General Description
The MAX6365–MAX6368 supervisory circuits simplify
power-supply monitoring, battery-backup control func-
tions, and memory write protection in microprocessor
(µP) systems. The circuits significantly improve the size,
accuracy, and reliability of modern systems with an ultra-
small integrated solution.
These devices perform four basic system functions:
1) Provide a µP reset output during V
CC
supply power-
up, power-down, and brownout conditions.
2) Internally control V
CC
to backup-battery switching to
maintain data or low-power operation for CMOS
RAM, CMOS µPs, real-time clocks, and other digital
logic when the main supply fails.
3) Provide memory write protection through internal
chip-enable gating during supply or processor faults.
4) Include one of the following options: a manual reset
input (MAX6365), a watchdog timer function
(MAX6366), a battery-on output (MAX6367), or an
auxiliary user-adjustable reset input (MAX6368).
The MAX6365–MAX6368 operate from V
CC
supply volt-
ages as low as 1.2V. The factory preset reset threshold
voltages range from 2.32V to 4.63V (see the
Ordering
Information
). In addition, each part is offered in three
reset output versions: push-pull active low, open-drain
active low, or open-drain active high (see the
Selector
Guide
). The MAX6365–MAX6368 are available in minia-
ture 8-pin SOT23 packages.
Applications
Critical µP/µC Power Portable/Battery-
Monitoring Powered Equipment
Fax Machines Set-Top Boxes
Industrial Control POS Equipment
Computers/Controllers
Features
o Low +1.2V Operating Supply Voltage (V
CC
or V
BATT
)
o Precision Monitoring of +5.0V, +3.3V, +3.0V, and
+2.5V Power-Supply Voltages
o On-Board Gating of Chip-Enable Signals, 1.5ns
Propagation Delay
o Debounced Manual Reset Input (MAX6365)
o Watchdog Timer, 1.6s Timeout (MAX6366)
o Battery-On Output Indicator (MAX6367)
o Auxiliary User-Adjustable RESET IN (MAX6368)
o Low 10µA Quiescent Supply Current
o Three Available Output Structures
Push-Pull RESET
Open-Drain RESET
Open-Drain RESET
o RESET/RESET Valid Down to 1.2V Guaranteed
(V
CC
or V
BATT
)
o Power-Supply Transient Immunity
o 150ms min Reset Timeout Period
o Miniature 8-Pin SOT23 Package
MAX6365–MAX6368
SOT23, Low-Power µP Supervisory Circuits
with Battery Backup and Chip-Enable Gating
________________________________________________________________
Maxim Integrated Products
1
Pin Configurations
19-1658; Rev 5; 10/11
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Ordering Information
*
These parts offer a choice of reset threshold voltages. From the
Reset Threshold Ranges table, insert the desired threshold volt-
age code in the blank to complete the part number. SOT parts
come in tape and reel only and must be ordered in 2500-piece
increments. See Device Marking Codes for a complete parts list,
including SOT top marks and standard threshold versions. See
Selector Guide for a listing of device features.
Devices are available in both leaded and lead(Pb)-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
-
Denotes a package containing lead(Pb).
T
= Tape and reel.
/V Denotes an automotive qualified part.
Pin Configurations continued at end of data sheet.
Typical Operating Circuit appears at end of data sheet.
