Document
19-0136; Rev. 2; 12/05
Power-Supply Monitor with Reset
MAX709
_______________General Description
The MAX709 provides a system reset during power-up, power-down, and brownout conditions. When VCC falls below the reset threshold, RESET goes low and holds the µP in reset for 140ms min after VCC rises above the threshold. The RESET output is guaranteed to be in the correct state with VCC 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.
_______________________Applications
Minimum Component Count, Low-Cost Processor Systems
__________Typical Operating Circuit
VCC MAX709
RESET
GND
VCC µP RESET
GND
___________________________Features
♦ +5V, +3.3V, and +3V Versions ♦ No External Components ♦ Low Cost ♦ Precise Power-Down Reset Threshold ♦ 140ms Min Power-On Reset Delay ♦ Immune to Short Negative VCC Transients ♦ 8-Pin DIP, µMAX, and SO Packages ♦ Low Supply Current: 35µA - MAX709R/S/T
65µA - MAX709L/M
______________Ordering Information
PART MAX709_CPA MAX709_CUA MAX709_CSA MAX709_C/D MAX709_EPA MAX709_EUA MAX709_ESA
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
Devices are available in both leaded and lead-free packaging. Specify lead free by adding the + symbol at the end of the part number when ordering. *Dice are specified at TA = +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
VOLTAGE (V)
L 4.65
M 4.40
T 3.08
S 2.93
R 2.63
__________________Pin Configuration
TOP VIEW N.C. 1 VCC 2 GND 3 N.C. 4
MAX709
8 N.C. 7 RESET 6 N.C. 5 N.C.
DIP/SO/µMAX
________________________________________________________________ Maxim Integrated Products 1
Call toll free 1-800-998-8800 for free samples or literature.
Power-Supply Monitor with Reset
MAX709
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage (with respect to GND)
VCC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V RESET. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to (VCC + 0.3V) Input Current, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20mA Output Current, RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20mA
Rate-of-Rise, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100V/µs Continuous Power Dissipation (TA = +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) . . . . . . . . 727mW
µMAX (derate 4.10mW/°C above +70°C) . . . . . . . . . . . . . 330mW
SO (derate 5.88mW.