Rainbow Electronics MAX6869 User Manual
General description, Applications, Features
General Description
The MAX6854–MAX6869 ultra-low-current (170nA, typ)
microprocessor (µP) supervisory circuits combine volt-
age monitoring, watchdog timer, and manual reset input
functions in a 5-pin SOT23 package. These devices
assert a reset signal whenever the monitored voltage
drops below the factory-trimmed reset threshold voltage,
manual reset is asserted, or the watchdog timer expires.
The reset output remains asserted for a minimum timeout
period after V
CC
rises above the reset threshold and
manual reset is deasserted. Factory-trimmed reset
threshold voltages are offered from +1.575V to +4.625V
in approximately 100mV increments (see Threshold
Suffix Guide). Each device is offered with six minimum
reset timeout options, ranging from 10ms to 1200ms.
The MAX6854–MAX6869 are offered in a variety of con-
figurations (see Selector Guide). The MAX6854–
MAX6856 and MAX6861–MAX6869 provide a manual
reset input, MR. The MAX6864–MAX6869 offer a watch-
dog timer that monitors activity at the WDI input for code
execution errors. The MAX6864–MAX6869 offer watch-
dog timeout options of 3.3s or 209s (typ). The
MAX6861–MAX6863 feature a pin-selectable reset delay
period of 10ms or 150ms (min). Push-pull active-low,
push-pull active-high, and open-drain active-low reset
outputs are available.
Applications
Portable/Battery-Powered Equipment
PDAs/Cell Phones
MP3 Players/Pagers
Glucose Monitors/Patient Monitors
Features
♦ Ultra-Low 170nA (typ) Supply Current
♦ Reset Thresholds from +1.575V to +4.625V in
Approximately 100mV Increments
♦ 6 Minimum Reset Timeout Period Options from
10ms to 1200ms
♦ Manual Reset Option
♦ Watchdog Timer Option
♦ Pin-Selectable 10ms/150ms (min) Reset Timeout
Period (MAX6861/MAX6862/MAX6863)
♦ Immune to Short V
CC
Transients
♦ Guaranteed Reset Valid to V
CC
= +1.1V
♦ Three Reset Output Options:
Push-Pull RESET
Push-Pull RESET
Open-Drain RESET
♦ No External Components
♦ Small 5-Pin SOT23 Package
♦ Pin Compatible to the TPS3836–TPS3838
(MAX6861/MAX6862/MAX6863)
MAX6854–MAX6869
Nanopower µP Supervisory Circuits with
Optional Manual Reset, Watchdog Timer
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
PART
†
TEMP RANGE
PIN-PACKAGE
MAX6854
UK_ _D_-T*
-40°C to +85°C
5 SOT23-5
MAX6855
UK_ _D_-T*
-40°C to +85°C
5 SOT23-5
19-3139; Rev 0; 2/04
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.
Ordering Information continued on last page.
†Insert reset threshold suffix (see Table 2, Threshold Suffix
Guide) after UK. Insert the number corresponding to the
desired reset timeout period (see Table 4, Reset Timeout
Period) after “D.”
Note: Sample stock is generally held on standard versions
only (see Table 5, Standard Versions Table). Standard versions
have an order increment of 2500 pieces. Nonstandard versions
have an order increment of 10,000 pieces. Contact factory for
availability of nonstandard versions.
*Future product—Contact factory for availability.
Pin Configurations appear at the end of data sheet.
Selector Guide appears at the end of data sheet.
Typical Operating Circuit
MAX6864
MAX6867
µP
V
CC
V
CC
GND
GND
MANUAL
RESET
RESET
I/O
V
CC
0.1µF
RESET
MR
WDI