MAX2510EEI+ Maxim Integrated Products, MAX2510EEI+ Datasheet - Page 11

• Manufacturer Part Number: MAX2510EEI+
• Description: RF Receiver IC TXRX IF W/RSSI&MODLTR
• Manufacturer: Maxim Integrated Products
• Type: Transceiverr

Specifications of MAX2510EEI+

• Package / Case: QSOP-28
• Operating Frequency: 600 MHz
• Operating Supply Voltage: 3 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 2. RXIN or RXIN Input Impedance
The interstage filter, located between the MIXOUT pin
and the LIMIN pin, is typically a three-terminal, 330Ω,
10.7MHz bandpass filter. This filter prevents the limiter
from acting on any undesired signals that are present
at the mixer’s output, such as LO feedthrough, out-of-
band channel leakage, and spurious mixer products.
The filter connections are also set up to feed DC bias
from VREF into LIMIN and MIXOUT through two 330Ω
filter-termination resistors. (See the Typical Operating
Circuit for more information).
The transmit outputs, TXOUT and TXOUT, are open-
collector outputs and therefore present a high
impedance.
For differential drive, TXOUT and TXOUT are connected
to V
load. A terminating resistor between TXOUT and
TXOUT sets the output impedance. This resistor pro-
vides a stable means of matching to the load.
TXOUT and TXOUT are voltage-swing limited, and
therefore cannot drive the specified maximum power
across more than 150Ω load impedance. This load
impedance typically consists of a shunt-terminating
resistor in parallel with a filter load impedance. To drive
higher output load impedances, the gain must be
reduced (via the GC pin) to avoid saturating the TX out-
put stage.
For single-ended applications, connect the unused TX
output output pin directly to V
The MAX2510 can be used as a front-end IC in appli-
cations where the RF carrier frequency is in the
400MHz ISM band. In this case, Maxim recommends
preceding the MAX2510 receiver section with a low-
CC
FREQUENCY
via chokes, and each side is AC coupled to the
(MHz)
100
200
300
400
500
______________________________________________________________________________________
Limiter/RSSI and Quadrature Modulator
Transmit Output Matching
400MHz ISM Applications
CC
SERIES IMPEDANCE
.
Receive IF Filter
275 - j203
149 - j184
Low-Voltage IF Transceiver with
94 - j143
64 - j109
53 - j87
(Ω)
noise amplifier (LNA) that can operate over the same
supply voltage range. The MAX2630–MAX2633 family
of amplifiers meets this requirement. In many applica-
tions, the MAX2510’s transmit output power is sufficient
to eliminate the need for an external power amplifier.
A well-designed PC board is an essential part of an RF
circuit. Use the MAX2510 evaluation kit and the recom-
mendations below as guides to generate your own
layout.
A star topology, which has a heavily decoupled central
V
ing coupling between different sections of the chip. The
V
one V
circuit. At the end of each of these traces is a bypass
capacitor that presents low impedance at the RF fre-
quency of interest. This method provides local decou-
pling at each V
leaking out of a supply pin sees a relatively high imped-
ance (formed by the V
tral V
other supply pin, minimizing Vcc supply-pin coupling.
A single ground plane suffices. Where possible, multi-
ple parallel vias aid in reducing inductance to the
ground plane.
Place the VREF decoupling capacitor (0.1µF typical) as
close to the MAX2510 as possible for best interstage fil-
ter performance. For best results, use a high-quality,
low-ESR capacitor.
Matching/biasing networks around the receive and
transmit pins should be symmetric and as close to the
chip as possible. A cutout in the ground plane under
the matching network components can be used to
reduce parasitic capacitance.
Decouple pins 19 and 21 (V
Tx ground), which should be directly connected the
ground plane. Similarly, decouple pin 8 directly to pin 7.
Refer to the Pin Description table for more information.
______________________Layout Issues
CC
CC
node, is the ideal power-supply layout for minimiz-
traces branch out from this node, each going to
CC
CC
node, and an even higher impedance to any
connection in the MAX2510 typical operating
CC
pin. At high frequencies, any signal
CC
trace impedance) to the cen-
Power-Supply Layout
CC
) directly to pin 20 (Rx,
11