MAXIM MAX2822ETM

19-2884; Rev 0; 7/03
KIT
ATION
EVALU
E
L
B
A
IL
AVA
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
Features
The MAX2822 single-chip transceiver is designed for
802.11b (11Mbps) applications operating in the 2.4GHz
to 2.5GHz ISM band. The transceiver includes all the
circuitry required to implement an 802.11b RF-to-baseband transceiver solution, including the power amplifier, transmit/receive switch, and 50Ω matching. The fully
integrated receive path, transmit path, VCO, frequency
synthesis, and baseband/control interface provide all
the required active RF circuitry. Only a small number of
passive components are needed to form the complete
radio front-end solution.
The IC eliminates the need for external IF SAW and RF
image-reject filters by utilizing a direct-conversion radio
architecture and monolithic baseband filters for both
receiver and transmitter. It is specifically optimized for
802.11b (11Mbps CCK) and 22Mbps PBCC™ applications. The baseband filtering and Rx and Tx signal
paths support the CCK modulation scheme for BER =
10-5 at the required sensitivity levels.
The transceiver is suitable for the full range of 802.11b
data rates (1Mbps, 2Mbps, 5.5Mbps, and 11Mbps) as
well as the higher-rate 22Mbps PBCC standard. The
MAX2822 is available in the very small 7mm x 7mm 48lead QFN or thin QFN packages. The small solution size
makes it ideal for small form-factor 802.11b applications
such as PDAs, SmartPhones, and embedded modules.
♦ 2.4GHz to 2.5GHz ISM Band Operation
♦ 802.11b (11Mbps CCK and 22Mbps PBCC) PHY
Compatible
♦ Integrated +17dBm PA
♦ Integrated PA Power Detector
♦ Integrated Transmit/Receive Switch
♦ Complete RF-to-Baseband Transceiver
Direct Up/Down Conversion
Monolithic Low-Phase-Noise VCO
Integrated Baseband Lowpass Filters
Integrated PLL with 3-Wire Serial Interface
Digital Bias Control for PA
Transmit Power Control
Receive Baseband AGC
Complete Baseband Interface
Digital Tx/Rx Mode Control
♦ -95dBm Rx Sensitivity at 1Mbps
♦ -85dBm Rx Sensitivity at 11Mbps
Applications
Ordering Information
802.11b PDAs and SmartPhones
♦ Single +2.7V to +3.0V Supply
♦ 2µA Shutdown Mode
♦ Very Small 48-Pin QFN Package
PART
TEMP RANGE
PIN-PACKAGE
802.11b Embedded Modules
MAX2822EGM
-40°C to +85°C
48 QFN
802.11b PC Cards, Mini-PCI Cards
MAX2822ETM
-40°C to +85°C
48 Thin QFN
Pin Configuration/Functional Diagram appears at end of
data sheet.
PBCC is a trademark of Texas Instruments, Inc.
________________________________________________________________ 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
MAX2822
General Description
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
ABSOLUTE MAXIMUM RATINGS
VCC Pins to GND ...................................................-0.3V to +3.6V
RF I/O: RFP, RFN (current into pin).....................................50mA
Baseband Inputs: TX_BBIP, TX_BBIN, TX_BBQP,
TX_BBQN to GND ..................................-0.3V to (VCC + 0.3V)
Baseband Outputs: RX_BBIP, RX_BBIN, RX_BBQP,
RX_BBQN to GND ..................................-0.3V to (VCC + 0.3V)
Analog Inputs: RX_AGC, TX_GC, TUNE, ROSCN,
ROSCP to GND ......................................-0.3V to (VCC + 0.3V)
Analog Outputs: PWR_DET, CP_OUT
to GND....................................................-0.3V to (VCC + 0.3V)
Digital Inputs: RX_ON, TX_ON, SHDNB, CSB, SCLK,
DIN, RF_GAIN, RX_1K to GND...............-0.3V to (VCC + 0.3V)
Bias Voltages: RBIAS, BYP ..................................+0.9V to +1.5V
Short-Circuit Duration Digital Output: DOUT ..........................10s
RF Input Power ...............................................................+10dBm
Continuous Power Dissipation (TA = +70°C)
48-Lead QFN (derate 27.0mW/°C above +70°C) ......2162mW
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
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.
DC ELECTRICAL CHARACTERISTICS
(MAX2822 EV kit: VCC = +2.7V to +3.0V, RF_GAIN = VIH, 0V ≤ VTX_GC ≤ +2.0V, 0V ≤ VRX_AGC ≤ +2.0V, RBIAS = 12kΩ, no input signals at RF and baseband inputs, RF I/O terminated into 50Ω though a 2:1 balun, receiver baseband outputs are open, transmitter
baseband inputs biased at +1.2V, registers set to default power-up settings, TA = -40°C to +85°C, unless otherwise noted. Typical
values are for VCC = +2.7V, TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETERS
CONDITIONS
Supply Voltage
MIN
TYP
2.7
Shutdown Current
SHDNB = VIL, RX_ON = VIL, TX_ON = VIL
Standby-Mode Supply Current
SHDNB = VIH, RX_ON = VIL,
TX_ON = VIL
TA = +25°C
Receive-Mode Supply Current
SHDNB = VIH, RX_ON = VIH,
TX_ON = VIL
TA = +25°C
Transmit-Mode Supply Current
SHDNB = VIH,
RX_ON = VIL,
TX_ON = VIH,
bias registers
set as in Table 9
UNITS
3.0
V
2
50
µA
25
35
TA = -40°C to +85°C
40
80
TA = -40°C to +85°C
100
110
POUT = +3dBm
POUT =
+12dBm
MAX
mA
mA
98
TA = +25°C
157
TA = -40°C to +85°C
175
185
POUT = +17dBm
mA
220
LOGIC INPUTS: SHDNB, RX_ON, TX_ON, SCLK, DIN, CSB, RF_GAIN
VCC 0.5
Digital Input Voltage High (VIH)
V
Digital Input Voltage Low (VIL)
0.5
V
Digital Input Current High (IIH)
-5
+5
µA
Digital Input Current Low (IIL)
-5
+5
µA
LOGIC OUTPUT: DOUT
Digital Output Voltage High (VOH)
Sourcing 100µA
Digital Output Voltage Low (VOL)
Sinking 100µA
VCC 0.5
V
0.5
V
ANALOG OUTPUT: PWR_DET
Power-Detector Output
Impedance
2
400
_______________________________________________________________________________________
Ω
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
(MAX2822 EV kit: VCC = +2.7V to +3.0V, RF_GAIN = VIH, 0V ≤ VTX_GC ≤ +2.0V, 0V ≤ VRX_AGC ≤ +2.0V, RBIAS = 12kΩ, no input signals at RF and baseband inputs, RF I/O terminated into 50Ω though a 2:1 balun, receiver baseband outputs are open, transmitter
baseband inputs biased at +1.2V, registers set to default power-up settings, TA = -40°C to +85°C, unless otherwise noted. Typical
values are for VCC = +2.7V, TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETERS
CONDITIONS
MIN
TYP
MAX
UNITS
RX BASEBAND I/O
RX_AGC Input Resistance
0V ≤ VRX_AGC ≤ +2.0V
Rx I/Q Common-Mode Voltage
Rx I/Q Output DC Offsets
3σ limit
50
kΩ
1.25
V
±15
mV
TX BASEBAND I/O
TX BB Input Common-Mode
Range
1.0
TX BBI and BBQ Input Bias
Current
1.2
1.4
V
-10
µA
kΩ
TX BB Input Impedance
Differential resistance
100
TX_GC Input Bias Current
0V ≤ VTX_GC ≤ +2.0V
10
µA
TX_GC Input Impedance
Resistance
250
kΩ
20
kΩ
REFERENCE OSCILLATOR INPUT
Reference Oscillator Input
Impedance
VOLTAGE REFERENCE
Reference Voltage
ILOAD = ±2mA
1.10
1.20
1.30
V
AC ELECTRICAL CHARACTERISTICS—RECEIVE MODE
(MAX2822 EV kit: VCC = +2.7V to +3.0V, fRF and fLO = 2400MHz to 2499MHz, fOSC = 22MHz or 44MHz, receive baseband output
levels = 500mVP-P, VSHDNB = VRX_ON = VIH, VTX_ON = VIL, VCSB = VIH, VSCLK = VDIN = VIL, VRF_GAIN = VIH, 0V ≤ VRX_AGC ≤ +2.0V,
RBIAS = 12kΩ, ICP = +2mA, BWPLL = 45kHz, registers set to default power-up settings, TA = +25°C, unless otherwise noted. Typical
values are for VCC = +2.7V, fLO = 2437MHz, fOSC = 22MHz, unless otherwise noted.) (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
2499
MHz
2499
MHz
RECEIVER CASCADED PERFORMANCE (RF INPUT TO BASEBAND OUTPUT)
RF Frequency Range
2400
LO Frequency Range
2400
RF_GAIN = VIH,
VRX_AGC = 0V
Voltage Gain (Note 3)
RF Gain Step
TA = +25°C
97
TA = -40°C to +85°C
95
105
RF_GAIN = VIH, VRX_AGC = +2.0V
35
RF_GAIN = VIL, VRX_AGC = 0V
75
RF_GAIN = VIL, VRX_AGC = +2.0V
3
From RF_GAIN = VIH to RF_GAIN = VIL
32
dB
dB
_______________________________________________________________________________________
3
MAX2822
DC ELECTRICAL CHARACTERISTICS (continued)
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
AC ELECTRICAL CHARACTERISTICS—RECEIVE MODE (continued)
(MAX2822 EV kit: VCC = +2.7V to +3.0V, fRF and fLO = 2400MHz to 2499MHz, fOSC = 22MHz or 44MHz, receive baseband output
levels = 500mVP-P, VSHDNB = VRX_ON = VIH, VTX_ON = VIL, VCSB = VIH, VSCLK = VDIN = VIL, VRF_GAIN = VIH, 0V ≤ VRX_AGC ≤ +2.0V,
RBIAS = 12kΩ, ICP = +2mA, BWPLL = 45kHz, registers set to default power-up settings, TA = +25°C, unless otherwise noted. Typical
values are for VCC = +2.7V, fLO = 2437MHz, fOSC = 22MHz, unless otherwise noted.) (Note 2)
PARAMETER
CONDITIONS
RF_GAIN = VIH, RX gain ≥ 80dB
DSB Noise Figure (Note 4)
Adjacent Channel Rejection
Input Third-Order Intercept Point (Note 6)
Input Second-Order Intercept Point (Note 7)
LO Leakage
MIN
TYP
MAX
5.5
6.0
RF_GAIN = VIH, RX gain = 50dB
8
RF_GAIN = VIL, RX gain = 50dB
35
RX gain = 70dB (Note 5)
45
RF_GAIN = VIH, RX gain = 80dB
-13
RF_GAIN = VIL, RX gain = 50dB
+19
UNITS
dB
dB
dBm
RF_GAIN = VIH, RX gain = 80dB
+23
RF_GAIN = VIL, RX gain = 50dB
+60
At balun input
-65
dBm
15
dB
MHz
Input Return Loss
dBm
RECEIVER BASEBAND
BASEBAND FILTER RESPONSE
-3dB Frequency
Attenuation Relative to Passband
Default bandwidth setting BW(2:0) = (010)
7
At 12.5MHz
40
At 16MHz
65
At 20MHz
70
At 25MHz
85
dB
BASEBAND OUTPUT CHARACTERISTICS
Rx I/Q Gain Imbalance
3σ limit
±1
dB
Rx I/Q Phase Quadrature Imbalance
3σ limit
±5
Degrees
Rx I/Q Output 1dB Compression
Differential voltage into 5kΩ
1
VP-P
Rx I/Q Output THD
VOUT = 500mVP-P at 5.5MHz, ZL = 5kΩ||5pF
-35
dBc
VRX_AGC = 0 to +2.0V
70
dB
AGC Slope
Peak gain slope
60
dB/V
AGC Response Time
20dB gain step (80dB to 60dB),
settling to ±1dB
2
µs
BASEBAND AGC AMPLIFIER
AGC Range
4
_______________________________________________________________________________________
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
(MAX2822 EV kit, characteristics relative to RFP/RFN: VCC = +2.7V to +3.0V, fRF and fLO = 2400MHz to 2499MHz, fOSC = 22MHz or
44MHz, transmit baseband input signal: 500mVP-P at 5.5MHz, VSHDNB = VRX_ON = VIL, VTX_ON = VIH, VCSB = VIH, VSCLK = VDIN =
VIL, VRF_GAIN = VIH, 0V ≤ VTX_AGC ≤ +2.0V, RBIAS = 12kΩ, ICP = +2mA, BWPLL = 45kHz, baseband inputs DC biased to +1.2V, registers set to default power-up settings, measurements taken within 1s of TXON rising edge, TA = +25°C, unless otherwise noted.
Typical values are for VCC = +2.7V, fLO = 2437MHz, fOSC = 22MHz, unless otherwise noted.) (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
TRANSMIT SIGNAL PATH: BASEBAND INPUT TO RF OUTPUT
RF Output Frequency Range
2400
2499
MHz
LO Output Frequency Range
2400
2499
MHz
11Mbps CCK signal,
ACPR (adj) ≤ -30dBc,
ACPR (alt) ≤ -50dBc
(Note 4)
Tx RF Output Power
TA = +25°C
+16.5
TA = -40°C to +85°C
+15.5
+17.5
dBm
Adjacent (adj):
-22MHz ≤ fOFFSET ≤ -11MHz,
11MHz ≤ fOFFSET ≤ 22MHz,
POUT = +16.5dBm
-33
Tx RF ACPR (Note 8)
dBc
Alternate (alt):
-33MHz ≤ fOFFSET < -22MHz,
22MHz < fOFFSET ≤ 33MHz,
POUT = +16.5dBm
In-Band Spurious Signals Relative to Carrier
Tx RF Harmonics
-56
fRF = 2400MHz to
2483MHz
(Note 9)
Unwanted sideband
-40
LO signal
-30
Spurs > ±22MHz
-80
11Mbps CCK at
+16.5dBm
2 × fRF
-45
3 × fRF
-30
< 2400MHz
-50
2500MHz to 3350MHz
-35
dBc
dBm
Tx RF Spurious Signal Emissions
(Outside 2400MHz to 2483.5MHz)
Nonharmonic Signals
> 3350MHz
-40
Tx RF Output Noise
fOFFSET ≥ 22MHz, 0V ≤ VTX_GC ≤ +2.0V
-125
dBm/Hz
Tx RF Output Return Loss
100Ω balanced output impedance,
POUT = +17dBm
10
dB
10
MHz
dBm
Tx BASEBAND FILTER RESPONSE
-3dB Frequency
Attenuation Relative to Passband
At 22MHz
25
At 44MHz
50
dB
Tx GAIN-CONTROL CHARACTERISTICS
Gain-Control Range
0V ≤ VTX_GC ≤ +2.0V
20
dB
Gain-Control Slope
Peak gain slope
30
dB/V
Gain-Control Response Time
VTX_GC = +2.0V to 0V step, settled to within
±1dB
0.3
µs
_______________________________________________________________________________________
5
MAX2822
AC ELECTRICAL CHARACTERISTICS—TRANSMIT MODE
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
AC ELECTRICAL CHARACTERISTICS—TRANSMIT MODE (continued)
(MAX2822 EV kit, characteristics relative to RFP/RFN: VCC = +2.7V to +3.0V, fRF and fLO = 2400MHz to 2499MHz, fOSC = 22MHz or
44MHz, transmit baseband input signal: 500mVP-P at 5.5MHz, VSHDNB = VRX_ON = VIL, VTX_ON = VIH, VCSB = VIH, VSCLK = VDIN =
VIL, VRF_GAIN = VIH, 0V ≤ VTX_AGC ≤ +2.0V, RBIAS = 12kΩ, ICP = +2mA, BWPLL = 45kHz, baseband inputs DC biased to +1.2V, registers set to default power-up settings, measurements taken within 1s of TXON rising edge, TA = +25°C, unless otherwise noted.
Typical values are for VCC = +2.7V, fLO = 2437MHz, fOSC = 22MHz, unless otherwise noted.) (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
POWER DETECTOR
Power-Detection Range
0.1V ≤ VPWR_DET ≤ 1.5V
17
POUT = +3dBm
±0.7
POUT = +17dBm
±0.5
Power-Detection Error (3σ Limit)
Fixed VPWR_DET,
TA = +25°C
Power-Detection Error Variation with
Temperature
TA = -40°C to +85°C, relative to TA = +25°C
dB
dB
±0.3
dB
AC ELECTRICAL CHARACTERISTICS—SYNTHESIZER
(MAX2822 EV kit: VCC = +2.7V to +3.0V, fRF and fLO = 2400MHz to 2499MHz, fOSC = 22MHz or 44MHz, SHDNB = VIH, CSB = VIH,
RBIAS = 12kΩ, ICP = +2mA, BWPLL = 45kHz, registers set to default power-up settings, TA = +25°C, unless otherwise noted. Typical
values are for VCC = +2.7V, fLO = 2437MHz, fOSC = 22MHz, unless otherwise noted.) (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
2499
MHz
FREQUENCY SYNTHESIZER
LO Frequency Range
Reference Frequency
2400
SYNTH:R(0) = 0
22
SYNTH:R(0) = 1
44
Minimum Channel Spacing
Charge-Pump Output Current
Charge-Pump Compliance Range
Reference Spur Level (Note 10)
1
MHz
±2
mA
VCC 0.4
0.4
-11MHz ≤ fOFFSET ≤ 11MHz
-41
-22MHz ≤ fOFFSET < -11MHz,
11MHz < fOFFSET ≤ 22MHz
-75
fOFFSET < -22MHz, fOFFSET > 22MHz
-90
fOFFSET = 10kHz
-80
fOFFSET = 100kHz
-87
Closed-Loop Integrated Phase Noise
Noise integrated from 100Hz to 10MHz,
measured at the TX_RF output
2.5
Reference Oscillator Input Level
AC-coupled sine wave input
200
fLO = 2400MHz
0.4
Closed-Loop Phase Noise
MHz
300
V
dBc
dBc/Hz
°RMS
500
mVP-P
VOLTAGE-CONTROLLED OSCILLATOR
VCO Tuning Voltage Range
VCO Tuning Gain
6
fLO = 2499MHz
fLO = 2400MHz
fLO = 2499MHz
2.3
170
130
_______________________________________________________________________________________
V
MHz/V
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
(MAX2822 EV kit: VCC = +2.7V to +3.0V, fRF and fLO = 2400MHz to 2499MHz, fOSC = 22MHz or 44MHz, SHDNB = VIH, CSB = VIH,
RBIAS = 12kΩ, ICP = +2mA, BWPLL = 45kHz, registers set to default power-up settings, TA = +25°C, unless otherwise noted. Typical
values are for VCC = +2.7V, fLO = 2437MHz, fOSC = 22MHz, unless otherwise noted.) (Note 2)
PARAMETER
Channel-Switching Time
CONDITIONS
MIN
fLO = 2400MHz ↔ 2499MHz,
fLO settles to ±10kHz (Note 11)
TYP
MAX
UNITS
150
200
µs
Rx to Tx, fLO settles to within ±30kHz,
relative to the rising edge of TX_ON
5
Tx to Rx, fLO settles to within ±30kHz,
relative to the rising edge of RX_ON
10
Standby-to-Receive Mode
Standby to Rx, fLO settles to within ±30kHz,
relative to the rising edge of RX_ON
10
µs
Standby-to-Transmit Mode
Standby to Tx, fLO settles to within ±30kHz,
relative to the rising edge of TX_ON
5
µs
µs
Rx/Tx Turnaround Time
AC ELECTRICAL CHARACTERISTICS—SERIAL INTERFACE TIMING
(MAX2822 EV kit: VCC = +2.7V to +3.0V, registers set to default power-up settings, TA = +25°C, unless otherwise noted.) (Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
SERIAL INTERFACE TIMING (SEE FIGURE 1)
tCSO
SCLK rising edge to CSB falling edge wait time
5
ns
tCSS
Falling edge of CSB to rising edge of first SCLK time
5
ns
tDS
Data-to-serial clock setup time
5
ns
tDH
Data-to-clock hold time
10
ns
tCH
Serial clock pulse-width high
10
ns
tCL
Clock pulse-width low
10
ns
tCSH
Last SCLK rising edge to rising edge of CSB
5
ns
tCSW
CSB high pulse width
10
ns
tCS1
Time between the rising edge of CSB and the next rising edge of SCLK
5
ns
fCLK
Clock frequency
50
MHz
Parameters are production tested at +25°C only. Min/max limits over temperature are guaranteed by design and characterization.
Guaranteed by design and characterization.
Defined as the baseband differential RMS output voltage divided by the RMS input voltage (at the RF balun input).
Specification excludes the loss of the external balun. The external balun loss is typically ~0.5dB.
CCK interferer at 25MHz offset. Desired signal equals -73dBm. Interferer amplitude increases until baseband output from
interferer is 10dB below desired signal. Adjacent channel rejection = PINTERFERER - PDESIRED .
Note 6: Measured at balun input. Two CW tones at -43dBm with 15MHz and 25MHz offset from the MAX2822 channel frequency.
IP3 is computed from 5MHz IMD3 product measured at the Rx I/Q output.
Note 7: Two CW interferers at -38dBm with 24.5MHz and 25.5MHz offset from the MAX2822 channel frequency. IP2 is computed
from the 1MHz IMD2 product measured at the RX I/Q output.
Note 8: VTXGC adjusted for +16.5dBm output power; adjacent and alternate channel power relative to the desired signal. Power
measured with 100kHz video BW and 100kHz resolution BW.
Note 9: CW tone at 2.25MHz offset from carrier with VTXGC set for maximum modulated POUT at -30dBc/-50dBc (ADJ/ALT) ACPR
limits. Unwanted sideband refers to suppressed image resulting from I/Q baseband input tones.
Note 10: Relative amplitude of reference spurious products appearing in the Tx RF output spectrum relative to a CW tone at
2.25MHz offset from the LO.
Note 11: Time required to reprogram the PLL, change the operating channel, and wait for the operating channel center frequency to
settle within ±10kHz of the nominal (final) channel frequency.
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
_______________________________________________________________________________________
7
MAX2822
AC ELECTRICAL CHARACTERISTICS—SYSTEM TIMING
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
MAX2822
Typical Operating Characteristics
(MAX2822 EV kit, VCC = +2.7V, fBB = 1MHz, fLO = 2437MHz, receive baseband outputs = 500mVP-P, transmit baseband inputs =
400mVP-P, ICP = +2mA, BWPLL = 45kHz, differential RF input/output matched to 50Ω through a balun, baseband input biased at
+1.2V, registers set to default power-up settings, TA = +25°C, unless otherwise noted.)
240
70
230
50
210
50
40
200
30
190
180
20
180
170
10
200
30
190
20
160
STBY
0
2.70
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90
2.75
2.80
RECEIVER GAIN
vs. GAIN-CONTROL VOLTAGE
60
LNA LOW GAIN
40
LNA HIGH GAIN
20
VRX_AGC = 2.0V
20
15
6
8 10 12 14 16 18 20
RECEIVER NOISE FIGURE vs. GAIN
fBB = 2.25MHz
fLO = 2437MHz
45
LOW-GAIN LNA
40
35
30
25
20
15
10
HIGH-GAIN LNA
10
LOW-GAIN LNA
5
0
2420
2400
2440
2460
2480
2500
0 10 20 30 40 50 60 70 80 90 100 110
FREQUENCY (MHz)
RX GAIN (dB)
RECEIVER BLOCKER REJECTION
vs. RF FREQUENCY
RECEIVER BLOCKER REJECTION
vs. CARRIER OFFSET
RECEIVER FILTER RESPONSE
(1kHz TO 1MHz)
2LO/3
LO/2
GAIN = 80dB
PINT (MAX) FOR SNR
DEGRADED TO 10dB
(PER = 8%)
-20
-30
-40
-50
GAIN = 80dB
PINT (MAX) FOR SNR
DEGRADED TO 10dB
(PER = 8%)
-60
-70
RF FREQUENCY (MHz)
0
-10
-20
RX_1K = VIH
-30
-40
RX_1K = VIL
-50
-60
-70
-80
-90
-80
800 1000 1200 1400 1600 1800 2000 2200 2400
MAX2822 toc09
-10
10
NORMALIZED RESPONSE (dB)
0
MAX2822 toc07
LO/3
INTERFERER LEVEL (dBm)
INTERFERER LEVEL (dBm)
4
VRX_AGC (V)
-60
8
2
50
0
-20
-50
-4 -2 0
OUTPUT POWER (dBm)
25
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
-10
-40
+3dBm APPLICATION
30
5
10
-30
80
HIGH-GAIN LNA
0
0
160
3.00
35
10
0
+12dBm APPLICATION
120
NOISE FIGURE (dB)
70
30
140
100
MAX2822 toc08
RECEIVER GAIN (dB)
80
50
2.95
160
170
40
RX GAIN, HIGH-GAIN LNA (dB)
90
2.90
+17dBm APPLICATION
180
RECEIVER VOLTAGE GAIN vs. FREQUENCY
MAX2822 toc04
VOUT = 500mVP-P
fBB = 1MHz
fLO = 2437MHz
100
2.85
200
VCC (V)
TEMPERATURE (°C)
110
220
TX, FIXED, POUT = +17dBm
210
40
0
60
TRACES END AT LINEARITY
LIMITS (-30dBc/-50dBc)
MAX2822 toc06
220
RX, LNA
LOW GAIN
ICC (mA)
80
RX, LNA
HIGH GAIN
TX ICC (mA)
240
60
STBY
220
90
230
10
250
250
70
TX (POUT = +17dBm)
240
MAX2822 toc05
RX AND STBY ICC (mA)
80
RX, LNA
HIGH GAIN
260
100
RX AND STBY ICC (mA)
RX, LNA
LOW GAIN
90
SUPPLY CURRENT vs. TX OUTPUT POWER
MAX2822 toc02
260
TX ICC (mA)
MAX2822 toc01
MAX2822 toc03
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
100
10
15
20
25
30
35
40
OFFSET FROM CARRIER (MHz)
45
50
1
10
100
FREQUENCY (kHz)
_______________________________________________________________________________________
1000
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
(MAX2822 EV kit, VCC = +2.7V, fBB = 1MHz, fLO = 2437MHz, receive baseband outputs = 500mVP-P, transmit baseband inputs =
400mVP-P, ICP = +2mA, BWPLL = 45kHz, differential RF input/output matched to 50Ω through a balun, baseband input biased at
+1.2V, registers set to default power-up settings, TA = +25°C, unless otherwise noted.)
-30
-40
-50
-60
-50
-60
-70
-80
-70
-90
-80
-100
1
-30
-40
-50
-60
1
2
3
4
5
6
7
8
0
5
10
15
20
25
30
35
FREQUENCY (MHz)
FREQUENCY (GHz)
BB FREQUENCY (MHz)
RECEIVER BASEBAND OUTPUT SPECTRUM
(MODULATED)
TRANSMITTER OUTPUT POWER
vs. SUPPLY VOLTAGE
TRANSMITTER OUTPUT POWER
vs. FREQUENCY
SIGNAL APPLIED
-60
-70
NO SIGNAL APPLIED
17
16
TA = +85°C
15
14
VIN = 400mVP-P 802.11b SIGNAL
VTX_GC FOR +17.0dBm OUTPUT
POWER AT 2437MHz, +25°C
13
12
-80
0
5
10
15
20
25
30
35
2.75
2.88
ACPR vs. OUTPUT POWER
+12dBm APP.
-50
802.11b
SPEC LIMITS
-32
-52
-34 ALT
-54
ALT
ALT
-36
-56
-38
-58
-60
ADJ
ADJ
-42
-62
0
2
2.90
2.95
4
6
8
10 12 14 16 18 20
OUTPUT POWER (dBm)
MAX2822 toc15
TA = +25°C
16.5
16.0
15.5
TA = +85°C
15.0
3.00
VIN = 400mVP-P 802.11b SIGNAL
VTX_GC FOR +17.0dBm OUTPUT
POWER AT 2437MHz, +25°C
2400
2420
2440
2460
2480
RF FREQUENCY (MHz)
TRANSMITTER OUTPUT SPECTRUM
TRANSMITTER GAIN
vs. GAIN-CONTROL VOLTAGE
fLO = 2437MHz
fBB = 1MHz
RBW = 100kHz
0
-10
-20
-30
-40
-50
-60
ADJ
-40
2.85
10
-48
17.0
14.5
20
POWER (dBm)
-28
-30
-46
+17dBm APP.
ACPR, ALTERNATE (dBc)
+3dBm APP.
TA = -40°C
17.5
VCC (V)
BB FREQUENCY (MHz)
-26
18.0
14.0
2.70
40
MAX2822 toc16
MAX2822 toc14
TA = +25°C
18.5
-70
5
2500
MAX2822 toc18
-50
18
TRANSMITTER OUTPUT POWER (dBm)
-40
TA = -40°C
40
19.0
NORMALIZED TRANSMITTER GAIN (dB)
-30
19
MAX2822 toc17
-20
TRANSMITTER OUTPUT POWER (dBm)
POUT IS 50Ω REFERRED
(SINGLE ENDED)
RX GAIN = 50dB
RBW = 100kHz
fLO = 2437MHz
LNA HIGH GAIN
-10
20
MAX2822 toc13
0
ACPR, ADJACENT (dBc)
-20
-80
0
100
10
POUT IS 50Ω REFERRED
(SINGLE ENDED)
RBW = 100kHz
fLO = 2437MHz
LNA HIGH GAIN
-10
-70
-110
-90
BASEBAND OUTPUT POWER (dBm)
-40
0
BASEBAND OUTPUT POWER (dBm)
-30
f-3dB = 7.5MHz
MAX2811 toc11
f-3dB = 8.5MHz
POUT IS 50Ω REFERRED
(SINGLE ENDED)
RBW = 100kHz
fLO = 2437MHz
LNA HIGH GAIN
-20
LEAKAGE POWER (dBm)
NORMALIZED RESPONSE (dB)
0
-20
-10
MAX2822 toc10
10
-10
RECEIVER BASEBAND OUTPUT SPECTRUM
(SINGLE TONE)
RECEIVER LEAKAGE SPECTRUM
MAX2822 toc12
RECEIVER FILTER RESPONSE
(1MHz TO 100MHz)
0
-5
TA = +85°C
TA = +25°C
-10
TA = -40°C
-15
-20
-25
NORMALIZED TO +25°C
VTX_GC = 0V
-30
-80
0
1
2
3
4
5
FREQUENCY (GHz)
6
7
8
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
VTX_GC (V)
_______________________________________________________________________________________
9
MAX2822
Typical Operating Characteristics (continued)
Typical Operating Characteristics (continued)
(MAX2822 EV kit, VCC = +2.7V, fBB = 1MHz, fLO = 2437MHz, receive baseband outputs = 500mVP-P, transmit baseband inputs =
400mVP-P, ICP = +2mA, BWPLL = 45kHz, differential RF input/output matched to 50Ω through a balun, baseband input biased at
+1.2V, registers set to default power-up settings, TA = +25°C, unless otherwise noted.)
2.60
-15
-20
-25
-30
-35
-40°C
2.50
2.45
+25°C
2.40
+85°C
2.35
-60
-70
-80
-90
-100
-45
2.25
-110
-50
2.20
10 15 20 25 30 35 40 45 50
1.5
2.0
2.5
1
10
100
1000
VCO/PLL SETTING TIME
RX/TX TURNAROUND TIME
PA POWER-DETECTOR OUTPUT VOLTAGE
vs. OUTPUT POWER
FREQUENCY ERROR (kHz)
10
0
-10
-20
30
20
10
0
-10
-20
-30
-30
-40
-40
-50
-50
40 80 120 160 200 240 280 320 360 400
TIME (µs)
TRIGGERED ON RISING EDGE OF TXON
SYNTHESIZER SETTINGS DO NOT CHANGE
40
2.0
MODULATED BASEBAND
INPUT SIGNAL
1.8
DETECTOR OUTPUT VOLTAGE (V)
50
1.6
MAX2822 toc24
fOFFSET (kHz)
20
0
1.0
VTUNE (V)
BWLOOP = 45kHz
fLO = 2499MHz TO 2400MHz
30
0.5
BASEBAND FREQUENCY (MHz)
50
40
-120
0
MAX2822 toc23
5
MAX2822 toc22
0
fOSC = 2437MHz
ICP = 2mA
PLL BW = 45kHz
TTL INTEGRATED PHASE NOISE = 2.0°RMS
-50
2.30
-40
10
-40
PHASE NOISE (dBc/Hz)
2.55
-10
LO FREQUENCY (GHz)
NORMALIZED RESPONSE (dB)
-5
2.65
MAX2822 toc20
NORMALIZED TO 1MHz
0
MAX2822 toc19
5
SYNTHESIZER CLOSED-LOOP
PHASE NOISE
LO FREQUENCY vs. TUNING VOLTAGE
MAX2822 toc21
TRANSMITTER BASEBAND
FILTER RESPONSE
FREQUENCY ERROR (kHz)
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
2
4
6
8
10 12 14 16 18 20
TIME (µs)
0
2
4
6
8
10 12 14 16 18 20
OUTPUT POWER (dBm)
______________________________________________________________________________________
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
VCC_LNA
RX_AGC
TX_ON
VCC_RMX
RX_ON
VCC_BUF
N.C.
RX_BBIP
RX_BBIN
RX_BBQN
RX_BBQP
RX_1K
DOUT
48
47
46
45
44
43
42
41
40
39
38
37
PROGRAMMING AND
MODE CONTROL
1
36 SHDNB
35 VCC_RXF
VREF 2
RF_GAIN
VCC_REF
4
GND
5
RFP
6
RFN
34 VCC_LO
3
INPUT
MATCH
33 VCC_VCO
32 BYP
MAX2822
T/R
SWITCH
90
31 TUNE
0
30 GND_VCO
7
GND
8
VCC_PA
9
OUTPUT
MATCH
PWR
DET
90
INTEGER-N
SYNTHESIZER
0
29 GND_CP
PWR_DET
28 CP_OUT
VCC_DRVR 10
27 VCC_CP
∑
VOS COMP
SERIAL
INTERFACE
BIAS 11
26 CSB
25 SCLK
13
14
15
16
17
18
19
20
21
22
23
24
VCC_TMX
TX_BBIN
TX_BBIP
TX_BBQP
TX_BBQN
VCC_TXF
GND_DIG
VCC_DIG
PWR_DET
ROSCP
ROSCN
DIN
TX_GC 12
______________________________________________________________________________________
11
MAX2822
Pin Configuration/Functional Diagram
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
MAX2822
Pin Description
PIN
NAME
FUNCTION
1
VCC_LNA
Supply Voltage Connection for LNA. Bypass with a capacitor as close to the pin as possible. Do not share
the bypass capacitor ground vias with other branches.
2
VREF
3
RF_GAIN
LNA Gain-Select Logic Input. Logic high for LNA high-gain mode, logic low for LNA low-gain mode.
4
VCC_REF
Supply Voltage for Bias Circuitry and Autotuner. Bypass with a capacitor as close to the pin as possible.
Do not share the bypass capacitor ground vias with other branches.
5, 8
GND
Ground
6
RFP
RF Balanced I/O Port (Positive). On-chip matched for 100Ω balanced.
7
RFN
9
VCC_PA
10
11
Voltage Reference Output for Baseband IC. Requires external RF bypass to GND.
RF Balanced I/O Port (Negative). On-chip matched for 100Ω balanced.
Supply Voltage Connection for Power Amplifier. Requires external RF bypass to GND.
VCC_DRVR Supply Voltage Connection for PA Driver. Requires external RF bypass to GND.
BIAS
Precision Bias Resistor Pin. Connect a 12kΩ precision resistor (≤ 2%) to GND.
Transmit Gain-Control Input. Analog high-impedance input. Connect directly to baseband IC DAC output.
See Figure 3 for transmitter gain vs. gain-control voltage.
12
TX_GC
13
VCC_TMX
Supply Voltage for Transmit Mixer and VGA. Bypass with a capacitor as close to the pin as possible.
Do not share the bypass capacitor ground vias with other branches.
14
TX_BBIN
Transmit Negative In-Phase Baseband Input. Analog high-impedance differential input. Connect directly
to baseband IC DAC voltage output. Requires a 1.2V common-mode voltage.
15
TX_BBIP
Transmit Positive In-Phase Baseband Input. Analog high-impedance differential input. Connect directly to
baseband IC DAC voltage output. Requires a 1.2V common-mode voltage.
16
TX_BBQP
Transmit Positive Quadrature Baseband Input. Analog high-impedance differential input. Connect directly
to baseband IC DAC voltage output. Requires a 1.2V common-mode voltage.
17
TX_BBQN
Transmit Negative Quadrature Baseband Input. Analog high-impedance differential input. Connect
directly to baseband IC DAC voltage output. Requires a 1.2V common-mode voltage.
18
VCC_TXF
Supply Voltage for Transmit Baseband Filter. Bypass with capacitor as close to the pin as possible.
Do not share the bypass capacitor ground vias with other branches.
19
GND_DIG
Digital Ground
20
VCC_DIG
Supply Voltage for Digital Circuitry. Bypass with capacitor as close to the pin as possible. Do not share
the bypass capacitor ground vias with other branches.
21
PWR_DET
Transmitter Power-Detector Output
22
ROSCP
Reference Oscillator Positive Input. Analog high-impedance differential input. DC-coupled. Requires
external AC-coupling. Connect an external reference oscillator to this analog input.
23
ROSCN
Reference Oscillator Negative Input. Analog high-impedance differential input. DC-coupled. Requires
external AC-coupling. Bypass this analog input to ground with capacitor for single-ended operation.
24
DIN
25
SCLK
3-Wire Serial Interface Data Input. Digital high-impedance input. Connect directly to baseband IC serial
interface CMOS output (SPI™/QSPI™/MICROWIRE™ compatible).
3-Wire Serial Interface Clock Input. Digital high-impedance input. Connect this digital input directly to
baseband IC serial interface CMOS output (SPI/QSPI/MICROWIRE compatible).
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
12
______________________________________________________________________________________
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
PIN
NAME
FUNCTION
26
CSB
3-Wire Serial Interface Enable Input. Digital high-impedance input. Connect directly to baseband IC serial
interface CMOS output (SPI/QSPI/MICROWIRE compatible).
27
VCC_CP
Supply Voltage for PLL Charge Pump. Bypass with capacitor as close to the pin as possible. Do not share
the bypass capacitor ground vias with other branches.
28
CP_OUT
PLL Charge-Pump Output. Analog high-impedance output. Current source. Connect directly to the PLL
loop filter input.
29
GND_CP
PLL Charge-Pump Ground. Connect to PC board ground plane.
30
GND_VCO
31
TUNE
32
BYP
33
VCC_VCO
34
VCC_LO
Supply Voltage for VCO, LO Buffers, and LO Quadrature Circuitry. Bypass with capacitor as close to the
pin as possible. Do not share the bypass capacitor ground vias with other branches.
35
VCC_RXF
Supply Voltage for Receiver Baseband Filter. Bypass with capacitor as close to the pin as possible. Do
not share the bypass capacitor ground vias with other branches.
36
SHDNB
Active-Low Shutdown Input. Digital high-impedance CMOS input. Connect directly to baseband IC modecontrol CMOS output. Logic low to disable all device functions. Logic high to enable normal chip operation.
37
DOUT
Serial Interface Data Output. Digital CMOS output. Optional connection.
38
RX_1K
Receiver 1kHz Highpass Bandwidth Control. Digital CMOS input. Connect directly to baseband IC CMOS
output. Controls receiver baseband highpass -3dB corner frequency; logic low for 10kHz, logic high for
1kHz. See the Applications Information section for proper use of this function.
39
RX_BBQP
Receive Positive Quadrature Baseband Output. Analog low-impedance differential buffer output. Connect
output directly to baseband ADC input. Internally biased to 1.2V common-mode voltage and can drive
loads up to 5kΩ || 5pF.
40
RX_BBQN
Receive Negative Quadrature Baseband Output. Analog low-impedance differential buffer output.
Connect output directly to baseband ADC input. Internally biased to 1.2V common-mode voltage and can
drive loads up to 5kΩ || 5pF.
41
RX_BBIN
Receive Negative In-Phase Baseband Output. Analog low-impedance differential buffer output. Connect
output directly to baseband ADC input. Internally biased to 1.2V common-mode voltage and can drive
loads up to 5kΩ || 5pF.
42
RX_BBIP
Receive Positive In-Phase Baseband Output. Analog low-impedance differential buffer output. Connect
output directly to baseband ADC input. Internally biased to 1.2V and can drive loads up to 5kΩ || 5pF.
43
N.C.
44
VCC_BUF
VCO Ground. Connect to PC board ground plane.
VCO Frequency Tuning Input. Analog high-impedance voltage input. Connect directly to the PLL loop
filter output.
VCO Bias Bypass. Bypass with a 2000pF capacitor to ground.
Supply Voltage for VCO. Bypass with capacitor as close to the pin as possible. Do not share the bypass
capacitor ground vias with other branches. Important note: Operate from separate regulated supply voltage.
No Connection. Make no connections to this pin.
Supply Voltage for Receiver Baseband Buffer. Bypass with capacitor as close to the pin as possible. Do
not share the bypass capacitor ground vias with other branches.
______________________________________________________________________________________
13
MAX2822
Pin Description (continued)
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
MAX2822
Pin Description (continued)
PIN
NAME
45
RX_ON
46
VCC_RMX
47
TX_ON
48
RX_AGC
Exposed
Paddle
GND
FUNCTION
Receiver-On Control Input. Digital CMOS input. Connect to baseband IC mode-control CMOS output.
Supply Voltage for Receiver Downconverter. Bypass with capacitor as close to the pin as possible. Do not
share the bypass capacitor ground vias with other branches.
Transmitter-On Control Input. Digital CMOS input. Connect directly to baseband IC mode-control CMOS
output.
Receive AGC Control. Analog high-impedance input. Connect directly to baseband IC DAC voltage
output. See Figure 2 for gain vs. VRX_AGC.
DC and AC Ground Return for IC. Connect to PC board ground plane using multiple vias.
Table 1. Operating Mode Truth Table
OPERATING MODE
MODE-CONTROL INPUTS
SHDNB
TX_ON
RX_ON
RX_PATH
TX_PATH
PLL/VCO/LO GEN
Shutdown
0
X
X
OFF
OFF
OFF
Standby
1
0
0
OFF
OFF
ON
Receive
1
0
1
ON
OFF
ON
Transmit
1
1
0
OFF
ON
ON
Not Allowed
1
1
1
—
—
—
Detailed Description
Operating Modes
The MAX2822 has four primary modes of operation:
shutdown, standby, receive active, and transmit active.
The modes are controlled by the digital inputs SHDNB,
TX_ON, and RX_ON. Table 1 shows the operating
mode vs. the digital mode-control inputs.
Shutdown Mode
Shutdown mode is enabled by driving SHDNB low. In
shutdown mode, all circuit blocks are powered down,
except for the serial interface circuitry. While the device
is in shutdown, the serial interface registers can still be
loaded by applying VCC to the digital supply voltage
(VCC_DIG). All previously programmed register values
are preserved during the shutdown mode, as long as
VCC_DIG is applied.
Standby Mode
Standby mode is achieved by driving SHDNB high, and
RX_ON and TX_ON low. In standby mode, the PLL,
VCO, LO generation circuitry, and filter autotuner are
powered on by default. The standby mode is intended
to provide time for the slower-settling circuitry (PLL and
autotuner) to turn on and settle to the correct frequency
before making Rx or Tx active. The 3-wire serial inter14
CIRCUIT BLOCK STATES
face is active and can load register values at any time.
Refer to the serial interface specifications for details.
Receive Mode
Receive mode is enabled by driving SHDNB high,
RX_ON high, and TX_ON low. In receive mode, all
receive circuit blocks are powered on and all VCO, PLL,
and autotuner circuits are powered on. None of the
transmit path blocks are active in this mode. Although
the receiver blocks turn on quickly, the DC offset nulling
requires ~10µs to settle. The receiver signal path is
ready ~10µs after a low-to-high transition on RX_ON.
Transmit Mode
Transmit mode is enabled by driving the digital inputs
SHDNB high, RX_ON low, and TX_ON high. In transmit
mode, all transmit circuit blocks are powered on and all
VCO, PLL, and autotuner circuits are powered on.
None of the receive path blocks are active in this mode.
Although the transmitter blocks turn on quickly, the
baseband DC offset calibration requires ~2.2µs to
complete. In addition, the Tx driver amplifier is ramped
from the low-gain state (minimum RF output) to highgain state (peak RF output) over the next 1µs to 2µs.
Also, the LO takes a few microseconds after TX_ON
rises to resettle. The transmit signal path is ready ~5µs
after a low-to-high transition on TX_ON.
______________________________________________________________________________________
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
The MAX2822 contains programmable registers to control various modes of operation for the major circuit
blocks. The registers can be programmed through the
3-wire SPI/QSPI/MICROWIRE-compatible serial port.
The MAX2822 includes five programmable registers:
1) Block-enable register
2) Synthesizer register
3) Channel frequency register
4) Receiver settings register
5) Transmitter settings register
Each register consists of 16 bits. The four most significant bits (MSBs) are the register’s address. The twelve
least significant bits (LSBs) are used for register data.
Table 2 summarizes the register configuration. A
detailed description of each register is provided in
Tables 4–8.
Data bits are shifted in the MSB first. The data sent to
the MAX2822, in 16-bit words, is framed by CSB. When
CSB is low, the clock is active and data is shifted with
the rising edge of the clock. When CSB transitions to
high, the shift register is latched into the register selected by the contents of the address bits. Only the last 16
bits shifted into the MAX2822 are retained in the shift
register. No check is made on the number of clock
pulses. Figure 1 documents the serial interface timing
for the MAX2822.
Power-Up Default States
The MAX2822 provides power-up loading of default
states for each of the registers. The states are loaded
on a VCC_DIG supply voltage transition from 0V to
V CC . The default values are retained until reprogrammed through the serial interface or the power-supply voltage is taken to 0V. The default state of each
register is described in Table 3. Note: Putting the IC in
shutdown mode does not change the contents of the
programming registers.
Block-Enable Register
The block-enable register permits individual control of
the enable state for each major circuit block in the
MAX2822. The actual enable condition of the circuit
block is a logical function of the block-enable bit setting
and other control input states. Table 4 documents the
logical definition of state for each major circuit block.
Synthesizer Register
The synthesizer register (SYNTH) controls the reference
frequency divider and charge-pump current of the PLL.
See Table 5 for a description of the bit settings.
Channel Frequency Register
The channel frequency register (CHANNEL) sets the RF
carrier frequency for the MAX2822. The channel is programmed as a number from 0 to 99. The actual frequency is 2400 + channel in MHz. The default setting is
37 for 2437MHz. See Table 6 for a description of the bit
settings.
CSB
tCSW
tCSO
tCSH
tCSS
SCLK
tDS
tCH
tDH
tCS1
tCL
DIN
BIT 1
BIT 2
BIT 6
BIT 7
BIT 8
BIT 14
BIT 15
BIT 16
tDV
tTR
tDO
DOUT
BIT 1
BIT 2
BIT 6
BIT 7
BIT 8
BIT 14
BIT 15
BIT 16
Figure 1. MAX2822 Serial Interface Timing Diagram
______________________________________________________________________________________
15
MAX2822
Programmable Registers
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
Receiver Settings Register
Transmitter Settings Register
The receiver settings register (RECEIVE) controls the
receive filter -3dB corner frequency and VGA DC offset
nulling parameters. The defaults are intended to provide proper operation. However, the filter frequency
and detector can be modified if desired. Do not reprogram VGA DC offset nulling parameters. These settings
were optimized during development. See Table 7 for a
description of the bit settings.
The transmitter settings register (TRANSMIT) provides
a 6-bit digital control of the PA bias and 1-bit enable for
the transmit power detector. Bits D0:D3 control the PA
output stage bias current (0000 lowest, 1111 highest)
and PA driver stage bias current (00 lowest, 11 highest). The appropriate values vs. target output power are
given in Table 9. The detector enable bit allows independent turn-on of the detector for testing purposes.
Table 2. Programming Register Definition Summary
4 ADDRESS BITS
REGISTER
NAME
ENABLE
12 DATA BITS
A3
A2
A1
A0
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
MSB
15
14
13
12
11
10
9
8
7
6
5
4
3
2
LSB
0
0
0
1
E11
E10
E9
E8
E7
E6
E5
E4
E3
E2
E1
E0
SYNTH
0
0
1
0
X
X
X
X
0
1
0
0
0
0
0
R0
CHANNEL
0
0
1
1
X
X
X
X
X
CF6
CF5
CF4
CF3
CF2
CF1
CF0
RECEIVE
0
1
0
0
2C2
2C1
2C0
1C2
1C1
1C0
DL1
DL0
SF
BW2
BW1
BW0
TRANSMIT
0
1
0
1
X
X
X
X
X
DE
DR1
DR0
PA3
PA2
PA1
PA0
X = Don’t care.
Table 3. Register Power-Up Defaults States
REGISTER
ADDRESS
DEFAULT
ENABLE
0001
0000 0001 1110
Block-Enable Control Settings (E)
SYNTH
0010
0000 0100 0000
Synthesizer Settings:
• Reference frequency (R)
CHANNEL
0011
0000 0010 0101
Channel frequency settings (CF)
RECEIVE
0100
1111 1101 0010
Receiver Settings:
• -3dB lowpass filter bandwidth (BW)
• Detector midpoint level (DL)
0000 0010 1101
Transmit Settings:
• PA bias (PA)
• PA driver bias (D)
• PA driver enable (DE)
TRANSMIT
16
0101
FUNCTION
______________________________________________________________________________________
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
ADDRESS
0001
DATA BIT CONTENT DEFAULT
MAX2822
Table 4. Block-Enable Register (ENABLE)
DESCRIPTION AND LOGICAL DEFINITION
D11
E(11)
0
Reserved
D10
E(10)
0
PA Bias-Control Enable (PAB_EN)
PAB_EN = SHDNB • (E(10) + TX_ON)
D9
E(9)
0
Transmit Baseband Filters Enable (TXFLT_EN)
TXFLT_EN = SHDNB • (E(9) + TX_ON)
D8
E(8)
0
Tx Upconverter + VGA + Driver Amp Enable (TXUVD_EN)
TXUVD_EN = SHDNB • (E(8) + TX_ON)
D7
E(7)
0
Reserved
D6
E(6)
0
Rx Downconverter + Filters + AGC Amps Enable (RXDFA_EN)
RXDFA_EN = SHDNB • (E(6) + RX_ON)
D5
E(5)
0
Receive LNA Enable (RXLNA_EN)
RXLNA_EN = SHDNB • (E(5) + RX_ON )
D4
E(4)
1
Autotuner Enable (AT_EN)
AT_EN = SHDNB • (E(4) + RX_ON + TX_ON)
D3
E(3)
1
PLL Charge-Pump Enable (CP_EN)
CP_EN = SHDNB • E(3)
D2
E(2)
1
PLL Enable (PLL_EN)
PLL_EN = SHDNB • E(2)
D1
E(1)
1
VCO Enable (VCO_EN)
VCO_EN = SHDNB • E(1)
D0
E(0)
0
Reserved
Table 5. Synthesizer Settings Register (SYNTH)
ADDRESS
0010
DATA BIT
CONTENT
DEFAULT
D11:D8
X
0000
DESCRIPTION
D7
—
0
Must be 0 for proper operation
D6
—
1
Must be 1 for proper operation
D5:D0
R(5:0)
000000
Reference Frequency Divider:
• 000000 = 22MHz
• 000001 = 44MHz
Reserved
Table 6. Channel Frequency Register (CHANNEL)
ADDRESS
0011
DATA BIT
CONTENT
DEFAULT
D11:D7
X
00000
D6:D0
CF(6:0)
0100101
DESCRIPTION
Reserved
Channel Frequency Select: fLO = (2400 + CF(6:0))MHz
• 0000000 = 2400MHz
• 0000001 = 2401MHz
• …………
• 1100010 = 2498MHz
• 1100011 = 2499MHz
______________________________________________________________________________________
17
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
Table 7. Receiver Settings Register (RECEIVE)
ADDRESS
DATA BIT
CONTENT
DEFAULT
D11:D4
—
11111111
D3
—
0
D2:D0
BW(2:0)
010
DESCRIPTION
Must be 11111111 for proper operation
Must be 0 for proper operation
Receive Filter -3dB Frequency Select (frequencies are
approximate):
• 000 = 8.5MHz
• 001 = 8.0MHz
• 010 = 7.5MHz
• 011 = 7.0MHz
• 100 = 6.5MHz
• 101 = 6.0MHz
0100
Table 8. Transmit Settings Register (TRANSMIT)
ADDRESS
DATA BIT
CONTENT
DEFAULT
D11:D7
X
X
Reserved
D6
DE
0
Transmit Power-Detector Enable
10
PA Predriver Bias:
•
11 = Highest predriver bias
•
…………
•
00 = Lowest predriver bias
D5:D4
D(1:0)
0101
D3:D0
PA(3:0)
1101
PA Bias Select:
•
1111 = Highest PA bias
•
…………
•
0000 = Lowest PA bias
Applications Information
Receive Path
RF I/O and Tx/Rx Switching
LNA
Given the LNA input is internally matched to 100Ω differential, it is important that the differential pair from
RFP/RFN to the RF BPF be an identical pair of transmission lines to present a 100Ω differential impedance to
the balun. Identical line layout on the differential input
traces is important in maintaining good IP2 performance and RF common-mode noise rejection.
The MAX2822 completely integrates the power amplifier, low-noise amplifier, transmit/receive (Tx/Rx) switch,
as well as all matching components, to allow direct
connection to the antenna through a balun or combination balun/filter. This single RF interface (RFP and RFN)
is internally matched to form a 100Ω balanced port—no
additional components are required to impedancematch the I/O. Most applications employ a 100Ω balanced to 50Ω single-ended RF bandpass filter between
the RF port and the antenna.
18
DESCRIPTION
The MAX2822 has two LNA gain modes that are digitally
controlled by the logic signal applied to RF_GAIN.
RF_GAIN high enables the high-gain mode, and
RF_GAIN low enables the low-gain mode. The LNA gain
step is nominally 32dB. In most applications, RF_GAIN
is connected directly to a CMOS output of the baseband
IC, and the baseband IC controls the state of the LNA
gain based on the detected signal amplitude.
______________________________________________________________________________________
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
Receive Gain Control
The MAX2822 receive path gain is varied through an
external voltage applied to the pin RX_AGC. Maximum
gain is at V RX_AGC = 0V and minimum gain is at
VRX_AGC = 2V. The RX_AGC input is a high-impedance
analog input designed for direct connection to the
RX_AGC DAC output of the baseband IC. The gaincontrol range, which is continuously variable, is typically 70dB. The gain-control characteristic is shown in the
Typical Operating Characteristics Receiver Voltage
Gain vs. Gain-Control Voltage graph and again as a
full-page plot in Figure 2.
Some local noise filtering through a simple RC network at
the input is permissible. However, the time constant of
this network should be kept sufficiently low to not limit the
desired response time of the Rx gain-control function.
Receiver Baseband Amplifier Outputs
The MAX2822 receiver baseband outputs (RX_BBIP,
RX_BBIN, RX_BBQP, and RX_BBQN) are differential
low-impedance buffer outputs. The outputs are
designed to be directly connected (DC-coupled) to the
in-phase (I) and quadrature-phase (Q) ADC inputs of
the baseband IC. The Rx I/Q outputs are internally
biased to +1.2V common-mode voltage. The outputs
are capable of driving loads up to 5kΩ || 5pF with the
full bandwidth baseband signals at a differential amplitude of 500mVP-P.
Proper board layout is essential to maintain good balance between I/Q traces. This provides good quadrature phase accuracy.
Transmit Path
Transmitter Baseband Inputs
The MAX2822 transmitter baseband inputs (TX_BBIP,
TX_BBIN, TX_BBQP, and TX_BBQN) are high-impedance differential analog inputs. The inputs are
designed to be directly connected (DC-coupled) to the
in-phase (I) and quadrature-phase (Q) DAC outputs of
the baseband IC. The inputs must be externally biased
to +1.2V common-mode voltage. Typically, the DAC
outputs are current outputs with external resistor loads
to ground. I and Q are driven by a 400mVP-P (nominal)
differential baseband signal.
Proper board layout is essential to maintain good balance between I/Q traces. This provides good quadrature phase accuracy by maintaining equal parasitic
capacitance on the lines. In addition, it is important not
to expose the Tx I/Q circuit board traces going from the
digital baseband IC to the MAX2822. The lines should
be shielded on an inner layer to prevent coupling of RF
to these Tx I/Q inputs and possible envelope demodulation of the RF signal.
Transmit Path Baseband Lowpass Filtering
The MAX2822 on-chip transmit lowpass filters provide
the filtering necessary to attenuate the unwanted higherfrequency spurious signal content that arises from the
DAC clock feedthrough and sampling images. In addition, the filter provides additional attenuation of the second sidelobe of signal spectrum. The filter frequency
response is set on-chip. No user adjustment or programming is required. The Typical Gain vs. Frequency profile
is shown in the Typical Operating Characteristics.
Transmitter DC Offset Calibration
In a zero-IF system, the DC offset of the Tx baseband
signal path must be reduced to as near zero as possible to minimize LO leakage at the RF output. Given that
the amplifier stages, baseband filters, and Tx DAC possess some finite DC offset that is too large for the
required LO leakage specification, it is necessary to
null the DC offset. The MAX2822 accomplishes this
through an on-chip calibration sequence. During this
sequence, the net Tx baseband signal path offsets are
sampled and cancelled in the baseband amplifiers.
This calibration occurs in the first ~2.2µs after TX_ON is
taken high. The calibration corrects for any DC offset
from the DAC, but this DC offset must not change after
this cal sequence. Be sure the DAC outputs are set to
zero state before taking TX_ON high.
______________________________________________________________________________________
19
MAX2822
Receiver Baseband Lowpass Filtering
The MAX2822 on-chip receive lowpass filters provide
the steep filtering necessary to attenuate the out-ofband (> 11MHz) interfering signals to sufficiently low levels to preserve receiver sensitivity. The filter frequency
response is precisely controlled on-chip and does not
require user adjustment. However, a provision is made to
permit the -3dB corner frequency and entire response to
be slightly shifted up or down in frequency. This is
intended to offer some flexibility in trading off adjacent
channel rejection vs. passband distortion. The filter -3dB
frequency is programmed through the serial interface.
The specific bit setting vs. -3dB frequency is shown in
Table 7. The typical receive baseband filter gain vs. frequency profile is shown in the Typical Operating
Characteristics. Default filter settings are optimal (-3dB
corner at 7.5MHz)—this provides the best trade-off
between noise filtering and baseband distortion to obtain
best receive sensitivity. No user adjustment is required.
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
RECEIVER GAIN vs. GAIN-CONTROL VOLTAGE
110
VOUT = 500mVP-P
fBB = 1MHz
fLO = 2437MHz
100
90
80
LNA HIGH GAIN
RECEIVER GAIN (dB)
70
60
LNA LOW GAIN
50
40
30
20
10
0
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
VRX_AGC (V)
Figure 2. Receiver Gain vs. VRX_AGC
20
______________________________________________________________________________________
1.8
2.0
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
MAX2822
TRANSMITTER GAIN vs. GAIN-CONTROL VOLTAGE
5
NORMALIZED TO +25°C
VTX_GC = 0V
0
NORMALIZED TRANSMITTER GAIN (dB)
-5
TA = +85°C
-10
TA = +25°C
TA = -40°C
-15
-20
-25
-30
0
0.2
0.4
0.6
0.8
1.0
VTX_GC (V)
1.2
1.4
1.6
1.8
2.0
Figure 3. Transmitter Gain vs. VTX_GC
______________________________________________________________________________________
21
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
idle current based on the output power level of the PA.
See Table 8 for a description of the TRANSMIT control
bits, and the corresponding PA predriver and PA bias
currents. These two bias current settings significantly
affect both efficiency and linearity. They should be chosen based on the target output power for the application.
Table 9 shows the recommended register settings for
three target output powers.
The DC offset circuitry uses a sample-and-hold technique to accomplish this DC offset nulling. Over time
(many seconds), the sample-and-hold storage cap
slowly discharges, causing the DC value at the Tx BB
to slowly increase, and the LO level in the RF output to
slowly increase. This can be seen on the bench during
evaluation, when the transceiver is left in Tx mode for
more than 30 to 60 seconds. Even under worst-case
conditions, however, the DC null value changes very little during the longest 802.11b Tx burst of 20ms—LO
suppression in 802.11b applications always remains
around the -30dBc typical level specified in the
Electrical Characteristics table.
Synthesizer
Channel Frequency and Reference Frequency
The synthesizer/PLL channel frequency and reference
settings establish the divider/counter settings in the
integer-N synthesizer of the MAX2822. Both the channel frequency and reference divider are programmable
through the serial interface. The channel frequency is
programmed as a channel number 0 to 99 to set the
carrier frequency to 2400MHz to 2499MHz (LO frequency = channel + 2400). The reference divider is
programmable to allow for 22MHz or 44MHz reference
oscillators. These settings are intended to cover only
the required 802.11b channel spacing and the two typical crystal oscillator options used in the radios.
Transmit Gain Control
The transmit gain-control input provides a direct analog
control over the transmit path gain. The transmit gain of
the MAX2822 is controlled by an external voltage at pin
TX_GC. The typical gain-control characteristic is provided in the Typical Operating Characteristics
Transmitter Gain Control vs. Gain-Control Voltage
graph and again as a full-page plot in Figure 3. The
input is a high-impedance analog input designed to
directly connect to the DAC output of the baseband IC.
Some local noise filtering through a simple RC network
at the input is permissible. However, the time constant
of this network should be kept sufficiently low so the
desired response time of the Tx gain-control function is
not limited.
Reference Oscillator Input
The reference oscillator inputs ROSCP and ROSCN are
high-impedance analog inputs. They are designed to
be connected to the reference oscillator output through
a coupling capacitor. The input amplitude can range
from 200mVP-P to 500mVP-P; therefore, in the case of a
reference oscillator with a CMOS output, the signal
must be attenuated before being applied to the ROSC
inputs. The signal can be attenuated with a resistor- or
capacitor-divider network.
During the Tx turn-on sequence, internally the gain is
set at the minimum while the Tx baseband offset calibration is taking place. The RF output is effectively
blanked for the first 2.2µs after TX_ON is taken high.
After 2.2µs, the blanking is released, and the gain-control amplifier ramps to the gain set by the external voltage applied to the TX_GC input.
Loop Filter
The PLL uses a classical charge pump into an external
loop filter (C-RC) in which the filter output connects to
the voltage tuning input of the VCO. This simple thirdorder lowpass loop filter closes the loop around the
synthesizer. The Typical Application Circuit shows the
loop filter elements around the MAX2822. The capacitor
and resistor values are set to provide the loop bandwidth required to achieve the desired lock time while
also maintaining loop stability. Refer to the MAX2822
Power Amplifier
The MAX2822 provides two programmable analog current sources for internally biasing the on-chip RF power
amplifier and the PA predriver. The PA predriver current
is controlled by two bits in the TRANSMIT control register
(TRANSMIT:D5, D4). The value of the PA bias current is
determined by four bits (TRANSMIT:D3–D0). This programmability permits optimizing of the power amplifier
Table 9. Suggested PA and PA Driver Bias Current Settings
22
TARGET OUTPUT POWER (dBm)
PA DRIVER BIAS SETTING
(TRANSMIT: D5, D4)
PA BIAS SETTING
(TRANSMIT: D3–D0)
+3
00
0011
+12
01
0111
+17
10
1101
______________________________________________________________________________________
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
PC Board Layout
Careful PC board layout is mandatory for any radio to
meet its specifications. General rules for RF layout
apply: keep differential pairs close together, keep all
RF traces as short as possible, keep RF bypassing as
close to the IC as possible, provide a separate filtered
supply line from a large central filter capacitor for each
VCC pin (star supply bypassing topology), and have
each ground pin use its own via to the ground plane—
do not connect ground pins directly to the ground slug
on the IC. In addition, below is a list of more specific
layout issues to keep in mind for the MAX2822:
• RF I/O: Keep RF differential pair from the IC to the
balun/filter electrically and environmentally symmetrical. That is, shape the top layer ground equally on
either side of the traces, and place the RF decoupling caps for the nearby RF supplies in a symmetrical fashion. This minimizes second-order distortion
of the signal on the differential pair.
• RBIAS: This external resistor sets the bias for the RF
section of the transceiver, and this pin is connected
directly to the bias section. The network connected
to this port must look high impedance to RF, so do
not place any RF filtering here—use only a 1% or
2% 12kΩ resistor, as specified in the Typical
Application Circuit. Place this resistor as close to
the IC as possible on the top layer of the PC board.
• GND_DIG: Use a via to connect this digital ground
to the main PC board ground plane. The small
inductance of the trace and the via helps to filter out
the noise from the digital interface, and helps keep
the main system ground clean. It is very important
not to connect this directly to the IC ground slug, or
directly to any other ground pins, which allows
noise from the digital section to couple into sensitive sections of the radio.
• PLL section (CP_OUT, GND_CP, GND_VCO,
TUNE): The capacitors directly at the output of the
PLL’s charge pump need to have their ground
return connected as close to the charge pump’s
ground as possible, and as isolated from the VCO’s
ground as possible. Create separate vias to the
ground plane for each of the two grounds (GND_CP
and GND_VCO). Referring to the Typical
Application Circuit, connect the ground side of C30
and C52 to the ground path for GND_CP, and connect the ground side of C31 to the ground path for
GND_VCO. Keeping the charge-pump return currents from bouncing the VCO’s ground minimizes
the LO comparison frequency spurs.
• BYP: This bypass capacitor is directly connected to
the VCO bias circuitry—it is used to filter out noise
within the loop bandwidth of the PLL (about 50kHz).
The value for this capacitor is critical—be sure to use
the 2000pF capacitor specified in the Typical
Application Circuit. Keep this cap as close to the IC
as possible, since noise pickup on this trace couples
directly into the VCO bias and degrade phase noise.
Supply and Regulation
The typical application circuit for the MAX2822 employs
two low-dropout linear regulators (LDOs)—one supplies
the internal VCO, and the other supplies everything
else (see the Pin Description table for details on supply
pin names, numbers, and functions). Supplying the
VCO from a dedicated LDO minimizes noise pickup by
the VCO that can degrade phase noise and produce
spurs. The VCO only draws 10mA, so power dissipation
is not an issue. Choose a small, low-noise, high-PSRR
LDO like the MAX8510. This LDO comes in a tiny 5-pin
SC70 package and is available in many preset output
voltages in the 2.7V to 3.0V range.
Having the VCO and the rest of the IC supplied from
different voltages is acceptable. Therefore, if the
MAX2822 main supply is 2.7V, but the application
already has a low-noise, 3.0V supply available, simply
run the VCO from this 3.0V supply—there is no need for
another dedicated 2.7V supply for the VCO.
Switching power supplies should not be used to directly
power any RF transceiver; the spurious content of their
outputs often falls in the middle of the system’s baseband
spectrum (50kHz to 11MHz). This can couple into the Tx
path and degrade the output spectrum, and can couple
into the Rx path and degrade sensitivity and BER.
When laying out the supply lines for the IC, always use
a star bypassing topology. Have a large (10µF) lowESR capacitor at the main supply connection point, and
run dedicated traces to each of the supply pins (there
are about ten in total). Each supply pin should have a
pair of smaller decoupling caps (10nF and 100pF work
well). It is especially important to isolate the supplies for
the LNA bias (VCC_LNA) and the Rx baseband filter
bias (VCC_BUF).
Also be sure to use local RF decoupling on the logic
lines. Proper decoupling minimizes noise pickup and
coupling.
______________________________________________________________________________________
23
MAX2822
EV kit schematic for component values. A 45kHz loop
bandwidth is recommended to ensure the loop settles
quickly enough to achieve 5µs Tx turnaround time and
10µs Rx turnaround time. This is the loop filter on the
EV kit. Narrowing the loop bandwidth increases the settling time and results in unacceptable Tx/Rx turnaround
time performance.
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
MAX2822
Typical Application Circuit
DIGITAL MODE-CONTROL SIGNALS
FROM/TO BASEBAND IC
Rx ANALOG OUTPUT SIGNAL
DIGITAL MODE-CONTROL
SIGNALS TO/FROM BASEBAND IC
TO BASEBAND IC
48
BIAS
TX_GC
DOUT
RX_1K
RX_BBQP
RX_BBQN
RX_BBIN
RX_BBIP
N.C.
VCC_BUF
RX_ON
PROGRAMMING AND
MODE CONTROL
1
36
2
35
3
4
34
INPUT
MATCH
33
5
6
32
MAX2822
T/R
SWITCH
90
31
8
9
30
OUTPUT
MATCH
PWR
DET
90
INTEGER-N
SYNTHESIZER
0
29
PWR_DET
28
10
27
∑
VOS COMP
SERIAL
INTERFACE
11
12
26
25
13
14
15
16
SHDNB
VCC_RXF
VCC_LO
VCC_VCO
BYP
TUNE
0
7
VCC_TMX
DAC OUTPUT
FROM BASEBAND IC
37
17
18
19
20
21
22
23
GND_VCO
GND_CP
CP_OUT
LOOP FILTER
VCC_CP
CSB
SCLK
SERIAL INTERFACE
TO BASEBAND IC
24
DIN
VCC_DRVR
38
ROSCN
VCC_PA
39
ROSCP
GND
40
PWR_DET
RFN
41
VCC_DIG
RFP
RF I/O
TO RF BPF AND ANT
42
GND_DIG
GND
43
VCC_TXF
VCC_REF
44
TX_BBQN
RF_GAIN
45
TX_BBQP
Rx GAIN-CONTROL SIGNALS
TO/FROM BASEBAND IC
46
TX_BBIP
VREF
TO BBIC
47
TX_BBIN
VCC_LNA
VCC_RMX
TX_ON
RX_AGC
DAC OUTPUT
FROM BASEBAND IC
REFERENCE
OSCILLATOR INPUT
Tx ANALOG INPUT SIGNAL
FROM BASEBAND IC
PA POWER-DETECTOR
OUTPUT
Chip Information
TRANSISTOR COUNT: 16,097
24
______________________________________________________________________________________
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
32, 44, 48L QFN.EPS
PACKAGE OUTLINE
32,44,48L QFN, 7x7x0.90 MM
21-0092
H
1
2
______________________________________________________________________________________
25
MAX2822
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
U
PACKAGE OUTLINE,
32,44,48L QFN, 7x7x0.90 MM
21-0092
26
______________________________________________________________________________________
H
2
2
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
32, 44, 48L QFN .EPS
D2
D
CL
D/2
b
D2/2
k
E/2
E2/2
E
CL
(NE-1) X e
E2
k
L
DETAIL A
e
(ND-1) X e
CL
CL
L
L
e
A1
A2
e
A
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE
32, 44, 48L QFN THIN, 7x7x0.8 mm
APPROVAL
DOCUMENT CONTROL NO.
21-0144
REV.
B
1
2
______________________________________________________________________________________
27
MAX2822
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
MAX2822
2.4GHz 802.11b Zero-IF Transceiver
with Integrated PA and Tx/Rx Switch
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
COMMON DIMENSIONS
EXPOSED PAD VARIATIONS
** NOTE: T4877-1 IS A CUSTOM 48L PKG. WITH 4 LEADS DEPOPULATED.
TOTAL NUMBER OF LEADS ARE 44.
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE
32, 44, 48L QFN THIN, 7x7x0.8 mm
APPROVAL
DOCUMENT CONTROL NO.
21-0144
REV.
B
2
2
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.
28 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.