MAXIM MAX2622, MAX2623, MAX2624 Technical data

General Description

The MAX2622/MAX2623/MAX2624 self-contained volt­age-controlled oscillators (VCOs) combine an integrat­ed oscillator and output buffer in a miniature 8-pin
µMAX package.

The inductor and varactor elements of the tank circuits
are integrated on-chip, greatly simplifying application of
the part. In addition, the center frequency of oscillation
and frequency span are factory preset to provide a
guaranteed frequency range versus control voltage. An
external tuning voltage controls the oscillation frequency.
The output signals are buffered by an amplifier stage
matched on-chip to 50Ω.

The MAX2622/MAX2623/MAX2624 operate from a
+2.7V to +5.5V supply voltage and require only 8mA of
supply current. In shutdown mode, the supply current is
reduced to 0.1µA.

Applications

866MHz to 868MHz European ISM Band
(MAX2622)

DECT 1/2 Frequency LO (MAX2623)

902MHz to 928MHz ISM Band, ±10.7MHz IF
(MAX2623)

902MHz to 928MHz ISM Band, 45MHz to
70MHz IF (MAX2624)

Features

♦ Fully Monolithic

♦ Guaranteed Performance

♦ On-Chip 50Ω Output Match

♦ Wide Choice of Frequencies

855MHz to 881MHz (MAX2622)
885MHz to 950MHz (MAX2623)
947MHz to 998MHz (MAX2624)

♦ +2.7V to +5.5V Single-Supply Operation

♦ Low-Current Shutdown Mode

♦ Smaller than Modules (8-Pin µMAX Package)

MAX2622/MAX2623/MAX2624

Monolithic Voltage-Controlled Oscillators

________________________________________________________________ Maxim Integrated Products 1

19-1528; Rev 1; 5/00

PART

MAX2622EUA

MAX2623EUA

MAX2624EUA

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

TEMP. RANGE PIN-PACKAGE

8 µMAX

8 µMAX

8 µMAX

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

Ordering Information

Typical Operating Circuit

Pin Configuration appears at end of data sheet.

For free samples and the latest literature, visit www.maxim-ic.com or phone [phone].
For small orders, phone [phone].

N.C.

TUNE

SHDN

TUNE

GND

SHDN

OSCILLATOR

CORE

MAX2622
MAX2623
MAX2624

BIAS

GND

OUT

V

V

OUT TO MIXER/
SYNTHESIZER

CC

CC

220pF

220pF

V

CC

MAX2622/MAX2623/MAX2624

Monolithic Voltage-Controlled Oscillators

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(Typical Operating Circuit, VCC= +2.7V to +5.5V, V

TUNE

= 1.4V, V

SHDN

= 2V, OUT = unconnected, TA= -40°C to +85°C, unless

otherwise noted. Typical values are at V

CC

= +3V, TA= +25°C.) (Note 1)

AC ELECTRICAL CHARACTERISTICS

(Typical Operating Circuit, VCC= +2.7V to +5.5V, V

TUNE

= 0.4V to 2.4V, V

SHDN

= 2V, TA= +25°C, unless otherwise noted. Typical

values measured at V

CC

= +3V.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

Note 1: Specifications are production tested at TA= +25°C. Limits over temperature are guaranteed by design and characterization.
Note 2: Tuning gain is measured at V

TUNE

= 0.4V with a 0.2V step to 0.6V. At low V

TUNE

, tuning gain is highest.

Note 3: Measurements taken on MAX262_ EV kit.

V

CC

to GND..............................................................-0.3V to +6V

TUNE, SHDN to GND .................................-0.3V to (V

CC

+ 0.3V)

OUT to GND ...............................................-0.3V to (V

CC

+ 0.6V)

Continuous Power Dissipation (TA= +70°C)

8-Pin µMAX (derate 5.7mW/°C above T

A

= +70°C).....457mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

V

SHDN

≤ 0.6V

0.4V ≤ V

TUNE

≤ 2.4V

V

SHDN

≤ 0.6V

V

SHDN

≥ 2.0V

CONDITIONS

µA

0.1 5

Shutdown Supply Current

mA

811.5

V

2.7 5.5

Supply Voltage

Supply Current

nA

0.01

TUNE Input Current

V

0.6

SHDN Input Voltage Low

V

2.0

SHDN Input Voltage High

µA

-0.5 0.5

SHDN Input Current Low

µA

-0.5 0.5

SHDN Input Current High

UNITSMIN TYP MAXPARAMETER

f

OFFSET

= 100kHz

f

OFFSET

= 1MHz

dBc/Hz

-101

Phase Noise

-119

V

CC

stepped from 2.8V to 3.3V

VSWR = 2:1, all phases

V

TUNE

= 0.4V (Note 3)

CONDITIONS

885 950

kHz/V

280

Supply Pushing

MHz

p-p

0.75

MAX2623, V

TUNE

= 0.4V to 2.4V, TA= -20°C to +75°C

Load Pulling

dBc

-27

Harmonics

dB

-10

Return Loss (Note 3)

dBm/Hz

-151

Noise Floor

dBm

-3

Output Power

UNITSMIN TYP MAXPARAMETER

MAX2622, V

TUNE

= 0.4V to 2.4V, TA= -40°C to +85°C

Oscillator Frequency Range MHz

855 881

V

TUNE

= 0.4V to 2.4V MHz/V

75 100

Maximum Tuning Gain (Note 2)

MAX2624, V

TUNE

= 0.4V to 2.4V, TA = -40°C to +85°C

947 998

MAX2622/MAX2623/MAX2624

Monolithic Voltage-Controlled Oscillators

_______________________________________________________________________________________ 3

Typical Operating Characteristics

(VCC= +3.0V, V

TUNE

= 0.4V to 2.4V, V

SHDN

= 2V, TA= +25°C, unless otherwise noted.)

MAX2622

VCO TUNING CURVE

1000

950

TA = -40°C

900

850

FREQUENCY (MHz)

800

750

0 1.00.5 1.5 2.0 2.5 3.0

V

(V)

TUNE

10

9

TA = +85°C

TA = +25°C

SUPPLY CURRENT

vs. TEMPERATURE

MAX2623

VCO TUNING CURVE

TA = -40°C

TA = +25°C

V

(V)

TUNE

TA = +85°C

MAX2622/23/24-05

1050

1000

950

900

FREQUENCY (MHz)

850

800

0 1.00.5 1.5 2.0 2.5 3.0

MAX2622/23/24-01

1100

1050

MAX2622/23/24-06

1000

950

FREQUENCY (MHz)

900

850

SHUTDOWN SUPPLY CURRENT

vs. TEMPERATURE

2.0

1.5

MAX2624

VCO TUNING CURVE

TA = -40°C

TA = +85°C

TA = +25°C

0 1.00.5 1.5 2.0 2.5 3.0

V

(V)

TUNE

MAX2622/23/24-02

MAX2622/23/24-07

8

SUPPLY CURRENT (mA)

7

-40 0 20-20 40 60 80
TEMPERATURE (°C)

PHASE NOISE

-60

-70

-80

-90

-100

PHASE NOISE (dBc)

-110

-120

-130
10 100 1000

OFFSET FREQUENCY (kHz)

MAX2622-03

1.0

SUPPLY CURRENT (µA)

0.5

0

-40 0-20 20 40 60 80
TEMPERATURE (°C)

NORMALIZED HARMONIC OUTPUT SPECTRUM

∆ = 29dBc

∆ = -48dBc

OUTPUT POWER

f

O

FREQUENCY

2f

O

MAX2622-04

3f

O

MAX2622/MAX2623/MAX2624

Detailed Description

Oscillator

The MAX2622/MAX2623/MAX2624 VCOs are imple­mented as an LC oscillator topology, integrating all of
the tank components on-chip. This fully monolithic
approach provides an extremely easy-to-use VCO,
equivalent to a VCO module. The frequency is con­trolled by a voltage applied to the TUNE pin, which is
internally connected to the varactor. The VCO core
uses a differential topology to provide a stable frequen­cy versus supply voltage and improve the immunity to
load variations. In addition, there is a buffer amplifier
following the oscillator core to provide added isolation
from load variations and to boost the output power.

Output Buffer

The oscillator signal from the core drives an output
buffer amplifier. The amplifier is constructed as a com­mon-emitter stage with an integrated on-chip reactive
output match. No external DC blocking capacitor is
required, eliminating the need for any external compo­nents. The output amplifier has its own VCCand GND
pins to minimize load-pulling effects. The amplifier
boosts the oscillator signal to a level suitable for driving
most RF mixers.

Applications Information

Tune Input

The tuning input is typically connected to the output of
the PLL loop filter. The loop filter is presumed to pro­vide an appropriately low-impedance source. It may
incorporate an extra RC filter stage to reduce high-fre­quency noise and spurious signals. Any excess noise
on the tuning input is directly translated into FM noise,
which can degrade the phase-noise performance of the
oscillator. Therefore, it is important to minimize the
noise introduced on the tuning input. A simple RC filter
with low corner frequency is needed during testing in
order to filter the noise present on the voltage source
driving the tuning line.

Layout Issues

Always use controlled impedance lines (microstrip,
coplanar waveguide, etc.) for high-frequency signals.
Always place decoupling capacitors as close to the
VCCpins as possible; for long VCClines, it may be nec­essary to add additional decoupling capacitors located
further from the device. Always provide a low-induc­tance path to ground, and keep GND vias as close to
the device as possible. Thermal reliefs on GND pads
are not recommended.

Monolithic Voltage-Controlled Oscillators

4 _______________________________________________________________________________________

NAME FUNCTION

1

N.C. No Connection. Not internally connected.

2 TUNE

Oscillator Frequency Tuning Voltage Input. High-impedance input with a voltage input range of 0.4V
(low frequency) to 2.4V (high frequency) adjustment.

PIN

3 GND

Ground Connection for Oscillator and Biasing. Requires a low-inductance connection to the circuit board
ground plane.

4

SHDN

Shutdown Logic Input. A high-impedance input logic level low disables the device and reduces supply current
to 0.1µA. A logic level high enables the device.

8 GND

Ground Connection for Output Buffer. Requires a low-inductance connection to the circuit board
ground plane.

7 OUT Buffered Oscillator Output

6 V

CC

Bias and Oscillator DC Supply Voltage Connection. Bypass with a 220pF capacitor to GND for low noise
and low spurious content performance from the oscillator.

5 V

CC

Output Buffer DC Supply Voltage Connection. Bypass with a 220pF capacitor to GND for best high­frequency performance.

Pin Description

MAX2622/MAX2623/MAX2624

Monolithic Voltage-Controlled Oscillators

_______________________________________________________________________________________ 5

Figure 1. Typical Application Circuit

Pin Configuration

MAX2622

N.C.

MAX2623
MAX2624

FROM

SYNTHESIZER

LOOP FILTER

SHDN

TOP VIEW

N.C.

1

TUNE

GND

SHDN

87GND

OSCILLATOR

CORE

BIAS

GND

OUT

V

V

OUT TO MIXER/
SYNTHESIZER

220pF

CC

V

CC

CC

220pF

2

OUTTUNE

MAX2622

GND

SHDN

MAX2623

3

MAX2624

4

V

6

CC

5

V

CC

µMAX

MAX2622/MAX2623/MAX2624

Monolithic Voltage-Controlled Oscillators

6 _______________________________________________________________________________________

Package Information

8LUMAXD.EPS