General Description
The MAX2622/MAX2623/MAX2624 self-contained volt-
age-controlled oscillators (VCOs) combine an integrat-
ed 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 50.
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 50Output 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
OSCILLATOR
CORE
BIAS
TUNE
TUNE
N.C.
SHDN
GND
OUT
VCC
VCC
VCC
GND
SHDN
220pF
OUT TO MIXER/
SYNTHESIZER
220pF
MAX2622
MAX2623
MAX2624
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 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX2622/MAX2623/MAX2624
Monolithic Voltage-Controlled Oscillators
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(Typical Operating Circuit, VCC = +2.7V to +5.5V, VTUNE = 1.4V, V SHDN = 2V, OUT = unconnected, TA= -40°C to +85°C, unless
otherwise noted. Typical values are at VCC = +3V, TA= +25°C.) (Note 1)
AC ELECTRICAL CHARACTERISTICS
(Typical Operating Circuit, VCC = +2.7V to +5.5V, VTUNE = 0.4V to 2.4V, V SHDN = 2V, TA= +25°C, unless otherwise noted. Typical
values measured at VCC = +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 VTUNE = 0.4V with a 0.2V step to 0.6V. At low VTUNE, tuning gain is highest.
Note 3: Measurements taken on MAX262_ EV kit.
VCC to GND..............................................................-0.3V to +6V
TUNE, SHDN to GND .................................-0.3V to (VCC + 0.3V)
OUT to GND ...............................................-0.3V to (VCC + 0.6V)
Continuous Power Dissipation (TA= +70°C)
8-Pin µMAX (derate 5.7mW/°C above TA = +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
VSHDN 0.6V
0.4V VTUNE 2.4V
VSHDN 0.6V
VSHDN 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
fOFFSET = 100kHz
fOFFSET = 1MHz dBc/Hz
-101
Phase Noise -119
VCC stepped from 2.8V to 3.3V
VSWR = 2:1, all phases
VTUNE = 0.4V (Note 3)
CONDITIONS
885 950
kHz/V
280
Supply Pushing
MHzp-p
0.75
MAX2623, VTUNE = 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, VTUNE = 0.4V to 2.4V, TA= -40°C to +85°C
Oscillator Frequency Range MHz
855 881
VTUNE = 0.4V to 2.4V MHz/V
75 100
Maximum Tuning Gain (Note 2)
MAX2624, VTUNE = 0.4V to 2.4V, TA = -40°C to +85°C 947 998
MAX2622/MAX2623/MAX2624
Monolithic Voltage-Controlled Oscillators
_______________________________________________________________________________________ 3
0
0.5
1.0
1.5
2.0
-40 0-20 20 40 60 80
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX2622/23/24-02
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
7
8
9
10
-40 0 20-20 40 60 80
SUPPLY CURRENT
vs. TEMPERATURE
MAX2622/23/24-01
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
-130
-110
-120
-90
-100
-70
-80
-60
10 100 1000
PHASE NOISE
MAX2622-03
OFFSET FREQUENCY (kHz)
PHASE NOISE (dBc)
750
800
850
900
950
1000
0 1.00.5 1.5 2.0 2.5 3.0
MAX2622
VCO TUNING CURVE
MAX2622/23/24-05
VTUNE (V)
FREQUENCY (MHz)
TA = +85°C
TA = +25°C
TA = -40°C
800
850
900
950
1000
1050
0 1.00.5 1.5 2.0 2.5 3.0
MAX2623
VCO TUNING CURVE
MAX2622/23/24-06
VTUNE (V)
FREQUENCY (MHz)
TA = +85°C
TA = +25°C
TA = -40°C
850
900
950
1000
1050
1100
0 1.00.5 1.5 2.0 2.5 3.0
MAX2624
VCO TUNING CURVE
MAX2622/23/24-07
VTUNE (V)
FREQUENCY (MHz)
TA = +85°C
TA = +25°C
TA = -40°C
fO2fO3fO
NORMALIZED HARMONIC OUTPUT SPECTRUM
MAX2622-04
FREQUENCY
OUTPUT POWER
= -48dBc
= 29dBc
Typical Operating Characteristics
(VCC = +3.0V, VTUNE = 0.4V to 2.4V, V SHDN = 2V, TA= +25°C, unless otherwise noted.)
MAX2622/MAX2623/MAX2624
Detailed Description
Oscillator
The MAX2622/MAX2623/MAX2624 VCOs are imple-
mented 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 con-
trolled 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 frequen-
cy 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 com-
mon-emitter stage with an integrated on-chip reactive
output match. No external DC blocking capacitor is
required, eliminating the need for any external compo-
nents. The output amplifier has its own VCC and 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 pro-
vide an appropriately low-impedance source. It may
incorporate an extra RC filter stage to reduce high-fre-
quency 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
VCC pins as possible; for long VCC lines, it may be nec-
essary to add additional decoupling capacitors located
further from the device. Always provide a low-induc-
tance 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
1N.C. No Connection. Not internally connected.
2TUNE 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
3GND Ground Connection for Oscillator and Biasing. Requires a low-inductance connection to the circuit board
ground plane.
4SHDN 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.
8GND Ground Connection for Output Buffer. Requires a low-inductance connection to the circuit board
ground plane.
7OUT Buffered Oscillator Output
6 VCC 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 VCC Output Buffer DC Supply Voltage Connection. Bypass with a 220pF capacitor to GND for best high-
frequency performance.
Pin Description
MAX2622/MAX2623/MAX2624
Monolithic Voltage-Controlled Oscillators
_______________________________________________________________________________________ 5
OSCILLATOR
CORE
BIAS
FROM
SYNTHESIZER
LOOP FILTER
TUNE
N.C.
SHDN
GND
OUT
VCC
VCC
VCC
GND
SHDN
220pF
220pF
MAX2622
MAX2623
MAX2624
OUT TO MIXER/
SYNTHESIZER
Figure 1. Typical Application Circuit
VCC
VCC
SHDN
1
2
8
7
GND
OUTTUNE
GND
N.C.
µMAX
TOP VIEW
3
4
6
5
MAX2622
MAX2623
MAX2624
Pin Configuration
MAX2622/MAX2623/MAX2624
Monolithic Voltage-Controlled Oscillators
6 _______________________________________________________________________________________
Package Information
8LUMAXD.EPS