19-1248; Rev 2; 2/02
10MHz to 1050MHz Integrated
RF Oscillator with Buffered Outputs
_________________General Description
____________________________Features
The MAX2620 combines a low-noise oscillator with two
output buffers in a low-cost, plastic surface-mount,
ultra-small µMAX package. This device integrates func-
tions typically achieved with discrete components. The
oscillator exhibits low-phase noise when properly
mated with an external varactor-tuned resonant tank
circuit. Two buffered outputs are provided for driving
mixers or prescalers. The buffers provide load isolation
to the oscillator and prevent frequency pulling due to
load-impedance changes. Power consumption is typi-
♦ Low-Phase-Noise Oscillator: -110dBc/Hz
(25kHz offset from carrier) Attainable
♦ Operates from Single +2.7V to +5.25V Supply
♦ Low-Cost Silicon Bipolar Design
♦ Two Output Buffers Provide Load Isolation
♦ Insensitive to Supply Variations
♦ Low, 27mW Power Consumption (V
= 3.0V)
CC
♦ Low-Current Shutdown Mode: 0.1µA (typ)
cally just 27mW in operating mode (V
= 3.0V), and
CC
drops to less than 0.3µW in standby mode. The MAX2620
operates from a single +2.7V to +5.25V supply.
________________________Applications
_______________Ordering Information
Analog Cellular Phones
Digital Cellular Phones
900MHz Cordless Phones
900MHz ISM-Band Applications
Land Mobile Radio
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 µMAX
MAX2620EUA
MAX2620E/D
Dice*
*Dice are tested at T = +25°C, DC parameters only.
A
Pin Configuration appears at end of data sheet.
Narrowband PCS (NPCS)
____________________________________________________Typical Operating Circuit
V
V
CC
CC
10Ω
1000pF
10nH
8
1000pF
1.5pF
V
1
1
OUT
CC
OUT TO MIXER
C5
1.5pF
C17
MAX2620
1.5pF
V
CC
2
3
TANK
FDBK
7
6
V
TUNE
V
2
CC
C3
1kΩ
0.1µF
51Ω
2.7pF
GND
OUT
CERAMIC
C6
RESONATOR
L1
1000pF
D1
ALPHA
SMV1204-34
C4
1pF
4
SHDN
BIAS
SUPPLY
5
OUT TO SYNTHESIZER
SHDN
V
CC
1000pF
900MHz BAND OSCILLATOR
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.