N84C161, N84C162 Supervisory Circuits with 2 EEPROM Serial 16-Kb I C Precision Reset Controller and Watchdog Timer (16K) www.onsemi.com Description The N84C161/2 is a complete memory and supervisory solution for microcontrollerbased systems. A serial EEPROM memory (16K) with hardware memory write protection, a system power supervisor with brown out protection and a watchdog timer are integrated together in low power CMOS technology. Memory interface is via an SOIC8 2 I C bus. CASE 751BD The 1.6second watchdog circuit returns a system to a known good state if a software or hardware glitch halts or hangs the system. The PIN CONFIGURATION N84C161 watchdog monitors the SDA line, making an additional PC board trace unnecessary. The lower cost N84C162 does not have a DC 1 8 V CC watchdog timer. RESET 2 7 RESET N84C161 The power supply monitor and reset circuit protects memory and N84C162 WP 3 6 SCL system controllers during power up/down and against brownout conditions. Five reset threshold voltages support 5 V, 3.3 V and 3 V GND 4 5 SDA systems. If power supply voltages are out of tolerance reset signals become active, preventing the system microcontroller, ASIC or peripherals from operating. Reset signals become inactive typically PIN FUNCTIONS 200 ms after the supply voltage exceeds the reset threshold level. With Pin Name Function both active high and low reset signals, interface to microcontrollers DC Do Not Connect and other ICs is simple. In addition, a reset pin can be used as a debounced input for pushbutton manual reset capability. RESET Active Low Reset I/O The N84C161/2 memory features a 16byte page. In addition, WP Write Protect hardware data protection is provided by a write protect pin WP and by GND Ground a V sense circuit that prevents writes to memory whenever V falls CC CC SDA Serial Data/Address below the reset threshold or until V reaches the reset threshold CC SCL Clock Input during power up. These devices are available in a green SOIC8 package. RESET Active High Reset I/O V Power Supply CC Features Watchdog Monitors SDA Signal (N84C161) 2 ORDERING INFORMATION 400 kHz I C Bus Compatible For Ordering Information details, see page 11. 2.7 V to 6 V Operation Low Power CMOS Technology 16Byte Page Write Buffer 1,000,000 Program/Erase Cycles Builtin Inadvertent Write Protection Manual Reset V Lock Out CC Write Protection Pin, WP 100 Year Data Retention Active High or Low Reset 8Pin SOIC Precision Power Supply Voltage Monitor Commercial and Industrial Temperature Ranges 5 V, 3.3 V and 3 V Systems These Devices are PbFree, Halogen Free/BFR Free Five Threshold Voltage Options and are RoHS Compliant Semiconductor Components Industries, LLC, 2016 1 Publication Order Number: May, 2018 Rev. 1 N84C161/DN84C161, N84C162 Table 1. RESET THRESHOLD OPTION Part Dash Minimum Thresh- Maximum Thresh- Number old old 45 4.50 4.75 42 4.25 4.50 30 3.00 3.15 28 2.85 3.00 25 2.55 2.70 BLOCK DIAGRAM EXTERNAL LOAD SENSEAMPS D OUT SHIFT REGISTERS ACK V CC WORD ADDRESS COLUMN GND BUFFERS DECODERS STA RT/ STOP SDA LOGIC 16K EEPROM XDEC CONTROL WP LOGIC DATA IN STORAGE HIGH VOLTAGE/ TIMING CONTROL RESET Controller STATE COUNTERS SCL Precision SLAVE WAT CH DO G Only for ADDRESS Vcc Monitor N84C161 COMPARATORS RESETRESET www.onsemi.com 2