The MAX7375 is a silicon oscillator, intended as a low-cost improvement replacing ceramic resonators, crys-tals, and crystal oscillator modules used as the clock source for microcontrollers and UARTs in 3V, 3.3V, and 5V applications.

The MAX7375 is a fully integrated oscillator, supplied at specific factory-trimmed frequencies with a Rail-to-Rail® 50% duty cycle square-wave output. The oscilla-tor frequency is generated directly without the use of a phase-locked loop (PLL). No additional components are used to set or adjust the frequency.

Unlike typical crystal and ceramic resonator oscillator circuits, the MAX7375 is highly resistant to vibration and EMI. The high output drive current and absence of high-impedance nodes also makes the oscillator less susceptible to dirty or humid operating conditions. With a wide operating temperature range, the oscillator is a good choice for demanding home appliance and auto-motive environments.

Available in 3-pin space-saving SC70 and SOT23 pack-ages, the MAX7375 is offered in standard and nonstan-dard factory-set frequencies ranging from 600kHz to 9.99MHz. See the MAX7381 data sheet for frequencies ≥10MHz. The MAX7375’s standard operating temperature range is -40°C to +125°C. See the Applications Information section for extended operating temperature range.

Applications

White Goods Portable Equipment Automotive

Microcontroller Systems

Appliances and Controls Hand-Held Products

Features

♦2.7V to 5.5V Operation

♦Factory-Trimmed Oscillator (600kHz to 9.99MHz)♦No External Components Required ♦±10mA Output Drive Current ♦2% Initial Accuracy ♦±50ppm/°C Temp Drift ♦Fast Startup Time: 5µs

♦40% to 60% Maximum Duty Cycle

♦5ns Output Rise and Fall Time-Low EMI

♦

Very Low EMI Susceptibility-No High-Impedance Nodes

♦Very Low Jitter: 160ps P-P at 8MHz

♦Tiny Surface-Mount Package (SC70, SOT23)♦-40°C to +125°C Temperature Range

MAX7375

3-Pin Silicon Oscillator

________________________________________________________________Maxim Integrated Products

1

Ordering Information

19-3060; Rev 2; 7/04

For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-42, or visit Maxim’s website at www.maxim-ic.com.

Typical Application Circuit

Pin Configuration and Selector Guide appear at end of data sheet.

Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd,

The MAX7375 is available in factory-set frequencies from 600kHz to 9.99MHz. There are seven standard versions (1MHz, 1.84MHz,3.58MHz, 3.69MHz, 4MHz, 4.19MHz, and 8MHz, as shown in the Selector Guide) with a required 2.5k order increment.Nonstandard frequencies are also available with a required 10k order increment. For nonstandard versions, contact factory for availability and ordering information. All versions available in tape-and-reel only.

M A X 7375

3-Pin Silicon Oscillator 2_______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V+ = 2.7V to 5.5V, T A = -40°C to +125°C, unless otherwise noted. Typical values are at V+ = 5V, T A = +25°C, unless otherwise noted.)(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 2:Typical frequencies are nominal values.

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

V+ to GND................................................................-0.3V to +6V CLOCK to GND............................................-0.3V to (V+ + 0.3V)Continuous Power Dissipation (T A = +70°C)

3-Pin SC70 (derate 2.9mW/°C over +70°C).................235mW 3-Pin SOT23 (derate 4mW/°C over +70°C...................320mW

Operating 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

MAX7375

3-Pin Silicon Oscillator

_______________________________________________________________________________________3

DUTY CYCLE vs. TEMPERATURE

M A X 7375 t o c 01

TEMPERATURE (°C)

D U T Y C Y C L

E (%)

110956580-105203550-2547484950515253545545

-40125

DUTY CYCLE vs. SUPPLY VOLTAGE

M A X 7375 t o c 02

SUPPLY VOLTAGE (V)

D U T Y C Y C L

E (%)

4.8

4.1

3.4

47

49

51

535545

2.7

5.5

SUPPLY CURRENT vs. TEMPERATURE

TEMPERATURE (°C)

S U P P L Y C U R R E N T (m A )

110956580-105203550-250.5

1.01.5

2.02.5

3.03.5

4.0

-40125

SUPPLY CURRENT vs. SUPPLY VOLTAGE

M A X 7375 t o c 04

SUPPLY VOLTAGE (V)S U P P L Y C U R R E N T (m A )

4.8

4.1

3.4

2.02.5

3.03.5

4.01.0

1.5

2.7

5.5FREQUENCY vs. SUPPLY VOLTAGE

M A X 7375 t o c 05

SUPPLY VOLTAGE (V)N O R M A L I Z E D F R E Q U E N C Y 4.84.13.40.9940.9960.9981.0001.0020.990

0.9922.7 5.50.980

0.9900.9851.0000.9951.0151.0101.0051.020

-4010-15356085110135

FREQUENCY vs. TEMPERATURE

M A X 7375 t o c 06

TEMPERATURE (°C)

N O R M A L I Z E D F R E Q U E N C Y SETTLING TIME FROM START

MAX7375 toc08

1µs/div

V+2V/div

CLOCK 2V/div

V+ = 3.3V

CLOCK OUTPUT WAVEFORM

WITH C L = 10pF

MAX7375 toc09

40ns/div

CLOCK 1V/div

V+ = 3.3V

Typical Operating Characteristics

(V+ = 5V, T A = +25°C, C L = 10pF, 8MHz output, unless otherwise noted.)

SUPPLY CURRENT vs. FREQUENCY

FREQUENCY (MHz)

S U P P L Y C U R R E N T (m A )

6.5

4.52.5

0.51.01.52.02.53.03.54.0

00.5

8.5

M A X 7375

Detailed Description

The MAX7375 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 MAX7375 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.

Supply Voltages

The MAX7375 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 table for limit values of power-supply and pin voltages.

Oscillator

The clock output is a push-pull configuration and is capable of driving a ground-connected 1k Ωload or a

positive supply connected 500Ωload to within 300mV of either supply rail. The clock output remains stable over the full operating voltage range and does not gen-erate short output cycles during either power on or power off. A typical startup characteristic is shown in the Typical Operating Characteristics section.

Output Jitter

The MAX7375’s jitter performance is given in the Electrical Characteristics table as a peak-to-peak value obtained by observing the output of the MAX7375 for 20s with a 500MHz oscilloscope. J itter measurements are approximately proportional to the period of the out-put frequency of the device. Thus, a 4MHz part has approximately twice the jitter value of an 8MHz part.The jitter performance of all clock sources degrades in the presence of mechanical and electrical interference.The MAX7375 is relatively immune to vibration, shock,and EMI influences and thus provides a considerably more robust clock source than crystal- or ceramic-res-onator-based oscillator circuits.

3-Pin Silicon Oscillator 4_______________________________________________________________________________________

Pin Description

Typical Operating Characteristics (continued)

(V+ = 5V, T A = +25°C, C L = 10pF, 8MHz output, unless otherwise noted.)

CLOCK OUTPUT WAVEFORM

WITH C L = 50pF

MAX7375 toc10

40ns/div

CLOCK 1V/div

V+ = 3.3V

CLOCK OUTPUT WAVEFORM

WITH C L = 100pF

MAX7375 toc11

40ns/div

CLOCK 1V/div

V+ = 3.3V

Applications Information

Interfacing to a Microcontroller Clock

Input

The MAX7375 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 MAX7375.Operate the MAX7375 and microcontroller (or other clock input device) from the same supply voltage level.Refer to the microcontroller data sheet for clock input compatibility with external clock signals.

The MAX7375 requires no biasing components or load capacitance. When using the MAX7375 to retrofit a crystal oscillator, remove all biasing components from the oscillator input.

Startup Performance

The MAX7375 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 MAX7375 until 5µs after the voltage on V+ has risen above 2.7V.

Extended Temperature Operation

The MAX7375 was tested to +135°C during product characterization and shown to function normally at this temperature (see T ypical Operating Characteristics ).However production test and qualification is only per-formed from -40°C to +125°C at this time. Contact the factory if operation outside this range is required.

Power-Supply Considerations

The MAX7375 operates with power-supply voltages in the 2.7V to 5.5V range. Good power-supply decoupling is needed to maintain the power-supply rejection per-formance of the MAX7375. 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 MAX7375 close to the microcontroller’s decoupling capacitor so that additional decoupling is not required.

A larger value of bypass capacitor is recommended if the MAX7375 is to operate with a large capacitive load.Use a bypass capacitor value of at least 1000 times that of the output load capacitance.

MAX7375

3-Pin Silicon Oscillator

_______________________________________________________________________________________5

Selector Guide

Pin Configuration

Chip Information

TRANSISTOR COUNT: 432PROCESS: BiCMOS

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.com/packages .)

M A X 7375

3-Pin Silicon Oscillator 6_______________________________________________________________________________________

MAX7375

3-Pin Silicon Oscillator

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 _____________________7

©2004 Maxim Integrated Products Printed USA

is a registered trademark of Maxim Integrated Products. Package Information (continued)

(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.com/packages.)下载本文