MAX6391/MAX6392 19-2210 Rev 2 12/05 Dual-Voltage P Supervisory Circuits with Sequenced Reset Outputs General Description Features The MAX6391/MAX6392 microprocessor (P) supervisory Preset V Reset Threshold Voltages from 1.58V CC circuits provide sequenced logic reset outputs for multi- to 4.63V (master supply) component or dual-voltage systems. Each device can Customer-Adjustable RESET IN2 to Monitor monitor two supply voltages and time-sequence two reset outputs to control the order in which system components Voltages Down to 625mV (secondary supply) are turned on and off. The MAX6391/MAX6392 increase Fixed (140ms min) RREESSEETT11 Timeout system reliability and reduce circuit complexity and cost compared to separate ICs or discrete components. Fixed (140ms min) or Customer-Adjustable RREESSEETT22 Timeout Period The MAX6391/MAX6392 monitor V as the master CC reset supply. Both RESET1 and RESET2 are asserted Guaranteed Reset Valid to V = 1V CC whenever V drops below the selected factory-fixed CC Active-Low Open-Drain Outputs or Push- reset threshold voltage. RESET1 remains asserted as Pull/Open-Drain Combination long as V is below the threshold and deasserts CC 140ms (min) after V exceeds the thresholds. CC Internal Open-Drain Pullup Resistors (for external RESET IN2 is monitored as the secondary reset supply V voltage connections) OH and is adjustable with an external resistive-divider net- Manual Reset Input (MAX6392 only) work. RESET2 is asserted whenever either V or CC RESET IN2 is below the selected thresholds. RESET2 Immune to Short Negative V Transients CC remains asserted 140ms (min) or a capacitor- 15A Typical Supply Current adjustable time period after V and RESET IN2 CC exceed their thresholds. RESET2 is always deasserted Few External Components after RESET1 during system power-up and is always Small 8-Pin SOT23 Package asserted before RESET1 during power-down. The MAX6391 includes two internal pullup resistors for Ordering Information RESET1 and RESET2 (the open-drain outputs can be PART* TEMP RANGE PIN-PACKAGE externally connected to the desired pullup voltages). The MAX6392 includes an active-low manual reset MAX6391KA -T -40C to +85C SOT23-8 input (MR) that asserts both RESET1 (push-pull) and MAX6392KA -T -40C to +85C SOT23-8 RESET2 (open drain). *Insert the desired suffix (see Selector Guide) into the blanks to The MAX6391/MAX6392 are available in small 8-pin complete the part number. The MAX6391/MAX6392 require a SOT23 packages and are specified over the -40C to 2.5k minimum order increment and are available in tape-and- +85C extended temperature range. reel only. Samples are typically available for standard versions (see Selector Guide for standard versions). Contact factory for Applications availability. Devices are available in both leaded and lead-free packaging. Computers Specify lead-free by replacing -T with +T when ordering. Controllers Pin Configurations Critical P Power Monitoring Set-Top Boxes TOP VIEW Printers RESET IN2 1 8 R1 Servers/Workstations V 2 7 RESET1 CC Industrial Equipment MAX6391 CSRT 3 6 R2 Multivoltage Monitoring GND 4 5 RESET2 SOT23-8 Typical Operating Circuit appears at end of data sheet. Pin Configurations continued at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.Dual-Voltage P Supervisory Circuits with Sequenced Reset Outputs ABSOLUTE MAXIMUM RATINGS V to GND...........................................................-0.3V to +6.0V Operating Temperature Range ...........................-40C to +85C CC Junction Temperature......................................................+150C RESET1 (MAX6392), RESET IN2, CSRT, Storage Temperature Range .............................-65C to +150C MR to GND ..............................................-0.3V to (V + 0.3V) CC Lead Temperature (soldering, 10s) .................................+300C RESET1 (MAX6391), RESET2, R1, R2 to GND......-0.3V to +6.0V Input Current (V , GND, CSRT, R1, R2, MR) .................20mA CC Output Current (RESET1, RESET2) ..................................20mA Continuous Power Dissipation (T = +70C) A 8-Pin SOT23 (derate 5.26mW/C above +70C)...........421mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = 1.2V to 5.5V, T = T to T , unless otherwise specified. Typical values are at V = +5V and T = +25C.) (Note 1) CC A MIN MAX CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS T = 0C to +85C 1.0 5.5 A V Range V CC T = -40C to +85C 1.2 5.5 A Supply Current I No load 15 25 A CC MAX639 UA46 4.50 4.63 4.75 MAX639 UA44 4.25 4.38 4.50 MAX639 UA31 3.00 3.08 3.15 MAX639 UA29 2.85 2.93 3.00 V Reset Threshold V MAX639 UA26 2.55 2.63 2.70 V CC TH1 MAX639 UA23 2.25 2.32 2.38 MAX639 UA22 2.12 2.19 2.25 MAX639 UA17 1.62 1.67 1.71 MAX639 UA16 1.54 1.58 1.61 RESET IN2 Threshold V V = 5V 610 625 640 mV TH2 CC RESET IN2 Input Current 50 nA V to RESET1 Delay t 20 CC RD1 V falling at 1mV/s (Note 2) s V or RESET IN2 to RESET2 CC CC t 10 RD2 Delay 2 MAX6391/MAX6392