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 Typical 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.

3-Pin Silicon Oscillator

_______________________________________________________________________________________

5

PART

FREQUENCY (MHz)

TOP MARK

MAX7375AXR105

1.00

AOV

MAX7375AXR185

1.84

AOU

MAX7375AXR365

3.58

AOT

MAX7375AXR375

3.69

AOS

MAX7375AXR405

4.00

AOR

MAX7375AXR425

4.19

AOQ

MAX7375AXR805

8.00

AOP

MAX7375AUR105

1.00

FZPZ

MAX7375AUR185

1.84

FZPT

MAX7375AUR365

3.58

FZPU

MAX7375AUR375

3.69

FZPV

MAX7375AUR405

4.00

FZPY

MAX7375AUR425

4.19

FZPW

MAX7375AUR805

8.00

FZPX

Selector Guide

CLOCK

1

3

GND

V+

MAX7375AXR

SC70

TOP VIEW

2V+

1

3

GND

CLOCK

MAX7375AUR

SOT23

2

Pin Configuration

Chip Information

TRANSISTOR COUNT: 432

PROCESS: BiCMOS