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 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
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.
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
Loading...