The MAX7375 is a silicon oscillator, intended as a low-cost
improvement replacing ceramic resonators, crystals, and
crystal oscillator modules used as the clock source for micro-
controllers and UARTs in 3V, 3.3V, and 5V applications.
The MAX7375 is a fully integrated oscillator, supplied at
specific factory-trimmed frequencies with a rail-to-rail 50%
duty cycle square-wave output. The oscillator frequency is
generated directly without the use of a phase-locked loop
(PLL). No additional components are used to set or adjust
the frequency.
Unlike typical crystal and ceramic resonator oscillator circuits,
the MAX7375 is highly resistant to vibration and EMI. The
high output drive current and absence of high-impedance
nodes also makes the oscillator less susceptible to dirty
or humid operating conditions. With a wide operating tem-
perature range, the oscillator is a good choice for demanding
home appliance environments.
Available in 3-pin space-saving SC70 package, the
MAX7375 is offered in standard and nonstandard factory-
set frequencies ranging from 600kHz to 9.99MHz. See
the MAX7381 data sheet for frequencies ≥ 10MHz. The
MAX7375’s standard operating temperature range is
-40°C to +125°C. See the
Applications Information
sec-
tion for extended operating temperature range.
Features
●
2.7V to 5.5V Operation
●
Factory-Trimmed Oscillator (600kHz to 9.99MHz)
●
No External Components Required
●
±10mA Output Drive Current
●
2% Initial Accuracy
●
±50ppm/°C Temp Drift
●
Fast Startup Time: 5µs
●
40% to 60% Maximum Duty Cycle
●
5ns Output Rise and Fall Time-Low EMI
●
Very Low EMI Susceptibility-No High-Impedance
Nodes
●
Very Low Jitter: 160ps
P-P
at 8MHz
●
Tiny Surface-Mount Package (SC70)
●
-40°C to +125°C Temperature Range
Ordering Information
PART
MAX7375AXR105-T
MAX7375AXR185-T
MAX7375AXR365-T
MAX7375AXR375-T
MAX7375AXR405-T
MAX7375AXR425-T
MAX7375AXR805-T
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
3 SC70-3
3 SC70-3
3 SC70-3
3 SC70-3
3 SC70-3
3 SC70-3
3 SC70-3
Applications
●
White Goods
●
Appliances and Controls
●
Hand-Held Products
●
Portable Equipment
●
Microcontroller Systems
Typical Application Circuit
2.7V TO 5.5V
V+
CLOCK
OSC1
µC
MAX7375
GND
OSC2
Note:
The MAX7375 is available in factory-set frequencies
from 600kHz to 9.99MHz. There are seven standard versions
(1MHz, 1.84MHz, 3.58MHz, 3.69MHz, 4MHz, 4.19MHz, and
8MHz, as shown in the Selector Guide) with a required 2.5k
order increment. Nonstandard frequencies are also available
with a required 10k order increment. For nonstandard versions,
contact factory for availability and ordering information. All ver-
sions available in tape-and-reel only.
Pin Configuration and Selector Guide appear at end of data
sheet.
19-3060; Rev 4; 4/14
MAX7375
3-Pin Silicon Oscillator
Absolute Maximum Ratings
V+ to GND ...............................................................-0.3V to +6V
CLOCK to GND ...........................................-0.3V to (V+ + 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
3-Pin SC70 (derate 2.9mW/°C over +70°C)................235mW
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
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
(V+ = 2.7V to 5.5V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at V+ = 5V, T
A
= +25°C, unless otherwise noted.)
(Note 1)
PARAMETER
Operating Supply Voltage
SYMBOL
V+
MAX7375A_R105
Operating Supply Current
I+
MAX7375A_R185
MAX7375A_R405
MAX7375A_R805
Output High Voltage
Output Low Voltage
V
OH
V
OL
V+ ≥ 2.7V, I
SOURCE
= 2.5mA
V+ ≥ 4.5V, I
SOURCE
= 9mA
V+ ≥ 2.7, I
SINK
= 10mA
V+ ≥ 4.5V, I
SINK
= 20mA
V+ = 3.0V,
T
A
= +25°C (Note 2)
V+ = 2.7V to 5.5V,
T
A
= +25°C (Note 2)
(Note 3)
(Note 3)
Observation for 20s using a 500MHz
oscilloscope (MAX7375A_R805)
t
R
t
F
(Note 3)
(Note 3)
45
MAX7375A_R_ _ _
MAX7375A_R_ _ _
-2
-4
±50
52
160
5.0
2.5
V+ - 0.4
V+ - 0.4
0.4
0.4
+2
%
+4
±325
57
ppm/°C
%
ps
P-P
ns
ns
CONDITIONS
MIN
2.7
0.55
0.8
1.7
3.2
TYP
MAX
5.5
1.1
1.25
4.2
6.4
V
V
mA
UNITS
V
Initial CLOCK Frequency
Accuracy
CLOCK Frequency Temperature
Sensitivity
Duty Cycle
Output Jitter
Output Rise Time
Output Fall Time
f
CLOCK
Note 1:
All parameters are tested at T
A
= +25°C. Specifications over temperature are guaranteed by design and characterization.
Note 2:
Typical frequencies are nominal values.
Note 3:
Guaranteed by design and characterization. Not production tested.
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MAX7375
3-Pin Silicon Oscillator
Typical Operating Characteristics
(V+ = 5V, T
A
= +25°C, C
L
= 10pF, 8MHz output, unless otherwise noted.)
MAX7375 toc01
MAX7375 toc02
54
53
DUTY CYCLE (%)
52
51
50
49
48
47
46
45
SUPPLY CURRENT (mA)
53
DUTY CYCLE (%)
51
49
47
45
3.5
3.0
2.5
2.0
1.5
1.0
0.5
V+ = 2.7V
V+ = 5V
V+ = 3.3V
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
2.7
3.4
4.1
4.8
5.5
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
MAX7375 toc04
MAX7375 toc05
NORMALIZED FREQUENCY
NORMALIZED FREQUENCY
3.5
SUPPLY CURRENT (mA)
3.0
2.5
2.0
1.5
1.0
1.000
0.998
0.996
0.994
0.992
0.990
1.015
1.010
1.005
1.000
0.995
0.990
0.985
2.7
3.4
4.1
4.8
5.5
2.7
3.4
4.1
4.8
5.5
0.980
-40
-15
10
35
60
85
110
135
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
3.5
SUPPLY CURRENT (mA)
3.0
2.5
2.0
1.5
1.0
0.5
0
0.5
2.5
V+ = 5.5V
MAX7375 toc07
4.0
SUPPLY CURRENT vs. FREQUENCY
SETTLING TIME FROM START
MAX7375 toc08
CLOCK OUTPUT WAVEFORM
WITH CL = 10pF
MAX7375 toc09
CLOCK
2V/div
CLOCK
1V/div
V+ = 3.3V
V+ = 5V
V+
2V/div
V+ = 2.7V
4.5
FREQUENCY (MHz)
6.5
8.5
1µs/div
V+ = 3.3V
40ns/div
V+ = 3.3V
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MAX7375 toc06
4.0
SUPPLY CURRENT vs. SUPPLY VOLTAGE
1.002
FREQUENCY vs. SUPPLY VOLTAGE
1.020
FREQUENCY vs. TEMPERATURE
MAX7375 toc03
55
DUTY CYCLE vs. TEMPERATURE
55
DUTY CYCLE vs. SUPPLY VOLTAGE
4.0
SUPPLY CURRENT vs. TEMPERATURE
MAX7375
3-Pin Silicon Oscillator
Typical Operating Characteristics (continued)
(V+ = 5V, T
A
= +25°C, C
L
= 10pF, 8MHz output, unless otherwise noted.)
CLOCK OUTPUT WAVEFORM
WITH C
L
= 50pF
MAX7375 toc10
CLOCK OUTPUT WAVEFORM
WITH C
L
= 100pF
MAX7375 toc11
CLOCK
1V/div
CLOCK
1V/div
V+ = 3.3V
40ns/div
40ns/div
V+ = 3.3V
Pin Description
PIN
SC70
1
2
3
NAME
V+
CLOCK
GND
Positive Supply Voltage
Clock Output. Output is push-pull.
Ground
FUNCTION
Detailed Description
The MAX7375 is a replacement for ceramic resonators,
crystals, and crystal oscillator modules as the clock
source for microcontrollers and UARTs in 3V, 3.3V, and
5V applications. The MAX7375 is an integrated oscilla-
tor, supplied at specific frequencies just like crystals and
resonators. A variety of popular standard frequencies are
available. No external components are required for setting
or adjusting the frequency.
supply connected 500Ω load to within 300mV of either
supply rail. The clock output remains stable over the full
operating voltage range and does not generate short out-
put cycles during either power on or power off. A typical
startup characteristic is shown in the
Typical Operating
Characteristics
section.
Output Jitter
Supply Voltages
The MAX7375 has been designed for use in systems with
nominal supply voltages of 3V, 3.3V, or 5V and is speci-
fied for operation with supply voltages in the 2.7V to 5.5V
range. Operation outside this range is not guaranteed.
See the
Absolute Maximum Ratings
table for limit values
of power-supply and pin voltages.
The MAX7375’s jitter performance is given in the
Electrical
Characteristics
table as a peak-to-peak value obtained
by observing the output of the MAX7375 for 20s with a
500MHz oscilloscope. Jitter measurements are approxi-
mately 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 all clock sources degrades in the
presence of mechanical and electrical interference. The
MAX7375 is relatively immune to vibration, shock, and
EMI influences and thus provides a considerably more
robust clock source than crystal- or ceramic-resonator-
based oscillator circuits.
Oscillator
The clock output is a push-pull configuration and is capa-
ble of driving a ground-connected 1kΩ load or a positive
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MAX7375
3-Pin Silicon Oscillator
Applications Information
Interfacing to a Microcontroller Clock Input
The MAX7375 clock output is a push-pull, CMOS, logic
output, which directly drives any microprocessor (µP) or
microcontroller (µC) clock input. There are no impedance-
matching issues when using the MAX7375. Operate
the MAX7375 and microcontroller (or other clock input
device) from the same supply voltage level. Refer to the
microcontroller data sheet for clock input compatibility
with external clock signals.
The MAX7375 requires no biasing components or load
capacitance. When using the MAX7375 to retrofit a crys-
tal oscillator, remove all biasing components from the
oscillator input.
Extended Temperature Operation
The MAX7375 was tested to +135°C during product
characterization and shown to function normally at this
temperature (see
Typical Operating Characteristics).
However, production test and qualification is only per-
formed from -40°C to +125°C at this time. Contact the
factory if operation outside this range is required.
Power-Supply Considerations
Startup Performance
The MAX7375 oscillator output stabilizes within a few
cycles of operation after V+ rises to a sufficient voltage to
start the oscillator, typically 1.65V at +25°C. Use a reset
or similar voltage-detection circuit to disable devices con-
nected to the MAX7375 until 5µs after the voltage on V+
has risen above 2.7V.
The MAX7375 operates with power-supply voltages in
the 2.7V to 5.5V range. Good power-supply decoupling
is needed to maintain the power-supply rejection per-
formance of the MAX7375. Use a 0.1µF surface-mount
ceramic capacitor connected between V+ and GND and
mounted as close as possible to the device. If possible,
mount the MAX7375 close to the microcontroller’s decou-
pling capacitor so that additional decoupling is not required.
A larger value of bypass capacitor is recommended if the
MAX7375 is to operate with a large capacitive load. Use
a bypass capacitor value of at least 1000 times that of the
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