MAX6854UK16D3-T Datasheet, PDF (1/17 Pages) Maxim Integrated Products – Nanopower muP Supervisory Circuits with Manual Reset and Watchdog Timer

19-3139; Rev 4; 12/05
Nanopower µP Supervisory Circuits with
Manual Reset and Watchdog Timer
General Description
The MAX6854/MAX6855/MAX6856/MAX6858/MAX6860–
MAX6869 ultra-low-current (170nA, typ) microprocessor
(µP) supervisory circuits combine voltage 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 assert-
ed, 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 the Threshold Suffix Guide).
Each device is offered with six minimum reset timeout
options, ranging from 10ms to 1200ms.
The MAX6854/MAX6855/MAX6856/MAX6858/MAX6860–
MAX6869 are offered in a variety of configurations (see
the Selector Guide). The MAX6854/MAX6855/MAX6856/
MAX6861–MAX6869 provide a manual reset input, MR.
The MAX6864–MAX6869 offer a watchdog timer that
monitors activity at the WDI input to prevent code execu-
tion errors. The MAX6864–MAX6869 offer watchdog
timeout options of 3.3s or 209s (typ). The MAX6861/
MAX6862/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
V_CC
MANUAL
RESET
Typical Operating Circuit
V_CC
RESET
MAX6864
MAX6867
MR
WDI
GND
0.1µF
V_CC
RESET
µP
I/O
GND
Features
♦ Ultra-Low 170nA (typ) Supply Current
♦ Reset Thresholds from +1.575V to +4.625V in
Approximately 100mV Increments
♦ Six 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/TPS3837/TPS3838
(MAX6861/MAX6862/MAX6863)
Ordering Information
PART^†
TEMP RANGE PIN-PACKAGE
MAX6854UK_ _D_-T
-40°C to +85°C 5 SOT23-5
MAX6855UK_ _D_-T
-40°C to +85°C 5 SOT23-5
†_{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.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
Pin Configurations and Selector Guide appear at end of
data sheet.
Ordering Information continued at end of data sheet.
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