General Description
The MAX6841–MAX6845 microprocessor (µP) supervi-
sory circuits monitor ultra-low-voltage power supplies in
µP and digital systems. They provide excellent circuit
reliability at low cost by eliminating external compo-
nents and adjustments when used with +0.9V to +1.5V
systems. Factory-trimmed reset thresholds are avail-
able for the MAX6841/MAX6842. The MAX6843/
MAX6844/MAX6845 provide a RESET IN input, allowing
the user to externally adjust the reset threshold. The
MAX6841–MAX6845 family features a debounced man-
ual reset input (MR). The reset comparator is designed
to ignore fast transients on VCC.
The MAX6841–MAX6845 assert a reset signal whenev-
er the VCC supply voltage declines below a preset or
adjustable threshold or whenever manual reset (MR) is
asserted. Reset remains asserted for a fixed timeout
delay after VCC has risen above the reset threshold and
when manual reset is deasserted. Five timeout periods
are available for each part: 150µs (voltage detector ver-
sion), 1.5ms, 30ms, 210ms, and 1.68s (typ).
The MAX6841/MAX6843 have an active-low push-pull
reset output. The MAX6841/MAX6842/MAX6844 have
an active-high push-pull reset output, and the
MAX6842/MAX6845 have an active-low open-drain
reset output. The active-low open-drain reset output
requires a pullup resistor that can be connected to a
voltage from 0 to VCC.
The low supply current (5.7µA) and small package
(SOT23-5) make the MAX6841–MAX6845 ideal for use
in portable equipment.
Applications
Computers
Controllers
Intelligent Instruments
Critical µP and µC Power Monitoring
Portable/Battery-Powered Equipment
Telecom/Networking Equipment
Basestations
Servers/Workstations
Features
♦Factory-Set Reset Threshold Voltages for
Monitoring Supplies from 0.9V to 1.5V
(MAX6841/MAX6842)
♦Adjustable Threshold RESET IN
(MAX6843/MAX6844/MAX6845)
♦Low Power Consumption: 5.7µA (typ)
♦±2.5% Reset Threshold Accuracy
Over Temperature
♦Five Timeout Periods: 150µs (Voltage Detector
Version), 1.5ms, 30ms, 210ms, and 1.68s
♦Available in Three Output Configurations
Push-Pull RESET
Push-Pull RESET
Open-Drain RESET
♦Guaranteed Reset Valid to VCC = 0.55V
(Active Low)
♦Manual Reset Input
♦Immune to Short VCC Transients
♦Space-Saving 5-Pin SOT23 Package
MAX6841–MAX6845
Ultra-Low-Voltage µP Reset Circuits and
Voltage Detectors
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-2625; Rev 1; 2/03
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.
Selector Guide and Typical Operating Circuit appear at end
of data sheet.
Pin Configurations
Note: Insert desired suffix letter (from the Threshold Suffix Guide
and the Active Timeout Period tables) into the blanks to com-
plete the part number. For example, the MAX6842GUKD1 has a
reset threshold of 1.11V and a typical reset timeout period of
1.5ms. Sample stock is generally available on standard versions
only (see the Standard Versions table). Standard versions
require a minimum order increment of 2.5k units. Nonstandard
versions must be ordered in 10k-unit increments. Contact factory
for availability. All parts are offered in tape-and-reel only.