Features and Benefits
- Guaranteed Reset Assertion at VCC = 1V
- Pin Compatible with LTC694/LTC695 for 3.3V Systems
- 200μA Typical Supply Current
- Fast (30ns Typ) Onboard Gating of RAM Chip Enable Signals
- SO-8 and S16 Packages
- 2.90V 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
The LTC694-3.3/LTC695-3.3 provide complete 3.3V power supply monitoring and battery control functions. These include power-on reset, battery back-up, RAM write protection, power failure warning and watchdog timing. The devices are pin compatible upgrades of the LTC694/LTC695 that are optimized for 3.3V systems. Operating power consumption has been reduced to 0.6mW (typical) and 3μW maximum in battery back-up mode. Microprocessor reset and memory write protection are provided when the supply falls below 2.9V. The RESET output is guaranteed to remain logic low with VCC as low as 1V.
The LTC694-3.3/LTC695-3.3 power the active 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 LTC694-3.3/LTC695-3.3 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.
- 3.3V Low Power Systems
- Critical μP Power Monitoring
- Intelligent Instruments
- Battery-Powered Computers and Controllers
- Automotive Systems
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.