________________General Description
The MAX2424/MAX2426 highly integrated front-end ICs
provide the lowest cost solution for cordless and ISM-
band radios operating in the 900MHz band. Both devices
incorporate a receive image-reject mixer (to reduce filter
cost) as well as a versatile transmit mixer. The devices
operate from a +2.7V to +4.8V single power supply,
allowing direct connection to a 3-cell battery stack.
The receive path incorporates an adjustable-gain LNA
and an image-reject downconverter with 35dB image
suppression. These features yield excellent combined
downconverter noise figure (4dB) and high linearity with
an input third-order intercept point (IIP3) of up to +2dBm.
The transmitter consists of a double-balanced mixer and
a power amplifier (PA) predriver that produces up to
0dBm (in some applications serving as the final power
stage). It can be used in a variety of configurations,
including BPSK modulation, direct VCO modulation, and
transmitter upconversion. For devices featuring trans-
mit as well as receive image rejection, refer to the
MAX2420/MAX2421/MAX2422/MAX2460/MAX2463
data sheet.
The MAX2424/MAX2426 have an on-chip local oscillator
(LO), requiring only an external varactor-tuned LC tank
for operation. The integrated divide-by-64/65 dual-mod-
ulus prescaler can also be set to a direct mode, in which
it acts as an LO buffer amplifier. Four separate power-
down inputs can be used for system power manage-
ment, including a 0.5μA shutdown mode.
The MAX2424/MAX2426 come in a 28-pin SSOP pack-
age.
________________________Applications
Cordless Phones
Wireless Telemetry
Wireless Networks
Spread-Spectrum Communications
Two-Way Paging
____________________________Features
o
Receive Mixer with 35dB Image Rejection
o
Adjustable-Gain LNA
o
Up to +2dBm Combined Receiver Input IP3
o
4dB Combined Receiver Noise Figure
o
Optimized for Common Receiver IF Frequencies:
10.7MHz (MAX2424)
70MHz (MAX2426)
o
PA Predriver Provides up to 0dBm
o
Low Current Consumption: 23mA Receive
20mA Transmit
9.5mA Oscillator
o
0.5μA Shutdown Mode
o
Operates from Single +2.7V to +4.8V Supply
M
900MHz Image-Reject Receivers
with Transmit Mixer
________________________________________________________________ Maxim Integrated Products
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
GND
GND
GND
TANK
TXON
PREOUT
PREGND
MOD
DIV1
VCOON
RXON
CAP2
TXIN
TXIN
LNAGAIN
TXOUT
GND
GND
RXIN
GND
RXOUT
CAP1
SSOP
TOP VIEW
MAX2424
MAX2426
TANK
V
CC
V
CC
V
CC
V
CC
V
CC
___________________Pin Configuration
19-1350 Rev 2; 2/99
EVALUATION KIT MANUAL
PART
MAX2424
EAI
MAX2426
EAI
-40°C to +85°C
-40°C to +85°C
TEMP. RANGE
PIN-PACKAGE
28 SSOP
28 SSOP
_______________Ordering Information
Functional Diagram appears at end of data sheet.
FOLLOWS DATA SHEET
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.