Tiny Low Frequency Clock Chip Supports Long Duration Timing from 1ms to 9.5hrs

The LTC6991 is simply programmed, using 1 to 3 resistors, with a maximum frequency error that is guaranteed to be less than 1.5%. The LTC6991 offers glitch-free, first cycle accurate start-up within 500us of power, and a reset function is available to truncate the output pulse and hold the output in a high or low state. The polarity of the reset input and the output signal can be configured for active-low or active-high operation. In addition, the output frequency of the LTC6991 can be dynamically controlled via a separate control voltage.

TimerBlox devices are solid state and can be operated under high acceleration, vibration and temperature extremes. No timing capacitors, no crystals, no microcontroller and no programming are required. They offer higher accuracy, stability and lower power consumption than typical resistor/capacitor-based oscillators. The 20mA source and sink capability enables direct driving of opto-isolators for electrical isolation. Fully specified over the temperature range of -40°C to 125°C, the TimerBlox parts are suitable for demanding automotive and industrial environments, where many oscillators and microcontrollers are unable to operate. The small SOT23 footprint allows each timing device to be placed at the point of use, without routing signals over long distances, providing an ideal timer for space-limited applications such as handheld and portable devices.

With the LTC6991, the designer can forget about big crystals, rows of counters and the headaches of programming, says Doug LaPorte, design manager for Linear Technology. The LTC6991 is extremely easy to use.