MAX2510
Low-Voltage IF Transceiver with
Limiter/RSSI and Quadrature Modulator
8 _______________________________________________________________________________________
Pin Description
PIN
Offset-Correction Capacitor Pins. Connect a 0.01µF capacitor between CZ and CZ.CZ, CZ
2, 3
Limiter Input. Connect a 330Ω (typical) resistor to VREF for DC bias, as shown in the Typical Operating
Circuit.
LIMIN1
FUNCTIONNAME
Gain-Control Pin. Applying a DC voltage to GC between 0V and 2.0V adjusts the transmitter gain by
more than 40dB. GC is internally terminated to 1.35V via an 85kΩ resistor.
GC5
Received Signal-Strength Indicator Output. The voltage on RSSI is proportional to the signal power at
LIMIN. The RSSI output sources current pulses into a 330pF (typical) external capacitor. This output is
internally terminated with 11kΩ, and this RC time constant sets the decay time.
RSSI4
Local-Oscillator Input Ground. Connect to PC board ground plane with minimal inductance.GND7
Differential LO Inputs. In a typical application, externally terminate LO with 50Ω to ground, then AC cou-
ple into LO. AC terminate LO directly to ground for single-ended operation, as shown in the Typical
Operating Circuit.
LO, LO
6, 9
Baseband In-Phase Inputs. The differential voltage across these inputs forms the quadrature modulator’s
I-channel input. The signal input level is typically up to 500mVp-p centered around a 1.4V (typical) DC
bias level on I.
I, I
15, 16
Differential Outputs of the Limiting Amplifier. These outputs are complementary emitter followers capable
of driving 250Ω single-ended loads to ±300mV.
LIMOUT,
LIMOUT
13, 14
Baseband Quadrature-Phase Inputs. The differential voltage across these inputs forms the quadrature
modulator’s Q-channel input. The signal input level is typically up to 500mVp-p, centered around a 1.4V
(typical) DC bias level on Q.
Q, Q
17, 18
Receiver Enable Pin. When high, RXEN enables the receiver if TXEN is low. If both RXEN and TXEN are
high, the part is in standby mode; if both are low, the part is in shutdown. See the Power Management
section for details.
RXEN12
Transmitter-Enable Pin. When high, TXEN enables the transmitter if RXEN is low. If both TXEN and
RXEN are high, the part is in standby mode; if both are low, the part is in shutdown. See the Power
Management section for details.
TXEN11
Differential Outputs of the Upconverter. In a typical application, these open-collector outputs are pulled
up to V
CC
with two external inductors and AC coupled to the load. See the Applications Information sec-
tion for more details, including information on impedance matching these outputs to a load.
TXOUT,
TXOUT
23, 24
Differential Inputs of the Downconverter Mixer. An impedance-matching network may be required in
some applications. See the Applications Information section for details.
RXIN,
RXIN
22, 25
Reference Voltage Pin. VREF provides an external bias voltage for the MIXOUT and LIMIN pins. Bypass
this pin with a 0.1µF capacitor to ground. The VREF voltage is equal to V
CC
/ 2. See the Typical
Operating Circuit for more information.
VREF28
Receiver Mixer Ground. Connect to PC board ground plane with minimal inductance.GND26
General-Purpose V
CC
Pins. Bypass with a 0.047µF low-inductance capacitor to GND.V
CC
19, 21
Local-Oscillator Input V
CC
Pin. Bypass directly to local-oscillator input ground (pin 8).V
CC
8
Limiter Ground. Connect to PC board ground plane with minimal inductance.GND10
Receiver/Transmitter Ground. Connect to PC board ground plane with minimal inductance.GND20
Single-Ended Output of the Downconverter Mixer. This pin is high-impedance and must be biased to the
VREF pin through an external terminating resistor whose value depends on the interstage filter character-
istics. See the Applications Information section for details.
MIXOUT27
