MAX2831ETM+ Maxim Integrated Products, MAX2831ETM+ Datasheet - Page 21

• Manufacturer Part Number: MAX2831ETM+
• Description: RF Transceiver 2.4GHz to 2.5GHz, 80 2.11g RF Transceiver
• Manufacturer: Maxim Integrated Products

Specifications of MAX2831ETM+

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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 oscil-
lator, RSSI, PA power detector (MAX2831), temperature
sensor, Rx and Tx I/Q error-detection circuitry, baseband-
control 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).
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 frequen-
cies, analog RSSI and integrated DC-offset correction cir-
cuitry. A logic-low on the RXTX input (pin 48) and a
logic-high on the SHDN input (pin 12) enable the receiver.
PIN
35
36
37
38
39
40
41
42
43
44
45
46
47
48
—
V
GNDTEST
V
RXBBQ+
V
TXBBQ+
RXBBQ-
TXBBQ-
RXBBI+
CCRXVGA
TXBBI+
RXBBI-
TXBBI-
NAME
CCRXMX
CCRXFL
RXHP
RXTX
EP
______________________________________________________________________________________
Detailed Description
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
Receiver Baseband Filter Supply Voltage
Transmitter Baseband I-Channel Differential Inputs
Transmitter Baseband Q-Channel Differential Inputs
Receiver Downconverters Supply Voltage
Connect to Ground
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.
RF Transceivers with Integrated PA
Receiver
2.4GHz to 2.5GHz 802.11g/b
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 com-
mon-mode noise rejection.
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 pro-
gramming 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)
SPI is a trademark of Motorola, Inc.
B7 OR D6
1
1
0
FUNCTION
Pin Description (continued)
B6 OR D5
1
0
X
Medium
NAME
High
Low
LNA Input Matching
Max gain - 16dB (typ)
Max gain - 33dB (typ)
LNA Gain Control
DESCRIPTION
Max gain
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