19-0136; Rev. 1; 6/94
Power-Supply Monitor with Reset
_______________General Description
The MAX709 provides a system reset during power-up,
power-down, and brownout conditions. When V
CC
falls
below the reset threshold, RESET goes low and holds
the µP in reset for 140ms min after V
CC
rises above the
threshold.
The RESET output is guaranteed to be in the correct
state with V
CC
down to 1V. The MAX709 provides
excellent circuit reliability and low cost by eliminating
external components and adjustments when used with
+5V, +3.3V, or +3V powered systems. The MAX709 is
available 8-pin DIP, µMAX, and SO packages.
___________________________Features
o
+5V, +3.3V, and +3V Versions
o
No External Components
o
Low Cost
o
Precise Power-Down Reset Threshold
o
140ms Min Power-On Reset Delay
o
Immune to Short Negative V
CC
Transients
o
8-Pin DIP, µMAX, and SO Packages
o
Low Supply Current: 35µA - MAX709R/S/T
65µA - MAX709L/M
MAX709
______________Ordering Information
PART
MAX709_CPA
MAX709_CUA
MAX709_CSA
MAX709_C/D
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 Plastic DIP
8 µMAX
8 SO
Dice
8 Plastic DIP
8 µMAX
8 SO
_______________________Applications
Minimum Component Count,
Low-Cost Processor Systems
MAX709_EPA
MAX709_EUA
MAX709_ESA
* Dice are specified at T
A
= +25°C, DC parameters only.
Note:
This part offers a choice of five different reset threshold
voltages. Select the letter corresponding to the desired
nominal reset threshold voltage, and insert it into the
blank to complete the part number.
RESET THRESHOLD
SUFFIX
L
M
T
S
R
VOLTAGE (V)
4.65
4.40
3.08
2.93
2.63
__________Typical Operating Circuit
__________________Pin Configuration
V
CC
V
CC
µP
RESET
V
CC
GND
GND
GND
N.C.
TOP VIEW
N.C.
MAX709
RESET
1
2
3
4
DIP/SO/µMAX
8
MAX709
N.C.
RESET
N.C.
N.C.
7
6
5
________________________________________________________________ Maxim Integrated Products
1
Call toll free 1-800-998-8800 for free samples or literature.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
