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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
Page 2
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
%
Page 3
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%
%
Page 4
MAX7383
Silicon Oscillator with Low-Power
Frequency Switching
4 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VCC= VL= 5V, TA= +25°C, frequency = 10MHz, unless otherwise noted.)
CLOCK OUTPUT WAVEFORM
(C
L
= 100pF)
MAX7383 toc10
20ns/div
SUPPLY CURRENT vs. FREQUENCY
MAX7383 toc11
FREQUENCY (MHz)
SUPPLY CURRENT (mA)
1514131211
2
3
4
5
1
10 16
CHANNEL 1 = CLOCK, CHANNEL 2 = SPEED
10µs/div
HIGH-SPEED TO LOW-SPEED
TRANSITION
MAX7383 toc12
SUPPLY CURRENT vs. SUPPLY VOLTAGE
4.0
FREQUENCY = 11.0592MHz
3.5
3.0
2.5
SUPPLY CURRENT (mA)
2.0
1.5
2.7 5.5
SUPPLY VOLTAGE (V)
5.14.74.33.93.53.1
2.0
1.5
MAX7383 toc04
1.0
0.5
0
-0.5
-1.0
FREQUENCY DEVIATION (%)
-1.5
-2.0
FREQUENCY DEVIATION
vs. SUPPLY VOLTAGE
FREQUENCY = 11.0592MHz
2.7 5.5
SUPPLY VOLTAGE (V)
5.14.73.1 3.5 3.9 4.3
4
MAX7383 toc05
3
2
1
0
-1
-2
FREQUENCY DEVIATION (%)
-3
-4
-55 135
FREQUENCY DEVIATION
vs. TEMPERATURE
FREQUENCY = 10MHz
MAX7383 toc06
9759-17 21
TEMPERATURE (°C)
SETTLING TIME FROM START
CHANNEL 1 = CLOCK, CHANNEL 2 = V
10µs/div
MAX7383 toc07
CH1 FREQ
9.992MHz
LOW RESOLUTION
CC
CLOCK OUTPUT WAVEFORM
= 10pF)
(C
L
20ns/div
MAX7383 toc08
CLOCK OUTPUT WAVEFORM
= 10pF)
(C
L
20ns/div
MAX7383 toc09
Page 5
MAX7383
Silicon Oscillator with Low-Power
Frequency Switching
_______________________________________________________________________________________ 5
Typical Operating Characteristics (continued)
(VCC= VL= 5V, TA= +25°C, frequency = 10MHz, unless otherwise noted.)
Pin Description
HIGH-SPEED TO LOW-SPEED
TRANSITION (DETAIL ZOOM)
40ns/div
CHANNEL 1 = CLOCK, CHANNEL 2 = SPEED
MAX7383 toc13
LOW-SPEED TO HIGH-SPEED
TRANSITION
10µs/div
CHANNEL 1 = CLOCK, CHANNEL 2 = SPEED
MAX7383 toc14
LOW-SPEED TO HIGH-SPEED
TRANSITION (DETAIL ZOOM)
100ns/div
CHANNEL 1 = CLOCK, CHANNEL 2 = SPEED
MAX7383 toc15
PIN NAME FUNCTION
1 CLOCK Push-Pull Clock Output
2 GND Ground
3 SPEED
4VCCPositive Supply Voltage. Bypass VCC to GND with a 0.1µF capacitor.
5 E.C. Externally Connected. Connect to Vcc.
Clock Speed Select Input. Drive SPEED low to select the 32kHz fixed frequency. Drive SPEED high to
select the factory-trimmed frequency.
Page 6
MAX7383
Detailed Description
The MAX7383 is a dual-speed clock generator for
microcontrollers (µCs) and UARTs in 3V, 3.3V, and 5V
applications. The MAX7383 is a replacement for two
crystal-oscillator modules, crystals, or ceramic resonators. The high-speed clock frequency is factory
trimmed to specific values. A variety of popular standard frequencies are available. The low-speed clock
frequency is fixed at 32.768kHz. See Table 1. No exter-
nal components are required for setting or adjusting the
frequency.
Oscillator
The push-pull clock output drives a 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 changing of the frequency. A typical oscillating startup is shown in the Typical Operating Characteristics.
Clock-Speed Selection
Drive SPEED low to select slow clock speed (nominally
32.768kHz) or high to select full clock speed. SPEED can
be connected to VCCor to GND to select fast or slow
clock speed, or connected to a logic output (such as a
µP GPIO port) used to change clock speed on the fly. If
SPEED is connected to a µP GPIO port, connect a pullup
or pulldown resistor to set the clock to the preferred
speed on power-up. SPEED input bias current is 2µA
max, so a resistor value as high as 500kΩ can be used.
Applications Information
Interfacing to a Microcontroller
Clock Input
The MAX7383 clock output is a push-pull, CMOS, logic
output that directly drives a µP or µC clock input. There
are no impedance-matching issues when using the
MAX7383. Refer to the microcontroller data sheet for
clock input compatibility with external clock signals.
The MAX7383 requires no biasing components or load
capacitance. When using the MAX7383 to retrofit a
crystal oscillator, remove all biasing components from
the oscillator input.
Output Jitter
The MAX7383’s jitter performance is given in the
Electrical Characteristics table as a peak-to-peak value
obtained by observing the output of the MAX7383 for
20s with a 12GHz oscilloscope. Jitter measurements
are approximately proportional to the period of the output of the device. Thus, a 10MHz device has approximately twice the jitter value of a 20MHz device. The
jitter performance of all clock sources degrades in the
presence of mechanical and electrical interference.
The MAX7383 is relatively immune to vibration, shock,
and EMI influences and thus provides a considerably
Silicon Oscillator with Low-Power
Frequency Switching
6 _______________________________________________________________________________________
Figure 1. Functional Diagram
Table 1. Standard Frequencies
For all other frequency options, contact factory.
Table 2. Standard Part Numbers
*Contact factory for availability.
V
CC
MAX7383
32kHz
(LF OSCILLATOR)
SPEED
LOGIC
10MHz TO
32MHz
(HF OSCILLATOR)
GND
UVLO
MUX
CLOCK
SUFFIX STANDARD FREQUENCY (MHz)
UK 10
UT 11.0592
VB 12
VT 14.7456
WB 16
YN 32
PART
MAX7383AXUK 10 AEVN
MAX7383AXUT 11.0592 AEVO
MAX7383AXVB 12 AEVP
MAX7383AXVT 14.7456 AEVQ
MAX7383AXWB 16 AEVT
MAX7383AXYN* 32 AEVS
FREQUENCY
(MHz)
TOP MARK
Page 7
more robust clock source than crystal or ceramic resonator-based oscillator circuits.
Initial Power-Up and Operation
An internal-undervoltage lockout function holds the
clock output low until the supply voltage has risen
above 2.5V. The clock output then starts at the frequency selected by SPEED.
Extended Temperature Operation
The MAX7383 was tested to +135°C during product characterization and shown to function normally at this temperature (see the Typical Operating Characteristics).
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 MAX7383 operates with power-supply voltages
from 2.7V and 5.5V. Good power-supply decoupling is
needed to maintain the power-supply rejection performance of the MAX7383. Bypass VCCto GND with a
0.1µF surface-mount ceramic capacitor. Mount the
bypassing capacitor as close to the device as possible.
Use a larger value of bypass capacitor recommended
if the MAX7383 is to operate with a large capacitive
load. Use a bypass capacitor value of at least 1000
times that of the output load capacitance.
Chip Information
TRANSISTOR COUNT: 2937
PROCESS: BiCMOS
MAX7383
Silicon Oscillator with Low-Power
Frequency Switching
_______________________________________________________________________________________ 7
Pin Configuration
TOP VIEW
1 5 E.C.CLOCK
MAX7383
2
GND
SPEED
34
SOT23
V
CC
Page 8
Silicon Oscillator with Low-Power
Frequency Switching
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.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.
MAX7383
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
.)
SOT-23 5L .EPS
PACKAGE OUTLINE, SOT-23, 5L
1
21-0057
E
1
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