MAX793/MAX794/MAX795 19-0366 Rev 6 3/10 3.0V/3.3V Adjustable Microprocessor Supervisory Circuits General Description Features MAX793/MAX794/MAX795 The MAX793/MAX794/MAX795 microprocessor (P) supervisory circuits monitor and control the activities of Precision Supply-Voltage Monitor: +3.0V/+3.3V Ps by providing backup-battery switchover, Fixed Reset Trip Voltage (MAX793/MAX795) Adjustable Reset Trip Voltage (MAX794) among other features such as low-line indication, P reset, write protection for CMOS RAM, and a watchdog Guaranteed Reset Assertion to V = 1V CC (see the Selector Guide below). The backup-battery volt- Backup-Battery Power SwitchingBattery age can exceed V , permitting the use of 3.6V lithium CC Voltage Can Exceed V CC batteries in systems using 3.0V to 3.3V for V . CC On-Board Gating of Chip-Enable Signals7ns The MAX793/MAX795 offer a choice of reset threshold Max Propagation Delay voltage range (denoted by suffix letter): 3.00V to 3.15V MAX793/MAX794 Only (T), 2.85V to 3.00V (S), and 2.55V to 2.70V (R). The Battery Freshness Seal MAX794s reset threshold is set externally with a resistor Battery OK Output (MAX793) divider. The MAX793/MAX794 are available in 16-pin Uncommitted Voltage Monitor for Power-Fail or DIP and narrow SO packages, and the MAX795 comes Low-Battery Warning in 8-pin DIP and SO packages. Independent Watchdog Timer (1.6s timeout) Manual Reset Input Ordering Information Selector Guide FEATURE MAX793 MAX794 MAX795 PIN- PART* TEMP RANGE Active-Low Reset PACKAGE Active-High Reset MAX793 CPE 0C to +70C 16 Plastic DIP Programmable Reset MAX793 CSE 0C to +70C 16 Narrow SO Threshold Ordering Information continued at end of data sheet. Low-Line Early Warning *The MAX793/MAX795 offer a choice of reset threshold voltage. Output Select the letter corresponding to the desired reset threshold Backup-Battery voltage range (T = 3.00V to 3.15V, S = 2.85V to 3.00V, R = Switchover 2.55V to 2.70V) and insert it into the blank to complete the part number. The MAX794s reset threshold is adjustable. External Switch Driver Devices are available in both leaded and lead-free packaging. Power-Fail Comparator Specify lead free by adding the + symbol at the end of the part Battery OK Output number when ordering. Watchdog Input Typical Operating Circuit Battery Freshness Seal Manual Reset Input (OPTIONAL) Si9433DY Chip-Enable Gating 3.0V OR 3.3V SILICONIX Pin-Package 16-DIP/SO 16-DIP/SO 8-DIP/SO 0.1F 0.1F PMOS Applications V BATT ON OUT CC CMOS RAM BATT CE OUT Battery-Powered Computers and Controllers 3.6V 0.1F V CC Embedded Controllers MAX793 ADDRESS A0-A15 CE IN WDO DECODER Intelligent Controllers MR I/O WDI +5V SUPPLY FAILURE NMI LOWLINE Critical P Power Monitoring PFO +5V V CC P Portable Equipment PFI RESET RESET BATT OK GND Pin Configurations appear at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.3.0V/3.3V Adjustable Microprocessor Supervisory Circuits ABSOLUTE MAXIMUM RATINGS Terminal Voltage (with respect to GND) Continuous Power Dissipation (T = +70C) A V ......................................................................-0.3V to +6.0V 8-Pin Plastic DIP (derate 9.09mW/C above +70C) .....727mW CC V ...................................................................-0.3V to +6.0V 8-Pin SO (derate 5.88mW/C above +70C)..................471mW BATT All Other Inputs ..................-0.3V to the higher of V or V 16-Pin Plastic DIP (derate 10.53mW/C above +70C) .842mW CC BATT Continuous Input Current 16-Pin Narrow SO (derate 9.52mW/C above +70C) ...696mW V .................................................................................200mA Operating Temperature Ranges CC V ................................................................................50mA MAX793 C /MAX794C /MAX795 C ......... 0C to +70C BATT GND ..................................................................................20mA MAX793 E /MAX794E /MAX795 E ........-40C to +85C Output Current Storage Temperature Range .............................-65C to +160C V ................................................................................200mA Lead Temperature (soldering, 10s) .................................+300C OUT All Other Outputs ..............................................................20mA Soldering Temperature (reflow) .......................................+260C 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 = 3.17V to 5.5V for the MAX793T/MAX795T, V = 3.02V to 5.5V for the MAX793S/MAX795S, V = 2.72V to 5.5V for the CC CC CC MAX793R/MAX794/MAX795R, V = 3.6V, T = T to T , unless otherwise noted. Typical values are at T = +25C.) BATT A MIN MAX A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS MAX79 C 1.0 5.5 Operating Voltage Range, V V , V (Note 1) CC BATT MAX79 E 1.1 5.5 V < 3.6V 46 60 CC MAX793/MAX794, MR = V CC V < 5.5V 62 80 CC V Supply Current CC I A SUPPLY (excluding I , I ) OUT CE OUT V < 3.6V 35 50 CC MAX795 A V < 5.5V 49 70 CC V Supply Current in CC MAX793/MAX794 32 45 V = 2.1V, CC Battery-Backup Mode I A SUPPLY V = 2.3V BATT MAX795 24 35 (excluding I ) OUT BATT Supply Current 1 A (excluding I ) (Note 2) OUT BATT Leakage Current, V = 0V, V = 0V 1 A CC OUT Freshness Seal Enabled Battery Leakage Current 0.5 A (Note 3) I = 75mA V - 0.3 V - 0.125 OUT CC CC OUT Output Voltage in V I = 30mA (Note 4) V - 0.12 V - 0.050 V OUT OUT CC CC Normal Mode I = 250A (Note 4) V - 0.001 V - 0.5mV OUT CC CC I = 250A V - 0.1 V - 0.034 OUT BATT BATT OUT Output Voltage in V V = 2.3V V OUT BATT Battery-Backup Mode I = 1mA V - 0.14 OUT BATT V - CC V > V > 1.75V (Note 5) 20 65 mV SW CC V BATT MAX793T/MAX795T 2.69 2.82 2.95 Battery Switch Threshold (V falling) MAX793S/MAX795S 2.55 2.68 2.80 CC V > V BATT CC V V SW (Note 6) MAX793R/MAX795R/ 2.30 2.41 2.52 MAX794 This value is identical to the reset threshold, V rising for V > V Battery Switch Threshold V - CC BATT RST CC (V rising) (Note 7) V CC BATT V < V 25 65 mV BATT RST 2 MAX793/MAX794/MAX795