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WLAN Reference Design with the MAX2830



Figure 1. The WLAN reference design features the MAX2380 RF transceiver.
Figure 1. The WLAN reference design features the MAX2830 RF transceiver.

Important Design Features

  • High-Performance Rx NF < 6dB (typ); Tx Output 15dBm (typ)
  • Small Size: 17mm x 24.7mm
  • Platform Design for Multiple Form-Factors such as Card Bus and Compact Flash

Figure 2. Block diagram of the WLAN reference design.
Figure 2. Block diagram of the WLAN reference design.

Figure 1. The WLAN reference design features the MAX2380 RF transceiver.
Figure 1. The WLAN reference design features the MAX2830 RF transceiver.

Important Design Features

  • High-Performance Rx NF < 6dB (typ); Tx Output 15dBm (typ)
  • Small Size: 17mm x 24.7mm
  • Platform Design for Multiple Form-Factors such as Card Bus and Compact Flash

Figure 2. Block diagram of the WLAN reference design.
Figure 2. Block diagram of the WLAN reference design.

Lab Measurements

Power Consumption Summary

Operating conditions: VCC = 2.85V; VBAT = 3.3V; fRF = 2.437GHz; RXTX and active-low SHDN set according to operating mode; active-low CS = high; SCLK = DIN = low; transmitter and receiver in maximum gain. There were no input signals at RF inputs. Baseband outputs are open. 100mVRMS differential, 54Mbps IEEE 802.11g OFDM signals were applied to I and Q baseband inputs of transmitter in transmit mode.

Parameter Test Conditions Meas. Unit
Supply Current Shutdown   µA
Standby; PLL + VCO + LO generator 28 mA
Rx active 58 mA
Tx active (most linear mode) at 3.3V for PA VCC, POUT = 15.7dBm 295 mA

Receive Summary

Operating conditions: VCC = 2.85V; TA = +25°C; fRF = 2.437GHz; fBB = 4MHz; Rx VOUT = 112mVRMS; fREF = 40MHz; active-low SHDN = high; RXTX = low; active-low CS = high; SCLK = DIN = low.

Parameter Test Condition Meas. Unit
Frequency Range   2.4 to 2.5 GHz
Total Voltage Gain   94 dB
RF Gain Steps Relative max gain (B7:B6 = 11) B7:B6 = 10 -16 dB
B7:B6 = 0X -33
BB Gain Range Ratio of max to min gain 61 dB
DSB NF LNA input referred, based on 10kHz to 8.6MHz integrated noise at I/Q baseband output. 1. B7:B6 = 11, voltage gain = 90dB 6.0 dB
2. B7:B6 = 11, voltage gain = 62dB 6.4
3. B7:B6 = 11, voltage gain = 48dB 7.0
I/Q Phase Error near DC Max gain < ±1 deg
IQ Gain Imbalance Max gain < 0.1 dB
Rx Sensitivity EVM < 9% Measured at J1 -73.6 dBm
Measured at J2 -72.6
EVM PIN = -65dBm 4.2 %
PIN = -40dBm 2.2
PIN = -10dBm 3.0

Transmit Summary

Operating conditions: VCC = 2.85V; VBAT = 3.3V; TA = +25°C; fRF = 2.437GHz; fREF = 40MHz; active-low SHDN = high; RXTX = high; active-low CS = high; SCLK = DIN = low; 100mVRMS, 54Mbps 802.11g OFDM signal applied to I and Q baseband inputs of transmitter.

Parameter Test Condition Meas. Unit
Frequency Range   2.4 to 2.5 GHz
Transmit Power For EVM = 5.6%; meets the ACPR spec 15.7 dBm/16MHz
Transmit EVM POUT = +15.7dBm 5.4%  
Adjacent Channel Power Ratio (for 54Mbps OFDM Signal) At 11MHz offset over 100kHz RBW See Figure 3 dBc
At 20MHz offset over 100kHz RBW
At 30MHz offset over 100kHz RBW

 

Operating Characteristics


Figure 3. ACPR performance at Tx power = 15.7dBm, EVM < 5.6%.

Figure 4. Rx I/Q constellation diagram at RF input = -40dBm, 54Mbps 64QAM, EVM = 2.2%.

Figure 5. Rx I/Q constellation diagram at PIN = -65dBm, 54Mbps 64QAM. The EVM is only 4.2%, which is better than the 9% requirement for sensitivity.

Detailed Description

This reference design is suitable for the full range of 802.11g OFDM data rates (6, 9, 12, 18, 24, 36, 48, and 54Mbps) and 802.11b QPSK data rates (1, 2, 5.5, and 11Mbps) at corresponding sensitivity levels. Using the MAX2830 chipset eliminates the need for external SAW filters, a RF switch, and a PA. Only a RF filter, RF balun, and a small number of passive components are required to form a complete 11b/g WLAN RF front-end solution that delivers high performance in a small PCB form-factor.

 
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MAX2830
PAおよびRx/Tx/ダイバーシティスイッチ内蔵、2.4GHz~2.5GHz 802.11g/b RFトランシーバ

  • ISM帯域動作:2.4GHz~2.5GHz
  • IEEE 802.11g/b対応(54Mbps OFDMおよび11Mbps CCK)
  • 完全RFトランシーバ、PA、Rx/Txおよびアンテナダイバーシティスイッチ、および水晶発振器