CAT1026, CAT1027 Dual Voltage Supervisory Circuits with EEPROM 2 Serial 2k-bit I C Description www.onsemi.com The CAT1026 and CAT1027 are complete memory and supervisory solutions for microcontrollerbased systems. A EEPROM Serial 2 2kbit I C memory and a system power supervisor with brownout protection are integrated together in low power CMOS technology. 2 Memory interface is via a 400 kHz I C bus. The CAT1026 and CAT1027 provide a precision VCC sense circuit with five reset threshold voltage options that support 5 V, 3.3 V and SOIC8 TSSOP8 CASE 751BD CASE 948S 3 V systems. The power supply monitor and reset circuit protects memory and systems controllers during power up/down and against brownout conditions. If power supply voltages are out of tolerance reset signals become active preventing the system microcontroller, ASIC, or peripherals from operating. The CAT1026 features two open drain reset outputs: one (RESET) MSOP8 TDFN8 CASE 846AD CASE 511AL drives high and the other (RESET) drives low whenever VCC falls below the threshold. Reset outputs become inactive typically 200 ms after the supply voltage exceeds the reset threshold value. With both active high and low reset signals, interface to microcontrollers and ORDERING INFORMATION other ICs is simple. CAT1027 has only a RESET output. In addition, For Ordering Information details, see page 13. the RESET pin can be used as an input for pushbutton manual reset capability. The CAT1026 and CAT1027 provide an auxiliary voltage sensor input, VSENSE, which is used to monitor a second system supply. The auxiliary high impedance comparator drives the open drain output, V , whenever the sense voltage is below 1.25 V threshold. LOW The CAT1027 is designed with a 1.6 second watchdog timer circuit that resets a system to a known state if software or a hardware glitch halts or hangs the system. The CAT1027 features a watchdog timer interrupt input, WDI. The onchip 2kbit EEPROM memory features a 16byte page. In addition, hardware data protection is provided by a V CC sense circuit that prevents writes to memory whenever V falls below the reset threshold or until VCC reaches the reset CC threshold during power up. Available packages include a surface mount, 8pin SOIC, 8 pin TSSOP, 8 pin TDFN and 8pin MSOP packages. The TDFN package thickness is 0.8 mm maximum. TDFN footprint is 3 x 3 mm. Features Precision V Power Supply Voltage Monitor 16Byte Page Write Buffer CC 5 V, 3.3 V and 3 V Systems Builtin Inadvertent Write Protection Five Threshold Voltage Options 1,000,000 Program/Erase Cycles Additional Voltage Monitoring Manual Reset Capability Externally Adjustable Down to 1.25 V 100 Year Data Retention Watchdog Timer (CAT1027 Only) Industrial and Extended Temperature Ranges Active High or Low Reset 8Pin, SOIC, TSSOP, MSOP or TDFN (3 x 3 mm Valid Reset Guaranteed at VCC = 1 V footprint) Packages 2 400 kHz I C Bus TDFN max Height is 0.8 mm 2.7 V to 5.5 V Operation These Devices are PbFree, Halogen Free/BFR Free Low Power CMOS Technology and are RoHS Compliant Semiconductor Components Industries, LLC, 2011 1 Publication Order Number: May, 2018 Rev. 19 CAT1026/DCAT1026, CAT1027 Table 1. RESET THRESHOLD OPTION Part Dash Minimum Maximum Number Threshold Threshold 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 WORDADDRESS COLUMN V SS BUFFERS DECODERS START/STOP SDA LOGIC 2kbit EEPROM XDEC CONTROL LOGIC DATA IN STORAGE HIGHVOLTAGE/ V CC Monitor TIMING CONTROL V CC STATE COUNTERS SCL RESET SLAVE + ADDRESS Controller WDI - COMPARATORS (CAT1027) V REF Auxiliary Voltage Monitor RESET RESET (CAT1026) V + SENSE V LOW - V REF www.onsemi.com 2