19-1090; Rev 1; 1/99
68HC11/Bidirectional-Compatible
µP Reset Circuit
General Description
The MAX6314 low-power CMOS microprocessor (µP)
supervisory circuit is designed to monitor power
supplies in µP and digital systems. The MAX6314’s
RESET
output is bidirectional, allowing it to be directly
connected to µPs with bidirectional reset inputs, such
as the 68HC11. It provides excellent circuit reliability
and low cost by eliminating external components and
adjustments. The MAX6314 also provides a debounced
manual reset input.
This device performs a single function: it asserts a reset
signal whenever the V
CC
supply voltage falls below a
preset threshold or whenever manual reset is
asserted. Reset remains asserted for an internally pro-
grammed interval (reset timeout period) after V
CC
has
risen above the reset threshold or manual reset is
deasserted.
The MAX6314 comes with factory-trimmed reset
threshold voltages in 100mV increments from 2.5V
to 5V. Preset timeout periods of 1ms, 20ms, 140ms,
and 1120ms (minimum) are also available. The device
comes in a SOT143 package.
For a µP supervisor with an open-drain reset pin, see
the MAX6315 data sheet.
o
Small SOT143 Package
o
RESET
Output Simplifies Interface to
Bidirectional Reset I/Os
o
Precision Factory-Set V
CC
Reset Thresholds:
100mV Increments from 2.5V to 5V
o
±1.8% Reset Threshold Accuracy at T
A
= +25°C
o
±2.5% Reset Threshold Accuracy Over Temp.
o
Four Reset Timeout Periods Available:
1ms, 20ms, 140ms, or 1120ms (minimum)
o
Immune to Short V
CC
Transients
o
5µA Supply Current
o
Pin-Compatible with MAX811
Features
MAX6314*
Ordering and Marking Information appears at end of
data sheet.
________________________Applications
Computers
Controllers
Intelligent Instruments
Critical µP and µC Power Monitoring
Portable/Battery-Powered Equipment
V
CC
Typical Operating Circuit
Pin Configuration
V
CC
TOP VIEW
GND
1
4
V
CC
LASER-
TRIMMED
RESISTORS
V
CC
68HC11**
µP
MAX6314
RESET
CIRCUITRY
4.7k
RESET
MR
RESET
2
3
MR
RESET
MAX6314
GND
SOT143
**OR OTHER µC/µP WITH BIDIRECTIONAL RESET I/O PIN.
* Patents Pending
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.