MIC706P/R/S/T, MIC708R/S/T P Supervisory Circuit General Description Features The MIC706 and MIC708 are inexpensive microprocessor Maximum supply current: 30A supervisory circuits that monitor power supplies in 3.0V Debounced manual reset input is TTL/CMOS and 3.3V microprocessor-based systems. The circuit compatible functions include a watchdog timer, microprocessor reset, Reset pulse width: 200ms power-failure warning, and a debounced manual reset Watchdog timer: 1.6s (MIC706) input. Precision supply voltage monitor The MIC706 offers a watchdog timer function, while the Easy power-fail warning or low-battery detect MIC708 has an active-high reset output in addition to the active-low reset output. Applications The R, S, and T versions are similar in all respects except Laptop and desktop computers for supply voltage reset threshold levels. The threshold Intelligent systems levels are 2.63, 2.93, and 3.08V, respectively. When the supply voltage drops below the reset threshold level, Critical microprocessor power monitoring /RESET (and RESET for the MIC708) is asserted. Printers The MIC706P is identical to the MIC706R, except that the Controllers Reset output is asserted high. Datasheets and support documentation are available on Micrels web site at: www.micrel.com. Typical Application Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC706P/R/S/, MIC708R/S/T Ordering Information Part Number Threshold (V) /RESET RESET WDI Junction Temperature Range Package MIC706PMY 2.63 40C to +85C 8-Pin SOIC MIC706RMY 2.63 40C to +85C 8-Pin SOIC MIC706SMY 2.93 40C to +85C 8-Pin SOIC MIC706TMY 3.08 40C to +85C 8-Pin SOIC MIC708RMY 2.63 40C to +85C 8-Pin SOIC MIC708SMY 2.93 40C to +85C 8-Pin SOIC MIC708TMY 3.08 40C to +85C 8-Pin SOIC Pin Configuration MIC706 MIC708 8-Pin SOIC (M) 8-Pin SOIC (M) (Top View) (Top View) Pin Description Pin Number Pin Number Pin Name Pin Name MIC706 MIC708 Manual reset input forces reset outputs to assert when pulled below 0.8V. An 1 1 /MR internal pull-up current of 250A on this input forces it high when left floating. This input can also be driven from TTL or CMOS logic. 2 2 VCC Primary supply input, +5V. 3 3 GND IC ground pin, 0V reference. Power-Fail Input: Internally-connected to the power-fail comparator which is referenced to 1.25V. The power-fail output (/PFO) remains high if PFI is above 4 4 PFI 1.25V. PFI should be connected to GND or V if the power-fail comparator is not OUT used. Power-Fail Output: The power-fail comparator is independent of all other function 5 5 /PFO on this device. Watchdog Input. The WDI input monitors microprocessor activity an internal watchdog timer resets itself with each transition on the watchdog input. If the WDI 6 N/A WDI pin is held high or low for longer than the watchdog timeout period, /WDO is forced to active low. The watchdog function can be disabled by floating the WDI pin. N/A 6 N/C Not internally connected. Revision 2.0 May 28, 2014 2