µP Reset Circuits with Manual Reset
The MAX6803/MAX6804/MAX6805 microprocessor (µP)
supervisory circuits monitor the power supplies in 2.85V
to 5.0V µP and digital systems. They increase cir-
cuit reliability and reduce cost by eliminating external
components and adjustments. They also feature a
debounced manual-reset input.
These devices perform a single function: they assert a
reset signal whenever the VCC supply voltage declines
below a preset threshold or whenever manual reset is
asserted. Reset remains asserted for a preset timeout
period after VCC has risen above the reset threshold or
after manual reset is deasserted. The only difference
among the three devices is their output. The MAX6804
(push/pull) and MAX6805 (open-drain) have an active-
low RESET output, while the MAX6803 (push/pull) has
an active-high RESET output. The MAX6803/MAX6804
are guaranteed to be in the correct state for VCC down
to 0.7V. The MAX6805 is guaranteed to be in the correct
state for VCC down to 1.0V.
The reset comparator in these ICs is designed to ignore
fast transients on VCC. Reset thresholds are factory-
trimmable between 2.63V and 4.80V, in approximately
100mV increments. These devices are available with a
1ms min, 20ms min, or 100ms min reset timeout period.
Ideal for space-critical applications, the MAX6803/
MAX6804/MAX6805 come packaged in a 4-pin SOT143.
For a lower threshold voltage version, see the MAX6335/
●● Intelligent Instruments
●● Critical µP/µC Power Monitoring
●● Portable/Battery-Powered Equipment
Typical Operating Circuit and Pin Configuration appear
at end of data sheet.
Selector Guide appears at end of data sheet.
●● Ultra-Low 0.7V Operating Supply Voltage
●● Low 4.0µA Supply Current
●● Precision Monitoring of 2.85V to 5.0V Power-Supply
●● Reset Thresholds Available from 2.63V to 4.80V,
in Approximately 100mV Increments
●● Debounced Manual-Reset Input
●● Fully Specified over Temperature
●● Three Power-On Reset Timeout Periods Available
(1ms min, 20ms min, 100ms min)
●● Low Cost
●● Three Available Output Structures: Push/Pull
RESET, Push/Pull RESET, Open-Drain RESET
●● Guaranteed RESET/RESET Valid to VCC = 0.7V
●● Power-Supply Transient Immunity
●● No External Components Required
●● 4-Pin SOT143 Package
●● Pin Compatible with MAX811/MAX812 and
TEMP RANGE PIN-PACKAGE
MAX6803US_ _D_-T -40°C to +125°C 4 SOT143
MAX6804US_ _D_-T -40°C to +125°C 4 SOT143
MAX6805US_ _D_-T -40°C to +125°C 4 SOT143
olds from 2.63V
are available in factory-set
to 4.80V, in approximately
Choose the desired reset threshold suffix from Table 1 and
insert it in the blanks following “US” in the part number.
Factory-programmed reset timeout periods are also available.
Insert the number corresponding to the desired nominal reset
timeout period (1 = 1ms min, 2 = 20ms min, 3 = 100ms min) in
the blank following “D” in the part number. There are 15 stan-
dard versions with a required order increment of 2500 pieces.
Sample stock is generally held on the standard versions only
(see Selector Guide). Contact the factory for availability of non-
standard versions (required order increment is 10,000 pieces).
All devices available in tape-and-reel only.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
19-1946; Rev 3; 7/14