19-3350; Rev 0; 7/04
Silicon Oscillator with Low-Power
Frequency Switching and Reset Output
General Description
Features
The MAX7378 dual-speed silicon oscillator with reset, is
a replacement for ceramic resonators, crystals, crystal-
oscillator modules, and discrete reset circuits. The
MAX7378 provides the primary and secondary clock
source and reset function for microcontrollers in 3V,
3.3V, and 5V applications. The MAX7378 features a
♦ 2.7V to 5.5V Operation
♦ Accurate High-Speed Oscillator: 600kHz to 10MHz
♦ Accurate Low-Speed 32kHz Oscillator
♦ Glitch-Free Switch Between High Speed and Low
Speed at Any Time
♦ Reset Output Holds the µC in Reset for 100µs
factory-programmed high-speed oscillator,
a
After Clock Startup
32.768kHz oscillator, a clock selector input, and a
microprocessor (µP) power-on-reset (POR) supervisor.
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.
♦
10mA Clock-Output ꢀriꢁe Capaꢂility
♦ 2% Initial Accuracy
50ppmꢃ°C Temperature Coefficient
♦
♦ 50% 7% Output ꢀuty Cycle
♦ 5ns Output Rise and Fall Time
Unlike typical crystal and ceramic resonator oscillator
circuits, the MAX7378 is resistant to vibration and EMI.
The high-output-drive current and absence of high-
impedance nodes make the oscillator less susceptible
to dirty or humid operating conditions. With a wide
operating temperature range as standard, the
MAX7378 is a good choice for demanding home appli-
ance, industrial, and automotive environments.
♦ Low Jitter: 160ps
at 8MHz
(Peak-to-Peak)
♦ 2.4mA Fast-Mode Operating Current (8MHz)
♦ 11µA Slow-Mode Operating Current (32kHz)
♦ -40°C to +125°C Temperature Range
Ordering Information
The MAX7378 is available in an 8-pin µMAX® package.
Refer to the MAX7384 data sheet for frequencies
≥10MHz. The MAX7378 standard operating tempera-
ture range is -40°C to +125°C. See the Applications
Information section for the extended operating temper-
ature range.
RESET
OUTPUT
PIN-
PACKAGE
PART
TEMP RANGE
Active high
push-pull
MAX7378A _ _ _ -40oC to +125oC
MAX7378B _ _ _ -40oC to +125oC
8 µMAX
Active low
push-pull
8 µMAX
Applications
MAX7378C _ _ _ -40oC to +125oC Open drain 8 µMAX
White Goods
Automotive
Standard version is shown in bold. The first letter after the part
number designates the reset output option. Insert the letter cor-
responding 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. See
Table 3 for standard part numbers.
Consumer Products
Appliances and Controls
Handheld Products
Portable Equipment
Microcontroller (µC) Systems
Typical Application Circuit
SUPPLY VOLTAGE
V
CC
V
L
OSC1
ENABLE
CLOCK
OSC2
RST
Pin Configuration appears at end of data sheet.
MAX7378
µC
RST/RST
I/O PORT
SPEED
µMAX is a registered trademark of Maxim Integrated Products, Inc.
________________________________________________________________ Maxim Integrated Products
1
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.