19-2242; Rev 1; 1/02
Ultra-Low-Voltage SC70 Voltage Detectors
and µP Reset Circuits
General Description
The MAX6832–MAX6840 are microprocessor (µP)
supervisory circuits used to monitor low-voltage power
supplies in µP and digital systems. They provide excel-
lent circuit reliability and low cost by eliminating exter-
nal components and adjustments when used with
+1.2V to +1.8V powered circuits.
These devices assert a reset signal whenever the V
CC
supply voltage declines below a preset threshold or
whenever manual reset (MR) is asserted. Reset remains
asserted for a fixed timeout delay after V
CC
has risen
above the reset threshold or when manual reset is
deasserted. Five different timeout periods are available:
70µs (voltage detector), 1.5ms, 30ms, 210ms, and 1.68s.
Reset thresholds suitable for operation with a variety of
supply voltages are available.
The MAX6832/MAX6835/MAX6838 have a push-pull
active-low reset output (RESET). The MAX6833/
MAX6836/MAX6839 have a push-pull active-high reset
output (RESET) and the MAX6834/MAX6837/MAX6840
have an open-drain active-low reset output (RESET). The
open-drain active-low reset output requires a pullup resis-
tor that can be connected to a voltage higher than V
CC
.
The MAX6835/MAX6836/MAX6837 feature a debounced
manual reset input (MR), while the MAX6838/MAX6839/
MAX6840 provide a RESET-IN input allowing the user to
externally adjust the reset threshold. The reset compara-
tor is designed to ignore fast transients on V
CC
.
Low supply current of 7.5µA makes the MAX6832–
MAX6840 ideal for use in portable equipment. These
devices are available in 3- and 4-pin SC70 packages.
Features
o
Factory-Set Reset Threshold Voltages for
Nominal Supplies from 1.2V to 1.8V
o
Low Power Consumption: 7.5µA (typ)
o
Space-Saving 3- and 4-Pin SC70 Packages
o
±2.5% Reset Threshold Accuracy Over
Temperature
o
Five Different Timeout Periods Available: 70µs
(voltage detector), 1.5ms, 30ms, 210ms, and 1.68s
o
Three Reset Output Configurations
Push-Pull
RESET
Push-Pull RESET
Open-Drain
RESET
o
Guaranteed Reset Valid to V
CC
=
0.55V—Active-Low
0.75V—Active-High
o
Adjustable Threshold Reset-In Option
o
Manual Reset Input Option
o
Immune to Short Negative V
CC
Transients
o
Pin Compatible with MAX803/MAX809/MAX810,
MAX6711/MAX6712/MAX6713, and
MAX6381–MAX6390 Series
MAX6832–MAX6840
Ordering Information
PART
MAX6832_XRD_-T
MAX6833_XRD_-T
MAX6834_XRD_-T
MAX6835_XSD_-T
MAX6836_XSD_-T
MAX6837_XSD_-T
MAX6838XSD_-T
MAX6839XSD_-T
MAX6840XSD_-T
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
3 SC70-3
3 SC70-3
3 SC70-3
4 SC70-4
4 SC70-4
4 SC70-4
4 SC70-4
4 SC70-4
4 SC70-4
Applications
Computers
Controllers
Intelligent Instruments
Critical µP and µC Power Monitoring
Portable/Battery-Powered Equipment
Pin Configurations appear at end of data sheet.
Typical Operating Circuit apears at end of data sheet.
Selector Guide appears at end of data sheet.
Insert the desired suffix letter from the Threshold Suffix Guide
(MAX6832–MAX6837) and the Active Timeout Period Guide
tables into the blanks to complete the part number. Sample
stock is generally available on standard versions only (see
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.
________________________________________________________________
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.
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