MAX697:Microprocessor Supervisory Circuits

Industry-Standard, Full-Function uP Supervisor

The MAX696/MAX697 supervisory circuits reduce the complexity and number of components required for power-supply monitoring and battery-control functions in microprocessor (µP) systems. These include µP reset and backup-battery switchover, watchdog timer, CMOS RAM write protection, and power-failure warning. The MAX696/MAX697 significantly improve system reliability and accuracy compared to that obtained with separate ICs or discrete components. The MAX696 and MAX697 are supplied in 16-pin packages and perform six functions: A reset output during power-up, power-down, and brownout conditions. The threshold for this "lowline" reset is adjustable by an external voltage-divider. A reset pulse if the optional watchdog timer has not been toggled within a specified time. Individual outputs for low-line and watchdog fault conditions. The reset time may be left at its default value of 50ms, or may be varied with an external capacitor or clock pulses. A separate 1.3V threshold detector for power-fail warning, low-battery detection, or to monitor a power supply other than VCC. The MAX696 also has battery-backup switching for CMOS RAM, CMOS microprocessor, or other low-power logic. The MAX697 lacks battery-backup switching, but has write-protection pins (active-low CE IN and active-low CE OUT) for CMOS RAM or EPROM. In addition, it consumes less than 250 microamperes.

Key Features
  • Adjustable Low-Line Monitor and Power-Down Reset
  • Power-OK/Reset Time Delay
  • Watchdog Timer—100ms, 1.6s, or Adjustable
  • Minimum Component Count
  • 1µA Standby Current
  • Battery-Backup Power Switching (MAX696)
  • On-Board Gating of Chip-Enable Signals (MAX697)
  • Separate Monitor for Power-Fail or Low-Battery Warning
MAX696, MAX697: Block Diagram
MAX696, MAX697: Block Diagram
Applications/Uses
  • Computers
  • Controllers
  • Critical µP Power Monitoring
  • Intelligent Instruments
DataSheet
titleDownload file
MAX696-MAX697 Data SheetMAX696-MAX697.pdf
Parametrics
Part NumberReset Thresh.
(V)
Reset OutICC
(µA)
Oper. Temp.
(°C)
Package/PinsBudgetary
Price
maxSee Notes
MAX6961.2 to 1.8Active High
Active Low
Push-Pull
4000-55 to +125
-40 to +85
0 to +70
CDIP(N)/16
LCC/20
PDIP(N)/16
SOIC(W)/16
$5.35 @1k

Part NumberReset Thresh.
(V)
Reset OuttRESETWatchdog FeatureWatchdog TimeoutSupervisor FeaturesReset Thresh. Accur.
(%)
ICC
(µA)
Package/PinsBudgetary
Price
min@ +25°CmaxSee Notes
MAX6971.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Active High
Active Low
Push-Pull
1ms to 15ms
15ms to 85ms
85ms to 300ms
300ms to 1s
<1ms
>1s
Adjustable
Input (WDI)
Input/Output (WDI/WDO)
1s to 2s
<1s
>2s
Adjustable
Adjustable Reset Input
Power Fail Comparator/Low Battery Detect
2.5300CDIP(N)/16
LCC/20
PDIP(N)/16
SOIC(W)/16
$5.35 @1k
Quality and Environmental Data
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX697C/DActiveDICE SALES,;NA pin;DICE;See data sheet
MAX697CPENo Longer AvailableMAX697CPE+PDIP(N),;16 pin;158.4 mm²0°C to +70°CNo
MAX697CPE+ActivePDIP(N),;16 pin;158.4 mm²0°C to +70°CLead Free
MAX697CWENo Longer AvailableMAX697CWE+SOIC(W),;16 pin;111.8 mm²0°C to +70°CNo
MAX697CWE+ActiveSOIC(W),;16 pin;111.8 mm²0°C to +70°CLead Free
MAX697CWE+TActiveSOIC(W),;16 pin;111.8 mm²0°C to +70°CLead Free
MAX697CWE-TNo Longer AvailableMAX697CWE+TW.SO;16 pin0°C to +70°CSee data sheet
MAX697EJENo Longer AvailableCDIP(N),;16 pin;173.5 mm²-40°C to +85°CNo
MAX697EPENo Longer AvailableMAX697EPE+PDIP(N),;16 pin;158.4 mm²-40°C to +85°CNo
MAX697EPE+ActivePDIP(N),;16 pin;158.4 mm²-40°C to +85°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX697EWENo Longer AvailableMAX697EWE+SOIC(W),;16 pin;111.8 mm²-40°C to +85°CNo
MAX697EWE+ActiveSOIC(W),;16 pin;111.8 mm²-40°C to +85°CLead Free
MAX697EWE+TActiveSOIC(W),;16 pin;111.8 mm²-40°C to +85°CLead Free
MAX697EWE-TNo Longer AvailableMAX697EWE+TW.SO;16 pin-40°C to +85°CSee data sheet
MAX697MJEActiveCDIP(N),;16 pin;173.5 mm²-55°C to +125°CNo
MAX697MJE/883BActiveCDIP(N),;16 pin;173.5 mm²-55°C to +125°CNo
MAX697MJE/HRNo Longer AvailableMAX697MJE/883BCDIP(N),;16 pin;173.5 mm²-55°C to +125°CNo
MAX697MLP/883BNo Longer AvailableLCC,;20 pin;82.6 mm²-55°C to +125°CNo
MAX696-MAX697.pdf MAX696
MAX697.pdf MAX697
MAX696-MAX697.pdf MAX697