MAXIM MAX7383 User Manual

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General Description

The MAX7383 dual-speed silicon oscillator replaces
ceramic resonators, crystals, and crystal-oscillator
modules as the primary and secondary clock source for
microcontrollers in 3V, 3.3V, and 5V applications. The
MAX7383 features a factory-programmed high-speed
oscillator, a 32.768kHz oscillator, and a clock-selector
input. The clock output can be switched at any time
between the high-speed clock and the 32.768kHz clock
for low-power operation. Switchover is synchronized
internally to provide glitch-free clock switching.

Unlike typical crystal and ceramic-resonator oscillator
circuits, the MAX7383 is resistant to vibration and EMI.
The high-output-drive current and absence of high­impedance nodes makes the oscillator less susceptible
to dirty or humid operating conditions. With a wide
operating temperature range as standard, the
MAX7383 is a good choice for demanding home appli­ance and automotive environments.

The MAX7383 is available with factory-programmed fre­quencies ranging from 10MHz to 32MHz. See Table 1
for standard frequencies and contact the factory for
custom frequencies. Refer to the MAX7377 data sheet
for frequencies less than 10MHz.

The MAX7383 is available in a 5-pin SOT23 package.
The MAX7383 standard operating temperature range is

-40°C to +125°C. See the Applications Information sec­tion for extended operating temperature range.

Applications

White Goods

Automotive

Consumer Products

Appliances and Controls

Handheld Products

Portable Equipment

Microcontroller Systems

Features

♦ 2.7V to 5.5V Operation

♦ High-Speed Oscillator from 10MHz to 32MHz

Low-Speed 32kHz Oscillator
Glitch-Free Clock-Speed Switching

♦ ±10mA Clock-Output Drive Capability

♦ 2.5% Initial Accuracy

♦ ±50ppm/°C (typ) Frequency Drift

♦ 50% Duty Cycle

♦ 5ns Output Rise and Fall Time

♦ Low Jitter: 80ps

P-P

at 16MHz

♦ 4mA Operating Current at 16MHz

♦ 13µA, 32kHz Operating Current

♦ -40°C to +125°C Temperature Range

♦ Small 5-Pin SOT23 Package

MAX7383

Silicon Oscillator with Low-Power

Frequency Switching

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

OSC1

OSC2

µC

GND

CLOCK

E.C.

V

CC

0.1µF

V

CC

2.7V TO 5.5V

MAX7383

I/O PORT

SPEED

Typical Operating Circuit

19-3492; Rev 0; 1/05

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.

*The first two letters are AX. Insert the two-letter code from
Table 2 in the remaining two positions for the desired frequen­cy range. Insert the two-letter code from Table 1 in the remain­ing two positions for the desired frequency range. Table 1 is
located at the end of the data sheet.

Pin Configuration appears at end of data sheet.

PART* TEMP RANGE

MAX7383AX _ _-T -40°C to +125°C 5 SOT23-5

PIN­PACKAGE

RESET

OUTPUT

Active high

push-pull

MAX7383

Silicon Oscillator with Low-Power
Frequency Switching

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

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

All Other Pins to GND...................................-0.3V to (V+ + 0.3V)

CLOCK Current ...............................................................±50mA

Input Current (SPEED)......................................................±50mA

Continuous Power Dissipation (T

A

= +70°C)

5-Pin SOT23 (derate 7.1mW/°C above +70°C)....571mW (U5-2)

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

ELECTRICAL CHARACTERISTICS

(Typical Operating Circuit, VCC= 2.7V to 5.5V, VL= VCC, TA= -40°C to +125°C. Typical values are at VCC= 5.0V, TA= +25°C,
unless otherwise noted.) (Note 1)

Operating Supply Voltage V

Operating Supply Current I

LOGIC INPUTS (SPEED)

Input High Voltage V

Input Low Voltage V

Input Current I

CLOCK OUTPUT

Output High Voltage V

Output Low Voltage V

Fast Clock Frequency Accuracy f

Fast Clock Temperature
Coefficient

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CC

f

= 16MHz, TA = -40°C to +125°C, no

CLOCK

load

f

= 14.7456MHz, TA = -40°C to

CLOCK

+125°C, no load

f

= 12MHz, TA = -40°C to +125°C, no

CLOCK

CC

IN

OH

OL

CLOCK

load

f

= 11.0592MHz, TA = -40°C to

CLOCK

+125°C, no load

f

= 10MHz, TA = -40°C to +125°C, no

CLOCK

load

f

= 32.768kHz, TA = -40°C to

CLOCK

+125°C, no load

IH

IL

VCC SPEED = 5.5V 2 µA

VL = 4.5V, I

VL = 2.7V, I

VL = 4.5V, I

VL = 2.7V, I

VCC = 5V, TA = +25°C, deviation from
selected frequency

VCC = 2.7V to 5.5V, TA = +25°C,
deviation from selected frequency

T

= -40°C to +125°C ±50 ±350 ppm/°C

A

SOURCE

SOURCE

SINK

SINK

2.7 5.5 V

8.7

8.0

6.5

6.0

5.4

13 25 µA

0.7 x V

CC

0.3 x V

CC

= 7.0mA

= 2.0mA

= 20mA

= 10mA

- 0.4 V

V

L

0.4 V

-2.5 +2.5

-5.0 +3.5

mA

V

V

%

MAX7383

Silicon Oscillator with Low-Power

Frequency Switching

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(Typical Operating Circuit, VCC= 2.7V to 5.5V, VL= VCC, TA= -40°C to +125°C. Typical values are at VCC= 5.0V, TA= +25°C,
unless otherwise noted.) (Note 1)

Note 1: All parameters tested at TA= +25°C. Specifications over temperature are guaranteed by design.
Note 2: Guaranteed by design. Not production tested.

Typical Operating Characteristics

(VCC= VL= 5V, TA= +25°C, frequency = 10MHz, unless otherwise noted.)

48.0

48.5

49.5

49.0

50.0

50.5

-55 21-17 59 97 135

DUTY CYCLE vs. TEMPERATURE

MAX7383 toc01

TEMPERATURE (°C)

DUTY CYCLE (%)

FREQUENCY = 10MHz

DUTY CYCLE vs. SUPPLY VOLTAGE

MAX7383 toc02

SUPPLY VOLTAGE (V)

DUTY CYCLE (%)

5.14.74.33.93.53.1

46

47

48

49

50

51

45

2.7 5.5

FREQUENCY = 11.0592MHz

2.90

3.00

2.95

3.10

3.05

3.20

3.15

3.25

-55 21 59-17 97 135

SUPPLY CURRENT vs. TEMPERATURE

MAX7383 toc03

TEMPERATURE (°C)

SUPPLY CURRENT (mA)

FREQUENCY = 10MHz

Slow Clock Frequency f

Slow Clock Temperature
Coefficient

Duty Cycle (Note 2) 40 50 60 %

Output Jitter

Output Rise Time t

Output Fall Time t

Undervoltage Lockout
Threshold

Undervoltage Lockout Hysteresis HYST

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CLOCK

R

F

VCC = 5V, TA = +25°C 32.268 32.768 33.268

VCC = 2.7V to 5.5V, TA = +25°C 31.768 32.768 33.768

= -40°C to +125°C ±50 ±325 ppm/°C

T

A

Observation of 16MHz for 20s using a
500MHz oscilloscope

80 ps

10% to 90% 5 ns

90% to 10% 5 ns

kHz

P-P

TA = +25°C 2.45 2.55

V

TH

VCC rising, deviation
from nominal threshold

= -40°C to

T

A

+125°C

Difference between rising and falling
thresholds

2.37 2.63

1%

%