CAT1024, CAT1025 Supervisory Circuits with 2 EEPROM Serial 2k-bit I C and Manual Reset Description www.onsemi.com The CAT1024 and CAT1025 are complete memory and supervisory solutions for microcontroller based systems. A 2k bit serial EEPROM 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 CAT1025 provides a precision VCC sense circuit and two open drain outputs: one (RESET) drives high and the other (RESET) drives TSSOP8 SOIC8 CASE 948S CASE 751BD low whenever VCC falls below the reset threshold voltage. The CAT1025 also has a Write Protect input (WP). Write operations are disabled if WP is connected to a logic high. The CAT1024 also provides a precision VCC sense circuit, but has only a RESET output and does not have a Write Protect input. MSOP8 TDFN8 All supervisors have a 1.6 second watchdog timer circuit that resets CASE 846AD CASE 511AL a system to a known state if software or a hardware glitch halts or hangs the system. For the CAT1024 and CAT1022, the watchdog timer monitors the SDA signal. The CAT1023 has a separate watchdog ORDERING INFORMATION timer interrupt input pin, WDI. For Ordering Information details, see page 13. The power supply monitor and reset circuit protect memory and system controllers during power up/down and against brownout conditions. Five reset threshold voltages support 5 V, 3.3 V and 3 V 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 200 ms after the supply voltage exceeds the reset threshold level. With both active high and low reset signals, interface to microcontrollers and other ICs is simple. In addition, the RESET pin or a separate input, MR, can be used as an input for pushbutton manual reset capability. The CAT1024/25 memory features a 16byte page. In addition, hardware data protection is provided by a VCC sense circuit that prevents writes to memory whenever VCC falls below the reset threshold or until VCC reaches the reset threshold during power up. Available packages include a surface mount 8pin SOIC, 8 pin TSSOP, 8pin TDFN and 8pin MSOP packages. The TDFN package thickness is 0.8 mm maximum. TDFN footprint is 3 x 3 mm. Features Precision Power Supply Voltage Monitor Builtin Inadvertent Write Protection 5 V, 3.3 V and 3 V Systems WP Pin (CAT1025) Five Threshold Voltage Options 1,000,000 Program/Erase Cycles Active High or Low Reset Manual Reset Input Valid Reset Guaranteed at VCC = 1 V 100 Year Data Retention 2 400 kHz I C Bus Industrial and Extended Temperature Ranges 2.7 V to 5.5 V Operation Green Packages Available with NiPdAu Lead Finished Low Power CMOS Technology These Devices are PbFree, Halogen Free/BFR Free 16Byte Page Write Buffer and are RoHS Compliant Semiconductor Components Industries, LLC, 2011 1 Publication Order Number: May, 2018 Rev. 21 CAT1024/DCAT1024, CAT1025 Table 1. THRESHOLD VOLTAGE 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 WP* LOGIC DATA IN STORAGE HIGHVOLTAGE/ TIMING CONTROL RESET Controller STATE COUNTERS SCL Precision SLAVE MR ADDRESS Vcc Monitor COMPARATORS RESET* RESET *CAT1025 Only www.onsemi.com 2