MAX7381AXR126+T [MAXIM]

TTL Output Clock Oscillator, 12MHz Nom;


型号：	MAX7381AXR126+T
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	TTL Output Clock Oscillator, 12MHz Nom 振荡器石英晶振机械
文件：	总6页 (文件大小：544K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

19-3697; Rev 0; 4/05

3-Pin Silicon Oscillator

General Description

Features

♦ 2.7V to 5.5V Operation

The MAX7381 is a silicon oscillator intended as a low-cost

improvement to ceramic resonators, crystals, and crystal

oscillator modules as the clock source for microcon-

trollers and UARTs in 3V, 3.3V, and 5V applications.

♦ Factory-Trimmed Oscillator (10MHz to 16MHz)

♦ No External Components Required

The MAX7381 is an integrated oscillator, supplied at spe-

cific frequencies, just like crystals and resonators, and

with a rail-to-rail, 50%, duty-cycle square-wave output.

The oscillator frequency is generated directly without the

use of a phase-locked loop (PLL). No additional compo-

nents are required for setting or adjusting the frequency.

♦

10mꢀ Output-ꢁriꢂe Current

♦ 2% Initial ꢀccuracy

100ppmꢃ/C Temperature ꢁriꢄt

♦

♦ Fast Startup Time: 5µs

Unlike typical crystal and ceramic resonator oscillator cir-

cuits, the MAX7381 is resistant to vibration and EMI. The

high output-drive current and absence of high-imped-

ance nodes make the oscillator invulnerable to dirty or

humid operating conditions. With a wide operating tem-

perature range as standard, the oscillator is a good

choice for demanding appliance and automotive environ-

ments. The MAX7381 is available with frequencies in the

10MHz to 16MHz range.

♦ 40% to 60% Maximum ꢁuty Cycle

♦ 5ns Output RiseꢃFall Time

♦ Very-Low-EMI Susceptibility (No High-Impedance

Nodes)

♦ No PLL

♦ Low Jitter: 180ps

at 16MHz

P-P

♦ -40/C to +125/C Temperature Range

The MAX7381 is offered in a space-saving 3-pin SC70

package. All ICs are guaranteed to operate over the

-55°C to +135°C temperature range and specified from

the -40°C to +125°C temperature range.

Ordering Information

Applications

White Goods

PꢀRT

TEMP RꢀNGE

-40°C to +125°C

PIN-PꢀCKꢀGE

3 SC70-3

MAX7381AXR106-T

MAX7381AXR126-T

MAX7381AXR146-T

MAX7381AXR166-T

Automotive

3 SC70-3

Appliances and Controls

Handheld Products

3 SC70-3

Portable Equipment

The MAX7381 is available in factory-set frequencies from

10MHz to 16MHz. There are four standard versions 10MHz,

12MHz, 14MHz, and 16MHz, shown in the Selector Guide) with

a required order increment of 2.5K. Nonstandard frequencies

are also available with a required order increment of 10K. For

nonstandard versions, contact factory for availability and

ordering information. All versions are available in tape and reel

only.

Microcontroller Systems

Typical Operating Circuit

2.7V TO 5.5V

Refer to the MAX7375 data sheet for output frequencies below

10MHz.

V+

OSC1

CLOCK

MAX7381

µC

GND

OSC2

Selector Guide appears at end of data sheet.

________________________________________________________________ Maxim Integrated Products

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.

3-Pin Silicon Oscillator

ꢀBSOLUTE MꢀXIMUM RꢀTINGS

V+ to GND.............................................................-0.3V to +6.0V

CLK to GND..................................................-0.3V to (V+ + 0.3V)

CLK Current ..................................................................... 50mA

Functional Temperature Range.........................-55°C to +135°C

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

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

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

Continuous Power Dissipation (T = + 70°C)

3-Pin SC70 (derate 2.9mW/°C over +70°C)..............235.3mW

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.

ELECTRICꢀL CHꢀRꢀCTERISTICS

(V+ = 2.7V to 5.5V, T = -40°C to +125°C, unless otherwise noted. Typical values are at V+ = 5V, T = +25°C, unless otherwise

noted.) (Note 1)

PꢀRꢀMETER

SYMBOL

CONꢁITIONS

MIN

TYP

MꢀX

5.5

UNITS

Operating Supply Voltage

V+

2.7

MAX7381AXR126

MAX7381AXR166

3.7

4.8

4.75

6.50

Operating Supply Current

Output High Voltage

I+

V+ -

0.4

V+ ≥ 2.7V, I

V+ ≥ 4.5V, I

= 2.5mA

= 9mA

SOURCE

V+ -

0.4

V+ ≥ 2.7V, I

V+ ≥ 4.5V, I

= 10mA

0.4

SINK

Output Low Voltage

On-Resistance

= 20mA

= 3V (typ value at T = +25°C)

0.11

0.17

0.15

Ω

= 5V (typ value at T = +25°C)

0.095

V+ = 5.0V,

= +25°C

MAX7381AXR_ _ _

-2%

-5%

+2%

+3%

Initial CLOCK Frequency

(Note 2)

MHz

CLOCK

V+ = 2.7V to 5.5V,

= +25°C

CLOCK Frequency Temperature

Sensitivity

T = -40°C to +125°C, (Note 3)

-350

100

+300

ppm/°C

Duty Cycle

(Note 3)

Observation for 20s using a 12GHz

oscilloscope (MAX7381AXR166)

Output Jitter

180

ps -

P P

Output Rise Time

Output Fall Time

Startup Time

µs

Note 1: All parameters tested at T = +25°C. Specifications over temperature are guaranteed by design and characterization.

Note 2: Typical frequencies are nominal values.

Note 3: Guaranteed by design and characterization. Not production tested.

_______________________________________________________________________________________

3-Pin Silicon Oscillator

Typical Operating Characteristics

(V+ = 5V, C = 10pF, 16MHz output, T = +25°C, unless otherwise noted.)

DUTY CYCLE vs. TEMPERATURE

DUTY CYCLE vs. SUPPLY VOLTAGE

SUPPLY CURRENT vs. TEMPERATURE

V+ = 5V

V+ = 3.3V

V+ = 2.7V

-40 -25 -10

20 35 50 65 80 95 110 125

TEMPERATURE (°C)

2.5

3.0

3.5

4.0

4.5

5.0

5.5

-40 -25 -10

20 35 50 65 80 95 110 125

SUPPLY VOLTAGE (V)

TEMPERATURE (°C)

SUPPLY CURRENT vs. SUPPLY VOLTAGE

FREQUENCY vs. SUPPLY VOLTAGE

FREQUENCY vs. TEMPERATURE

1.010

1.005

1.000

0.995

0.990

0.985

0.980

1.035

1.025

1.015

1.005

0.995

0.985

0.975

2.5

3.0

3.5

4.0

4.5

5.0

5.5

2.5

3.0

3.5

4.0

4.5

5.0

5.5

-40 -25 -10

20 35 50 65 80 95 110 125

SUPPLY VOLTAGE (V)

TEMPERATURE (°C)

CLOCK OUTPUT WAVEFORM

SUPPLY CURRENT vs. FREQUENCY

SETTLING TIME FROM START

WITH C = 10pF

MAX7381 toc09

MAX7381 toc08

CLOCK

1V/div

CLOCK

2V/div

V+

2V/div

V+ = 3.3V

V+ = 5V

20ns/div

100ns/div

FREQUENCY (MHz)

_______________________________________________________________________________________

3-Pin Silicon Oscillator

Typical Operating Characteristics (continued)

(V+ = 5V, C = 10pF, 16MHz output, T = +25°C, unless otherwise noted.)

CLOCK OUTPUT WAVEFORM

WITH C = 50pF

WITH C = 100pF

MAX7381 toc10

MAX7381 toc11

CLOCK

1V/div

CLOCK

1V/div

V+ = 3.3V

20ns/div

Detailed Description

Pin Description

The MAX7381 is a replacement for ceramic resonators,

crystals, and crystal-oscillator modules as the clock

source for microcontrollers and UARTs in 3V, 3.3V, and

5V applications. The MAX7381 is an integrated oscilla-

tor, supplied at specific frequencies just like crystals

and resonators. A variety of popular standard frequen-

cies are available. No external components are

required for setting or adjusting the frequency.

NꢀME

FUNCTION

Positive Supply Voltage. Bypass V+

to GND with a 0.1µF surface-mount

ceramic capacitor.

V+

Clock Output. CLOCK is a push-

pull output.

CLOCK

GND

Ground

Supply Voltages

The MAX7381 has been designed for use in systems

with nominal supply voltages of 3V, 3.3V, or 5V and is

specified for operation with supply voltages in the 2.7V

to 5.5V range. Operation outside this range is not guar-

anteed. See the Absolute Maximum Ratings for limit

values of power-supply and pin voltages.

are approximately proportional to the period of the out-

put frequency of the device.

The jitter performance of all clock sources degrades in

the presence of mechanical and electrical interference.

The MAX7381 is relatively immune to vibration, shock,

and EMI influences, and thus provides a considerably

more robust clock source than crystal- or ceramic-

resonator-based oscillator circuits.

Oscillator

The clock output is a push-pull configuration and is

capable of driving a ground-connected 1kΩ load or a

positive-supply-connected 500Ω load to within 400mV

of either supply rail. The clock output remains stable

over the full operating voltage range. A typical startup

characteristic is shown in the Typical Operating

Characteristics section.

Applications Information

Interfacing to a Microcontroller

Clock Input

The MAX7381 clock output is a push-pull, CMOS, logic

output, which directly drives any microprocessor (µP)

or microcontroller (µC) clock input. There are no imped-

ance-matching issues when using the MAX7381.

Operate the MAX7381 and microcontroller (or other

clock-input device) from the same supply voltage.

Refer to the microcontroller data sheet for clock-input

compatibility with external clock signals.

Output Jitter

The MAX7381’s jitter performance is given in the

Electrical Characteristics table as a peak-to-peak value

obtained by observing the output of the MAX7381 for

20s with a 500MHz oscilloscope. Jitter measurements

_______________________________________________________________________________________

3-Pin Silicon Oscillator

The MAX7381 requires no biasing components or load

capacitance. When using the MAX7381 to retrofit a

crystal oscillator, remove all biasing components from

the oscillator input.

Chip Information

PROCESS: BiCMOS

Startup Performance

The MAX7381 oscillator output stabilizes within a few

cycles of operation after V+ rises to a sufficient voltage

to start the oscillator, typically 1.65V at +25°C. Use a

reset or similar voltage-detection circuit to disable

devices connected to the MAX7381 until 20µs after the

voltage on V+ has risen above 2.7V.

Selector Guide

PꢀRT

FREQUENCY (MHz)

TOP MꢀRK

APE

MAX7381AXR106

MAX7381AXR126

MAX7381AXR146

MAX7381AXR166

APG

ARC

Power-Supply Considerations

The MAX7381 operates with power-supply voltages in

the 2.7V to 5.5V range. Power-supply decoupling is

needed to maintain the power-supply rejection perfor-

mance of the MAX7381. Use a 0.1µF surface-mount

ceramic capacitor connected between V+ and GND

and mounted as close to the device as possible. If pos-

sible, mount the MAX7381 close to the microcontroller’s

decoupling capacitor so that additional decoupling is

not required.

APH

Pin Configuration

TOP VIEW

V+

GND

MAX7381

A larger value bypass capacitor is recommended if the

MAX7381 is driving a large capacitive load. Use a

bypass capacitor value of at least 1000 times the out-

put-load capacitance.

CLOCK

SC70

_______________________________________________________________________________________

3-Pin Silicon Oscillator

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,

go to www.maxim-ic.comꢃpackages.)

PACKAGE OUTLINE, 3L SC70

21-0075

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.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 6

Printed USA

is a registered trademark of Maxim Integrated Products, Inc.

MAX7381AXR126+T [MAXIM]

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