LTC693 - Microprocessor Supervisory Circuits

Features

  • Guaranteed Reset Assertion at VCC = 1V
  • 1.5mA Maximum Supply Current
  • Fast (35ns Maximum) Onboard Gating of RAM Chip Enable Signals
  • 4.40V Precision Voltage Monitor
  • Power OK/Reset Time Delay: 200ms or Adjustable
  • Minimum External Component Count
  • 1μA Maximum Standby Current
  • Voltage Monitor for Power-Fail or Low Battery Warning
  • Thermal Limiting
  • Performance Specified Over Temperature
  • Superior Upgrade for MAX690 Family
  • SO8 and SO16 Packaging

Typical Application

LTC693 Typical Application
LTC693 Typical Application

Description

The LTC692/LTC693 provide complete power supply monitoring and battery control functions for microprocessor reset, battery backup, CMOS RAM write protection, power failure warning and watchdog timing. A precise internal voltage reference and comparator circuit monitor the power supply line. When an out-of-tolerance condition occurs, the reset outputs are forced to active states and the chip enable output unconditionally write-protects external memory. In addition, the RESET output is guaranteed to remain logic low even with VCC as low as 1V.

The LTC692/LTC693 power the active CMOS RAMs with a charge-pumped NMOS power switch to achieve low dropout and low supply current. When primary power is lost, auxiliary power, connected to the battery input pin, powers the RAMs in standby through an efficient PMOS switch.

For an early warning of impending power failure, the LTC692/LTC693 provide an internal comparator with a user-defined threshold. An internal watchdog timer is also available, which forces the reset pins to active states when the watchdog input is not toggled prior to a preset timeout period.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC693CN#PBF N-16 N C 05-08-1510 (N16) Yes
LTC693CSW#PBF SW-16 SW C 05-08-1620 (SW16) Yes
LTC693CSW#TRPBF SW-16 SW C 05-08-1620 (SW16) Yes


LTC693 Package Drawing
LTC693 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC693CN#PBF N-16 C $4.58 $3.70 Yes
LTC693CSW#PBF SW-16 C $5.00 $4.05 Yes
LTC693CSW#TRPBF SW-16 C $4.11 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Click here to view our complete list of demo boards

Applications

  • Critical μP Power Monitoring
  • Intelligent Instruments
  • Battery-Powered Computers and Controllers
  • Automotive Systems

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

Models for the following parts are available in LTspice:
LTC693

Technical Support