DS1830

www.maxim-ic.com FEATURES § 5V (DS1830) or 3.3V (DS1830A) power-on reset § Excellent for systems that need power-on resets in a consistent sequence § Asserts resets during power transients § Pushbutton reset input for system override § Selectable reset timing § Reduces need for discrete components § Precision temperature-compensated voltage reference § 8-pin DIP, 8-pin SO, or space saving 8-pin µSOP § Operating temperature of -40°C to +85°C § Open-drain, active-low inputs DS1830/A DS183 DS1830/A Reset Sequence Pushbutton PIN ASSIGNMENT PIN DESCRIPTION 1 PBRST - Pushbutton Reset Input 2 TD - Time Delay Select Input 3 TOL 4 GND - VCC Tolerance Select Input - Ground 8 VCC 7 RST1 - Power Supply - Reset 1 Output 6 RST2 - Reset 2 Output 5 RST3 - Reset 3 Output DESCRIPTION The DS1830 Reset Sequencer monitors the power supply for an in-tolerance condition and the pushbutton reset input for a manual reset. First a precision temperature-compensated reference and comparator circuit monitors the status of the power supply and when an out-of-tolerance condition is detected, an internal power fail signal is generated that forces the reset lines to go to an active state. If the power supply returns to an in-tolerance condition, RST1 will release followed by RST2 and finally RST3 . Sequencing of resets allows for systems to power-up in an orderly manner providing superior reliability. Note: Some revisions of this device may incorporate deviations from published specifications...