MAXIM MAX7377 User Manual
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General Description
The MAX7377 dual-speed silicon oscillator with reset is
a replacement for ceramic resonators, crystals, crystal
oscillator modules, and discrete reset circuits. The
device provides the primary and secondary clock
source for microcontrollers in 3V, 3.3V, and 5V applications. The MAX7377 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 MAX7377 is resistant to vibration and EMI.
The high-output-drive current and absence of highimpedance nodes make the oscillator less susceptible
to dirty or humid operating conditions. With a wide
operating temperature range as standard, the MAX7377
is a good choice for demanding home appliance,
industrial, and automotive environments.
The MAX7377 is available in factory-programmed frequencies from 32.768kHz to 10MHz. See Table 1 for
standard frequencies and contact the factory for custom frequencies.
The MAX7377 is available in a 5-pin SOT23 package.
Refer to the MAX7383 data sheet for frequencies
≥10MHz. The MAX7377 standard operating temperature range is -40°C to +125°C. See the Applications
Information section for the extended operating temperature range.
Applications
White Goods Handheld Products
Automotive Portable Equipment
Consumer Products Microcontroller Systems
Appliances and Controls
Features
♦ 2.7V to 5.5V Operation
♦ Accurate High-Speed 600kHz to 10MHz Oscillator
♦ Accurate Low-Speed 32kHz Oscillator
♦ Glitch-Free Switch Between High Speed and Low
Speed at Any Time
♦ ±10mA Clock-Output Drive Capability
♦ 2% Initial Accuracy
♦ ±50ppm/°C Temperature Coefficient
♦ 50% Duty Cycle
♦ 5ns Output Rise and Fall Time
♦ Low Jitter: 160ps
(P-P)
at 8MHz (No PLL)
♦ 3mA Fast-Mode Operating Current (8MHz)
♦ 13µA Slow-Mode Operating Current (32kHz)
♦ -40°C to +125°C Temperature Range
MAX7377
Silicon Oscillator with Low-Power
Frequency Switching
________________________________________________________________ Maxim Integrated Products 1
Pin Configuration
Ordering Information
19-3474; Rev 0; 10/04
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. See Table 1 at the end of the data
sheet for the two-letter code.
PART TEMP RANGE PIN-PACKAGE
M AX7377AX _ _- T -40°C to +125°C5 SOT23-5
Typical Application Circuit appears at end of data sheet.
TOP VIEW
15E.C.CLOCK
MAX7377
2
GND
SPEED
34
SOT23
V
CC
MAX7377
Silicon Oscillator with Low-Power
Frequency Switching
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC= 2.7V to 5.5V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at VCC= 5V and TA = +25°C.) (Note 1)
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 +6V
All Other Pins to GND ................................-0.3V to (V
CC
+ 0.3V)
CLOCK Current ................................................................±10mA
Continuous Power Dissipation (T
A
= +70°C)
5-Pin SOT23
(derate 7.1mW/°C above +70°C) ...................571mW (U5 - 2)
Operating Temperature Range .........................-40°C to +135°C
Junction Temperature .....................................................+150°C
Storage Temperature Range.............................-60°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
PARAMETER
CONDITIONS
UNITS
Operating Supply Voltage V
CC
2.7 5.5 V
f
CLOCK
= 8MHz, no load 3 5 mA
Operating Supply Current I
CC
f
CLOCK
= 32.768kHz, no load 13 25 µA
LOGIC INPUT (SPEED)
Input High Voltage V
IH
0.7 x
V
Input Low Voltage V
IL
0.3 x
V
Input Current I
IN
2µA
CLOCK OUTPUT
VCC = 4.5V, I
SOURCE
= 9mA
V
CC
- 0.4
Output High Voltage V
OH
VCC = 2.7V, I
SOURCE
= 2.5mA
V
CC
- 0.4
V
VCC = 4.5V, I
SINK
= 20mA 0.4
Output Low Voltage V
OL
VCC = 2.7V, I
SINK
= 10mA 0.4
V
VCC = 5V, TA = +25°C (Note 2) -2 +2
Initial Fast CLOCK Frequency
Accuracy
VCC = 2.7V to 5.5V, TA = +25°C -4 +4
%
SYMBOL
MIN TYP MAX
V
CC
f
FCLOCK
V
CC
MAX7377
Silicon Oscillator with Low-Power
Frequency Switching
_______________________________________________________________________________________ 3
Note 1: All parameters are tested at TA= +25°C. Specifications over temperature are guaranteed by design.
Note 2: The frequency is determined by part number selection. See Table 1.
Note 3: Guaranteed by design. Not production tested.
ELECTRICAL CHARACTERISTICS (continued)
(VCC= 2.7V to 5.5V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at VCC= 5V and TA = +25°C.) (Note 1)
PARAMETER
CONDITIONS
UNITS
Fast CLOCK Frequency
Temperature Sensitivity
(Note 3)
ppm/oC
VCC = 5V, TA = +25°C (Note 2)
Initial Slow CLOCK Frequency
Accuracy
VCC = 2.7V to 5.5V, TA = +25°C
kHz
Slow CLOCK Frequency
Temperature Sensitivity
(Note 3)
ppm/oC
CLOCK Output Duty Cycle 43 50 57 %
CLOCK Output Jitter
Observation of 8MHz output for 20s using a
500MHz oscilloscope
ps
P-P
CLOCK Output Rise Time t
R
10% to 90% 5 ns
CLOCK Output Fall Time t
F
90% to 10% 5 ns
Startup Delay VCC rising from 0 to 5V in 1µs
µs
TA = +25°C
2.2
Output Undervoltage Lockout UVLO VCC rising
T
A
= -40°C to +125°C
V
Output Undervoltage Lockout
Hysteresis
V
THYS
45 mV
SYMBOL
f
SCLOCK
MIN TYP MAX
±50 ±325
32.440 32.768 33.096
31.785 33.751
±50 ±325
160
100
2.15
2.05 2.35
2.25
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