MAX6845:Ultra-Low-Voltage µP Reset Circuits and Voltage Detectors

Ultra-Low-Voltage SC70 µP Supervisors Monitor Supplies Down to 0.9V with No External Components

The MAX6841–MAX6845 microprocessor (µP) supervisory circuits monitor ultra-low-voltage power supplies in µP and digital systems. They provide excellent circuit reliability at low cost by eliminating external components and adjustments when used with +0.9V to +1.5V systems. Factory-trimmed reset thresholds are available for the MAX6841/MAX6842. The MAX6843/MAX6844/MAX6845 provide a RESET IN input, allowing the user to externally adjust the reset threshold. The MAX6841–MAX6845 family features a debounced manual reset input (active-low MR). The reset comparator is designed to ignore fast transients on VCC. The MAX6841–MAX6845 assert a reset signal whenever the VCC supply voltage declines below a preset or adjustable threshold or whenever manual reset (active-low MR) is asserted. Reset remains asserted for a fixed timeout delay after VCC has risen above the reset threshold and when manual reset is deasserted. Five timeout periods are available for each part: 150µs (voltage detector version), 1.5ms, 30ms, 210ms, and 1.68s (typ). The MAX6841/MAX6843 have an active-low push-pull reset output. The MAX6841/MAX6842/MAX6844 have an active-high push-pull reset output, and the MAX6842/MAX6845 have an active-low open-drain reset output. The active-low open-drain reset output requires a pullup resistor that can be connected to a voltage from 0 to VCC. The low supply current (5.7µA) and small package (SOT23-5) make the MAX6841–MAX6845 ideal for use in portable equipment.

Key Features
  • Factory-Set Reset Threshold Voltages for Monitoring Supplies from 0.9V to 1.5V (MAX6841/MAX6842)
  • Adjustable Threshold RESET IN (MAX6843/MAX6844/MAX6845)
  • Low Power Consumption: 5.7µA (typ)
  • ±2.5% Reset Threshold Accuracy Over Temperature
  • Five Timeout Periods: 150µs (Voltage Detector Version), 1.5ms, 30ms, 210ms, and 1.68s
  • Available in Three Output Configurations
    • Push-Pull active-low RESET
    • Push-Pull RESET
    • Open-Drain active-low RESET
  • Guaranteed Reset Valid to VCC = 0.55V (Active Low)
  • Manual Reset Input
  • Immune to Short VCC Transients
  • Space-Saving 5-Pin SOT23 Package
MAX6841, MAX6842, MAX6843, MAX6844, MAX6845: Typical Operating Circuit
MAX6841, MAX6842, MAX6843, MAX6844, MAX6845: Typical Operating Circuit
Applications/Uses
  • Computers
  • Controllers
  • Critical µP and µC Power Monitoring
  • Intelligent Instruments
  • Portable Battery-Powered Equipment
  • Servers and Workstations
  • Telecom/Networking Equipment
  • Wireless Base Stations
DataSheet
titleDownload file
MAX6841-MAX6845 Data SheetMAX6841-MAX6845.pdf
Parametrics
Part NumberReset Thresh.
(V)
Reset OuttRESETWatchdog FeatureSupervisor FeaturesReset Thresh. Accur.
(%)
ICC
(µA)
Package/PinsBudgetary
Price
min@ +25°CmaxSee Notes
MAX68420 to 1.2
1.2 to 1.8
Active High
Active Low
Open Drain
Push-Pull
1ms to 15ms
15ms to 85ms
85ms to 300ms
<1ms
>1s
No WatchdogManual Reset2.520SOT/5$1.42 @1k
MAX68430 to 1.2
1.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Active Low
Push-Pull
Adjustable Reset Input
Manual Reset
SOT/5$1.86 @1k
MAX68450 to 1.2
1.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Active Low
Open Drain
Adjustable Reset Input
Manual Reset
SOT/5$2.04 @1k
Quality and Environmental Data
Related Products
  • MAX6834:Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits
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  • MAX6837:Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits
  • MAX6838:Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits
  • MAX6835:Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits
  • MAX6840:Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits
  • MAX6836:Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits
  • MAX6833:Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6845UKD0+ActiveSOT,;5 pin;9 mm²-40°C to +85°CLead Free
MAX6845UKD0+TActiveSOT,;5 pin;9 mm²-40°C to +85°CLead Free
MAX6845UKD0-TNo Longer AvailableMAX6845UKD0+TSOT,;5 pin;9 mm²-40°C to +85°CNo
MAX6845UKD1+TActiveSOT,;5 pin;9 mm²-40°C to +85°CLead Free
MAX6845UKD1-TNo Longer AvailableMAX6845UKD1+TSOT,;5 pin;9 mm²-40°C to +85°CNo
MAX6845UKD2+TActiveSOT,;5 pin;9 mm²-40°C to +85°CLead Free
MAX6845UKD2-TNo Longer AvailableMAX6845UKD2+TSOT,;5 pin;9 mm²-40°C to +85°CNo
MAX6845UKD3+ActiveSOT,;5 pin;9 mm²-40°C to +85°CLead Free
MAX6845UKD3+TActiveSOT,;5 pin;9 mm²-40°C to +85°CLead Free
MAX6845UKD3-TNo Longer AvailableMAX6845UKD3+TSOT,;5 pin;9 mm²-40°C to +85°CNo
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6845UKD4+TActiveSOT;-40°C to +85°CSee data sheet
MAX6845UKD4-TNo Longer AvailableMAX6845UKD4+TSOT,;5 pin;9 mm²-40°C to +85°CNo
MAX6841-MAX6845.pdf MAX6845
MAX6845.pdf MAX6845
典型工作电路 MAX6845