Detailed Description

Signal Paths and Operation Modes

The MAX2351/MAX2354/MAX2358/MAX2359/MAX2530/

MAX2531/MAX2537/MAX2538 have multiple RF signal

paths. The cellular signal path has five modes of opera-

tion using a 4-gain-mode LNA and a 3-gain-mode mixer.

Similarly, the PCS signal path has four modes of opera-

tion made up of a 2-gain-mode LNA and a 3-gain-mode

mixer. The cellular and PCS mixer’s IF output can be

routed to either the IF0 or IF1 port. The GPS signal path

consists of a single-mode GPS, LNA, and mixer, which

has a dedicated IF output port. Tables 1 and 2 summa-

rize the modes of operation.

Low-Noise Amplifiers

The MAX2351/MAX2358/MAX2530/MAX2531/MAX2538

incorporate three LNA signal paths for the cellular,

PCS, and GPS bands. Using Maxim’s latest advanced

BiCMOS SiGe process, these LNAs deliver 1dB noise

figure for cellular, PCS, and GPS bands. The cellular

band LNAs have four modes of operation: high gain/

high linearity (HGHL), high gain/low linearity (HGLL),

midgain (MG), and low gain (LG). The PCS band LNAs

have two modes of operation: high gain/high linearity

and low gain. The GPS LNA has only one mode.

The BAND input selects the frequency band. The G1,

G2, and MODE pins are logic inputs that control the

LNA modes (see Table 2). Use HGHL mode when high

Quadruple-Mode PCS/Cellular/GPS LNA/Mixers

_______________________________________________________________________________________

9

Pin Description (continued)

PIN

MAX2351

MAX2358

MAX2354 MAX2359

MAX2530

MAX2531

MAX2538

MAX2537

NAME

FUNCTION

16

16

16

16

16

LO_OUT

PCS and Cellular LO Output. Output frequency is equal to

mixer LO frequency. Internally matched with DC-blocking

capacitor. If not used, connect pin to ground or leave open.

17

17

17

17

17

2.7V to 3.3V Supply Pin. Connect a 100pF bypass capacitor

as close as possible to the pin.

18, 19

18, 19

18, 19

18, 19

18, 19

IF0+, IF0-

Differential IF Output Port 0. Requires a pullup inductor and a

DC-blocking capacitor at each pin, which can be used as part

——

—

20, 21

20, 21

GIF+, GIF-

GPS IF Output. Requires a pullup inductor and a DC-blocking

capacitor at each pin, which can be used as part of the

22, 23

22, 23

22, 23

22, 23

22, 23

IF1+, IF1-

Differential IF Output Port 1. Requires a pullup inductor and a

DC-blocking capacitor at each pin, which can be used as part

24

24

—

24

24

CMIX_IN

Cellular Mixer Input. Internally matched to 50

Ω, including an

on-chip DC-blocking capacitor.

25

—

25

25

—

PMIX_IN

PCS Mixer Input. Internally matched to 50

Ω. Requires a DC-

blocking capacitor.

26

26

26

26

26

IF_SEL

IF Select Logic Input. Logic low selects IF0 port, and logic

high selects IF1 port.

27

—

—

27

27

BAND

BAND Logic Input. See Table 2 for details.

28

—

28

28

—

PLNA_OUT

PCS LNA Output. Requires a pullup inductor and a DC-

blocking capacitor, which can be used as part of the

matching network.

EP

EP

EP

EP

EP

Exposed

Exposed Pad. RF and DC ground.