Threshold detector and reset generator
• Very low current consumption, typically 10 µA
• 10 factory programmed threshold voltages available
covering trip voltages from 4.75 to 2.55 V
• ±50 mV trip point accuracy over full temperature range
• Variable RESET delay
• RESET pulse polarity selection
• Defined outputs at 0.6 V (typ.)
• Comparator for second level detection
(e.g. overvoltage detection)
• Advance warning of power fail
• Operating temperature range −40 to +85 °C.
The PCF1252-Xs are low-power CMOS voltage threshold
detectors designed especially for supervision of
microcontroller/microprocessor systems for detection of
power-on/off conditions and generation of a system reset
pulse. The PCF1252-X also provides a POWF (power fail)
output which is activated at a precise factory-programmed
trip point. A system RESET output has a built-in delay with
duration determined by an external capacitor (CCT).
A second comparator (comparator 2) has been included to
enable the possibility of a second monitoring point in the
plastic dual in-line package; 8 leads (300 mil)
plastic small outline package; 8 leads; body width 3.9 mm
1. X = 0 to 9; depending on threshold voltage.
handbook, full pagewidth
Fig.1 Block diagram.
1998 Apr 16