MAX2410
Low-Cost RF Up/Downconverter
with LNA and PA Driver
10 ______________________________________________________________________________________
PA Driver
The PA driver typically has 15dB of gain, which is
adjustable over a 35dB range via the GC pin. At full
gain, the PA driver has a noise figure of 3.5dB at
1.9GHz.
For input and output matching information, refer to the
Typical Operating Characteristics
for plots of PA Driver
Input and Output Impedance vs. Frequency.
Receive Mixer
The receive mixer is a wideband, double-balanced
design with excellent noise figure and linearity. The
inputs to the mixer are the RF signal at the RXMXIN pin
and the LO inputs at LO and LO. The downconverted
output signal appears at the IFOUT port. The conver-
sion gain of the receive mixer is typically 8.3dB with a
noise figure of 9.8dB.
RF Input
The RXMXIN input is typically connected to the LNA
output through an off-chip filter. This input is externally
matched to 50Ω. See the
Typical Operating Circuit
for an example matching network and the RXMXIN
Impedance vs. Frequency graph in the
Typical Operating
Characteristics
.
Local-Oscillator Inputs
The LO and LO pins are internally terminated with 50Ω
on-chip resistors. AC couple the LO signal to these
pins. If a single-ended LO source is used, connect LO
directly to ground.
IF Output Port
The MAX2410’s receive mixer output appears at the
IFOUT pin, an open-collector output that requires an
external pull-up inductor to V
CC
. This inductor can be
part of a matching network to the desired IF imped-
ance. Alternatively, a resistor can be placed in parallel
with the pull-up inductor to set a terminating impedance.
The MAX2411A, a similar part to the MAX2410, has the
same functionality as the MAX2410 but offers a differ-
ential, bidirectional (transmit and receive) IF port. This
allows sharing of TX and RX IF filters, which for some
applications provides a lower cost, smaller solution.
Transmit Mixer
The transmit mixer takes an IF signal at the IFIN pin and
upconverts it to an RF frequency at the TXMXOUT pin.
The conversion gain is typically 10dB and the output
1dB compression point is typically -11.4dBm at
1.9GHz.
RF Output
The transmit mixer output appears on the TXMXOUT
pin. It is an open-collector output that requires an exter-
nal pull-up inductor to V
CC
for DC biasing, which can
be part of an impedance-matching network. Consult
the
Typical Operating Characteristics
for a plot of
TXMXOUT Impedance vs Frequency.
IF Input
The IFIN pin is a self-biasing input that must be AC-
coupled to the IF source. Refer to the
Typical Operating
Characteristics
for plots of Input and Output Impedance
vs. Frequency.
Local-Oscillator Inputs
The LO and LO pins are terminated with 50Ω on-chip
resistors. AC couple the LO signal to these pins. If a
single-ended LO source is used, connect LO directly to
GND.
Advanced System
Power Management
RXEN and TXEN are the two separate power-control
inputs for the receiver and the transmitter. If both inputs
are at logic 0, the part enters shutdown mode and the
supply current drops below 1µA. When one input is
brought to a logic 1, the corresponding function is
enabled. If RXEN and TXEN are both set to logic 1, the
part enters standby mode as described in the
Standby
Mode
section. Table 1 summarizes these operating
modes.
Power-down is guaranteed with a control voltage at or
below 0.6V. The power-down function is designed to
reduce the total power consumption to less than 1µA in
less than 2.5µs. Complete power-up will happen in the
same amount of time.
Table 1. Advanced System Power-
Management Functions
Receive01
Standby Mode11
Transmit10
Shutdown00
RXEN FUNCTIONTXEN
