19-3491; Rev 1; 3/07
Silicon Oscillator with Reset Output
and Enable
The MAX7382 silicon oscillator replaces ceramic resonators, crystals, and crystal-oscillator modules as the
clock source for microcontrollers in 3V, 3.3V, and 5V
applications. The MAX7382 features a factory-programmed oscillator, a microprocessor (µP) power-onreset (POR) supervisor, and a clock enable input.
Unlike typical crystal and ceramic-resonator oscillator
circuits, the MAX7382 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, the MAX7382 is a good
choice for demanding home appliance and automotive
environments.
The MAX7382 is available with factory-programmed frequencies ranging from 10MHz to 16MHz. See Table 2
for standard frequencies and contact the factory for
custom frequencies and POR thresholds.
The MAX7382 is available in a 5-pin SOT23 package.
The MAX7382 operating temperature range is -40°C to
+125°C.
Applications
White Goods
Features
♦ 2.7V to 5.5V Operation
♦ 10MHz to 16MHz Oscillator
♦ Integrated POR (Factory Programmable)
♦ ±10mA Clock Output Drive Capability
♦ Clock Enable Input
♦ 2.5% Initial Accuracy
♦ ±100ppm/°C Frequency Drift
♦ 50% Duty Cycle
♦ 5ns Output Rise and Fall Time
♦ Typical 4.5mA Operating Current at 16MHz
♦ Typical 0.5µA Shutdown Supply Current
♦ -40°C to +125°C Temperature Range
♦ Small 5-Pin SOT23 Package
Ordering Information
PART*
TEMP RANGE
PINPACKAGE
RESET
OUTPUT
Automotive
Active-low
MAX7382B_ _ _-T -40°C to +125°C 5 SOT23-5 push-pull
Consumer Products
MAX7382C_ _ _-T -40°C to +125°C 5 SOT23-5 Open drain
Appliances and Controls
*Standard version is shown in bold. The first letter after the part
number designates the reset output option. Insert the letter
corresponding to the desired reset threshold level from Table 1
in the next position. Insert the two-letter code from Table 2 in
the remaining two positions for the desired frequency range.
Table 1 and Table 2 are located at the end of the data sheet.
Handheld Products
Portable Equipment
Microcontroller Systems
Typical Operating Circuit
VCC 2.7V TO 5.5V
0.1µF
VCC
CLOCK
OSC1
OSC2
MAX7382
ENABLE
RST
RST
µC
GND
Pin Configuration appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX7382
General Description
MAX7382
Silicon Oscillator with Reset Output
and Enable
ABSOLUTE MAXIMUM RATINGS
VCC to GND ...........................................................-0.3V to +6.0V
All Other Pins to GND.................................-0.3V to (VCC + 0.3V)
CLOCK, RST Current .......................................................±50mA
Input Current (ENABLE) ...................................................±50mA
Continuous Power Dissipation (TA = +70°C)
5-Pin SOT23 (derate 7.1mW/°C above +70°C) ....571mW (U5-2)
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
ELECTRICAL CHARACTERISTICS
(Typical Operating Circuit, VCC = 3.0V to 5.5V, TA = -40°C to +125°C. Typical values are at VCC = 5.0V, TA = +25°C, unless otherwise noted.) (Notes 1 and 2)
PARAMETER
Operating Supply Voltage
Operating Supply Current
Shutdown Supply Current
SYMBOL
CONDITIONS
VCC
ICC
ISHDN
MIN
TYP
2.7
MAX
UNITS
5.5
V
fCLOCK = 16MHz, VCC = 5.5V, no load
8.7
fCLOCK = 14MHz, VCC = 5.5V, no load
8.0
fCLOCK = 12MHz, VCC = 5.5V, no load
6.5
fCLOCK = 11MHz, VCC = 5.5V, no load
6.0
fCLOCK = 10MHz, VCC = 5.5V, no load
5.4
ENABLE = 0V
0.5
1
mA
µA
LOGIC INPUTS (ENABLE)
Input High Voltage
VIH
Input Low Voltage
VIL
Input Current
IIN
0.7 x
VCC
V
VCC = VENABLE = 5.5V
0.3 x
VCC
V
2
µA
CLOCK OUTPUT
VCC = 4.5V, ISOURCE = 7.0mA
Output High Voltage
VOH
Output Low Voltage
VOL
Clock Frequency Accuracy
Clock Temperature Coefficient
2
fCLOCK
VCC = 3.0V, ISOURCE = 2.0mA for
MAX7382xSxx
VCC 0.4
V
VCC = 4.5V, ISINK = 20mA
0.4
VCC = 3.0V, ISINK = 10mA
VCC = 5V (for MAX7382xMxx) or VCC = 3.3V
(for MAX7382xSxx), TA = +25°C, deviation
from nominal frequency
-2.5
VCC = 3.0V to 5.5V, TA = +25°C, deviation
from nominal frequency
-5.0
(Note 3)
V
+2.5
%
+3.5
±100
_______________________________________________________________________________________
±550
ppm/°C
Silicon Oscillator with Reset Output
and Enable
(Typical Operating Circuit, VCC = 3.0V to 5.5V, TA = -40°C to +125°C. Typical values are at VCC = 5.0V, TA = +25°C, unless otherwise noted.) (Notes 1 and 2)
PARAMETER
SYMBOL
Duty Cycle
CONDITIONS
(Note 3)
MIN
TYP
MAX
UNITS
40
50
60
%
Output Period Jitter
JP
fOUT = 16MHz; ±6σ period jitter
±240
ps
Output Rise Time
tR
10% to 90%, CL = 10pF
5
ns
Output Fall Time
tF
90% to 10%, CL = 10pF
5
ns
Power-On-Reset Threshold
Accuracy
VCC rising, deviation
from nominal
threshold (VTH)
(Table 1)
Power-On-Reset Hysteresis
Difference between rising and falling
thresholds
Power-On-Reset Delay
PORdly
TA = +25°C
-2
+2
-5
+5
%
VCC rising from 0 to 5V in 1µs at +25°C
1
%
122
µs
RESET OUTPUT (RST)
VCC = 4.5V, ISOURCE = 7.0mA
(MAX7382xMxx)
Output High Voltage (Note 4)
Output Low Voltage
Note 1:
Note 2:
Note 3:
Note 4:
VOH
VOL
VCC = 3.0V, ISOURCE = 2.0mA
(MAX7382xSxx)
VCC 0.4
VCC = 4.5V, ISINK = 20mA (MAX7382xMxx)
VCC = 3.0V, ISINK = 10mA (MAX7382xSxx)
V
0.4
V
All parameters tested at TA = +25°C. Specifications over temperature are guaranteed by design.
Oscillator is enabled when VCC > VTH.
Guaranteed by design. Not production tested.
For push-pull output only.
_______________________________________________________________________________________
3
MAX7382
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(VCC = VENABLE = 5V, TA = +25°C, frequency = 10MHz, unless otherwise noted.)
DUTY CYCLE
vs. SUPPLY VOLTAGE
FREQUENCY = 10MHz
49.0
48.5
MAX7382 toc02
3.25
3.20
SUPPLY CURRENT (mA)
49.5
FREQUENCY = 11MHz
50
DUTY CYCLE (%)
49
48
47
46
45
48.0
-55
-17
21
59
97
3.10
FREQUENCY = 10MHz
3.05
3.00
2.90
2.7
135
3.15
2.95
3.1
3.5
3.9
4.3
4.7
5.1
5.5
-55
-17
21
59
97
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
FREQUENCY DEVIATION
vs. SUPPLY VOLTAGE
FREQUENCY DEVIATION
vs. TEMPERATURE
3.0
2.5
FREQUENCY = 11MHz
1.5
1.0
0.5
0
-0.5
-1.0
135
4
MAX7382 toc06
3.5
2.0
FREQUENCY = 10MHz
3
FREQUENCY DEVIATION (%)
FREQUENCY = 11MHz
FREQUENCY DEVIATION (%)
MAX7382 toc04
4.0
MAX7382 toc05
DUTY CYCLE (%)
50.0
SUPPLY CURRENT vs. TEMPERATURE
51
MAX7382 toc01
50.5
MAX7382 toc03
DUTY CYCLE vs. TEMPERATURE
SUPPLY CURRENT (mA)
MAX7382
Silicon Oscillator with Reset Output
and Enable
2
1
0
-1
-2
2.0
-3
-1.5
-4
-2.0
1.5
2.7
3.1
3.5
3.9
4.3
4.7
5.1
2.7
5.5
3.1
3.5
3.9
4.3
4.7
5.1
-55
5.5
-17
21
59
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
SETTLING TIME FROM START
CLOCK OUTPUT WAVEFORM
(CL = 10pF)
CLOCK OUTPUT WAVEFORM
(CL = 10pF)
CH1 FREQ
9.992MHz
LOW RESOLUTION
CH2
2V/div
2V/div
2V/div
CH1
2V/div
10µs/div
135
MAX7382 toc09
MAX7382 toc08
MAX7382 toc07
20ns/div
20ns/div
CHANNEL 1 = CLOCK, CHANNEL 2 = VCC
4
97
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
Silicon Oscillator with Reset Output
and Enable
CLOCK OUTPUT WAVEFORM
(CL = 100pF)
MAXIMUM TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
MAX7382 toc11
0.1
10m
1m
100µ
VRESET = 4.32V
4
3
2
10µ
1µ
0.04
20ns/div
5
SUPPLY CURRENT (mA)
2V/div
MAXIMUM TRANSIENT DURATION (s)
1
SUPPLY CURRENT
vs. FREQUENCY
MAX7382 toc12
MAX7382 toc10
1
0.09
0.14
0.19
0.24
10
11
12
RESET THRESHOLD OVERDRIVE (V)
13
14
15
16
FREQUENCY (MHz)
Pin Description
PIN
NAME
1
CLOCK
FUNCTION
2
GND
Push-Pull Clock Output
Ground
3
RST
Reset Output. Open-drain or push-pull output. See the Ordering Information.
4
VCC
Positive Supply Voltage. Bypass VCC to GND with a 0.1µF capacitor.
5
ENABLE
Active High Clock Enable Input. See the ENABLE Input section for more details.
Detailed Description
The MAX7382 is a clock generator with integrated reset
for microcontrollers (µCs) and UARTs in 3V, 3.3V, and
5V applications. The MAX7382 is a replacement for
crystal-oscillator modules, crystals, or ceramic resonators, and a system reset IC. The clock frequency
and reset threshold voltage are factory trimmed to specific values (see Tables 1 and 2). A variety of popular
standard frequencies are available. No external components are required for setting or adjusting the frequency.
Oscillator
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.
ENABLE Input
The MAX7382 has an active-high enable input that controls the clock and reset outputs. The clock output is
driven low and RST asserts when the device is disabled. Drive ENABLE low to disable the clock output on
next rising edge. Drive ENABLE high to activate the
clock output.
The push-pull clock output is enabled when VCC > VTH
(Table 1) and drives a load to within 400mV of either
supply rail. The clock output remains stable over the full
_______________________________________________________________________________________
5
MAX7382
Typical Operating Characteristics (continued)
(VCC = VENABLE = 5V, TA = +25°C, frequency = 10MHz, unless otherwise noted.)
MAX7382
Silicon Oscillator with Reset Output
and Enable
Applications Information
Interfacing to a Microcontroller
Clock Input
The MAX7382 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
MAX7382. Refer to the microcontroller data sheet for
clock input compatibility with external clock signals.
The MAX7382 requires no biasing components or load
capacitance. When using the MAX7382 to retrofit a
crystal oscillator, remove all biasing components from
the oscillator input.
Table 1. Standard Reset Threshold
Levels
SUFFIX
S
M
RESET THRESHOLD (V)
2.89 standard value
4.38 standard value
Contact factory for nonstandard reset threshold options from
2.5V < VTH < 4.38V.
Table 2. Standard Frequencies
SUFFIX
STANDARD FREQUENCY (MHz)
Reset Output
UK
10
The MAX7382 is available with two reset output stage
options: push-pull active-low and open-drain active-low.
RST is asserted when the monitored input (VCC) drops
below the internal VTH threshold and remains asserted
for 120µs after the monitored input exceeds the internal
VTH threshold. The open-drain RST output requires an
external pullup resistor.
UT
11
VB
12
VT
14
WB
16
Output Jitter
The MAX7382’s jitter performance is given in the
Electrical Characteristics table as a ±6σ period jitter
value. Jitter measurements are approximately proportional to the period of the output of the device. The jitter
performance of all clock sources degrades in the presence of mechanical and electrical interference. The
MAX7382 is relatively immune to vibration, shock, and
EMI influences and thus provides a considerably more
robust clock source than crystal or ceramic resonatorbased oscillator circuits.
VCC 2.7V TO 5.5V
Table 3. Standard Part Numbers
PART
RESET
THRESHOLD
(V)
FREQUENCY
(MHz)
TOP
MARK
MAX7382CSUK
MAX7382CSUT
MAX7382CSVB
MAX7382CSVT
MAX7382CSWB
MAX7382CMUK
MAX7382CMUT
MAX7382CMVB
MAX7382CMVT
MAX7382CMWB
2.89
2.89
2.89
2.89
2.89
4.38
4.38
4.38
4.38
4.38
10
11
12
14
16
10
11
12
14
16
AEVU
AEYG
AEVM
AEYI
AEVK
AEXV
AEXW
AEVJ
AEXX
AEVH
Initial Power-Up and Operation
MAX7382
POR
ENABLE
For all other frequency options, contact factory.
OSCILLATOR
LOGIC
GND
RST
CLOCK
An internal power-up reset holds the clock output low
and asserts RST until the supply voltage has risen
above the power-on- reset threshold (VTH).
RST holds the microcontroller in a reset condition until
120µs after the clock has started up. This reset delay
ensures that the clock output and the microcontroller’s
internal clock circuits have stabilized before the system
is allowed to start. Typical microcontroller reset delay
ranges from 1ms to 250ms to allow a slow crystal oscillator circuit to start up. The MAX7382 has a fast startup,
eliminating the need for such a long reset delay.
Figure 1. Functional Diagram
6
_______________________________________________________________________________________
Silicon Oscillator with Reset Output
and Enable
Pin Configuration
TOP VIEW
CLOCK
1
GND 2
5
ENABLE
4
VCC
MAX7382
RST 3
SOT23
Chip Information
PROCESS: BiCMOS
_______________________________________________________________________________________
7
MAX7382
Power-Supply Considerations
The MAX7382 operates with a 2.7V and 5.5V powersupply voltage. Good power-supply decoupling is
needed to maintain the power-supply rejection performance of the MAX7382. Bypass VCC to GND with a
0.1µF surface-mount ceramic capacitor. Mount the
bypassing capacitor as close to the device as possible.
If possible, mount the MAX7382 close to the microcontroller’s decoupling capacitor so that additional decoupling is not required. Use a larger value of bypass
capacitor recommended if the MAX7382 is to operate
with a large capacitive load. Use a bypass capacitor
value of at least 1000 times that of the output load
capacitance.
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
MAX7382
Silicon Oscillator with Reset Output
and Enable
Revision History
Pages changed at Rev 1: 1–8
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
© 2007 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
