power-on reset cycle. The MAX7378 reset circuit fea-

tures internal hysteresis that creates two trip points: one

for rising supply voltage and one for falling supply volt-

age. The standard threshold values (see Table 1) are

the trip points for rising supply voltage. The trip point

for falling supply voltage is calculated by subtracting

the hysteresis value from the rising supply trip point.

The hysteresis prevents the reset output from oscillat-

(see Maximum Transient Duration vs. Reset Threshold

in the Typical Operating Characteristics).

Extended Temperature Operation

The MAX7378 was tested to +135°C during product

characterization and shown to function normally at

this temperature (see the Typical Operating Characteris-

tics). However, production test and qualification is only

performed from -40°C to +125°C at this time. Contact the

factory if operation outside this range is required.

Power-Supply Considerations

The MAX7378 operates with a 2.7V and 5.5V power-

cuits. Good power-supply decoupling is needed to

maintain the power-supply rejection performance of the

0.1µF surface-mount ceramic capacitor. Mount the

bypassing capacitors as close to the device as possi-

ble. If possible, mount the MAX7378 close to the µC’s

decoupling capacitor so that additional decoupling is

not required. A larger value bypass capacitor is recom-

mended if the MAX7378 is to operate with a large

capacitive load. Use a bypass capacitor value of at

least 1000 times that of the output load capacitance.

Silicon Oscillator with Low-Power

Frequency Switching and Reset Output

8

_______________________________________________________________________________________

Pin Configuration

TOP VIEW

1

2

3

4

8

7

6

5

N.C.

ENABLE

GND

CLOCK

RST

SPEED

MAX7378

µMAX

SUFFIX

RESET THRESHOLD (V)

R

2.57

M

4.29

SUFFIX

STANDARD FREQUENCY (MHz)

MG

1

OK

1.8432

QT

3.39545

QW

3.6864

RD

4

RH

4.1943

TP

8

Table 1. Standard Reset Threshold Levels

Table 2. Standard Frequencies

For all other reset threshold options, contact the factory.

For all other frequency options, contact the factory.