MAX708

Low-Cost, µP Supervisory Circuits

Low-Cost Reset + Watchdog ICs


Description

The MAX705–MAX708/MAX813L microprocessor (µP) supervisory circuits reduce the complexity and number of components required to monitor power-supply and battery functions in µP systems. These devices significantly improve system reliability and accuracy compared to separate ICs or discrete components.

The MAX705/MAX706/MAX813L provide four functions:

  1. A reset output during power-up, power-down, and brownout conditions.
  2. An independent watchdog output that goes low if the watchdog input has not been toggled within 1.6 seconds.
  3. A 1.25V threshold detector for power-fail warning, low-battery detection, or for monitoring a power supply other than +5V.
  4. An active-low manual-reset input.

The MAX707/MAX708 are the same as the MAX705/MAX706, except an active-high reset is substituted for the watchdog timer. The MAX813L is the same as the MAX705, except RESET is provided instead of active-low RESET.

Two supply-voltage monitor levels are available: The MAX705/MAX707/MAX813L generate a reset pulse when the supply voltage drops below 4.65V, while the MAX706/MAX708 generate a reset pulse below 4.40V. All four parts are available in 8-pin DIP, SO and µMAX® packages.

MAX705, MAX706, MAX707, MAX708, MAX813, MAX813L: Typical Operating Circuit MAX705, MAX706, MAX707, MAX708, MAX813, MAX813L: Typical Operating Circuit Enlarge+

Key Features

  • Supervisory-Function Integration Significantly Improves System Reliability While Reducing Board Space
    • µMAX Package
    • Guaranteed Active Low RESET Valid at VCC = 1V
      • 200ms Reset Pulse Width
      • Debounced TTL/CMOS-Compatible Manual-Reset Input
      • Active-High Reset Output (MAX707/MAX708/MAX813L)
    • Precision-Supply Voltage Monitor
      • 4.65V (MAX705/MAX707/MAX813L)
      • 4.40V (MAX706/MAX708)
    • Voltage Monitor for Power-Fail or Low-Battery Warning

Applications/Uses

  • Computers
  • Controllers
  • Critical µP Power Monitoring
  • Intelligent Instruments
Part Number Reset Thresh.
(V)
Reset Out tRESET Watchdog Feature Watchdog Timeout Supervisor Features Reset Thresh. Accur.
(%)
ICC
(µA)
Package/Pins Budgetary
Price
min @ +25°C max See Notes
MAX705  3.3 to 5.5
Active Low
Push-Pull
85ms to 300ms
Input (WDI)
Input/Output (WDI/WDO)
1s to 2s
Adjustable Reset Input
Manual Reset
Power Fail Comparator/Low Battery Detect
2.5 350
µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
$2.78 @1k
MAX706 
Active Low
Push-Pull
Input (WDI)
Input/Output (WDI/WDO)
1s to 2s
µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
$1.82 @1k
MAX707 
Active High
Active Low
Push-Pull
No Watchdog -
µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
$2.01 @1k
MAX708 
Active High
Active Low
Push-Pull
No Watchdog -
µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
$1.82 @1k
See All Supervisors (1 Monitored Voltage) (265)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Quality and Environmental Data

Product Reliability Reports: MAX708.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Related Resources


MAX16135
Low-Voltage, Precision, Single/Dual/Triple/Quad-Voltage μP Supervisors

  • High Precision
  • Programmable OV Threshold: 104% to 111%
  • Programmable UV Threshold: 89% to 96%

MAX16133
Low-Voltage, Precision, Single/Dual/Triple/Quad-Voltage μP Supervisors

  • High Precision
  • Programmable OV Threshold: 104% to 111%
  • Programmable UV Threshold: 89% to 96%

MAX16134
Low-Voltage, Precision, Single/Dual/Triple/Quad-Voltage μP Supervisors

  • High Precision
  • Programmable OV Threshold: 104% to 111%
  • Programmable UV Threshold: 89% to 96%

MAX16132
Low-Voltage, Precision, Single/Dual/Triple/Quad-Voltage μP Supervisors

  • High Precision
  • Programmable OV Threshold: 104% to 111%
  • Programmable UV Threshold: 89% to 96%