Silicon Oscillator with Reset Output

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5

Detailed Description

The MAX7376 is a clock generator with integrated reset

for µCs and UARTs in 3V, 3.3V, and 5V applications

(Figure 1). The MAX7376 is a replacement for crystal

oscillator modules, crystals, or ceramic resonators and

a system-reset IC. The clock frequency is factory

trimmed to specific values. A variety of popular stan-

dard frequencies are available (Table 2). No external

components are required for setting or adjusting the

frequency.

Supply Voltage

The MAX7376 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. See the Absolute Maximum Ratings sec-

tion 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 500Ω or a posi-

tive-supply-connected 250Ω load to within 400mV of

either supply rail. The clock output remains stable over

the full operating voltage range and does not generate

short output cycles during either power-on or power-off.

A typical startup characteristic is shown in the Typical

Operating Characteristics.

Applications Information

Interfacing to a µC Clock Input

The MAX7376 clock output is a push-pull, CMOS, logic

output that directly drives any µP or µC clock input.

There are no impedance-matching issues when using

the MAX7376. The MAX7376 is not sensitive to its posi-

tion on the board and it does not need to be placed right

next to the µP. Refer to the µC data sheet for clock-input

compatibility with external clock signals. The MAX7376

requires no biasing components or load capacitance.

When using the MAX7376 to retrofit a crystal oscillator,

remove all biasing components from the oscillator input.

RST Reset Output Options

The MAX7376 is available with three reset output stage

options: push-pull with active-low output, push-pull with

active-high output, and open drain with active-low out-

put. The RST output is asserted when the monitored

remains asserted for 100µs after the monitored input

RST output requires an external pullup resistor.

Output Jitter

The MAX7376’s jitter performance is given in the

Electrical Characteristics table as a peak-to-peak value

obtained by observing the output of the MAX7376 for

20s with a 500MHz oscilloscope. Jitter values are

approximately proportional to the period of the output

frequency of the device. Thus, a 4MHz part has

approximately twice the jitter value of an 8MHz part.

The jitter performance of clock sources degrades in the

presence of mechanical and electrical interference.

Pin Description

PIN

NAME

FUNCTION

1

CLOCK

Push-Pull Clock Output

2

GND

Ground

3

RST

Reset Output. See the RST Reset Output Options section for more details.

5

E.C.

LOGIC

600kHz TO 10MHz

POR

MUX

RST/RST

CLOCK

BIAS_V

MAX7376

Figure 1. Functional Diagram