MAX795 MAXIM [Maxim Integrated Products], MAX795 Datasheet
MAX795
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MAX795 Summary of contents
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... MAX793_CSE MAX793_EPE MAX793_ESE Ordering Information continued on last page. * The MAX793/MAX795 offer a choice of reset threshold voltage. Select the letter corresponding to the desired reset threshold voltage range (T = 3.00V to 3.15V 2.85V to 3.00V 2.55V to 2.70V) and insert it into the blank to complete the part number. The MAX794’s reset threshold is adjustable. ...
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... 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 MAX793R/MAX794/MAX795R 3.6V, T BATT ...
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... Adjustable Microprocessor ELECTRICAL CHARACTERISTICS (continued 3.17V to 5.5V for the MAX793T/MAX795T MAX793R/MAX794/MAX795R 3.6V, T BATT PARAMETER SYMBOL Reset Threshold (Note 8) V RST RESET IN Threshold V RST IN (MAX794 only) RESET IN Leakage Current (MAX794 only) Reset Timeout Period t RP LOWLINE-to-Reset Threshold LOWLINE Falling ...
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... Adjustable Microprocessor Supervisory Circuits ELECTRICAL CHARACTERISTICS (continued 3.17V to 5.5V for the MAX793T/MAX795T MAX793R/MAX794/MAX795R 3.6V, T BATT PARAMETER SYMBOL RESET Output Voltage Low V OL BATT ON Output V OL Voltage Low V All Inputs Including PFO IH (Note 10 MANUAL RESET INPUT MR Pulse Width t MR MR-to-Reset Delay ...
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... FALLING 100 -40 - TEMPERATURE ( C) V SUPPLY CURRENT vs. TEMPERATURE CC (NORMAL OPERATING MODE) 70 MAX793/ MAX795 MAX793/ MAX795 3. 250 BATT 0 80 100 -40 - TEMPERATURE ( C) RESET COMPARATOR PROPAGATION DELAY vs. TEMPERATURE ( MAX ...
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Adjustable Microprocessor Supervisory Circuits ____________________________Typical Operating Characteristics (continued +25°C, unless otherwise noted.) A MAX794 RESET IN THRESHOLD AND LOWLINE-TO-RESET IN THRESHOLD vs. TEMPERATURE 1.242 1.241 V RESET IN 1.240 1.239 LOWLINE RST 1.238 1.237 ...
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... Adjustable Microprocessor ______________________________________________________________Pin Description PIN NAME MAX793/ MAX795 MAX794 1 1 OUT BATT OK (MAX793) 3 — RESET IN (MAX794) 4 — PFI 5 3 BATT GND 7 — PFO 8 — — WDO 10 — WDI OUT 13 — RESET 14 — LOWLINE 15 7 RESET ...
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... Adjustable Microprocessor Supervisory Circuits _______________Detailed Description General Timing Characteristics The MAX793/MAX794/MAX795 are designed for 3.3V and 3V systems, and provide a number of supervisory functions (see the Selector Guide on the front page). Figures 1 and 2 show the typical timing relationships of the various outputs during power-up and power-down with typical V rise and fall times ...
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Adjustable Microprocessor brownout conditions. RESET is guaranteed logic low for 0V < V < RST greater than 1V. Without a backup battery ( RESET is guaranteed valid for V CC ...
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... Reset is guaranteed to assert before the power supply falls below 2.85V (3.3V - 14%). The MAX793R/MAX795R are optimized to monitor 3.0V ±10% power supplies. Reset will not occur until V falls below 2.7V (3.0V - 10%), but is guaranteed to occur before the supply falls below 2.55V (3.0V - 15%). ...
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... Figure 6. Generating a Reset on Each Watchdog Fault Internal gating of chip-enable (CE) signals prevents erro- neous data from corrupting CMOS RAM in the event of an undervoltage condition. The MAX793/MAX794/MAX795 use a series transmission gate from OUT (Figure 7). During normal operation (reset not asserted), the CE transmission gate is enabled and passes all CE transitions ...
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... Adjustable Microprocessor Supervisory Circuits MAX793 MAX794 MAX795 CHIP-ENABLE OUTPUT CONTROL RESET P GENERATOR Figure 7. Chip-Enable Transmission Gate The CE transmission gate remains disabled and CE IN remains high impedance (regardless activity) for the first half of the reset timeout period (t time a reset is generated. While disabled high impedance. When the CE transmission gate is enabled, the impedance appears as a 46Ω ...
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... If the system MAX793 must also contend with a more rapid V MAX794 as when the main battery is disconnected or a high- MAX795 side switch is opened during normal operation, use capacitance on the V CE OUT the shutdown routine (Figure 11). First, calculate the worst-case time required for the sys- ...
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Adjustable Microprocessor Supervisory Circuits MAX793 PFI MAX794 R2 GND PFO TRIP – TRIP PFT PFH ...
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Adjustable Microprocessor V RST V CC 3.6V 3.3V V OUT V = 3.6V BATT Figure 13. Battery Switchover Timing Table 1. Input and Output Status in Battery-Backup Mode PIN NAME STATUS Connected to BATT through an internal OUT 140Ω ...
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... V is absent even though a backup CC battery is connected to the BATT input. Applications that do not use the MR input (including all MAX795 applications) are unaffected by this phenomenon. Also, applications that do not use PFO are unaffected if PFI is tied ...
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... TRIP TRIP PFT – H PFT PFH WHERE V = 1.237V PFT V = 10mV PFH V = DIODE FORWARD VOLTAGE DROP TRIP RESET RESET N P MAX793 MAX794 MAX795 GND GND *OPTIONAL ...
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... PFI. PFO can be used to generate an interrupt to the µ cause reset to assert (Figure 12). Since the RESET output is open drain, the MAX793/ MAX794/MAX795 interface easily with µPs that have bidirectional reset pins, such as the Motorola 68HC11. Connecting the RESET output of the µP supervisor ...
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... MAX795_ESA -40°C to +85°C * The MAX793/MAX795 offer a choice of reset threshold voltage. Select the letter corresponding to the desired reset threshold volt- age range (T = 3.00V to 3.15V 2.85V to 3.00V 2.55V to 2.70V) and insert it into the blank to complete the part number. ...
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Adjustable Microprocessor Supervisory Circuits ________________________________________________________Package Information Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit ...