The MAX2820/MAX2820A and MAX2821/MAX2821A
single-chip zero-IF transceivers are designed for the
802.11b (11Mbps) applications operating in the
2.4GHz to 2.5GHz ISM band. The transceivers are
nearly identical, except the MAX2821 and MAX2821A
also provide a low-power shutdown mode and an ana-
log voltage reference output. The MAX2820A/
MAX2821A are cost-reduced versions, virtually identi-
cal in pinout and performance to the MAX2820/
MAX2821. The transceivers include all the circuitry
required to implement an 802.11b RF-to-baseband
transceiver solution, providing a fully integrated
receive path, transmit path, VCO, frequency synthesis,
and baseband/control interface. Only a PA, RF switch,
RF BPF, and a small number of passive components are
needed to form the complete radio front-end solution.
The ICs eliminate the need for external IF and base-
band filters by utilizing a direct-conversion radio archi-
tecture and monolithic baseband filters for both
receiver and transmitter. They are specifically opti-
mized for 802.11b (11Mbps CCK) 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 devices are suitable for the full range of 802.11b
data rates (1Mbps, 2Mbps, 5.5Mbps, and 11Mbps) and
also the higher-rate 22Mbps PBCCTM standard. The
MAX2820 and MAX2821 are available in a 7mm × 7mm
48-lead QFN package. The MAX2820, MAX2821,
MAX2820A, and MAX2821A are available in a 48-lead
thin QFN package.