MAX7387_06 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – System Monitoring Oscillator with Watchdog and Power Fail

19-3896; Rev 1; 1/06
System Monitoring Oscillator with
Watchdog and Power Fail
General Description
The MAX7387/MAX7388 replace ceramic resonators,
crystals, and supervisory functions for microcontrollers
in 3.3V and 5V applications.
The MAX7387/MAX7388 provide a clock source together
with integrated reset, watchdog, and power-fail func-
tions. The watchdog timer is pin programmable and
provides watchdog timeout values in the 16ms to
2048ms range. The power-fail output provides early
warning of power failure. The power-fail threshold on the
MAX7388 is internally set. The MAX7387 also provides
a separate watchdog output that is used as a status
indicator or to control safety-critical system elements.
The MAX7387/MAX7388 clock outputs are factory pro-
grammed to a frequency in the 1MHz to 16MHz range.
Four standard frequencies are available. Other frequen-
cies are available upon request. The maximum operating
supply current is 5.5mA (max) with a clock frequency of
12MHz.
Unlike typical crystal and ceramic resonator oscillator
circuits, the MAX7387/MAX7388 are resistant to EMI
and vibration, and operate reliably at high tempera-
tures. The high-output drive current and absence of
high-impedance nodes make the oscillator invulnerable
to dirty or humid operating conditions.
The MAX7387/MAX7388 are available in 10-pin and 8-pin
µMAX^® packages, respectively. The MAX7387/MAX7388
standard operating temperature range is from -40°C to
+125°C.
White Goods
Automotive
Appliances and Controls
Applications
Handheld Products
Portable Equipment
Microcontroller Systems
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Features
♦ Robust Microcontroller Clock and Supervisor in a
Single Package
♦ Integrated Reset, Watchdog, and Power-Fail
Functions
♦ Pin-Programmable Watchdog Timeout
♦ +2.7V to +5.5V Operation
♦ Factory-Trimmed Oscillator
♦ Reset Valid Down to 1.1V Supply Voltage
♦ ±10mA Clock-Output Drive Current
♦ ±4% Total Accuracy for -40°C to +125°C
♦ ±2.75% Total Accuracy for 0°C to +85°C
♦ -40°C to +125°C Temperature Range
♦ 8- and 10-Pin µMAX Surface-Mount Packages
♦ 5.5mA Operating Current (12MHz)
♦ 1MHz to 16MHz Factory Preset Frequency
Ordering Information
PART
TEMP RANGE
MAX7387srff -40^oC to +125^oC
MAX7388srff -40^oC to +125^oC
PIN-PACKAGE
10 µMAX
8 µMAX
PKG CODE
U10-2
U8-1
Note: “s” is a placeholder for the reset output type. Insert the
symbol found in Table 3 in the place of “s.” “r” is a placeholder
for the power-on reset (POR) voltage. Insert the symbol found in
Table 2 in the place of “r.” “ff” is a placeholder for the nominal
output frequency. Insert the symbol found in Table 4 in the
place of “ff.” For example, MAX7387CMTP describes a device
with 4.38V reset level, open-collector RST output, and a clock
output frequency of 8MHz.
Typical Application Circuit, Functional Diagram, and Selector
Guide appear at end of data sheet.
Pin Configurations
TOP VIEW
PFI 1
V_CC 2
WDS1 3
WDS2 4
GND 5
MAX7387
10 CLOCK
9 RST/RST
8 WDI
7 PFO
6 WDO
TOP VIEW
V_CC 1
WDS1 2
WDS2 3
GND 4
MAX7388
8 CLOCK
7 RST/RST
6 WDI
5 PFO
µMAX
µMAX
________________________________________________________________ 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.