MAXIM MAX2831ETM

19-0363; Rev 2; 3/11
KIT
ATION
EVALU
E
L
B
AVAILA
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
The MAX2831/MAX2832 direct conversion, zero-IF, RF
transceivers are designed specifically for 2.4GHz to
2.5GHz 802.11g/b WLAN applications. The MAX2831
completely integrates all circuitry required to implement
the RF transceiver function, providing an RF power
amplifier (PA), RF-to-baseband receive path, basebandto-RF transmit path, VCO, frequency synthesizer, crystal
oscillator, and baseband/control interface. The MAX2832
integrates the same functional blocks except for the PA.
Both devices include a fast-settling sigma-delta RF synthesizer with smaller than 20Hz frequency steps and a
digitally tuned crystal oscillator allowing use of a low-cost
crystal. The devices also integrate on-chip DC-offset
cancellation and I/Q errors and carrier leakage-detection
circuits. Only an RF bandpass filter (BPF), crystal, RF
switch, and a small number of passive components are
needed to form a complete 802.11g/b WLAN RF frontend solution.
The MAX2831/MAX2832 completely eliminate the need
for an external SAW filter by implementing on-chip monolithic filters for both the receiver and transmitter. The
baseband filters are optimized to meet the IEEE 802.11g
standard and proprietary turbo modes up to 40MHz
channel bandwidth. These devices are suitable for the full
range of 802.11g OFDM data rates (6Mbps to 54Mbps)
and 802.11b QPSK and CCK data rates (1Mbps to
11Mbps). The ICs are available in a small, 48-pin TQFN
package measuring only 7mm x 7mm x 0.8mm.
Applications
Features
♦ 2.4GHz to 2.5GHz ISM Band Operation
♦ IEEE 802.11g/b Compatible (54Mbps OFDM and
11Mbps CCK)
♦ Complete RF Transceiver, PA, and Crystal
Oscillator (MAX2831)
Best-in-Class Transceiver Performance
62mA Receiver Current
2.6dB Rx Noise Figure
-76dBm Rx Sensitivity (54Mbps OFDM)
No I/Q Calibration Required
0.1dB/0.35° Rx I/Q Gain/Phase Imbalance
33dB RF and 62dB Baseband Gain Control
Range
60dB Range Analog RSSI per RF Gain Setting
Fast Rx I/Q DC-Offset Settling
Programmable Baseband Lowpass Filter
20-Bit Sigma-Delta Fractional-N PLL with
< 20Hz Step Size
Digitally Tuned Crystal Oscillator
+18.5dBm Transmit Power (5.6% EVM with
54Mbps OFDM)
31dB Tx Gain Control Range
Integrated Power Detector (MAX2831)
Serial or Parallel Gain-Control Interface
> 40dB Tx Sideband Suppression without
Calibration
Tx/Rx I/Q Error Detection
♦ Transceiver Operates from +2.7V to +3.6V
Wi-Fi, PDA, VOIP, and Cellular Handsets
♦ PA Operates from +2.7V to +4.2V (MAX2831)
Wireless Speakers and Headphones
♦ Low-Power Shutdown Mode
General 2.4GHz ISM Radios
♦ Small 48-Pin TQFN Package
(7mm x 7mm x 0.8mm)
Ordering Information
TEMP RANGE
PIN-PACKAGE
MAX2831ETM+T
PART
-40°C to +85°C
48 TQFN-EP*
MAX2832ETM+T
-40°C to +85°C
48 TQFN-EP*
*EP = Exposed pad.
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
Pin Configuration appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX2831/MAX2832
General Description
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
ABSOLUTE MAXIMUM RATINGS
VCCTXPA, VCCPA and TXRF_ to GND ....................-0.3V to +4.5V
VCCLNA, VCCTXMX, VCCPLL, VCCCP, VCCXTAL, VCCVCO,
VCCRXVGA, VCCRXFL, and VCCRXMX_ to GND....-0.3V to +3.9V
B6, B7, B3, B2, SHDN, B5, CS, SCLK, DIN, B1, TUNE, B4,
TXBBI_, TXBBQ_, RXHP, RXTX, RXBBI_, RXBBQ_, RSSI,
BYPASS, CPOUT, LD, CLOCKOUT, XTAL, CTUNE, RXRF_ to
GND .......................................-0.3V to (Operating VCC + 0.3V)
RXBBI_, RXBBQ_, RSSI, BYPASS, CPOUT, LD, CLOCKOUT
Short-Circuit Duration ..........................................................10s
RF Input Power ...............................................................+10dBm
Continuous Power Dissipation (TA = +70°C)
48-Pin TQFN (derates 27.8mW/°C above +70°C) ..........2.22W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
CAUTION! ESD SENSITIVE DEVICE
DC ELECTRICAL CHARACTERISTICS
(MAX2831 EV kit: VCC_ = 2.7V to 3.6V, VCCPA = VCCTXPA = 2.7V to 4.2V, TA = -40°C to +85°C, Rx set to the maximum gain. CS =
high, RXHP = SCLK = DIN = low, RSSI and clock output buffer are off, no signal at RF inputs, all RF inputs and outputs terminated
into 50Ω, receiver baseband outputs are open. 100mVRMS differential I and Q signals (54Mbps IEEE 802.11g OFDM) applied to I/Q
baseband inputs of transmitter in transmit mode, fREF = 40MHz, and registers set to recommended settings and corresponding test
mode, unless otherwise noted. Typical values are at VCC = 2.8V, VCCPA = 3.3V, and TA = +25°C, LO frequency = 2.437GHz, unless
otherwise noted. RF inputs/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit PCB, balun,
and SMA connectors.) (Note 1)
PARAMETERS
Supply Voltage
CONDITIONS
Rx I/Q Output Common-Mode
Voltage Variation
VCCPA, VCCTXPA
2.7
4.2
Rx mode
TA = +25°C
20
TA = +25°C
28
TA = -40°C to +85°C
TA = +25°C
MAX2831, transmit section
82
104
258
82
MAX2831, PA, POUT = +18.2dBm
209
86
Rx calibration mode
TA = +25°C
101
Tx calibration mode
TA = +25°C
78
0.98
1.2
TA = -40°C (relative to TA = +25°C)
-17
TA = +85°C (relative to TA = +25°C)
15
Tx Baseband Input Bias Current
Source current
35
78
MAX2832
DC-coupled
V
µA
62
TA = -40°C to +85°C
TA = +25°C at default common-mode setting
UNITS
35
Tx mode, TA = +25°C,
VCC = 2.8V, VCCPA =
3.3V, (Note 2)
Tx Baseband Input CommonMode Voltage Operating Range
2
MAX
3.6
Standby mode
Rx I/Q Output Common-Mode
Voltage
TYP
2.7
Shutdown mode,
B7: B1 = 0000000,
reference oscillator not
applied
Supply Current
MIN
VCC_
0.9
_______________________________________________________________________________________
1.33
mA
V
mV
1.3
V
22
µA
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
(MAX2831 EV kit: VCC_ = 2.7V to 3.6V, VCCPA = VCCTXPA = 2.7V to 4.2V, TA = -40°C to +85°C, Rx set to the maximum gain. CS =
high, RXHP = SCLK = DIN = low, RSSI and clock output buffer are off, no signal at RF inputs, all RF inputs and outputs terminated
into 50Ω, receiver baseband outputs are open. 100mVRMS differential I and Q signals (54Mbps IEEE 802.11g OFDM) applied to I/Q
baseband inputs of transmitter in transmit mode, fREF = 40MHz, and registers set to recommended settings and corresponding test
mode, unless otherwise noted. Typical values are at VCC = 2.8V, VCCPA = 3.3V, and TA = +25°C, LO frequency = 2.437GHz, unless
otherwise noted. RF inputs/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit PCB, balun,
and SMA connectors.) (Note 1)
PARAMETERS
CONDITIONS
MIN
TYP
MAX
UNITS
LOGIC INPUTS: SHDN, RXTX, SCLK, DIN, CS, B7:B1, RXHP
VCC 0.4
Digital Input-Voltage High, VIH
V
Digital Input-Voltage Low, VIL
0.4
V
Digital Input-Current High, IIH
-1
+1
µA
Digital Input-Current Low, IIL
-1
+1
µA
LOGIC OUTPUTS: LD, CLOCKOUT
Digital Output-Voltage High, VOH
Sourcing 100µA
Digital Output-Voltage Low, VOL
Sinking 100µA
VCC 0.4
V
0.4
V
AC ELECTRICAL CHARACTERISTICS—Rx Mode
(MAX2831 EV kit: VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA =+25°C, fRF = 2.439GHz, fLO = 2.437GHz; receiver baseband I/Q outputs at 112 mVRMS (-19dBV), fREF = 40MHz, SHDN = CS = high, RXTX = SCLK = DIN = low, with power matching for the differential
RF pins using the typical applications and registers set to default settings and corresponding test mode, unless otherwise noted.
Unmodulated single-tone RF input signal is used with specifications which normally apply over the entire operating conditions, unless
otherwise indicated. RF inputs/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit PCB,
balun, and SMA connectors.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
2.5
GHz
RECEIVER SECTION: LNA RF INPUT-TO-BASEBAND I/Q OUTPUTS
RF Input Frequency Range
RF Input Return Loss
2.4
High RF gain
18
Mid RF gain
11
Low RF gain
Maximum gain, B7:B1 =
1111111
Total Voltage Gain
Minimum gain, B7:B1 =
0000000
14
TA = +25°C
86
TA = -40°C to +85°C
83
TA = +25°C
98
dB
3
From high-gain mode (B7:B6 = 11) to medium-gain
mode (B7:B6 = 10)
-16
From high-gain mode (B7:B6 = 11) to low-gain mode
(B7:B6 = 0X)
-33
Gain change from high gain to medium gain, high gain to
low, or medium gain to low gain; gain settling to within
±2dB of steady state; RXHP = 1
0.2
8
dB
RF Gain Steps (Note 3)
RF Gain-Change Settling Time
dB
µs
_______________________________________________________________________________________
3
MAX2831/MAX2832
DC ELECTRICAL CHARACTERISTICS (continued)
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
AC ELECTRICAL CHARACTERISTICS—Rx Mode (continued)
(MAX2831 EV kit: VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA =+25°C, fRF = 2.439GHz, fLO = 2.437GHz; receiver baseband I/Q outputs at 112 mVRMS (-19dBV), fREF = 40MHz, SHDN = CS = high, RXTX = SCLK = DIN = low, with power matching for the differential
RF pins using the typical applications and registers set to default settings and corresponding test mode, unless otherwise noted.
Unmodulated single-tone RF input signal is used with specifications which normally apply over the entire operating conditions, unless
otherwise indicated. RF inputs/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit PCB,
balun, and SMA connectors.) (Note 1)
PARAMETER
Baseband Gain Range
DSB Noise Figure
CONDITIONS
From maximum baseband gain (B5:B1 = 11111) to
minimum baseband gain (B5:B1 = 00000)
In-Band Output P-1dB
Out-of-Band Input IP3 (Note 4)
TYP
MAX
UNITS
55
62
67
dB
Voltage gain = maximum with B7:B6 = 11
2.6
Voltage gain = 50dB with B7:B6 = 11
3.2
Voltage gain = 45dB with B7:B6 = 10
16
Voltage gain = 15dB with B7:B6 = 0X
In-Band Compression Point
Based on EVM
MIN
-19dBVRMS baseband
output EVM degrades to
9%
dB
34
B7:B6 = 11
-41
B7:B6 = 10
-24
B7:B6 = 0X
-6
Voltage gain = 90dB, with B7:B6 = 11
2.5
B7:B6 = 11
-12
B7:B6 = 10
-4
B7:B6 = 0X
24
dBm
VP-P
dBm
I/Q Phase Error
1σ variation (without calibration)
±0.35
Degrees
I/Q Gain Imbalance
1σ variation (without calibration)
±0.1
dB
RX I/Q Output Load Impedance
(R || C)
Minimum differential resistance
10
kΩ
Maximum differential capacitance
10
pF
Tx-to-Rx Conversion Gain for Rx
I/Q Calibration
For receiver gain, B7:B1 = 1101111 (Note 5)
0.5
dB
Baseband VGA Settling Time
Gain change from B5:B1 = 10111 to B5:B1 = 00111; gain
settling to within ±2dB of steady state
0.1
µs
I/Q Output DC Step when RXHP
Transitions from 1 to 0 in
Presence of 802.11g Short
Sequence
After switching RXHP to logic 0 from initial logic 1, during
ideal short sequence data at -55dBm input in AWGN
channel, for -19dBV output; normalized to RMS signal on
I and Q outputs; transition point varied from 0 to 0.8µs in
steps of 0.1µs
-5
dBc
I/Q Output DC Droop
After switching RXHP to 0, D13:D12, Register 7
(A3:A0 = 0111)
±1
V/s
I/Q Static DC Offset
RXHP = 1, B7:B1 = 1101110, 1σ variation
±1
mV
Spurious Signal Emissions from
LNA input
RF = 1GHz to 26.5GHz
-51
dBm
RECEIVER BASEBAND FILTERS
Gain Ripple in Passband
10kHz to 8.5MHz at baseband
±1.3
DBP-P
Group-Delay Ripple in Passband
10kHz to 8.5MHz at baseband
±45
nsP-P
4
_______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
(MAX2831 EV kit: VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA =+25°C, fRF = 2.439GHz, fLO = 2.437GHz; receiver baseband I/Q outputs at 112 mVRMS (-19dBV), fREF = 40MHz, SHDN = CS = high, RXTX = SCLK = DIN = low, with power matching for the differential
RF pins using the typical applications and registers set to default settings and corresponding test mode, unless otherwise noted.
Unmodulated single-tone RF input signal is used with specifications which normally apply over the entire operating conditions, unless
otherwise indicated. RF inputs/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit PCB,
balun, and SMA connectors.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
At 8.5MHz
3.2
At 15MHz
27
At 20MHz
50
At > 40MHz
80
RSSI Minimum Output Voltage
RLOAD ≥ 10kΩ || 5pF
0.4
RSSI Maximum Output Voltage
RLOAD ≥ 10kΩ || 5pF
2.4
V
30
mV/dB
Baseband Filter Rejection
(Nominal Mode)
dB
RSSI
RSSI Slope
RSSI Output Settling Time
To within 3dB of steady
state
+32dB signal step
200
-32dB signal step
600
V
ns
_______________________________________________________________________________________
5
MAX2831/MAX2832
AC ELECTRICAL CHARACTERISTICS—Rx Mode (continued)
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
AC ELECTRICAL CHARACTERISTICS—Tx Mode
(MAX2831 EV kit: VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fRF = 2.439GHz , fLO = 2.437GHz. fREF = 40MHz, SHDN =
RXTX = CS = high, and SCLK = DIN = low, with power matching for the differential RF pins using the typical applications circuit.
100mVRMS sine and cosine signal (or 100mVRMS 54Mbps IEEE 802.11g I/Q signals wherever OFDM is mentioned) applied to baseband I/Q inputs of transmitter (differential DC-coupled). Registers set to recommend settings and corresponding test mode, unless
otherwise noted. RF inputs/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit PCB, balun,
and SMA connectors.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
2.5
GHz
TRANSMIT SECTION: Tx BASEBAND I/Q INPUTS TO RF OUTPUTS
RF Output Frequency Range
2.4
54Mbps 802.11g
OFDM signal
Output power adjusted
to meet 5.6% EVM,
and spectral mask
18.5
B6:B1 = 000000
-7.5
MAX2831
802.11b signal,
141mVRMS,
IEEE802.11b I/Q
signals
Output Power
MAX2832
dBm
Output power adjusted
to meet spectral mask
21
-3dB VGA back off
-5.3
B6:B1 = 000000
-31.5
Unwanted Sideband Suppression
Without I/Q calibration, B6:B1 = 100001
-42
dBc
Carrier Leakage at Center
Frequency of Channel
Without DC offset correction
-30
dBc
Transmitter Spurious Signal
Emissions (MAX2831)
Transmitter Spurious Signal
Emissions (MAX2832)
6
B6:B1 = 111000,
OFDM signal
B6:B1 = 111111,
OFDM signal
1/3 x fLO
-67
< 1GHz
-36
> 1GHz
-47
2/3 x fLO
-64
4/3 x fLO
-42
5/3 x fLO
-65
8/3 x fLO
-51
2 x fLO
-33
3 x fLO
-54
1/3 x fLO
-78
< 1GHz
-65
> 1GHz
-72
2/3 x fLO
-78
4/3 x fLO
-46
5/3 x fLO
-72
8/3 x fLO
-46
2 x fLO
-60
3 x fLO
-75
_______________________________________________________________________________________
dBm/
MHz
dBm/
MHz
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
(MAX2831 EV kit: VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fRF = 2.439GHz , fLO = 2.437GHz. fREF = 40MHz, SHDN =
RXTX = CS = high, and SCLK = DIN = low, with power matching for the differential RF pins using the typical applications circuit.
100mVRMS sine and cosine signal (or 100mVRMS 54Mbps IEEE 802.11g I/Q signals wherever OFDM is mentioned) applied to baseband I/Q inputs of transmitter (differential DC-coupled). Registers set to recommend settings and corresponding test mode, unless
otherwise noted. RF inputs/outputs specifications are referenced to device pins and do not include 1dB loss from EV kit PCB, balun,
and SMA connectors.) (Note 1)
PARAMETER
RF Output Return Loss
CONDITIONS
Off-chip balun + match, singleended
MIN
TYP
MAX2831
-20
MAX2832
-10
MAX
UNITS
dB
Tx I/Q Input Load Impedance
(R || C)
Minimum differential resistance
20
kΩ
Maximum differential capacitance
0.7
pF
Baseband -3dB Corner
Frequency
D1:D0 = 01, Register 8
(A3:A0 = 1000)
11
MHz
Baseband Filter Rejection
At 30MHz, in nominal mode
62
dB
Minimum Power Detector Output
Voltage
Short sequence transmitter power = +9dBm
0.3
V
Maximum Power Detector Output
Voltage
Short sequence transmitter power = +19dBm
1.2
V
0.3
µs
Nominal mode
RF Power Detector Response Time
TRANSMITTER LO LEAKAGE AND I/Q CALIBRATION USING LO LEAKAGE AND SIDEBAND DETECTOR (see the Tx/Rx
Calibration Mode section)
Tx BASEBAND I/Q INPUTS TO RECEIVER OUTPUTS
LO Leakage and Sideband
Detector Output
Amplifier Gain Range
Lower -3dB Corner Frequency
Calibration register,
D12:D11 = 00,
A3:A0 = 0110
Output at 1 x fTONE
(for LO leakage = -29dBc),
fTONE = 2MHz, 100mVRMS
-34
Output at 2 x fTONE
(for LO leakage = -240dBc),
fTONE = 2MHz, 100mVRMS
-44
D12:D11 = 00 to D12:D11 = 11, A3:A0 = 0110
dBVRMS
30
dB
1
MHz
_______________________________________________________________________________________
7
MAX2831/MAX2832
AC ELECTRICAL CHARACTERISTICS—Tx Mode (continued)
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
AC ELECTRICAL CHARACTERISTICS—Frequency Synthesis
(MAX2831 EV kit: VCC_ = 2.7V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, SCLK =
DIN = low, PLL loop bandwidth = 150kHz, and TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
2.5
GHz
FREQUENCY SYNTHESIZER
RF Channel Center Frequency
2.4
Channel Center Frequency
Programming Minimum Step Size
20
Hz
Charge-Pump Comparison
Frequency
20
MHz
Reference Frequency Range
Reference Frequency Input
Levels
Reference Frequency Input
Impedance (R || C)
Closed-Loop Phase Noise
Closed-Loop Integrated Phase
Noise
20
AC-coupled to XTAL pin
44
800
Resistance (XTAL)
Capacitance (XTAL)
mVP-P
5
kΩ
4
pF
fOFFSET = 1kHz
-86
fOFFSET = 10kHz
-94
fOFFSET = 100kHz
-94
fOFFSET = 1MHz
-110
fOFFSET = 10MHz
-120
RMS phase jitter; integrate from 10kHz to 10MHz offset
Charge-Pump Output Current
Reference Spurs
20MHz offset
VCO Frequency Error
Measured from Tx-Rx or Rx-Tx
transition
MHz
dBc/Hz
0.9
Degrees
1
mA
-55
dBc
3µs to 9µs
50
> 9µs
1
kHz
VOLTAGE-CONTROLLED OSCILLATOR
Pushing
Referred to 2400MHz LO, VCC varies by 0.3V
VCO Tuning Voltage Range
LO Tuning Gain
8
210
0.5
kHz
2.2
VTUNE = 0.5V
103
VTUNE = 2.2V
86
_______________________________________________________________________________________
V
MHz/V
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
(MAX2831 EV kit: VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, fLO = 2.437GHZ, fREF = 40MHz, SHDN = CS = high, SCLK = DIN = low,
and TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
CRYSTAL OSCILLATOR
On-Chip Tuning Capacitance
Range
Maximum capacitance, A3:A0 = 1110, D6:D0 = 1111111
15.4
Minimum capacitance, A3:A0 = 1110, D6:D0 = 0000000
0.5
On-Chip Tuning Capacitance
Step Size
pF
0.12
pF
ON-CHIP TEMPERATURE SENSOR
TA = -40°C
Output Voltage
A3:A0 = 1000, D9:D8 = 01
0.35
TA = +25°C
1
TA = +85°C
1.6
V
AC ELECTRICAL CHARACTERISTICS—Timing
(MAX2831 EV kit: VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA =+25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, SCLK =
DIN = low, PLL loop bandwidth = 150kHz, and TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
SYSTEM TIMING (See Figure 3)
From SHDN rising edge to LO settled within 1kHz using
external reference frequency input
Turn-On Time
60
µs
Crystal Oscillator Turn-On Time
90% of final output amplitude level
1
ms
Channel Switching Time
Loop BW = 150kHz, fRF = 2.5GHz to 2.4GHz
25
µs
2
Rx/Tx Turnaround Time
Measured from Tx or Rx
enable rising edge; signal
settling to within ±2dB of
steady state
Rx to Tx
µs
Tx to Rx, RXHP = 1
Tx Turn-On Time (from Standby
Mode)
From Tx-enable active rising edge; signal settling to
within ±2dB of steady state
Tx Turn-Off Time (from Standby
Mode)
From Tx-enable inactive rising edge
Rx Turn-On Time (from Standby
Mode)
Rx Turn-Off Time (from Standby
Mode)
2
1.5
µs
1
µs
From Rx-enable active rising edge; signal settling to
within ±2dB of steady state
1.9
µs
From Rx-enable inactive rising edge
0.1
µs
_______________________________________________________________________________________
9
MAX2831/MAX2832
AC ELECTRICAL CHARACTERISTICS—Miscellaneous Blocks
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
AC ELECTRICAL CHARACTERISTICS—Timing (continued)
(MAX2831 EV kit: VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA =+25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, SCLK =
DIN = low, PLL loop bandwidth = 150kHz, and TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
3-WIRE SERIAL-INTERFACE TIMING (See Figure 2)
SCLK Rising Edge to CS Falling
Edge Wait Time, tCSO
6
ns
Falling Edge of CS to Rising
Edge of First SCLK Time, tCSS
6
ns
DIN to SCLK Setup Time, tDS
6
ns
DIN to SCLK Hold Time, tDH
6
ns
SCLK Pulse-Width High, tCH
6
ns
SCLK Pulse-Width Low, tCL
6
ns
Last Rising Edge of SCLK to
Rising Edge of CS or Clock to
Load Enable Setup Time, tCSH
6
ns
CS High Pulse Width, tCSW
20
ns
Time Between the Rising Edge of
CS and the Next Rising Edge of
SCLK, tCS1
6
ns
Clock Frequency, fCLK
20
MHz
Rise Time, tR
2
ns
Fall Time, tF
2
ns
Note 1: Min and max limits are guaranteed by test at TA = +25°C and +85°C and guaranteed by design and characterization at
TA = -40°C. The power-on register settings are not production tested. Recommended register setting must be loaded after
VCC is supplied.
Note 2: Guaranteed by design and characterization.
Note 3: The nominal part-to-part variation of the RF gain step is ±1dB.
Note 4: Two tones at +25MHz and +48MHz offset with -35dBm/tone. Measure IM3 at 2MHz.
Note 5: Tx I/Q inputs = 100mVRMS.
10
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
TA = +85°C
40
35
LNA = MEDIUM GAIN
20
15
61
10
0
Rx EVM vs. PIN
Rx EVM vs. VOUT
LNA = LOW GAIN
LNA = HIGH GAIN
20
18
3.0
MAX2831/32 toc05
22
LNA = MEDIUM GAIN
2.5
PIN = -50dBm
LNA = HIGH GAIN
16
LNA MEDIUM/HIGHGAIN SWITCH POINT
2.0
EVM (%)
LNA MEDIUM/LOWGAIN SWITCH POINT
EVM (%)
14
-3
-4
LNA = LOW GAIN
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32
BASEBAND GAIN SETTINGS
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32
BASEBAND GAIN SETTINGS
MAX2831/32 toc04
-2
LNA = MEDIUM GAIN
20
0
Rx IN-BAND OUTPUT P-1dB vs. GAIN
-1
40
5
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC (V)
0
50
30
LNA = HIGH GAIN
10
TA = -40°C
60
MAX2831/32 toc06
TA = +25°C
25
GAIN (dB)
NF (dB)
64
62
LNA = HIGH GAIN
80
30
63
12
10
8
-5
1.5
1.0
6
4
-6
0.5
2
0
75
85
0
-80
95
OFDM EVM WITH OFDM JAMMER
vs. OFFSET FREQUENCY
PIN = -62dBm
fOFFSET = 20MHz
-60
-50 -40 -30
PIN (dBm)
-20
-10
0
-50
-60
-80
dBM
fOFFSET = 25MHz
-90
-120
-20
LOW GAIN
-25
-140
PJAMMER (dBm)
-15
HIGH GAIN
-130
fOFFSET = 40MHz
-35
MID GAIN
-10
-110
-45
-5
RBW = 300kHz
LNA = LOW GAIN
-100
-55
LNA INPUT RETURN LOSS
vs. RF FREQUENCY
MAX2831/32 toc08
-40
-70
-65
-29 -27 -25 -23 -21 -19 -17 -15 -13 -11 -9
VOUT (dBVRMS)
Rx EMISSION SPECTRUM, LNA INPUT
MAX2831/32 toc07
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-70
INPUT RETURN LOSS (dB)
45
55
GAIN (dB)
4x VCO
35
1.5 VCO LEAKAGE
25
2x VCO LEAKAGE
3x VCO
15
MAX2831/32 toc09
-7
VCO LEAKAGE
OUTPUT P-1dB (dBVRMS)
90
70
65
ICC (mA)
LNA = LOW GAIN
MAX2831/32 toc03
66
100
MAX2831/32 toc02
45
MAX2831/32 toc01
67
EVM (%)
Rx VOLTAGE GAIN
vs. BASEBAND GAIN SETTING
NOISE FIGURE
vs. BASEBAND GAIN SETTINGS
Rx ICC vs. VCC
-25
-30
DC
26.5GHz
2300
2350
2400 2450 2500
RF FREQUENCY (MHz)
2550
______________________________________________________________________________________
2600
11
MAX2831/MAX2832
Typical Operating Characteristics
(MAX2831 EV kit, VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, RXHP =
SCLK = DIN = low.)
Typical Operating Characteristics (continued)
(MAX2831 EV kit, VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, RXHP =
SCLK = DIN = low.)
Rx RSSI STEP RESPONSE
(+32dB LNA GAIN STEP)
Rx RSSI OUTPUT vs. INPUT POWER
Rx RSSI STEP RESPONSE
(-32dB LNA GAIN STEP)
MAX2831/32 toc11
MAX2831/32 toc10
3.0
LNA = HIGH GAIN
2.5
RSSI OUTPUT (V)
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
MAX2831/32 toc12
3V
3V
0
0V
1.45V
1.5V
LNA = MEDIUM GAIN
2.0
1.5
1.0
LNA = LOW GAIN
0.5
0.45
0V
0
200ns/div
200ns/div
Rx I/Q DC OFFSET SETTLING RESPONSE
(+8dB BB VGA GAIN STEP)
Rx I/Q DC OFFSET SETTLING RESPONSE
(-8dB BB VGA GAIN STEP)
Rx I/Q DC OFFSET SETTLING RESPONSE
(-16dB BB VGA GAIN STEP)
MAX2831/32 toc13
MAX2831/32 toc14
-120 -100
-80
-60 -40
PIN (dBm)
-20
0
20
MAX2831/32 toc15
3V
2.5V
2.0V
0V
0V
0V
10mV
10mV
10mV
5mV
5mV
5mV
0V
0mV
0V
40ns/div
40ns/div
400ns/div
Rx I/Q DC OFFSET SETTLING RESPONSE
(-32dB BB VGA GAIN STEP)
I/Q OUTPUT DC ERROR DROOP
(RxHP = 1→0; 100Hz MODE)
Rx BB VGA SETTLING RESPONSE
(+8 GAIN STEP)
MAX2831/32 toc16
MAX2831/32 toc17
MAX2831/32 toc18
3V
3V
3V
0V
0V
0V
0V
10mV
-5mV
500mV
5mV
-10mV
0V
-500mV
0V
400ns/div
12
20ms/div
40ns/div
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Rx BB VGA SETTLING RESPONSE
(-8 GAIN STEP)
Rx BB VGA SETTLING RESPONSE
(-16 GAIN STEP)
MAX2831/32 toc19
Rx BB VGA SETTLING RESPONSE
(-32 GAIN STEP)
MAX2831/32 toc20
MAX2831/32 toc21
3V
3V
3V
0V
0V
0V
500mV
500mV
500mV
0V
0V
0V
-500mV
-500mV
-500mV
40ns/div
40ns/div
40ns/div
RF LNA SETTLING RESPONSE
(HIGH TO MEDIUM)
RF LNA SETTLING RESPONSE
(HIGH TO LOW)
Rx BB FREQUENCY RESPONSE vs.
FINE SETTING (COARSE SETTING = 8.5MHz)
MAX2831/32 toc23
3V
20
3V
MAX2831/32 toc24
MAX2831/32 toc22
0
0V
0V
500mV
500mV
0V
0V
-500mV
-500mV
dB
-20
-40
-60
-80
-100
1
100ns/div
Rx BB FREQUENCY RESPONSE vs.
COARSE SETTING (FINE SETTING = 010)
RX BASEBAND FILTER
GROUP DELAY
MAX2831/32 toc25
0
100
HISTOGRAM: Rx STATIC DC OFFSET
MAX2831/32 toc26
20
10
FREQUENCY (MHz)
78
65
MAX2831/32 toc27
100ns/div
MEAN: 0mV
STD: 0.977mV
SAMPLE SIZE: 1006
-20
52
dB
20ns/div
-40
-60
39
26
-80
13
-100
-120
0
1
10
FREQUENCY (MHz)
100
1
12
1σ/div
FREQUENCY (MHz)
______________________________________________________________________________________
13
MAX2831/MAX2832
Typical Operating Characteristics (continued)
(MAX2831 EV kit, VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, RXHP =
SCLK = DIN = low.)
Typical Operating Characteristics (continued)
(MAX2831 EV kit, VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, RXHP =
SCLK = DIN = low.)
HISTOGRAM: Rx PHASE IMBALANCE
95
Tx ICC vs. VCC
88
MAX2831/32 toc29
MAX2831/32 toc28
MEAN: 0dB
STD: 0.064dB
SAMPLE SIZE: 951
115
114
MEAN: 0.3°
STD: 0.314°
SAMPLE SIZE: 1013
MAX2831/32 toc30
HISTOGRAM: Rx GAIN IMBALANCE
138
TA = +85°C
86
92
76
69
57
46
38
23
19
0
82
80
0
TA = -40°C
78
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC (V)
HISTOGRAM: Tx LO LEAKAGE
HISTOGRAM: Tx SIDEBAND
SUPPRESSION
HISTOGRAM: Tx OUTPUT POWER
VARIATION
60
12
MAX2831/32 toc32
MAX2831/32 toc31
72
MEAN: -42dBc
STD: 1.9dB
SAMPLE SIZE: 1000
32
48
8
24
36
6
16
24
4
8
12
2
0
MEAN: 18.5dBm
GAIN ADJUSTED
TO ACHIEVE 5.6%
EVM
10
0
0
1σ/div
1σ/div
0.1dB/div
Tx BASEBAND FREQUENCY RESPONSE
Tx OUTPUT POWER vs. FREQUENCY
(B6:B1 = 111111)
(MAX2832 ONLY)
Tx OUTPUT POWER vs. GAIN SETTING
(MAX2832 ONLY)
-1.0
TA = -40°C
POUT (dBm)
-30
-40
-50
-60
-70
-80
-1.5
TA = +25°C
-2.0
-2.5
TA = +85°C
0.1
1
10
BASEBAND FREQUENCY (MHz)
100
-5
-10
-15
-20
-25
-3.0
-30
-3.5
-35
-40
-4.0
-90
MAX2831/32 toc36
-20
-0.5
POUT (dBm)
-10
0
MAX2831/32 toc35
0
MAX2831/32 toc34
0
MAX2831/32 toc33
1σ/div
MEAN: -33.45dBc
STD: 6.31dB
SAMPLE SIZE: 999
40
84
1σ/div
48
14
ICC (mA)
TA = +25°C
FILTER RESPONSE (dB)
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
2.40
2.42
2.44
2.46
FREQUENCY (GHz)
2.48
2.50
0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64
GAIN SETTINGS
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
11g SPECTRAL MASK
(MAX2832 ONLY)
2.00
1.75
1.50
1.25
-24
-18
-12
-6
OUTPUT POWER (dBm)
-70
-79
-80
-89
-90
-99
-100
2387
0
2407
2467
-110
2487
DC
26.5GHz
Tx GAIN VARIATION vs. FREQUENCY
(B6:B1 = 101001)
VCCPA = 2.7V
4
250
TA = -40°C
TA = +25°C
220
1dB/div
VCCPA = 3.0V
MAX2831/32 toc40
VCCPA = 3.3V
280
PA SUPPLY CURRENT (mA)
MAX2831/32 toc39a
VCCPA = 4.2V
5
2447
PA SUPPLY CURRENT vs. POUT
8
6
2427
FREQUENCY (MHz)
Tx EVM vs. POUT
7
-60
-69
2x VCO
-50
-59
3x VCO
-40
-49
MAX2831/32 toc41
-30
TA = +85°C
190
VCCPA = 4.2V
160
3
VCCPA = 2.7V, 3.0V, 3.3V
130
2
2
4
6
0
8 10 12 14 16 18 20 22
POUT (dBm)
2
TA = +25°C
19
2.40
8 10 12 14 16 18 20 22 24
POUT (dBm)
-9
MAX2831/32 toc42
GAIN ADJUSTED TO ACHIEVE 5.6% EVM
6
-19
POUT = 18.64dBm
EVM = 5.6%
-29
2.42
2.44
2.46
FREQUENCY (GHz)
2.48
2.50
802.11g POUT vs. GAIN SETTING
(UPPER GAIN CONTROL RANGE)
11g SPECTRAL MASK
Tx OUTPUT POWER vs. FREQUENCY
20
4
22
MAX2831/32 toc44
0
MAX2831/32 toc43
20
dBm
-39
18
-49
POUT (dBm)
EVM (%)
-30
-39
-109
1.00
POUT (dBm)
-20
4x VCO
dBm
EVM (%)
2.25
RBW = 1MHz
802.11g SIGNAL
2x RF
2.50
-29
MAX2831/32 toc38
-10
dBm
2.75
POUT = -2.17dBm
EVM = 2.12%
-19
RF
VCO
-9
MAX2831/32 toc36a
3.00
Tx OUTPUT SPURS
(MAX2832 ONLY)
MAX2831/32 toc37
EVM vs. Tx OUTPUT POWER
(MAX2832 ONLY)
-59
-69
18
16
-79
17
-89
TA = +85°C
TA = -40°C
16
2.40
2.42
2.44
2.46
FREQUENCY (GHz)
14
-99
2.48
2.50
-109
2387
12
2407
2427
2447
FREQUENCY (MHz)
2467
2487
40
44
48
52
56
GAIN SETTINGS
60
______________________________________________________________________________________
64
15
MAX2831/MAX2832
Typical Operating Characteristics (continued)
(MAX2831 EV kit, VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, RXHP =
SCLK = DIN = low.)
Typical Operating Characteristics (continued)
(MAX2831 EV kit, VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, RXHP =
SCLK = DIN = low.)
1.2
fRF = 2.5GHz
0.8
0.6
1.0
0.8
0.6
0.4
0.2
0.2
0
0
4
2
4
50mV
TA = -40°C,
+25°C
0.6
0
2
4
6
8 10 12 14 16 18 20 22
POUT (dBm)
PA OUTPUT POWER HISTORGRAM
FOR 1.1V POWER DETECTOR OUTPUT
TX I/Q INPUT
12
MEAN = 18.5dBm
10
6
20dBm
POWER DETECTOR
MAX2831/32 toc47
0.8
8
-300mV
0V
1.0
6 8 10 12 14 16 18 20 22
OUTPUT POWER (dBm)
-50mV
1V
TA = +85°C
1.2
PA OUTPUT ENVELOPE RESPONSE
MAX2831/32 toc48
300mV
1.4
0
0
POWER-DETECTOR OUTPUT
PA ENVELOPE
1.6
0.2
6 8 10 12 14 16 18 20 22
OUTPUT POWER (dBm)
20dB GAIN STEP
1.8
0.4
VCCPA = 3.3V, 4.2V
MAX2831/32 toc49
2
VCCPA = 2.7V, 3.0V
1.2
0.4
0
MAX2831/32 toc46
1.6
1.4
POWER DETECTOR OVER TEMPERATURE
2.0
POWER DETECTOR (V)
1.4
1.0
1.8
POWER DETECTOR (V)
fRF = 2.4GHz
1.6
MAX2831/32 toc45
1.8
POWER DETECTOR OVER SUPPLY VOLTAGE
2.0
4
0
2
PA ENVELOPE
-20dBm
0
100ns/div
0.1dB/div
1µs/div
PA OUTPUT RETURN LOSS
vs. RF FREQUENCY
Tx OUTPUT SPURS
-15
MAX2831/32 toc52
10
0
-10
VCO
2x RF
2x VCO
3x RF
4x RF
-20
-30
-20
RBW = 1MHz
802.11g SIGNAL
RF
MAX2831/32 toc51
OUTPUT RETURN LOSS (dB)
-10
-40
-50
-60
-25
-70
-80
-30
2300
16
2350
2400 2450 2500
RF FREQUENCY (MHz)
2550
2600
-90
DC
26.5GHz
______________________________________________________________________________________
MAX2831/32 toc50
POWER DETECTOR OVER FREQUENCY
2.0
POWER DETECTOR (V)
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
2500
2450
2400
MAX2831/32 toc54
-60
-70
PHASE NOISE (dBc/Hz)
2550
LO FREQUENCY (MHz)
-50
MAX2831/32 toc53
2600
CHANNEL SWITCHING FREQUENCY
SETTLING (FROM 2500MHz TO 2400MHz)
LO PHASE NOISE
vs. OFFSET FREQUENCY
LO FREQUENCY vs. VTUNE
MAX2831/32 toc55
50kHz
-80
-90
10kHz/
div
-100
-110
-120
-130
2350
-140
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4
VTUNE (V)
-150
0.001
PLL SETTLING TIME FROM
SHUTDOWN TO STANDBY MODE
0
10
PLL SETTLING TIME
FROM STANDBY TO Tx
MAX2831/32 toc56
50kHz
-50kHz
0.01
0.1
1
OFFSET FREQUENCY (MHz)
10kHz/
div
Rx TO Tx TURNAROUND
PLL SETTLING TIME
MAX2831/32 toc57
50kHz
5kHz/
div
-25kHz
-50kHz
0
2ms
0
CRYSTAL OFFSET FREQUENCY (Hz)
fCLOCK = 40MHz
CLOAD = 5pF
3V
5kHz/div
0V
-25kHz
0
50µs
10ns/div
50µs
CRYSTAL-OSCILLATOR OFFSET FREQUENCY
vs. CRYSTAL-OSCILLATOR TUNING BITS
MAX2831/32 toc60
MAX2831/32 toc59
25kHz
0
30µs
CLOCK OUTPUT
Tx-Rx TURNAROUND PLL SETTLING TIME
MAX2831/32 toc58
25kHz
10kHz/
div
-50kHz
250µs
800
700
600
500
400
300
200
100
0
-100
-200
-300
-400
-500
-600
-700
-800
KYOCERA
(CX-3225SB)
MAX2831/32 toc61
2300
0 10 20 30 40 50 60 70 80 90 100110120130
CTUNE (DIGITAL BITS)
______________________________________________________________________________________
17
MAX2831/MAX2832
Typical Operating Characteristics (continued)
(MAX2831 EV kit, VCC_ = 2.8V, VCCPA = VCCTXPA = 3.3V, TA = +25°C, fLO = 2.437GHz, fREF = 40MHz, SHDN = CS = high, RXHP =
SCLK = DIN = low.)
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
RX/TX GAIN
CONTROL
B3
TXRF+
TXRF-
RX/TX GAIN
CONTROL
MODE CONTROL
RXBBI-
VCCRXVGA
VCCRXFL
TXBBQ-
TXBBQ+
TXBBI-
TXBBI+
RXBBI+
37
MUX
MAX2831
2
RSSI
36
35
TO
RSSI
MUX
3
MUX
34
4
33
5
32
90°
6
IMUX QMUX
31
0°
PLL
7
AM
DETECTOR
8
÷
9
30
29
CRYSTAL
OSCILLATOR/
BUFFER
28
TEMP
SENSOR TO RSSI
MUX
10
27
POWER DETECTOR
B2
11
SHDN
38
TEMP
SENSOR
RSSI
12
VCCTXPA
13
SERIAL
INTERFACE
RSSI
MUX
14
15
RX/TX GAIN
CONTROL
16
17
18
26
÷
19
SERIAL INPUTS
20
21
25
22
REFERENCE
CLOCK BUFFER
OUTPUT
23
RXBBQ+
RXBBQB4
BYPASS
TUNE
GNDVCO
VCCVCO
CTUNE
XTAL
VCCXTAL
GNDCP
VCCCP
24
CPOUT
TX OUTPUT
39
B1
VCCPA
40
LD
B7
41
CLOCKOUT
RX GAIN
CONTROL
42
VCCPLL
RXRF-
43
DIN
RXRF+
44
VCCTXMX
B6
45
RSSI
RX/TX
GAIN CONTROL
46
RX I OUTPUTS
1
B5
RX INPUT
47
CS
GNDRXLNA
VCCRXMX
GNDTEST
RXTX
48
VCCLNA
RX BASEBAND HPF
CORNER FREQUENCY
CONTROL
TX INPUT
RXHP
MODE
CONTROL
SCLK
MAX2831/MAX2832
Block Diagrams/Typical Operating Circuits
RX/TX GAIN
CONTROL
NOTE: ALL GROUND (PINS 2, 26, AND 31) AND BYPASS CAPACITORS’ GROUND REQUIRE THEIR OWN VIAS TO GROUND.
DO NOT CONNECT THEM TO THE EXPOSED PADDLE GROUND.
18
______________________________________________________________________________________
RX Q
OUTPUTS
RX/TX GAIN
CONTROL
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
TXRF+
TXRFRX/TX GAIN
CONTROL
MODE CONTROL
RXBBI-
RXBBI+
VCCRXVGA
VCCRXFL
TXBBQ-
TXBBQ+
TXBBI-
TXBBI+
5
36
35
MUX
34
32
90°
6
31
0°
PLL
7
AM
DETECTOR
8
÷
9
30
29
CRYSTAL
OSCILLATOR/
BUFFER
28
TEMP
SENSOR TO RSSI
MUX
10
B2
11
SHDN
37
33
TEMP
SENSOR
RSSI
12
VCCTXPA
13
RSSI
MUX
14
15
RX/TX GAIN
CONTROL
27
SERIAL
INTERFACE
16
17
18
SERIAL INPUTS
26
÷
19
DIN
B3
38
4
SCLK
RX/TX GAIN
CONTROL
RSSI
VCCTXMX
TX OUTPUT
39
TO
RSSI
MUX
3
IMUX QMUX
VCCPA
40
20
21
25
22
REFERENCE
CLOCK BUFFER
OUTPUT
23
RXBBQ+
RXBBQB4
RX Q
OUTPUTS
RX/TX GAIN
CONTROL
BYPASS
TUNE
GNDVCO
VCCVCO
CTUNE
XTAL
VCCXTAL
GNDCP
VCCCP
24
CPOUT
B7
41
MAX2832
2
RSSI
RX GAIN
CONTROL
42
B1
RXRF-
43
LD
RXRF+
44
CLOCKOUT
B6
45
MUX
CS
RX/TX
GAIN CONTROL
46
RX I OUTPUTS
1
B5
RX INPUT
47
VCCPLL
GNDRXLNA
VCCRXMX
GNDTEST
RXTX
48
VCCLNA
RX BASEBAND HPF
CORNER FREQUENCY
CONTROL
TX INPUT
RXHP
MODE
CONTROL
RX/TX GAIN
CONTROL
NOTE: ALL GROUND (PINS 2, 26, AND 31) AND BYPASS CAPACITORS’ GROUND REQUIRE THEIR OWN VIAS TO GROUND.
DO NOT CONNECT THEM TO THE EXPOSED PADDLE GROUND.
______________________________________________________________________________________
19
MAX2831/MAX2832
Block Diagrams/Typical Operating Circuits (continued)
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
MAX2831/MAX2832
Pin Description
20
PIN
NAME
1
VCCLNA
2
GNDRXLNA
3
B6
4
RXRF+
5
RXRF-
6
B7
7
VCCPA
8
B3
9
TXRF+
10
TXRF-
11
B2
12
SHDN
13
VCCTXPA
FUNCTION
LNA Supply Voltage
LNA Ground
Receiver and Transmitter Gain-Control Logic-Input Bit 6
LNA Differential Input. Input is internally AC-coupled and matched to 100Ω differential. Connect
directly to a 2:1 balun.
Receiver Gain-Control Logic-Input Bit 7
Supply Voltage for Second Stage of Power Amplifier
Receiver and Transmitter Gain-Control Logic-Input Bit 3
Power-Amplifier Differential Output for the MAX2831. PA output must be AC-coupled. PA driver
internally AC-coupled differential outputs and matched to 100Ω differential for the MAX2832. Connect
directly to a 2:1 balun.
Receiver and Transmitter Gain-Control Logic-Input Bit 2
Active-Low Shutdown and Standby Logic Input. See Table 31 for operating modes.
Supply Voltage for First-Stage of PA and PA Driver
14
B5
Receiver and Transmitter Gain-Control Logic-Input Bit 5
15
CS
Active-Low Chip-Select Logic Input of 3-Wire Serial Interface (See Figure 2)
16
RSSI
17
VCCTXMX
18
SCLK
RSSI, PA Power Detector (MAX2831 Only) or Temperature-Sensor Multiplexed Analog Output
Transmitter Upconverter Supply Voltage
Serial-Clock Logic Input of 3-Wire Serial Interface (See Figure 2)
19
DIN
20
VCCPLL
Data Logic Input of 3-Wire Serial Interface (See Figure 2)
21
CLOCKOUT
22
LD
Lock-Detect Logic Output of Frequency Synthesizer. Output high indicates that the frequency synthesizer
is locked. Output programmable as CMOS or open-drain output. (See Tables 16 and 20.)
23
B1
Receiver and Transmitter Gain-Control Logic-Input Bit 1
24
CPOUT
Charge-Pump Output. Connect the frequency synthesizer’s loop filter between CPOUT and TUNE
(see the Block Diagrams/Typical Operating Circuits).
25
VCCCP
PLL Charge-Pump Supply Voltage
PLL and Registers Supply Voltage. Connect to the supply voltage to retain the register settings.
Reference Clock Buffer Output
26
GNDCP
Charge-Pump Circuit Ground
27
VCCXTAL
Crystal Oscillator Supply Voltage
28
XTAL
29
CTUNE
Connection for Crystal Oscillator Off-Chip Capacitors. When using an external reference clock input,
leave CTUNE unconnected.
30
VCCVCO
VCO Supply Voltage
31
GNDVCO
32
TUNE
33
BYPASS
34
B4
Crystal or Reference Clock Input. AC-couple a crystal or a reference clock to this analog input.
VCO Ground
VCO TUNE Input (see the Block Diagrams/Typical Operating Circuits)
On-Chip VCO Regulator Output Bypass. Bypass with a 0.1µF to 1µF capacitor to GND. Do not
connect other circuitry to this point.
Receiver and Transmitter Gain-Control Logic-Input Bit 4
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
PIN
NAME
35
RXBBQ-
FUNCTION
36
RXBBQ+
37
RXBBI-
38
RXBBI+
39
VCCRXVGA
40
RXHP
41
VCCRXFL
Receiver Baseband Q-Channel Differential Outputs. In TX calibration mode, these pins are the LO
leakage and sideband detector outputs.
Receiver Baseband I-Channel Differential Outputs. In TX calibration mode, these pins are the LO
leakage and sideband detector outputs.
Receiver VGA Supply Voltage
Receiver Baseband AC-Coupling High-Pass Corner Frequency Control Logic Input
42
TXBBQ-
43
TXBBQ+
44
TXBBI-
45
TXBBI+
Receiver Baseband Filter Supply Voltage
Transmitter Baseband I-Channel Differential Inputs
Transmitter Baseband Q-Channel Differential Inputs
46
VCCRXMX
Receiver Downconverters Supply Voltage
47
GNDTEST
Connect to Ground
48
RXTX
—
EP
RX/TX Mode Control Logic Input. See Table 31 for operating modes.
Exposed Paddle. Connect to the ground plane with multiple vias for proper operation and heat
dissipation. Do not share with any other pin grounds and bypass capacitors' ground.
Detailed Description
The MAX2831/MAX2832 single-chip, low-power, direct
conversion, zero-IF transceivers are designed to support
802.11g/b applications operating in the 2.4GHz to
2.5GHz band. The fully integrated transceivers include a
receive path, transmit path, voltage-controlled oscillator
(VCO), sigma-delta fractional-N synthesizer, crystal oscillator, RSSI, PA power detector (MAX2831), temperature
sensor, Rx and Tx I/Q error-detection circuitry, basebandcontrol interface and linear power amplifier (MAX2831).
The only additional components required to implement a
complete radio front-end solution are a crystal, a pair of
baluns, a BPF, a switch, and a small number of passive
components (RCs, no inductors required).
Receiver
The fully integrated receiver achieves a noise figure of
2.6dB in high-gain mode, and an input compression point
of -6dBm in low-gain mode, while consuming only 62mA
of supply current. The receiver integrates an LNA and
VGA with a 95dB digitally programmable gain control
range, direct-conversion downconverters, I/Q baseband
lowpass filters with programmable LPF corner frequencies, analog RSSI and integrated DC-offset correction circuitry. A logic-low on the RXTX input (pin 48) and a
logic-high on the SHDN input (pin 12) enable the receiver.
LNA Input Matching
The LNA features a differential input that is internally
AC-coupled and internally matched to 100Ω. Connect a
2:1 balun transformer directly to the RXRF+ (pin 4) and
RXRF- (pin 5) ports to convert the differential 100Ω
input impedance to a single-ended 50Ω input. Provide
electrically symmetrical input traces from the LNA input
to the balun to maintain IP2 performance and RF common-mode noise rejection.
LNA Gain Control
The LNA has three gain modes: max gain, max gain 16dB, and max gain - 33dB. The three LNA gain modes
can be serially programmed through the SPI™ interface
by programming bits D6:D5 in Register 11 (A3:A0 =
1011) or programmed in parallel through the digital
logic gain-control pins, B7 (pin 6) and B6 (pin 3). Set
bit D12 = 1 in Register 8 (A3:A0 = 1000) to enable programming through the SPI interface, or set bit D12 = 0
to enable parallel programming. See Table 1 for LNA
gain-control settings.
Table 1. LNA Gain-Control Settings (Pins
B7:B6 or Register A3:A0 = 1011, D6:D5)
B7 OR D6
B6 OR D5
NAME
DESCRIPTION
1
1
High
Max gain
1
0
Medium
Max gain - 16dB (typ)
0
X
Low
Max gain - 33dB (typ)
SPI is a trademark of Motorola, Inc.
______________________________________________________________________________________
21
MAX2831/MAX2832
Pin Description (continued)
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Baseband Variable-Gain Amplifier
The receiver baseband variable-gain amplifiers provide
62dB of gain control range programmable in 2dB steps.
The VGA gain can be serially programmed through the
SPI interface by setting bits D4:D0 in Register 11 (A3:A0
= 1011) or programmed in parallel through the digital
logic gain-control pins, B5 (pin 14), B4 (pin 34), B3 (pin
8), B2 (pin 11), and B1 (pin 23). Set bit D12 = 1 in
Register 8 (A3:A0 = 1000) to enable serial programming
through the serial interface or set bit D12 = 0 to enable
parallel programming through the external logic pins.
See Table 2 for the gain-step value and Table 3 for
baseband VGA gain-control settings.
Receiver Baseband Lowpass Filter
The receiver integrates lowpass filters that provide an
upper -3dB corner frequency of 8.5MHz (nominal mode)
with 50dB of attenuation at 20MHz, and 45ns of group
delay ripple in the passband (10kHz to 8.5MHz). The
upper -3dB corner frequency is tightly controlled on-chip
and does not require user adjustment. However, provisions are made to allow fine tuning of the upper -3dB corner frequency. In addition, coarse frequency tuning
allows the -3dB corner frequency to be set to 7.5MHz
(11b mode), 8.5MHz (11g mode), 15MHz (turbo 1 mode),
and 18MHz (turbo 2 mode) by programming bits D1:D0
in Register 8 (A3:A0 = 1000). See Table 4. The coarse
corner frequency can be fine-tuned approximately ±10%
in 5% steps by programming bits D2:D0 in Register 7
(A3:A0 = 0111). See Table 5 for receiver LPF fine -3dB
corner frequency adjustment.
Table 2. Receiver Baseband VGA GainStep Value (Pins B5:B1 or Register D4:D0,
A3:A0 = 1011)
Table 4. Receiver LPF Coarse -3dB
Corner Frequency Settings in Register
(A3:A0 = 1000)
BITS (D1:D0)
-3dB CORNER
FREQUENCY (MHz)
MODE
00
01
7.5
8.5
11b
11g
10
15
Turbo 1
11
18
Turbo 2
Table 5. Receiver LPF Fine -3dB Corner
Frequency Adjustment in Register
(A3:A0 = 0111)
BITS (D2:D0)
% ADJUSTMENT RELATIVE TO
COARSE SETTING
2
000
90
4
001
95
B3/D2
8
010
100
B4/D3
16
011
105
32
100
110
PIN/BIT
GAIN STEP (dB)
B1/D0
B2/D1
B5/D4
Table 3. Baseband VGA Gain-Control
Settings in Receiver Gain-Control Register
(Pin B5:B1 or Register D4:D0, A3:A0 = 1011)
22
Baseband Highpass Filter
and DC Offset Correction
The receiver implements programmable AC and nearDC coupling of I/Q baseband signals. Temporary ACcoupling is used to quickly remove LO leakage and
other DC offsets that could saturate the receiver outputs. When DC offsets have settled, near DC-coupling
is enabled to avoid attenuation of the received signal.
AC-coupling is set (-3dB highpass corner frequency of
600kHz) when a logic-high is applied to RXHP (pin 40).
Near DC-coupling is set (-3dB highpass corner frequency of 100Hz nominal) when a logic-low is applied
to RXHP. Bits D13:D12 in Register 7 (A3:A0 = 0111)
allow the near DC-coupling -3B highpass corner frequency to be set to 100Hz (D13:D12 = 00), 4kHz
(D13:D12 = X1), or 30kHz (D13:D12 = 10). See Table 6.
Table 6. Receiver Highpass Filter -3dB
Corner Frequency Programming
RXHP
A3:A0 = 0111,
D13:D12
Max
1
XX
600k
11110
Max - 2dB
0
00
100 (recommended)
11101
Max - 4dB
0
X1
4k
:
:
0
10
30k
00000
Min
B5:B1 OR D4:D0
GAIN
11111
-3dB HIGHPASS CORNER
FREQUENCY (Hz)
X = Don’t care.
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Received Signal-Strength Indicator (RSSI)
The RSSI output (pin 16) can be programmed to multiplex an analog output voltage proportional to the
received signal strength, the PA output power
(MAX2831), or the die temperature. Set bits D9:D8 = 00
in Register 8 (A3:A0 = 1000) to enable the RSSI output
in receive mode (off in transmit mode). Set bit D10 = 1
to enables the RSSI output when RXHP = 1, and disable the RSSI output when RXHP = 0. Set bit D10 = 0 to
enable the RSSI output independent of RXHP. See
Table 7 for a summary of the RSSI output versus register programming and RXHP.
The received signal strength indicator provides an analog voltage proportional to the log of the sum of the
squares of the I and Q channels, measured after the
receive baseband filters and before the variable-gain
amplifiers. The RSSI analog output voltage is proportional to the RF input signal level and LNA gain state
over a 60dB range, and is not dependent upon VGA
gain. See the graph RX RSSI Output vs. Input Power in
the Typical Operating Characteristics for further details.
Register 8 (A3:A0 = 1000) and bit D5:D3 in Register 7
(A3:A0 = 0111). The -3dB corner-frequency is tightly controlled on-chip and does not require user adjustment.
Additionally, provisions are made to fine tune the -3dB corner frequency through bits D5:D3 in the Filter
Programming register (A3:A0 = 0111). See Tables 8 and 9.
Table 7. RSSI Pin Truth Table
INPUT CONDITIONS
A3:A0 = 1000,
D9:D8
A3:A0 = 1000,
D10
RXHP
RSSI OUTPUT
X
0
0
No signal
00
0
1
RSSI
01
0
1
Temperature
sensor
10
0
1
Power detector
(MAX2831)
00
1
X
RSSI
01
1
X
Temperature
sensor
10
1
X
Power detector
(MAX2831)
X = Don’t care.
Table 8. Transmitter LPF Coarse -3dB
Corner Frequency Settings in Register
(A3:A0 = 1000)
-3dB CORNER
FREQUENCY (MHz)
MODE
00
8
11b
Transmitter
01
11
11g
The transmitter integrates baseband lowpass filters,
direct-upconversion mixers, a VGA, a PA driver, and a linear RF PA with a power detector (MAX2831). A logic-high
on the RXTX input (pin 48) and a logic-high on the SHDN
input (pin 12) enable the transmitter.
10
16.5
Turbo 1
11
22.5
Turbo 2
Transmitter I/Q Baseband Inputs
The differential analog inputs of the transmitter baseband
amplifier I/Q inputs (TXBBI+, TXBBI-, TXBBQ+, TXBBQ-)
have a differential impedance of 20kΩ || 1pF. The inputs
require an input common-mode voltage of 0.9V to 1.3V,
which is provided by the DC-coupled I and Q DAC outputs of the accompanying baseband IC.
Transmitter Baseband Lowpass Filtering
The transmitter integrates lowpass filters that can be
tuned to -3dB corner frequencies of 8MHz (11b),
11MHz (11g), 16.5MHz (turbo 1 mode), and 22.5MHz
(turbo 2 mode) through programming bits D1:D0 in
BITS (D1:D0)
Table 9. Transmitter LPF Fine -3dB
Corner Frequency Adjustment in
Register (A3:A0 = 0111)
BITS (D5:D3)
% ADJUSTMENT RELATIVE TO
COARSE SETTING
000
90
001
95
010
100
011
105
100
110 (11g)
101
115
101–111
Not used
______________________________________________________________________________________
23
MAX2831/MAX2832
Receiver I/Q Baseband Outputs
The differential outputs (RXBBI+, RXBBI-, RXBBQ+,
RXBBQ-) of the baseband amplifiers have a differential
output impedance of ~300Ω, and are capable of driving differential loads up to 10kΩ || 10pF. The outputs
are internally biased to a common-mode voltage of
1.1V and are intended to be DC-coupled to the inphase (I) and quadrature (Q) analog-to-digital data
converter inputs of the accompanying baseband IC.
Additionally, the common-mode output voltage can be
adjusted from 1.1V to 1.4V through programming bits
D11:D10 in Register 15 (A3:A0 = 1111).
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Transmitter Variable-Gain Amplifier
The variable-gain amplifier of the transmitter provides
31dB of gain control range programmable in 0.5dB
steps over the top 8dB of the gain control range and in
1dB steps below that. The transmitter gain can be programmed serially through the SPI interface by setting
bits D5:D0 in Register 12 (A3:A0 = 1100) or in parallel
through the digital logic gain-control pins B6:B1 (pins
3, 6, 8, 11, 14, 23, and 34, respectively). Set bit D10 =
0 in Register 9 (A3:A0 = 1001) to enable parallel programming, and set bit D10 = 1 to enable programming
through the 3-wire serial interface. See Table 10 for the
transmitter VGA gain-control settings.
Table 10. Transmitter VGA Gain-Control
Settings
NUMBER
D5:D0 Or
B6:B1
OUTPUT SIGNAL POWER
63
111111
Max
62
111110
Max - 0.5dB
61
111101
Max - 1.0dB
The PA of the MAX2831 has a 100Ω differential output
that is internally matched. The output has to be AC-coupled using two off-chip 1.5pF capacitors to a 100Ω:50Ω
balun. Provide electrically symmetrical traces from the
PA output to the balun to present a balanced load and to
reduce out-of-band spurs.
Power Detector (MAX2831)
The MAX2831 integrates a voltage-peak detector at the
PA output and provides an analog voltage proportional
to PA output power. See the Power Detector Over
Frequency and Power Detector Over Supply Voltage
graphs in the Typical Operating Characteristics. Set bits
D9:D8 = 10 in Register 8 (A3:A0 = 1000) to multiplex the
power-detector analog output voltage to the RSSI output
(pin 16).
:
:
:
49
110001
Max - 7dB
48
110000
Max - 7.5dB
47
101111
Max - 8dB
46
101110
Max - 8dB
45
101101
Max - 9dB
Synthesizer Programming
44
101100
Max - 9dB
The MAX2831/MAX2832 integrate a 20-bit sigma-delta
fractional-N synthesizer, allowing the device to achieve
excellent phase-noise performance (0.9° RMS from
10kHz to 10MHz), fast PLL settling times, and an RF frequency step-size of 20Hz. The synthesizer includes a
divide-by-1 or a divide-by-2 reference frequency
divider, an 8-bit integer portion main divider with a divisor range programmable from 64 to 255, and a 20-bit
fractional portion main-divider. Bit D2 in Register 5
(A3:A0 = 0101) sets the reference oscillator divider ratio
to 1 or 2. Bits D7:D0 in Register 3 (A3:A0 = 0011) set
the integer portion of the main divider. The 20-bit fractional portion of the main-divider is split between two
registers. The 14 MSBs of the fractional portion are set
in Register 4 (A3:A0 = 0100), and the 6 LSBs of the fractional portion of the main divider are set in Register 3
(A3:A0 = 0011). See Tables 11 and 12.
:
:
:
5
000101
Max - 29dB
4
000100
Max - 29dB
3
000011
Max - 30dB
2
000010
Max - 30dB
1
000001
Max - 31dB
0
000000
Max - 31dB
Power-Amplifier Driver Output Matching (MAX2832)
The PA driver of the MAX2832 has a 100Ω differential
output with on-chip AC-coupling capacitors. Provide
electrically symmetrical traces to present a balanced
load to the PA driver output to help maintain driver linearity and RF common-mode rejection.
24
Power-Amplifier Bias, Enable Delay
and Output Matching (MAX2831)
The MAX2831 integrates a 2-stage PA, providing
+18.5dBm of output power at 5.6% EVM (54Mbps
OFDM signal) in 802.11g mode while exceeding the
802.11g spectral mask requirements. The first and second stage PA bias currents are set through programming bits D2:D0 and bits D6:D3 in Register 10 (A3:A0 =
1010), respectively. An adjustable PA enable delay, relative to the transmitter enable (RXTX low-to-high transition), can be set from 200ns to 7µs through
programming bits D13:D10 in Register 10 (A3:A0 =
1010).
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
LO Frequency Divider = fRF / fCOMP = 2437MHz /
20MHz = 121.85
Integer Divider = 121 (d) = 0111 1001 (binary)
Fractional Divider = 0.85 x (220 - 1) = 891289 (decimal)
= 1101 1001 1001 1001 1001
See Table 13 for integer and fractional divider ratios for
802.11g/b systems using a 20MHz comparison frequency.
Table 11. Integer Divider Register (A3:A0 = 0011)
BIT
RECOMMENDED
D13:D8
00000
D7:D0
01111001
DESCRIPTION
6 LSBs of 20-Bit Fractional Portion of Main Divider
8-Bit Integer Portion of Main Divider. Programmable from 64 to 255.
Table 12. Fractional Divider Register (A3:A0 = 0100)
BIT
RECOMMENDED
D13:D0
11011001100110
DESCRIPTION
14 MSBs of 20-Bit Fractional Portion of Main Divider
Table 13. IEEE 802.11g/b Divider-Ratio Programming Words
INTEGER DIVIDER
FRACTIONAL DIVIDER
fRF
(MHz)
(fRF / fCOMP)
A3:A0 = 0011, D7:D0
A3:A0 = 0100, D13:D0
A3:A0 = 0011, D13:D8
2412
120.6
0111 1000b
2666h
1Ah
2417
120.85
0111 1000b
3666h
1Ah
2422
121.1
0111 1001b
0666h
1Ah
2427
121.35
0111 1001b
1666h
1Ah
2432
121.6
0111 1001b
2666h
1Ah
2437
121.85
0111 1001b
3666h
1Ah
2442
122.1
0111 1010b
0666h
1Ah
2447
122.35
0111 1010b
1666h
1Ah
2452
122.6
0111 1010b
2666h
1Ah
2457
122.85
0111 1010b
3666h
1Ah
2462
123.1
0111 1011b
0666h
1Ah
2467
123.35
0111 1011b
1666h
1Ah
2472
123.6
0111 1011b
2666h
1Ah
2484
124.2
0111 1100b
0CCCh
33h
______________________________________________________________________________________
25
MAX2831/MAX2832
Calculating Integer and Fractional Divider Ratios
The desired integer and fractional divider ratios can be
calculated by dividing the RF frequency (fRF) by fCOMP.
For nominal 802.11g/b operation, a 40MHz reference
oscillator is divided by 2 to generate a 20MHz comparison frequency (fCOMP). The following method can be
used when calculating divider ratios supporting various
reference and comparison frequencies:
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Crystal Oscillator
The crystal oscillator has been optimized to work with
low-cost crystals (e.g., Kyocera CX-3225SB). See Figure
1. The crystal oscillator frequency can be fine tuned
through bits D6:D0 in Register 14 (A3:A0 = 1110), which
control the value of C TUNE from 0.5pF to 15.4pF in
0.12pF steps. See the Crystal-Oscillator Offset
Frequency vs. Crystal-Oscillator Tuning Bits graph in the
Typical Operating Characteristics. The crystal oscillator
can be used as a buffer for an external reference frequency source. In this case, the reference signal is ACcoupled to the XTAL pin, and capacitors C1 and C2 are
not connected. When used as a buffer, the XTAL input
pin has to be AC-coupled. The XTAL pin has an input
impedance of 5kΩ || 4pF, (set D6:D0 = 0000000 in
Register 14 A3:A0 = 1110).
MAX2831
MAX2832
XTAL
C1
CTUNE
C2
28
29
CTUNE
1.35kΩ
FOR EXTERNAL REFERENCE CLOCK SET, C1 = C2 = OPEN
Figure 1. Crystal Oscillator Schematic
26
5.9kΩ
Reference Clock Output Divider/Buffer
The reference oscillator of the MAX2831/MAX2832 has
a divider and a buffered output for routing the reference clock to the accompanying baseband IC. Bit D10
in Register 14 (A3:A0 = 1110) sets the buffer divider to
divide by 1 or 2, independent of the divide ratio for the
reference frequency provided to the PLL. Bit B9 in the
same register enables or disables the reference buffer
output. See the Clock Output waveform in the Typical
Operating Characteristics.
Loop Filter
The PLL charge-pump output, CPOUT (pin 24), connects to an external third-order, lowpass RC loop-filter,
which in turn connects to the voltage tuning input,
TUNE (pin 32), of the VCO, completing the PLL loop.
The charge-pump output sink and source current is
1mA, and the VCO tuning gain is 103MHz/V at 0.5V
tune voltage and 86MHz/V at 2.2V tune voltage. The RC
loop-filter values have been optimized for a loop bandwidth of 150kHz, to achieve the desired Tx/Rx turnaround settling time, while maintaining loop stability
and good phase noise. Refer to the MAX2831 EV kit
schematic for the recommended loop-filter component
values. Keep the line from this pinto the tune input as
short as possible to prevent spurious pickup.
Lock-Detector Output
The PLL features a logic lock-detect output. A logic-high
indicates the PLL is locked, and a logic-low indicates
the PLL is not locked. Bit D5 in Register 5 (A3:A0 =
0101) enables or disables the lock-detect output. Bit
D12 in Register 1 (A3:A0 = 0001) configures the lockdetect output as a CMOS or open-drain output. In opendrain output mode, bit D9 in Register 5 (A3:A0 = 0101)
enables or disables an internal 30kΩ pullup resistor
from the open-drain output.
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
The MAX2831/MAX2832 include 16 programmable, 18bit registers. The 14 most significant bits (MSBs) are
used for register data. The 4 least significant bits
(LSBs) of each register contain the register address.
See Table 14 for a summary of the registers and recommended register settings.
Register data is loaded through the 3-wire SPI/
MICROWIRE™-compatible serial interface. Data is
MICROWIRE is a trademark of National Semiconductor Corp.
Table 14. Recommended Register Settings*
REGISTER
DATA
ADDRESS
TABLE
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
(A3:A0)
0
0
1
0
1
1
1
0
1
0
0
0
0
0
0
0000
15
1
0
1
0
0
0
1
1
0
0
1
1
0
1
0
0001
16
2
0
1
0
0
0
0
0
0
0
0
0
0
1
1
0010
17
3
0
0
0
0
0
0
0
1
1
1
1
0
0
1
0011
18
4
1
1
0
1
1
0
0
1
1
0
0
1
1
0
0100
19
5
0
0
0
0
0
0
1
0
1
0
0
1
0
0
0101
20
6
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0110
21
7
0
1
0
0
0
0
0
0
1
0
0
0
1
0
0111
22
8
1
0
0
0
0
0
0
0
1
0
0
0
0
1
1000
23
9
0
0
0
0
1
1
1
0
1
1
0
1
0
1
1001
24
10
0
1
1
1
0
1
1
0
1
0
0
1
0
0
1010
25
11
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1011
26
12
0
0
0
0
0
1
0
1
0
0
0
0
0
0
1100
27
13
0
0
1
1
1
0
1
0
0
1
0
0
1
0
1101
28
14
0
0
0
0
1
1
0
0
1
1
1
0
1
1
1110
29
15
0
0
0
0
0
1
0
1
0
0
0
1
0
1
1111
30
*The power-on register settings are not production tested. Recommended register settings must be loaded after VCC is supplied.
BIT 1
DIN
BIT 2
BIT 15
BIT 16
BIT 23
BIT 24
SCLK
tCH
tDS
tCS1
tCL
CS
tCSO
tCSS
tDH
tCSH
tCSW
Figure 2. 3-Wire SPI Serial-Interface Timing Diagram
______________________________________________________________________________________
27
MAX2831/MAX2832
shifted in MSB first and is framed by CS. When CS is
low, the clock is active, and data is shifted with the rising edge of the clock. When CS transitions high, the
shift register is latched into the register selected by the
contents of the address bits. See Figure 2. Only the last
18 bits shifted into the device are retained in the shift
register. No check is made on the number of clock
pulses. For programming data words less than 14 bits
long, only the required data bits and the address bits
need to be shifted, resulting in faster Rx and Tx gain
control where only the LSBs need to be programmed.
Programmable Registers and
3-Wire SPI-Interface
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Table 15. Register 0 (A3:A0 = 0000)
DATA BITS
RECOMMENDED
D13:D11
000
D10
1
D9:D0
1101000000
DESCRIPTION
Set to recommended value.
Fractional-N PLL Mode Enable. Set 1 to enable the fractional-N PLL or set 0 to enable the
integer-N PLL.
Set to recommended value.
Table 16. Register 1 (A3:A0 = 0001)
DATA BITS
RECOMMENDED
D13
0
Set to recommended value.
DESCRIPTION
D12
1
Lock-Detector Output Select. Set to 1 for CMOS Output. Set to 0 for open-drain output. Bit D9
in register (A3:A0 = 0101) enables or disables an internal 30kΩ pullup resistor in open-drain
output mode.
D11:D0
000110011010
Set to recommended value.
Table 17. Register 2 (A3:A0 = 0010)
DATA BITS
RECOMMENDED
D13:D0
01000000000011
DESCRIPTION
Set to recommended value.
This register contains the 8-bit integer portion and 6 LSBs of the fractional portion of the divider ratio of the synthesizer.
Table 18. Register 3 (A3:A0 = 0011)
BIT
RECOMMENDED
D13:D8
00000
D7:D0
01111001
DESCRIPTION
6 LSBs of 20-Bit Fractional Portion of Main Divider
8-Bit Integer Portion of Main Divider. Programmable from 64 to 255.
Table 19. Register 4 (A3:A0 = 0100)
BIT
RECOMMENDED
D13:D0
11011001100110
DESCRIPTION
14 MSBs of 20-Bit Fractional Portion of Main Divider
Table 20. Register 5 (A3:A0 = 0101)
28
BIT
RECOMMENDED
D13:D10
0000
DESCRIPTION
Set to recommended value.
Lock-Detect Output Internal Pullup Resistor Enable. Set to 1 to enable internal 30kΩ pullup
resistor or set to 0 to disable the resistor. Only available when lock-detect, open-drain output
is selected (A3:A0 = 0010, D12 = 1).
D9
0
D8:D6
010
D5
1
D4:D3
00
Set to recommended value.
D2
1
Reference Frequency Divider Ratio to PLL. Set to 0 to divide by 1. Set to 1 to divide by 2.
D1:D0
00
Set to recommended value.
Set to recommended value.
Lock-Detect Output Enable. Set to 1 to enable the lock-detect output or set to 0 to disable the
output. The output is high impedance when disabled.
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
DATA BIT
RECOMMENDED
D13
0
Set to recommended value.
D12:D11
00
Tx I/Q Calibration LO Leakage and Sideband Detector Gain-Control Bits. D12:D11 = 00: 9dB;
01 19dB; 10: 29dB; 11: 39dB.
D10:D7
0000
D6
1
D5:D2
1000
DESCRIPTION
Set to recommended value.
Power-Detector Enable in Tx Mode. Set to 1 to enable the power detector or set to 0 to
disable the detector.
Set to recommended value.
D1
0
Tx Calibration Mode. Set to 1 to place the device in Tx calibration mode or 0 to place the
device in normal Tx mode when RXTX is set to 1 (see Table 31).
D0
0
Rx Calibration Mode. Set to 1 to place the device in Rx calibration mode or 0 to place the
device in normal Rx mode when RXTX is set to 0 (see Table 31).
Table 22. Register 7 (A3:A0 = 0111)
BIT
RECOMMENDED
DESCRIPTION
D13:D12
01
D11:D6
000000
D5:D3
100
Transmitter Lowpass Filter Corner Frequency Fine Adjustment (Relative to Coarse Setting).
See Table 8. Bits D1:D0 in A3:A0 = 1000 provide the lowpass filter corner coarse adjustment.
D2:D0
010
Receiver Lowpass Filter Corner Frequency Fine Adjustment (Relative to Coarse Setting). See
Table 5. Bits D1:D0 in A3:A0 = 1000 provide the lowpass filter corner coarse adjustment.
Receiver Highpass Corner Frequency Setting for RXHP = 0. Set to 00 for 100Hz, X1 for 4kHz,
and 10 for 30kHz.
Set to recommended value.
Table 23. Register 8 (A3:A0 = 1000)
BIT
RECOMMENDED
DESCRIPTION
D13
1
Set to recommended value.
D12
0
Enable Receiver Gain Programming Through the Serial Interface. Set to 1 to enable
programming through the 3-wire serial interface (D6:D0 in Register A3:A0 = 1011). Set to 0 to
enable programming in parallel through external digital pins (B7:B1).
D11
0
Set to recommended value.
D10
0
RSSI Operating Mode. Set to 1 to enable RSSI output independent of RXHP. Set to 0 to
disable RSSI output if RXHP = 0, and enable the RSSI output if RXHP = 1.
D9:D8
00
RSSI, Power Detector or Temperature Sensor Output Select. Set to 00 to enable the RSSI
output in receive mode. Set to 01 to enable the temperature sensor output in receive and
transmit modes. Set to 10 to enable the power-detector output in transmit mode. See Table 7.
D7:D2
001000
D1:D0
01
Set to recommended value.
Receiver and Transmitter Lowpass Filter Corner Frequency Coarse Adjustment. See Tables 4
and 7.
______________________________________________________________________________________
29
MAX2831/MAX2832
Table 21. Register 6 (A3:A0 = 0110)
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Table 24. Register 9 (A3:A0 = 1001)
BIT
RECOMMENDED
D13:D11
000
D10
0
D9:D0
1110110101
DESCRIPTION
Set to recommended value.
Enable Transmitter Gain Programming Through the Serial or Parallel Interface. Set to 1 to
enable programming through the 3-wire serial interface (D5:D0 in Register A3:A0 = 1011).
Set to 0 to enable programming in parallel through external digital pins (B6:B1).
Set to recommended value.
Table 25. Register 10 (A3:A0 = 1010)
BIT
RECOMMENDED
D13:D10
0111
DESCRIPTION
Power-Amplifier Enable Delay. Sets a delay between RXTX low-to-high transition and internal PA
enable. Programmable in 0.5µs steps. D13:D10 = 0001 (0.2µs) and D13:D10 = 1111 (7µs).
D9:D7
011
Set to recommended value.
D6:D3
0100
Second-Stage Power-Amplifier Bias Current Adjustment. Set to XXXX for 802.11g/b.
D2:D0
100
First-Stage Power-Amplifier Bias Current Adjustment. Set to XXX for 802.11g/b.
Table 26. Register 11 (A3:A0 = 1011)
BIT
RECOMMENDED
D13:D7
0000000
D6:D5
11
D4:D0
11111
DESCRIPTION
Set to recommended value.
LNA Gain Control. Set to 11 for high-gain mode. Set to 10 for medium-gain mode, reducing
LNA gain by 16dB. Set to 0X for low-gain mode, reducing LNA gain by 33dB.
Receiver VGA Control. Set D4:D0 = 00000 for minimum gain and D4:D0 = 11111 for
maximum gain.
Table 27. Register 12 (A3:A0 = 1100)
BIT
RECOMMENDED
D13:D6
00000101
D5:D0
000000
DESCRIPTION
Set to recommended value.
Transmitter VGA Gain Control. Set D5:D0 = 000000 for minimum gain, and set D5:D0 =
111111 for maximum gain.
Table 28. Register 13 (A3:A0 = 1101)
BIT
30
RECOMMENDED
DESCRIPTION
D13:D10
0011
Set to recommended value.
D9:D6
1010
Set to recommended value.
D5:D0
010010
Set to recommended value.
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
BIT
RECOMMENDED
D13:D11
000
D10
0
Reference Clock Output Divider Ratio. Set 1 to divide by 2 or set 0 to divide by 1.
D9
1
Reference Clock Output Enable. Set 1 to enable the reference clock output or set 0 to disable.
D8:D7
10
Set to recommended value.
D6:D0
XXXXXXX
MAX2831/MAX2832
Table 29. Register 14 (A3:A0 = 1110)
DESCRIPTION
Set to recommended value.
Crystal-Oscillator Fine Tune. Tunes crystal oscillator over ±20ppm to within ±1ppm.
X = Don’t care.
Table 30. Register 15 (A3:A0 = 1111)
BIT
RECOMMENDED
DESCRIPTION
D13:D12
00
Set to recommended value.
D11:D10
00
Receiver I/Q Output Common-Mode Voltage Adjustment. Set D11:D10 = 00: 1.1V,
01: 1.2V, 10: 1.3V, 11: 1.45V.
D9:D0
0101000101
Set to recommended value.
Table 31. Operating Mode Table
LOGIC PINS
REGISTER
SETTINGS
CIRCUIT BLOCK STATES
MODE
Shutdown
SHDN
RXTX
D1:D0
(A3:A0 = 0110)
Rx PATH
Tx PATH
PLL, VCO,
LO GEN,
AUTO-TUNER
CALIBRATION
SECTIONS ON
0
0
00
Off
Off
Off
None
Standby
0
1
00
Off
Off
On
None
Rx
1
0
X0
On
Off
On
None
Tx
1
1
0X
Off
On
On
None
Rx Calibration
1
0
X1
On
(except LNA)
Upconverters
On
Cal tone, RF phase
shift, Tx filter
Tx Calibration
1
1
1X
Off
On (except PA
driver and PA)
On
AM detector,
Rx I/Q buffers
X = Don’t care.
______________________________________________________________________________________
31
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Modes of Operation
The modes of operation for the MAX2831/MAX2832 are
shutdown, standby, transmit, receive, transmitter calibration, and receiver calibration. See Table 31 for a summary of the modes of operation. The logic-input pins, SHDN
(pin 12) and RXTX (pin 48), control the various modes.
Shutdown Mode
The MAX2831/MAX2832 feature a low-power shutdown
mode that disables all circuit blocks, except the serialinterface and internal registers, allowing the registers to
be loaded and values maintained, as long as VCC is
applied. Set SHDN and RXTX logic-low to place the
device in shutdown mode.
After supply voltage ramp up, supply current in shutdown mode could be high. Program the default value to
SPI register 0 to eliminate high shutdown current.
Standby Mode
The standby mode is used to enable the frequency
synthesizer block while the rest of the device is powered down. In this mode, the PLL, VCO, and LO generators are on, so that Tx or Rx modes can be quickly
enabled from this mode. Set SHDN to a logic-low and
RXTX to a logic-high to place the device in standby
mode.
Receive (Rx) Mode
The complete receive signal path is enabled in this
mode. Set SHDN to logic-high and RXTX to logic-low to
place the device in Rx mode.
Transmit (Tx) Mode
The complete transmitter signal path is enabled in this
mode. Set SHDN and RXTX to logic-high to place the
device in Tx mode.
Tx/Rx Calibration Mode
The MAX2831/MAX2832 feature Rx/Tx calibration modes
to detect I/Q imbalances and transmit LO leakage. In the
Tx calibration mode, all Tx circuit blocks, except the PA
driver and external PA, are powered on and active. The
AM detector and receiver I and Q channel buffers are
also on, along with multiplexers in the receiver side to
route this AM detector’s signal. In this mode, the LO
leakage calibration is done only for the LO leakage signal that is present at the center frequency of the channel
(i.e., in the middle of the OFDM or QPSK spectrum). The
LO leakage calibration includes the effect of all DC offsets in the entire baseband paths of the I/Q modulator
and direct leakage of the LO to the I/Q modulator output.
32
The LO leakage and sideband detector output are
taken at the receiver I and Q channel outputs during
this calibration phase.
During Tx LO leakage and I/Q imbalance calibration, a
sine and cosine signal (f = fTONE) is input to the baseband I/Q Tx pins from the baseband IC. At the LO leakage and sideband-detector output, the LO leakage
corresponds to the signal at fTONE and the sideband
suppression corresponds to the signal at 2 x fTONE. The
output power of these signals vary 1dB for 1dB of variation in the LO leakage and sideband suppression. To
calibrate the Tx path, first set the power-detector gain
to 9dB using D12:D11 in Register 5 (see Table 21).
Adjust the DC offset of the baseband inputs to minimize
the signal at fTONE (LO leakage). Then, adjust the baseband input relative magnitude and phase offsets to
reduce the signal at 2 x fTONE.
In Rx calibration mode, the calibrated Tx RF signal is
internally routed to the Rx inputs. In this mode, the
VCO/LO generator/PLL blocks are powered on and
active except for the low-noise amplifier (LNA).
Applications Information
Layout Issues
The MAX2831 EV kit can be used as a starting point for
layout. For best performance, take into consideration
grounding and RF, baseband, and power-supply routing. Make connections from vias to the ground plane as
short as possible. Do not connect the device ground
pin to the exposed paddle ground. Keep the buffered
clock
output
trace
as
short
as
possible. Do not share the trace with the RF input layer,
especially on or inter-layer or back side of the board.
On the high-impedance ports, keep traces short to minimize shunt capacitance. EV kit Gerber files can be
requested at www.maxim-ic.com.
Power-Supply Layout
To minimize coupling between different sections of the
IC, a star power-supply routing configuration with a
large decoupling capacitor at a central VCC node is recommended. The VCC traces branch out from this node,
each going to a separate VCC node in the circuit. Place
a bypass capacitor as close as possible to each supply
pin. This arrangement provides local decoupling at
each VCC pin. Use at least one via per bypass capacitor
for a low-inductance ground connection. Do not share
the capacitor ground vias with any other branch and the
exposed paddle ground.
______________________________________________________________________________________
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
MAX2831/MAX2832
POWER SUPPLY
ON
POWER
3-WIRE SERIAL INTERFACE AVAILABLE
IREF
SHDN
MAC
SHUTDOWN
MAX2831/MAX2832
RXTX
MAC SPI
CS
CS (SELECT)
SCLK
SCLK (CLOCK)
DIN
DIN (DATA)
SPI:
CHANNEL FREQUENCY, PA BIAS, TRANSMITTER LINEARITY,
RECEIVER RSSI OPERATION, CALIBRATION MODE, ETC.
INTERNAL PA
ENABLED
0 TO 7µs
(DRIVES POWER RAMP CONTROL)
SHUTDOWN
MODE
RECEIVE
MODE
STANDBY
MODE
PA ENABLE
TRANSMIT
MODE
Figure 3. Timing Diagram
Chip Information
PROCESS: BiCMOS
RXBBI-
RXBBI+
VCCRXVGA
RXHP
VCCRXFL
TXBBQ-
TXBBQ+
TXBBI-
TXBBI+
GNDTEST
RXTX
TOP VIEW
VCCRXMX
Pin Configuration
Package Information
48 47 46 45 44 43 42 41 40 39 38 37
VCCLNA
1
GNDRXLNA
2
35 RXBBQ-
B6
3
34 B4
RXRF+
4
33 BYPASS
RXRF-
5
32 TUNE
B7
6
VCCPA
7
+
36 RXBBQ+
31 GNDVCO
MAX2831
MAX2832
30 VCCVCO
B3
8
29 CTUNE
TXRF+
9
28 XTAL
TXRF-
10
27 VCCXTAL
B2
11
SHDN
12
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
"+", "#", or "-" in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND PATTERN
NO.
48 TQFN-EP
T4877+4
21-0144
90-0130
26 GNDCP
EP
25 VCCCP
CPOUT
B1
LD
CLOCKOUT
VCCPLL
DIN
SCLK
RSSI
VCCTXMX
CS
B5
VCCTXPA
13 14 15 16 17 18 19 20 21 22 23 24
TQFN
______________________________________________________________________________________
33
MAX2831/MAX2832
2.4GHz to 2.5GHz 802.11g/b
RF Transceivers with Integrated PA
Revision History
REVISION
NUMBER
REVISION
DATE
0
10/06
Initial release
1
3/10
Removed MAX2832 future product reference and made minor corrections
2
3/11
Corrected conditions for Rx I/Q Output Common-Mode Voltage Variation in the
DC Electrical Characteristics; corrected Tables 14, 17, and 27; added text to
Shutdown Mode section
DESCRIPTION
PAGES
CHANGED
—
1, 2, 10, 18, 19, 20
2, 27, 28,
30, 32
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
34 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2011 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.