HA16117F Datasheet | Hitachi Semiconductor

Description The HA16117F Series of ICs make a micro-processor (MPU) system fail-safe by monitoring its power supply to detect voltage drops, and monitoring a P-RUN (program running) pulse to detect system crashes. Also referred to as watchdog timers, these devices are essential in systems that aim for high levels of crash protection. Fabricated by a CMOS process, they consume little power and are ideally suited for batteryoperated systems. These ICs are available in versions for industrial and munications equipment and automotive applications, as well as for consumer products. Functions - Power-on reset  Sends a RES signal to the MPU for a fixed time at power-on - Watchdog timer (WDT)  Monitors a P-RUN signal from the MPU and sends the MPU a RES signal if P-RUN departs from a set frequency range - Auto-reset  Outputs RES signals to the MPU at clocked intervals while P-RUN remains abnormal - Supply voltage supervision  Outputs a low RES signal if the supply voltage (same as the MPU's VCC) falls below a low threshold level (VTL). The threshold differs for different ICs in the series, allowing designers to choose an IC matching system requirements (see ordering information) Features - Low power consumption : Operating (ACC pin low) = 0.5 m W (Typ) : Standby (ACC pin high) = 0.2 m W (Typ) - Watchdog timer on/off control by ACC input signal - Independent auto-reset high and low times (t RH and t RL) - Watchdog monitoring by frequency filtering (independent of duty cycle) - High-precision low voltage detection (±2%) - Space- and weight-saving 8-pin SOP package HA16117F Series Ordering Information The HA16117F Series includes three ICs with different low threshold levels (VTL). Type No. HA16117FPA/FPAJ HA16117FPB/FPBJ HA16117FPC/FPCJ Low Threshold Voltage (VTL) 4.4 V Typ 4.2 V Typ 4.0 V Typ Pin Arrangement VCC P-RUN CF CR 1 2 3 4 8 7 6 5 Tadj ACC GND RES (Top view) Pin Description Pin No. 1 2 3 4 5 6 7 8 Symbol VCC P-RUN CF CR RES GND ACC Tadj - Function Power...