0.010
0.100 M C
0.500
TYP
0.080 C
Package Style: QFN, 32-Pin, 5x5
Features
• Complete IEEE802.11b Transceiver
including VCOs
3rd Order
Bes LPF
24 VREF
RF PLL
Voltage
Regulator
IF Synth Analog
IF IN- 2
5.000
± 0.050
23 DIG REG
• Small 32-pin Leadless Package
• Minimal External Components Required
22 VCC PLL4
VCC IF 3
• Low Receive Current
21 SCLK
RX IF
Voltage
Regulator 1
RX IF
Voltage
Regulator 2
• High Performance Super-het Architecture
SPI Serial Port
20 SSB
Frac-N Digital
P&R
R BIAS 4
D/A
MUX
19 SDI
VCC RF2 5
VCC RF1 6
Ordering Information
Digital
Voltage
Regulator
IF OUT- 7
18 MCLK
LC Trap
RF PLL
Voltage
Regulator
RF Synth Analog
IF OUT+ 8
10
11
12
13
14
15
16
TX VGC
RF OUT
VCC RF3
RF IN
LNA GS
VCC PLL1
PLL REG
MODE1
17 MODE0
9
Functional Block Diagram
Rev A0 050209
RF2958
RF2958TR13
RF2958 PCBA
2.4GHz Spread-Spectrum Transceiver
2.4GHz Spread-Spectrum Transceiver (Tape & Reel)
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
11-263
RF2958
Absolute Maximum Ratings
Parameter
Refer to “Handling of PSOP and PSSOP Products” on page 16-15 for
special handling information.
Supply Voltage
Control Voltages
Input RF Level
Operating Ambient Temperature
Storage Temperature
Parameter
Rating
Unit
-0.5 to +3.6
-0.5 to +3.6
+12
-40 to +85
-40 to +150
VDC
VDC
dBm
°C
°C
Specification
Min.
Typ.
Max.
Refer to “Soldering Specifications” on page 16-13 for special soldering information.
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
VCC =3.0V, T=+25°C, MCLK=44MHz,
unless otherwise specified
Receiver LNA/RF
RF Frequency Range
IF Frequency Range
Voltage Gain - High
Voltage Gain - Low
Noise Figure - High Gain
Noise Figure - Low Gain
Input IP3 - High Gain
Input IP3 - Low Gain
Input P1dB - High Gain
Input P1dB - Low Gain
Input Return Loss
Output Impedance
Image Rejection
Condition
2400
363
32
(20dB
power)
-1
(-13dB
power)
35
(23dB
power)
+2
(-10dB
power)
4
32
2500
385
38
(26dB
power)
+5
(-7dB
power)
MHz
MHz
dB
dB
dBm
dBm
dBm
dBm
dBm
dBm
dB
Ω
dB
-23
+8
-30
-2
10
750
30
374MHz ±11MHz
LNA/mixer voltage gain (Note: into output
impedance). LNA/mixer/SAW filter voltage
gain. LNA GS=1
LNA/mixer voltage gain. LNA GS=0
Z0 =50Ω
Receiver
IF VGA/Baseband
IF Frequency Range
IF Input Impedance
Voltage Gain - High
374
750
70
MHz
Ω
dB
Voltage Gain - Low
4
dB
Gain Accuracy
±3
Gain Response Time
Gain Flatness
Input Referred Noise
Input V1dB
Output Distortion
Output Voltage
Output V1dB
11-264
-0.25
500
1.0
0.75
1.25
dB
300
ns
+0.25
dB
11
uVRMS
mVP-P
%
VP-P
VP-P
VGC =1.25V (measured to single-ended output)
VGC =1.95V (measured to single-ended output)
For a given RX VGC voltage, the measured
gain should lie within ±3dB of ideal
Measured with a DC step from 1.3V to 1.8V
to 90% final value (within 1dB)
374MHz ±11MHz, relative to gain at
374MHz
Measured into the IF VGA pin.
1dB compression of IF strip.
Measured at input to RF3002 single-ended.
Single-ended.
Rev A0 050209
RF2958
Parameter
Specification
Min.
Typ.
Max.
Unit
Condition
Receiver
IF VGA/Baseband, cont’d
Group Delay
Filter Rejection
Output Impedance
I/Q Magnitude Error
I/Q Phase Error
I/Q DC Offset
DC Step
VREF
VREF Output Current
15
20
1.65
1.0
1.7
±0.35
±3.0
10
40
1.75
ns
dB
Ω
dB
°
mV
mV
V
mA
Transfer function - 3 pole Bessel at 9MHz
f<1MHz
SQRT [(VOUTI -VREF)^2+(VOUTQ -VREF)^2)]
VGC step 1.3V to 1.8V, PIN =-50dBm
3% variation
Source
Transmitter
Modulator/Baseband
I/Q Magnitude Error
I/Q Phase Error
Input Signal (Single-Ended)
Input Signal Magnitude
Input P1dB
Voltage Gain to IF
Output Voltage
Output SNR
Carrier Leakage
±0.35
±3.0
-20
dB
°
mVP-P
mVP-P
mVP-P
dB
mVP-P
dB
dBc
20
mVP-P
uVRMS
200
282
566
4
448
6
564
32
8
710
SQRT(I^2+Q^2)
6dB from input
Measure from complex magnitude to IFVP-P
Connected to SAW filter
Single sideband modulation
VGA Driver/Upconverter
Input P1dB
Input Referred Noise
Minimum Gain
Maximum Gain
Gain Response Time
Image Rejection
RF LO Leakage
Output Voltage
Minimum Output Power
Maximum Output Power
Rev A0 050209
550
0
300
dB
dB
ns
1000
dB
dBm
mVP-P
17
30
-25
-36
-12
0
dBm
dBm
6dB from max input
Measured in 11MHz bandwidth at 2.442GHz
upconverter gain >12dB
TX VGC at 1.3V
TX VGC at 1.9V
Measured with 300mV change in gain on
TXVGC to 90% of final POUT.
FLO =2048MHz to 2110MHz
802.11b output with 7dB to 20dB gain
(needed for +20dBm POUT).
TXVGC at 1.3V
Meeting 802.11b Spectral Mask
11-265
RF2958
Parameter
Specification
Min.
Typ.
Max.
Unit
Condition
Digital Input
Specifications
Apply to pins: SSB, SDI, SCLK,
MODE0, MODE1
Input High Voltage (VIH)
Input Low Voltage (VIL)
Input High Static Current (IIH)
Input Low Static Current (IIL)
Reset Time
Apply to pins: SSB, SDI, SCLK
Input Setup Time (TSU)*
Input Hold Time (THLD)*
Input Rise/Fall Time (TRFI)
Input Clock to Select Time (TCS)
Input Clock Pulse Width High
(TCWH)
Input Clock Pulse Width Low
(TCWL)
PLL Recalibration Pulse Width
(TRC)
0.7VDD
0.3VDD
5
5
50
5
5
V
V
µA
µA
µs
Exiting Reset mode or using SPI Reset
5
22
ns
ns
ns
ns
ns
22
ns
1/fr
s
For fr=22MHz, TRC is 45.5ns minimum
V
V
ns
With 1mA load
With 1mA load
With 20pF maximum load capacitance measured from 10% to 90% of output voltage
Output at (VDD -0.3V)
Output at 0.3V
MCLK can be driven DC-coupled by a
CMOS clock oscillator with rail-to-rail outputs. Other oscillator configurations may
require AC-coupling.
5
Digital Driver Output
Apply to pin: SDI (output mode)
Output High Voltage (VOH)
Output Low Voltage (VOL)
Output Rise/Fall Time (TRFO)
Output Current Source (|IOH|)
Output Current Sink (|IOL|)
0.8VDD
0.2VDD
5
3.8
10
mA
mA
500
mV
MCLK Input (AC-Coupled)
Apply to pin: MCLK
Peak-to-Peak Input Voltage
(VP-P)
DC Bias at MCLK (MCLK_DC)
0.6
1.1
V
Specification Valid Range
Temperature
-30
+70
°C
Supply Voltage
2.7
3.0
3.6
V
Transmit Current
50
68
80
mA
Receive Current
30
52
60
mA
Idle Current
5
28
40
mA
Reset Current
1
2
mA
Hibernate Current
0.2
0.5
mA
*Setup and Hold Times are measured from the time where the waveforms cross VDD/2.
11-266
MODE0=0, MODE1=1
MODE0=1, MODE1=0
MODE0=0, MODE1=0
MODE0=1, MODE1=1
Rev A0 050209
RF2958
Digital Timing Specifications
TCWH
TCS
TCWL
SSB
SCLK
MSB
LSB
SDI
TSU
Internal Recal pulse
Rev A0 050209
THLD
TRC
11-267
RF2958
Pin
1
2
3
4
Function
IF IN+
IF INVCC IF
R BIAS
5
6
7
8
9
VCC RF2
VCC RF1
IF OUTIF OUT+
TX VGC
10
11
RF OUT
VCC RF3
12
13
14
15
16
17
18
19
20
21
22
RF IN
LNA GS
VCC PLL1
PLL REG
MODE1
MODE0
MCLK
SDI
SSB
SCLK
VCC PLL4
23
24
DIG REG
VREF
25
Q BYP
26
27
TX Q
I BYP
28
29
30
31
32
Pkg
Base
TX I
VCC BB
RX Q
RX I
RX VGC
GND
ESD
11-268
Description
Differential input from IF SAW filter. See application schematic for matching circuit.
See pin 1.
Power supply for IF circuitry. Provide 330pF bypass capacitor close to this pin.
Bandgap voltage reference for on-chip biasing. Install a 22.1kΩ,
1% resistor from this pin to ground.
Power supply for TX and RX bias, LO buffers and mixers. Provide 6pF bypass capacitor close to this pin.
See pin 5.
Differential output to IF SAW filter. See application schematic for matching circuit.
See pin 7.
TX analog gain control. Depending on desired operation mode, transmitter gain can be controlled through
this pin or the three-wire digital interface. This pin can also provide a bias voltage to an external PA. See
theory of operation for details.
TX PA driver output.
Power supply for LNA and TX output driver. Power should be connected to this pin through an inductor or a
long 50Ω transmission line RF-shorted with a 6pF capacitor at the other end.
RX input from antenna.
Gain select pin for the internal LNA. High-gain operation is selected when this pin is a logic ‘1’.
Power supply for the PLL RF LO synthesizer. Provide 0.01µF and 6pF bypass capacitors close to this pin.
Internal PLL regulator output. Bypass with 10nF capacitor. Do not connect to VCC or ground.
Controls operational state of the device. See Theory of Operation section for details.
See pin 16.
Reference oscillator for the PLL synthesizer.
Data signal for the synchronous three-wire digital control interface.
Chip select signal for the synchronous three-wire digital control interface.
Clock signal for the synchronous three-wire digital control interface.
Power supply for the PLL IF LO synthesizer. Provide 0.01µF and 330pF bypass capacitors close to this
pin.
Internal digital regulator output. Bypass with 10nF capacitor. Do not connect to VCC or ground.
I/Q DC reference voltage for the baseband processor. This pin should be connected to a high impedance
on the baseband processor.
Baseband differential input signal for the TX quadrature channel. For single-ended applications, bypass to
ground with a 0.01µF capacitor.
Baseband input signal for the TX quadrature channel.
Baseband differential input signal for the TX in-phase channel. For single-ended applications, bypass to
ground with a 0.01µF capacitor.
Baseband input signal for the TX in-phase channel.
Power supply for baseband circuitry. Provide 0.01µF bypass capacitor close to this pin.
Baseband output signal for the RX quadrature channel.
Baseband output signal for the RX in-phase channel.
Analog gain control for the RF IF amplifier.
Device ground. Connect directly to PCB ground plane.
All pins except pin 12 are provided with electrostatic discharge protection to 3kV using the human body
model.
Rev A0 050209
RF2958
RX VGC
RX I
RX Q
VCC BB
TX I
I BYP
TX Q
Q BYP
Pin Out
32
31
30
29
28
27
26
25
IF IN+ 1
24 VREF
IF IN- 2
23 DIG REG
VCC IF 3
22 VCC PLL4
R BIAS 4
21 SCLK
VCC RF2 5
20 SSB
VCC RF1 6
19 SDI
IF OUT-
18 MCLK
7
Rev A0 050209
9
10
11
12
13
14
15
16
RF OUT
VCC RF3
RF IN
LNA GS
VCC PLL1
PLL REG
MODE1
17 MODE0
TX VGC
IF OUT+ 8
11-269
RF2958
RX VGC
RX I
RX Q
VCC BB
TX I
I BYP
TX Q
Q BYP
Detailed Functional Block Diagram
32
31
30
29
28
27
26
25
3rd Order
Bes LPF
IF IN+ 1
3rd Order
Bes LPF
3rd Order
Bes LPF
24 VREF
3rd Order
Bes LPF
RF PLL
Voltage
Regulator
IF Synth Analog
IF IN- 2
23 DIG REG
22 VCC PLL4
VCC IF 3
21 SCLK
RX IF
Voltage
Regulator 1
RX IF
Voltage
Regulator 2
SPI Serial Port
20 SSB
Frac-N Digital
P&R
R BIAS 4
D/A
MUX
19 SDI
VCC RF2 5
VCC RF1 6
Digital
Voltage
Regulator
IF OUT- 7
LC Trap
RF PLL
Voltage
Regulator
RF Synth Analog
IF OUT+ 8
11-270
18 MCLK
9
10
11
12
13
14
15
16
TX VGC
RF OUT
VCC RF3
RF IN
LNA GS
VCC PLL1
PLL REG
MODE1
17 MODE0
Rev A0 050209
RF2958
Theory of Operation
The RF2958 is a single-chip transceiver designed specifically for IEEE 802.11b wireless LAN applications. In addition to
typical transceiver functions of RF conversion of both the transmit and receive signals, the RF2958 incorporates a lownoise amplifier (LNA) and a dual phase-locked loop (PLL) frequency synthesizer to reduce end-product component
count and to simplify integration into end-products. The RF2958 uses a superheterodyne frequency conversion architecture in both the transmit and receive signal paths for superior performance in 802.11b applications. It also incorporates
power conservation functionality to increase battery life in portable and mobile applications. When used with the RF3002
baseband processor and RF5189 power amplifier (PA), the RF2958 is part of a complete PHY solution for 802.11b applications (see figure below, 2.4GHz IEEE 802.11b Chipset Block Diagram).
fC = 374 MHz
BW = 20 MHz
RF3002
RF2958
RXVGC
DAC
CCA
RX VGC
RX VGC
RF5189
CCA
ANT SEL
RX I
REF
TX/RX
SWITCH
TX VGC
TX PE
RX PE
802.11
Preamble/
Header
I IN
ADC
RX Q
ANTENNA
DIVERSITY
SWITCH
LNA GS
VREF
Data Converter
Reference
Demodulator
fC = 2450 MHz
BW = 100 MHz
RX DATA
Q IN
ADC
RX RDY
TX I
DATA CLK
TX VGC
DAC
Control
Port
SPI
Mode Control
TX Q
I OUT
DAC
PLL/Power
Control Registers
TX DATA
Modulator
Serial Data
Interface
RF PLL
IF PLL
Q OUT
DAC
TX RDY
802.11
Preamble/
Header
Tx Length
Tx Signal
Service
RX PE
TX PE
M CLK
SDI
SYSTEM ARCHITECTURE
The overall system architecture is based around a superheterodyne conversion process. For the transmitter side, the
baseband in-phase (I) and quadrature (Q) signal components are converted to an intermediate frequency (IF) of
374MHz. An external SAW filter is used to filter out undesired spurious frequencies. The IF is then converted to the overthe-air radio frequency (RF) between 2.412GHz and 2.483GHz using low-side injection. The RF output drives a PA to
amplify the signal to the desired power level at the antenna. Generally the PA is followed by a TX/RX switch and a band
pass filter which eliminates the undesired sideband resulting from the mixing process before broadcasting the signal
through the antenna.
The receiver is the inverse of this process. The signal from the antenna passes through the band pass filter, which is in
this case acting as a pre-selection filter. The received signal passes through the integrated LNA and is converted to an IF
of 374MHz. The signal then passes through a SAW filter, which acts to reject adjacent channels as defined by the
802.11 standard. Due to the bandwidth of this filter, adjacent channels must be at least 20MHz apart. The filtered IF signal is then downconverted to baseband I and Q components.
The local oscillators required by the mixing process are generated by internal IF and RF PLL frequency synthesizers.
These are controlled through a three-wire serial data interface.
Rev A0 050209
11-271
RF2958
GENERAL APPLICATION INFORMATION
This part is used at high frequencies. Proper attention to layout and component selection is critical in order to achieve the
specified performance. Values for DC blocking capacitors and power supply bypass capacitors should be selected so
that they are series self-resonant at the frequency of operation. In addition, transmission line techniques should always
be used on signal lines at RF frequencies, and may be required on signal lines at IF frequencies if connections are long
with respect to wavelength.
The RF2958 should be powered from regulated supply. If not sharing this supply with the MCLK oscillator, the MCLK
oscillator should also be powered from a well-regulated supply. Avoid sharing the RF2958 and MCLK oscillator supplies
with the baseband processor and/or MAC.
Power supply bypassing of VCC lines for the PLL is critical in order to minimize the effects of power supply noise on
phase noise performance. In addition to RF/IF bypassing, these lines should be bypassed with low-frequency capacitors.
A value of 0.01µF is sufficient for most applications, but performance should be verified by looking at a modulated signal
on a vector signal analyzer or a constant signal on a spectrum analyzer or phase noise test set.
Since this is a mixed-signal device, care should be taken to separate traces connecting to digital circuits from those connecting to analog circuits. Power supply bypassing is important to keep the noise contributions of digital circuits to a minimum. It is generally better to start with more bypassing than you think you need, then remove components and reevaluate performance.
ENABLE/DISABLE MODES
Operation of the device is controlled by the MODE0 and MODE1 pins according to the following truth table.
MODE0
0
0
1
1
MODE1
0
1
0
1
Function
Idle
Transmit Enable
Receive Enable
Reset
When switching between modes, ensure that MODE0 and MODE1 are high for less than three master clock cycles to
avoid inadvertently entering reset modes. To enter reset mode, ensure that MODE0 and MODE1 are high for at least five
master clock cycles.
In Idle mode, the IF and RF PLLs are locked and the baseband circuitry is powered; everything else is disabled. In Reset
mode, the voltage regulators for the digital circuitry inside the part are enabled; everything else is disabled.
Additionally, there is a hibernate mode in which everything is disabled. This mode is entered by writing the value 8h to
Register 0 while in hibernate mode. The MODE0 and MODE1 pins should be held high while in hibernate mode. To exit
this mode, toggle the states of one or both MODE pins. All registers will need to be reprogrammed on exiting hibernate
mode.
RECEIVER
Front End LNA/Mixer
The LNA/Mixer provides 35dB conversion gain to IF in high-gain mode to detect weak signals at the antenna. In low-gain
mode, the LNA/Mixer provides 2dB conversion gain. The LNA GS pin selects gain mode. When LNA GS is high, the part
is in high-gain mode. The mixer output is connected to the IF OUT pins as a differential signal for connecting to an external SAW filter. Proper matching at the input and output of the SAW filter is essential for maintaining performance through
the system. The IF input and output differential impedances are 750Ω nominal.
The same filter is used for transmitter and receiver. Internal switches control which signal is present at the SAW filter. If
AC-coupling is required for the SAW filter, use values less than 150pF to ensure that switching speed will not be seriously degraded.
11-272
Rev A0 050209
RF2958
IF/Baseband
The filtered IF signal is processed through a variable gain amplifier controlled through the RX VGC pin. The IF signal is
then downconverted to baseband I and Q signals, which are then filtered on-chip with third order Bessel filters. The
IF-to-baseband conversion gain range is 4dB to 72dB depending on the voltage present on the RX VGC pin. The gain
slope is negative over a range of 1.2V to 2.0V.
The single-ended I and Q outputs should be DC-coupled to the baseband processor. The DC reference voltage should
be provided to the baseband processor through the VREF pin to eliminate the potential for a signal blocker at DC.
TRANSMITTER
The I and Q inputs are differential. To use single-ended inputs, place 0.01µF capacitors at the I BYP and Q BYP pins.
The inputs should be DC-coupled from the baseband processor. In order to improve carrier suppression at RF, the DC
reference voltage should be provided to the baseband processor through the VREF pin. The baseband input signals are
filtered on-chip using third order Bessel filters for spectral shaping. The signals are then complex upconverted to IF. The
IF mixer output is amplified and connected to the IF OUT pins as a differential signal for connecting to the external SAW
filter as described above.
The differential signal from the SAW filter is then amplified using a variable gain amplifier. The gain of this amplifier can
be controlled either through the analog TX VGC pin or digitally from the baseband processor or MAC, depending on
application. The signal is then upconverted to the desired RF output frequency and amplified to a level appropriate to
drive a PA to the desired output level at the antenna.
In order to further extend battery life, the TX VGC pin can be used to control the bias of the external PA. If the user of the
end-product determines that he/she does not require full output power, the PA bias and the gain of the IF variable gain
amplifier can be controlled by the RF2958 to reduce the current consumption of the PA, thereby increasing battery life.
Contact RFMD Applications Engineering for guidance on implementing this feature.
DUAL FREQUENCY SYNTHESIZER
IF LO PLL
The IF PLL is an integer-N PLL nominally programmed to a center frequency of 748MHz. This frequency is divided by
two at the IF converter. A 44MHz oscillator is required to provide the PLL reference frequency through the MCLK pin.
See the Register Details and Serial Data Interface sections for details on programming.
RF LO PLL
The RF LO PLL is a fractional-N PLL programmed to an appropriate frequency to convert the 374MHz IF to the desired
RF channel. The nominal step size is 22MHz with a fractional modulus of 224. The 44MHz reference frequency is divided
to the appropriate step size. See the Register Details and Serial Data Interface sections for details on programming.
Note: To ensure proper operation of the PLLs, program Register 12 [17:16] to ‘11b’. All other bits in Register 12 should
be set to ‘0’.
Rev A0 050209
11-273
RF2958
SERIAL DATA INTERFACE
A three wire serial data interface allows user programming of the internal control registers in the RF2958. The serial data
interface consists of the serial select (SSB), serial data in (SDI) and serial clock (SCLK) pins. The SDI is a bi-directional
pin, by default it is configured as an input to the serial interface, but during a read session it is used as an output.
The first bit in a serial transfer (the MSB) is the read/write (R/W) bit. R/W = 1 for a read, and R/W = 0 for a write.
The figure below shows a timing diagram for a serial transfer to the RF2958 serial data interface. The serial select (SSB)
pin is normally high. A serial transfer is initiated by taking SSB low. The address and data bits on the serial data in (SDI)
pin are shifted in on rising edges of the serial clock (SCLK) pin, MSB first. The data is latched and changes take effect on
the falling edge of the clock pulse corresponding to the last (18th) data bit in the addressed register. If the transfer is interrupted, such that the 18th data bit clock pulse does not occur, then no data is written to the register.
When the synthesizers are programmed, an internal pulse is generated alerting the synthesizer that a new setting is
required. In order to guarantee that this internal pulse is long enough, the time between the falling edge of the last serial
clock pulse and the rising edge of SSB must be at least 1/fr.
The RF2958 can be reset to its power on condition (including register defaults) by writing ‘011111b’ plus 18 don’t care
bits to the serial data interface. The reset is actually performed when the SSB is raised after the write. Although this command can be performed during any settings of the MODE0 and MODE1 pins, care should be taken to ensure that the
registers are reprogrammed in a sufficient time to perform any transmit or receive operations.
Serial Write
SSB
SDI
rw=0
addr4
addr3
addr1
addr0
addr4
addr3
addr1
addr0
data17
data16
data1
data0
SCLK
Serial Read
SSB
SDI
rw=1
data17
data16
data1
data0
SCLK
sdi pin direction - input
11-274
sdi pin direction - output
Rev A0 050209
RF2958
REGISTER DETAILS
The individual registers and bits are described below. A write instruction to address 11111 causes global reset. All programming values are binary unless otherwise specified.
Configuration Register 1 (CFG1)-Address 00000
Location
Bit Name
Default
CFG1(17:16)
CFG1(15:14)
reserved
REF_SEL(1:0)
00
00
CFG1(3)
HYBERNATE
0
CFG1(2)
RF_VCO_
REG_EN
1
CFG1(1)
IF_VCO_
REG_EN
1
CFG1(0)
IF_VGA_
REG_EN
1
IF PLL Register 1 (IFPLL1)-Address 00001
Location
Bit Name
Default
IFPLL1(17)
PLL_EN1
0
IFPLL1(16)
KV_EN1
0
IFPLL1(15)
VTC_EN1
1
IFPLL1(14)
LPF1
0
IFPLL1(13)
CPL1
0
IFPLL1(12)
PDP1
1
IFPLL1(11)
AUTOCAL_
EN1
0
IFPLL1(10)
LD_EN1
0
IFPLL1(9)
P1
0
IFPLL1(8:4)
IFPLL1(3:0)
Reserved
DAC1(3:0)
00000
3h
Rev A0 050209
Function
Reserved, program to zero (0)
Reference Divider Value
0
0
Divide by 2
1/2 high, 1/2 low
0
1
Divide by 3
1/3 high, 2/3 low
1
0
Divide by 44
1/44 high, 43/44 low
1
1
Divide by 1 (bypass)
Sleep Mode Current
0=nominal sleep mode current
1=very low sleep mode current
RF VCO Regulator Enable
0=disabled
1=enabled
IF VCO Regulator Enable
0=disabled
1=enabled
IF VGA Regulator Enable
0=disabled
1=enabled
Function
IF PLL Enable
0=disabled
1=enabled
IF PLL KV Calibration Enable
0=disabled
1=enabled
IF PLL Coarse Tune Enable
0=VCO coarse tuning system is disabled
1=VCO coarse tuning system is enabled
IF PLL Loop Filter Bypass
0=Internal loop filter is used
1=Internal loop filter is bypassed and External loop filter is used
IF PLL Charge Pump Leakage Current
0=minimum value
1=2xminimum value
IF PLL Phase Detector Polarity
0=positive, VCO frequency increases with increasing tuning voltage
1=negative, VCO frequency decreases with increasing tuning voltage
IF PLL Auto Calibration Enable
0=disabled
1=enabled
IF PLL Lock Detect Enable
0=disabled
1=enabled
IF PLL Prescaler Modulus
0=4/5 Mode
1=8/9 Mode
Reserved, program to zero (0)
IF VCO Coarse Tuning Voltage
LPF_V1=int (coarse tuning voltage/VDD)x16
11-275
RF2958
IF PLL Register 2 (IFPLL2)-Address 00010
Location
Bit Name
Default
IFPLL2(17:16)
IFPLL2(15:0)
Reserved
IF_N(15:0)
0
22h
Function
Reserved, program to zero (0)
IFPLL divide-by-N value
IF PLL Register 3 (IFPLL3)-Address 00011
Location
Bit Name
Default
IFPLL3(17)
IFPLL3(16:8)
Reserved
DN1(16:8)
0
1FFh
IFPLL3(7:4)
IFPLL3(3:0)
CT_DEF1(3:0)
KV_DEF1(3:0)
7h
8h
Function
Reserved, program to zero (0)
IF VCO KV Calibration, delta N value (signed 2’s complement)
DeltaF=DN1/(Fr)
IF VCO Coarse Tuning Value
IF VCO KV Calibration, default value
RF PLL Register 4 (RFPLL1)-Address 00100
Location
Bit Name
Default
RFPLL1(17)
PLL_EN
0
RFPLL1(16)
KV_EN
0
RFPLL1(15)
VTC_EN
1
RFPLL1(14)
LPF
0
RFPLL1(13)
CPL
0
RFPLL1(12)
PDP
1
RFPLL1(11)
AUTOCAL_EN
0
RFPLL1(10)
LD_EN
0
RFPLL1(9)
P
0
RFPLL1(8:4)
RFPLL1(3:0)
Reserved
DAC(3:0)
00000
3h
Function
RF PLL Enable
0=disabled
1=enabled
RF PLL KV Calibration Enable
0=disabled
1=enabled
RF PLL Coarse Tune Enable
0=VCO coarse tuning system is disabled
1=VCO coarse tuning system is enabled
RF PLL Loop Filter Bypass
0=Internal loop filter is used
1=Internal loop filter is bypassed and External loop filter is used
RF PLL Charge Pump Leakage Current
0=minimum value
1=2xminimum value
RF PLL Phase Detector Polarity
0=positive, VCO frequency increases with increasing tuning voltage
1=negative, VCO frequency decreases with increasing tuning voltage
RF PLL Auto Calibration Enable
0=disabled
1=enabled
RF PLL Lock Detect Enable
0=disabled
1=enabled
RF PLL Prescaler Modulus
0=8/9 Mode
1=8/10 Mode
Reserved, program to zero (0)
RF VCO Coarse Tuning Voltage
LPF_V1=int (coarse tuning voltage/VDD)x16
RF PLL Register 5 (RFPLL2)-Address 00101
Location
Bit Name
Default
RFPLL2(17:6)
RFPLL2(5:0)
N2(11:0)
NUM2(23:18)
5Eh
0
Function
RF PLL Divide By N Value
RF PLL Numerator Value
RF PLL Register 6 (RFPLL3)-Address 00110
Location
Bit Name
Default
RFPLL3(17:0)
11-276
NUM2(17:0)
0
Function
RF PLL Numerator Value
Rev A0 050209
RF2958
RF PLL Register 7 (RFPLL4)-Address 00111
Location
Bit Name
Default
RFPLL4(17)
RFPLL4(16:8)
Reserved
DN(8:0)
0
145 h
RFPLL4(7:4)
RFPLL4(3:0)
CT_DEF(3:0)
KV_DEF(3:0)
7h
8h
Calibration Register 8 (CAL1)-Address 01000
Location
Bit Name
Default
CAL1(17:13)
TVCO(4:0)
0Fh
CAL1(12:8)
TLOCK(4:0)
07h
CAL1(7:3)
M_CT_VALUE
(4:0)
LD_WINDOW
(2:0)
08h
CAL1(2:0)
2h
TXRX Register 9 (TXRX1)-Address 01001
Location
Bit Name
Default
TXRX1(17)
RXDCFBBYPS
0
TXRX1(16:15)
PCONTROL
(1:0)
00
TXRX1(14:10)
TXVGC(4:0)
00000
TXRX1(9:7)
RXLPFBW
(2:0)
010
TXRX1(6:4)
TXLPFBW
(2:0)
010
TXRX1(3)
TXDIFFMODE
0
TXRX1(2)
TXENMODE
0
TXRX1(1)
INTBIASEN
0
TXRX1(0)
TXBYPASS
0
Rev A0 050209
Function
Reserved, program to zero (0)
RF VCO KV Calibration, delta N value (signed 2’s complement)
DN=(deltaF/Fr)*256
RF VCO Coarse Tuning Value
RF VCO KV Calibration, default value
Function
VCO1 Warm-up Time
TVCO1=(approximate warm-up time)x(Fr/32)
VCO1 Tuning Gain Calibration, approximate lock time
TLOCK1=(approximate lock time)x(Fr/128)
VCO1 Coarse Tune Calibration Reference clock averaging time
M_CT_VALUE=(averaging time)x(Fr/32)
Lock Detect Resolution 0 through 7
Function
Receiver DC Removal Loop
0=Enable DC Removal Loop
1=Disable DC Removal Loop
00
External TXVGC Controls VGA
01
External TXVGC Controls VGA
10
Internal Control of VGA from Register TXVGC(4:0)
11
Internal Control of VGA from Power Control
Transmit Variable Gain Select
0h-1Fh High gain to low gain
Receive Baseband Low Pass Filter Bandwidth Selection
000=Wide Bandwidth
111=Narrow Bandwidth
Transmit Baseband Low Pass Filter Bandwidth Selection
000=Wide Bandwidth
111=Narrow Bandwidth
Switches Between Single-Ended and Differential Mode
0=Single-ended mode
1=Differential mode
Input Buffer Enable TX
0=Input Buffer Controlled by TXEN
1=Input Buffer Controlled by BBEN
Internal Bias Enable
0=Disabled - External Bias Required
1=Enabled - Internal Bias Enabled
TX Baseband Filters Bypass
0=Not Bypassed
1=Bypassed
11-277
RF2958
Power Control Register 10 (PCNT1)-Address 01010
Location
Bit Name
Default
PCNT1(17:15)
MID_BIAS(2:0)
000
PCNT1(14:9)
P_DESIRED
(5:0)
000000
PCNT1(8:3)
PC_OFFSET
(5:0)
000000
PCNT1(2:0)
TX_DELAY
(2:0)
000
Power Control Register 11 (PCNT2)-Address 01011
Location
Bit Name
Default
PCNT2(17:12)
MAX_POWER
(5:0)
000000
PCNT2(11:6)
MID_POWER
(5:0)
000000
PCNT2(5:0)
MIN_POWER
(5:0)
000000
Function
Used to setup the voltage provided by the PA_BIAS AMPLIFIER to determine the BIAS VOLTAGE to provide to the PA when the desired output
power is MID_POWER. The MID_BIAS selection will select a VOUT on
PBIAS between 1.6V and 2.6V.
User selectable desired output power at antenna. The 5 MSB’s are integer
portion in dBm. The LSB is 0.5dBm. Example: +19.5dBm is represented by
100111.
User programmable offset to adjust to process/board variations in the
power control loop. This is a 2’s-complement value with the LSB equal to
0.5dB.
User programmable delay to allow a single TX_PE line to be used to enable
the BBP and the radio function. Programmable in 0.5us increments from
0us to 3.5us.
Function
User programmable MAX output power provided when PABIAS=2.6V. This
allows the power control function to be customized for various PA’s. The 5
MSB’s are integer portion in dBm. The LSB is 0.5dBm.
User programmable MAX output power provided when
PABIAS=MID_BIAS. This allows the power control function to be customized for various PA’s. The 5 MSB’s are integer portion in dBm. The LSB is
0.5dBm.
User programmable MAX output power provided when PABIAS=1.6V. This
allows the power control function to be customized for various PA’s. The 5
MSB’s are integer portion in dBm. The LSB is 0.5dBm.
VCOT1 Register 1 (VCOT1)-Address 01100
Location
Bit Name
Default
VCOT1(17)
AUX
0
VCOT1(16)
AUX1
0
VCOT1(15:0)
Reserved
0
Function
IF VCO Band Current Compensation
0=disabled
1=enabled
RF VCO Band Current Compensation
0=disabled
1=enabled
Reserved, program to zero (0)
Test Register 1 (TEST)-Address 11011
This is a test register for internal use only.
11-278
Rev A0 050209
RF2958
Demodulator Gain versus RXVGC versus Temperature
1000.0
80.0
Demodulator Gain vs. RXVGC @ -30°C
Demodulator Gain vs. RXVGC @ 25°C
Demodulator Gain vs. RXVGC @ 70°C
70.0
IV1dB vs. Gain @ -30°C
IV1dB vs. Gain @ 25°C
IV1dB vs. Gain @ 70°C
60.0
100.0
Input Voltage (mV P-P)
Demodulator Gain (dB)
Demodulator Input V1dB versus Gain versus
Temperature
50.0
40.0
30.0
20.0
10.0
1.0
10.0
0.0
-10.0
0.1
1.3
1.4
1.5
1.6
1.7
1.8
1.9
-10.0
2.0
0.0
10.0
RXVGC (V)
20.0
30.0
40.0
50.0
60.0
70.0
80.0
Demodulator Voltage Gain (dB)
Output V1dB versus Gain versus Temperature
Demodulator Magnitude and Phase Error
0.20
10000.0
OV1dB vs. Gain @ -30°C
OV1dB vs. Gain @ 25°C
OV1dB vs. Gain @ 70°C
0.20
0.00
0.15
-0.20
I/Q Phase Error (°)
Output V1dB (mV P-P)
-0.40
1000.0
0.10
-0.60
-0.80
0.05
-1.00
-1.20
0.00
-1.40
-1.60
I/Q Magnitude Error (dB)
1.2
-0.05
Phase Error vs. Frequency
-1.80
100.0
Magnitude Error vs. Frequency
-2.00
-10.0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
Demodulator Voltage Gain (dB)
-12.0 -10.0 -8.0 -6.0
-0.10
-4.0 -2.0
0.0
2.0
4.0
6.0
8.0
10.0 12.0
Baseband Frequency (Hz)
TX/RX Baseband Filter Response
5
0
Voltage Gain (dB)
-5
-10
-15
-20
-25
-30
-35
000
001
010
011
100
101
110
111
-40
1.00E+00
1.00E+01
1.00E+02
Frequency (MHz)
Rev A0 050209
11-279
RF2958
Upconverter Gain versus Analog TXVGC
Upconverter Gain versus Digital TXVGC
30.0
30.0
Upconverter Gain vs. TXVGC @ -30°C
Upconverter Gain vs. TXVGC @ -30°C
Upconverter Gain vs. TXVGC @ 25°C
25.0
Upconverter Gain vs. TXVGC @ 70°C
20.0
Voltage Gain (dB)
20.0
Voltage Gain (dB)
Upconverter Gain vs. TXVGC @ 25°C
25.0
Upconverter Gain vs. TXVGC @ 70°C
15.0
10.0
5.0
15.0
10.0
5.0
0.0
0.0
-5.0
-5.0
-10.0
-10.0
0.5
0.7
0.9
1.1
1.3
1.5
1.7
1.9
2.1
2.3
2.5
0.0
5.0
10.0
TXVGC (V)
8.0
8.0
6.0
6.0
4.0
4.0
2.0
0.0
-2.0
25.0
30.0
35.0
2.0
0.0
-2.0
-4.0
Upconverter Output P1dB vs. TXVGC
@ -30°C
Upconverter Output P1dB vs. TXVGC
@ 25°C
Upconverter Output P1dB vs. TXVGC
@ 70°C
-6.0
20.0
Upconverter P1dB versus Digital TXVGC
Output P1dB (dBm)
Output P1dB (dBm)
Upconverter P1dB versus Analog TXVGC
-4.0
15.0
TXVGC Value
Upconverter Output P1dB vs. TXVGC @ -30°C
-6.0
Upconverter Output P1dB vs. TXVGC @ 25°C
Upconverter Output P1dB vs. TXVGC @ 70°C
-8.0
-8.0
0.5
0.7
0.9
1.1
1.3
1.5
1.7
1.9
2.1
2.3
2.5
0.0
TXVGC (V)
5.0
10.0
15.0
20.0
25.0
30.0
35.0
TXVGC Value
Modulator Magnitude Error and Image Suppression
0.10
36.50
Image Suprression vs. Frequency
Magnitude Error vs. Frequency
36.00
Image Suppression (dB)
35.00
0.00
34.50
34.00
-0.05
33.50
33.00
I/Q Magnitude Error (dB)
0.05
35.50
-0.10
32.50
32.00
31.50
-0.15
-12.0 -10.0 -8.0 -6.0 -4.0 -2.0
0.0
2.0
4.0
6.0
8.0
10.0 12.0
Baseband Frequency (MHz)
11-280
Rev A0 050209
RF2958
PCB Design Requirements
PCB Surface Finish
The PCB surface finish used for RFMD’s qualification process is Electroless Nickel, immersion Gold. Typical thickness is
3µinch to 8µinch Gold over 180µinch 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 = 0.69 x 0.28 (mm) Typ.
B = 0.28 x 0.69 (mm) Typ.
C = 3.40 (mm) Sq.
3.50 (mm)
Typ.
0.50 (mm) Typ.
Pin 32
B
B
B
B
B
B
B
B
Pin 1
Pin 24
A
A
A
A
A
A
0.50 (mm) Typ.
A
A
C
A
A
A
A
A
A
A
A
1.75 (mm)
Typ.
3.50 (mm)
Typ.
0.63 (mm) Typ.
B
B
B
B
B
B
B
B
Pin 16
0.63 (mm) Typ.
1.75 (mm)
Typ.
Figure 1. PCB Metal Land Pattern (Top View)
Rev A0 050209
11-281
RF2958
PCB Solder Mask Pattern
Liquid Photo-Imageable (LPI) solder mask is recommended. The solder mask footprint will match what is shown for the
PCB Metal Land Pattern with a 3mil expansion to accommodate solder mask registration clearance around all pads. The
center-grounding pad shall also have a solder mask clearance. Expansion of the pads to create solder mask clearance
can be provided in the master data or requested from the PCB fabrication supplier.
A = 0.79 x 0.38 (mm) Typ.
B = 0.38 x 0.79 (mm) Typ.
C = 3.55 (mm) Sq.
3.50 (mm)
Typ.
0.50 (mm) Typ.
Pin 32
B
B
B
B
B
B
B
B
Pin 1
Pin 24
A
A
A
A
A
A
0.50 (mm) Typ.
A
A
C
A
A
A
A
A
A
A
A
1.75 (mm)
Typ.
3.50 (mm)
Typ.
0.63 (mm) Typ.
B
B
B
B
B
B
B
B
Pin 16
0.63 (mm) Typ.
1.75 (mm)
Typ.
Figure 2. PCB Solder Mask Pattern (Top View)
Thermal Pad and Via Design
The PCB Metal Land Pattern has been designed with a thermal pad that matches the exposed die paddle size on the
bottom of the device.
Thermal vias are required in the PCB layout to effectively conduct heat away from the package. The via pattern has been
designed to address thermal, power dissipation and electrical requirements of the device as well as accommodating
routing strategies.
The via pattern used for the RFMD qualification is based on thru-hole vias with 0.203mm to 0.330mm finished hole size
on a 0.5mm to 1.2mm grid pattern with 0.025mm plating on via walls. If micro vias are used in a design, it is suggested
that the quantity of vias be increased by a 4:1 ratio to achieve similar results.
11-282
Rev A0 050209