X40021: Dual Voltage Monitor with Integrated CPU Supervisor and System Battery Switch

The X40021 combines power-on reset control, watchdog timer, supply voltage supervision, and secondary supervision, and manual reset, in one package. This combination lowers system cost, reduces board space requirements, and increases reliability.

Applying voltage to VCC activates the power-on reset circuit which holds RESET/RESET active for a period of time. This allows the power supply and system oscillator to stabilize before the processor can execute code.

Key Features
  • Dual voltage detection and reset assertion
    • Three standard reset threshold settings (4.6V/2.9V, 4.6V/2.6V, 2.9V/1.6V)
    • VTRIP2 programmable down to 0.9V
    • Adjust low voltage reset threshold voltages using special programming sequence
    • Reset signal valid to VCC = 1V
    • Monitor two voltages or detect power fail
  • Battery switch backup
  • VOUT: 5mA to 50mA from VCC, 250µA from VBATT
  • Fault detection register
  • Selectable power-on reset timeout (0.05s, 0.2s, 0.4s, 0.8s)
  • Selectable watchdog timer interval (25ms, 200ms, 1.4s, off)
  • Debounced manual reset input
  • Low power CMOS
    • 25µA typical standby current, watchdog on
    • 6µA typical standby current, watchdog off
    • 1µA battery current in backup mode
  • 400kHz 2-wire interface
  • 2.7V to 5.5V power supply operation
  • Available packages
    • 14-lead SOIC, TSSOP
  • Monitor voltages: 5V to 1.6V
  • Memory security
  • Pb-free plus anneal available (RoHS compliant)
Applications
  • Communications equipment
    • Routers, hubs, switches
    • Disk arrays
  • Industrial systems
    • Process control
    • Intelligent instrumentation
  • Computer systems
    • Desktop computers
    • Network servers
Typical Diagram
Datasheets
TitleTypeUpdatedSizeOther Languages
X40020, X40021 DatasheetPDF29 Jul 2015427 KB
White Papers
TitleTypeUpdatedSizeOther Languages
Five Easy Steps to Create a Multi-Load Power SolutionPDF30 Jan 2017502 KB
How Green is Your Cloud?PDF05 May 2015275 KB
Order Information
Part NumberPackage TypeWeight(g)PinsMSL RatingPeak Temp (°C)RoHS Status
X40021S14-A14 Ld SOIC0.1314240
X40021S14-AT114 Ld SOIC T+R0.1314240
X40021S14-B14 Ld SOIC0.1314240
X40021S14-BT114 Ld SOIC T+R0.1314240
X40021S14-C14 Ld SOIC0.1314240
X40021S14-CT114 Ld SOIC T+R0.1314240
X40021S14I-A14 Ld SOIC0.1314240
X40021S14I-AT114 Ld SOIC T+R0.1314240
X40021S14I-B14 Ld SOIC0.1314240
X40021S14I-BT114 Ld SOIC T+R0.1314240
X40021S14I-C14 Ld SOIC0.1314240
X40021S14I-CT114 Ld SOIC T+R0.1314240
X40021V14-A14 Ld TSSOP0.05414240
X40021V14-AT114 Ld TSSOP T+R0.05414240
X40021V14-B14 Ld TSSOP0.05414240
X40021V14-BT114 Ld TSSOP T+R0.05414240
X40021V14-C14 Ld TSSOP0.05414240
X40021V14-CT114 Ld TSSOP T+R0.05414240
X40021V14I-A14 Ld TSSOP0.05414240
X40021V14I-AT114 Ld TSSOP T+R0.05414240
X40021V14I-B14 Ld TSSOP0.05414240
X40021V14I-BT114 Ld TSSOP T+R0.05414240
X40021V14I-C14 Ld TSSOP0.05414240
X40021V14I-CT114 Ld TSSOP T+R0.05414240
X40020, X40021 Datasheet 29 Jul 2015
Five Easy Steps to Create a Multi-Load Power Solution 30 Jan 2017
How Green is Your Cloud? 05 May 2015