MAX2751EUA+T - Hytronics

General Description

The MAX2750/MAX2751/MAX2752 are self-contained volt-

age-controlled oscillators (VCOs) intended for use in the

2.4GHz to 2.5GHz ISM band. Each IC combines a fully

integrated oscillator and output buffer in a miniature 8-pin

µMAX package.

The inductor and varactor elements of the tank are inte-

grated on-chip, greatly simplifying application of the part.

The only required external components are a couple of

supply bypass capacitors. The IC provides direct connec-

tion to the VCO tuning voltage input and the VCO buffer

output. The tuning voltage input range is +0.4V to +2.4V,

and the oscillator frequency tuning range is factory adjust-

ed to provide guaranteed limits. The output signal is

buffered by an amplifier stage (internally matched to 50Ω)

to provide higher output power and isolate the device from

load impedance variations.

The MAX2750/MAX2751/MAX2752 operate over a +2.7V

to +5.5V supply voltage range. Internal regulation of the

oscillator supply voltage eliminates the need for an exter-

nal LDO regulator for the VCO. The IC also provides a dig-

itally controlled shutdown mode to permit implementation

of sophisticated power-supply management. In shutdown,

the supply current is reduced to less than 1µA.

________________________Applications

802.11b DSSS WLAN

802.11 FHSS WLAN

Home RF

2.4GHz Bluetooth ISM Proprietary Radio

Features

♦Guaranteed Frequency Tuning Range

MAX2750: 2400MHz to 2500MHz (Zero IF)

MAX2751: 2120MHz to 2260MHz

(240MHz to 280MHz IF)

MAX2752: 2025MHz to 2165MHz

(335MHz to 375MHz IF)

♦On-Chip Tank Circuit

♦Internally Matched Output Buffer Amplifier

♦Low-Current Shutdown Mode

♦+2.7V to +5.5V Supply Voltage Range

♦Miniature 8-Pin µMAX Package

MAX2750/MAX2751/MAX2752

2.4GHz Monolithic

Voltage-Controlled Oscillators

OSCILLATOR

CORE

BIAS

TUNE

BYP

SHDN

GND

OUT

VCC1

VCC

VCC2

GND

SHDN

OUT TO MIXER/

SYNTHESIZER

MAX2750

MAX2751

MAX2752

Typical Operating Circuit

19-1825; Rev 1; 5/12

EVALUATION KIT

AVAILABLE

Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX2750EUA+ -40°C to +85°C 8 μMAX

MAX2751EUA+ -40°C to +85°C 8 μMAX

MAX2752EUA+ -40°C to +85°C 8 μMAX

Pin Configuration appears at end of data sheet.

Denotes a lead(Pb)-free/RoHS-compliant package.

Devices are also available in a tape-and-reel packaging. Specify

tape and reel by adding “T” to the part number when ordering.

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

ABSOLUTE MAXIMUM RATINGS

MAX2750/MAX2751/MAX2752

2.4GHz Monolithic

Voltage-Controlled Oscillators

DC ELECTRICAL CHARACTERISTICS

(VCC = +2.7V to +5.5V, VTUNE = +0.4V to +2.4V, V SHDN ≤+2V, OUT = connected to 50Ωload, TA= -40°C to +85°C. Typical values

are at VCC = +3.0V, TA= +25°C, unless otherwise noted.) (Note 1)

AC ELECTRICAL CHARACTERISTICS

(MAX2750/MAX2751/MAX2752 EV kit, VCC = +2.7V to +5.5V, VTUNE = +0.4V to +2.4V, V SHDN ≤+2V, OUT = connected to 50Ωload,

TA= +25°C. Typical values are at VCC = +3.0V, unless otherwise noted.)

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.

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

TUNE, SHDN, BYP, OUT to GND ...............-0.3V to (VCC + 0.3V)

Continuous Power Dissipation (TA= +70°C)

µMAX (derate 4.8mW/°C above TA= +70°C)...........387.8mW

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

Soldering Temperature (reflow) .......................................+260°C

PARAMETER CONDITIONS MIN TYP MAX UNITS

Supply Voltage 2.7 5.5 V

TA = +25oC11.3 14.4

MAX2750 TA = -40oC to +85oC14.1 17.0

TA = +25oC9.7 12.1

MAX2751 TA = -40oC to +85oC12.7 15.9

TA = +25oC10 12.1

Supply Current

MAX2752 TA = -40oC to +85oC12.8 15.2

Shutdown Supply Current 0.2 1 μA

SHDN Input Voltage Low 0.6 V

SHDN Input Voltage High 2.0 V

SHDN Input Current Low V SHDN ≤ 0.6V -2 2 μA

SHDN Input Current High V SHDN ≥ 2.0V -2 2 μA

TUNE Input Current 0.4 ≤ V TUNE ≤ 2.4V 0.02 nA

PARAMETER CONDITIONS MIN TYP MAX UNITS

MAX2750 2400 2500 MHz

MAX2751 2120 2260 MHz

Oscillator Guaranteed

Frequency Limits (Note1)

V TUNE = +0.4V to +2.4V,

TA = -40oC to +85oC

MAX2752 2025 2165 MHz

fOFFSET = 4MHz -125 dBc/Hz

Phase Noise Noise floor -151 dBm/Hz

fOSC = 2400MHz, +3V 140

MAX2750 fOSC = 2500MHz, +3V 90

fOSC = 2120MHz, +3V 175

MAX2751 fOSC = 2260MHz, +3V 110

fOSC = 2025MHz, +3V 170

Tuning Gain (Note 2)

MAX2752 fOSC = 2165MHz, +3V 105

MHz/V

Output Power -3 dBm

Return Loss 12 dB

Harmonics -30 dBc

MAX2750/MAX2751/MAX2752

2.4GHz Monolithic

Voltage-Controlled Oscillators

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 the oscillator’s guaranteed frequency limits.

Note 3: Turn-on time to within 3dB of final output power

Note 4: Turn-off time to output power of -10dBm.

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2750/MAX2751/MAX2752 EV kit, VCC = +2.7V to +5.5V, VTUNE = +0.4V to +2.4V, V SHDN ≤+2V, OUT = connected to 50Ωload,

TA= +25°C. Typical values are at VCC = +3.0V, unless otherwise noted.)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Load Pulling VSWR = 2:1, all phases 4 MHzp-p

Supply Pushing VCC stepped: +3.3V to +2.8V 1.3 MHz/V

Oscillator Turn-On Time (Note 3) Exiting shutdown 8 μs

Oscillator Turn-Off Time (Note 4) Entering shutdown 5 μs

MAX2750/51/52 toc01

SUPPLY CURRENT (mA)

-40 0 20-20 40 60 80

TEMPERATURE (°C)

MAX2750/MAX2751/MAX2752

SUPPLY CURRENT vs. TEMPERATURE

MAX2750

MAX2752

MAX2751

0.1

0.3

0.2

0.4

0.5

-40 0-20 20 40 60 80

MAX2750/51/52 toc02

TEMPERATURE (°C)

SHUTDOWN CURRENT (μA)

MAX2750/MAX2751/MAX2752

SHUTDOWN CURRENT vs. TEMPERATURE

MAX2750/51/52 toc03

0.2

0.4

0.8

0.6

1.0

TUNE INPUT CURRENT (nA)

-40 0 20-20 40 60 80

TEMPERATURE (°C)

MAX2750/MAX2751/MAX2752

TUNING CURRENT vs. TEMPERATURE

2200

2300

2400

2500

2600

0 1.00.5 1.5 2.0 2.5 3.0

MAX2750/51/52 toc04

VTUNE (V)

FREQUENCY (MHz)

MAX2750

VCO TUNING CURVE

TA = +85°C

TA = +25°C

TA = -40°C

1850

1950

2050

2150

2250

2350

0 0.5 1.0 1.5 2.0 2.5 3.0

MAX2750/51/52 toc05

VTUNE (V)

FREQUENCY (MHz)

MAX2751

VCO TUNING CURVE

TA = +85°C

TA = +25°C

TA = -40°C

1850

1950

2050

2150

2250

2350

0 0.5 1.0 1.5 2.0 2.5 3.0

MAX2750/51/52 toc06

VTUNE (V)

FREQUENCY (MHz)

MAX2752

VCO TUNING CURVE

TA = +85°C

TA = +25°C

TA = -40°C

Typical Operating Characteristics

(Circuit of Figure 1, VCC = +3.0V, VTUNE = +0.4V to +2.4V, VSHDN ≤2V, TA = +25°C, unless otherwise noted.)

MAX2750/MAX2751/MAX2752

2.4GHz Monolithic

Voltage-Controlled Oscillators

Pin Description

0.1 1 10

PHASE NOISE

MAX2750/51/52 toc07

OFFSET FREQUENCY (MHz)

PHASE NOISE (dBc/Hz)

-150

-130

-140

-110

-120

-90

-100

-80

-60

-70

-50

MAX2750/51/52 toc08

TEMPERATURE (°C)

OUTPUT POWER (dBm)

-5

-4

-3

-2

-40 0-20 20 40 60 80

MAX2751

OUTPUT POWER vs. TEMPERATURE

MAX2750/51/52 toc09

ƒO3ƒO

OUTPUT POWER (dBm)

FREQUENCY

Δ = 48dBc

Δ MKR

-30.00dB Δ = 30dBc

NORMALIZED HARMONIC

OUTPUT SPECTRUM

2ƒO

Typical Operating Characteristics (continued)

(Circuit of Figure 1, VCC = +3.0V, VTUNE = +0.4V to +2.4V, VSHDN ≤2V, TA = +25°C, unless otherwise noted.)

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0 4682 101214 1816 20

OSCILLATOR TURN-ON TIME

MAX2750/51/52 toc10

TIME (μs)

OUTPUT POWER (dBm)

8μs

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0 46821012141816 20

OSCILLATOR TURN-OFF TIME

MAX2750/51/52 toc11

TIME (μs)

OUTPUT POWER (dBm)

4μs

PIN NAME FUNCTION

1 BYP VCO Bypass. Bypass with a 0.1µF capacitor to GND.

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).

3 GND 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 less than 1.0µA. A logic level high enables the device.

CC1 Bias and Oscillator DC Supply Voltage Connection. Bypass separately from PIN6 with a 220pF

capacitor to GND for low noise and low spurious content performance from the oscillator.

CC2 Output Buffer DC Supply Voltage Connection. Bypass separately from PIN5 with a 220pF capacitor to

GND for best high frequency performance.

7 OUT Buffered Oscillator Output. Incorporates an internal DC blocking capacitor. OUT is internally matched

to 50Ω.

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

ground plane.

MAX2750/MAX2751/MAX2752

2.4GHz Monolithic

Voltage-Controlled Oscillators

Detailed Description

Oscillator

The MAX2750/MAX2751/MAX2752 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 internally matched to

50Ωincluding an on-chip DC blocking capacitor. No

external DC blocking capacitor is required, eliminating

the need for any external components. 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 provides an appropri-

ately low-impedance source. The input 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 intro-

duced 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.

OSCILLATOR

CORE

BIAS

TUNE

LOOP FILTER

BYP

0.1μF

SHDN

GND

OUT

VCC1

VCC

VCC2

GND

SHDN

220pF

MAX2750

MAX2751

MAX2752

OUT TO MIXER/

SYNTHESIZER

FROM

SYNTHESIZER

Figure 1. Typical Application Circuit

MAX2750/MAX2751/MAX2752

2.4GHz Monolithic

Voltage-Controlled Oscillators

VCC2

VCC1

SHDN

GND

OUTTUNE

GND

BYP

μMAX

TOP VIEW

MAX2750

MAX2751

MAX2752

Pin Configuration Chip Information

PROCESS: BiPOLAR

Package Information

For the latest package outline information and land patterns

(footprints), go to www.maxim-ic.com/packages. Note that a

“+”, “#”, or “-” in the package code indicates RoHS status only.

Package drawings may show a different suffix character, but

the drawing pertains to the package regardless of RoHS status.

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

8 µMAX U8+1 21-0036 90-0092

2.4GHz Monolithic

Voltage-Controlled Oscillators

MAX2750/MAX2751/MAX2752

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in

the Electrical. Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated Products, 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 _____________________

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 10/00 Initial release —

1 5/12

Added information for lead-free compliant options, added Absolute Maximum

Ratings information, updated TOC 11 1, 2, 4