HA16117FPAJ Renesas, HA16117FPAJ Datasheet - Page 3

• Manufacturer Part Number: HA16117FPAJ
• Description: Watch Dog Timer
• Manufacturer: Renesas

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 battery-
operated systems.
These ICs are available in versions for industrial and communications equipment and automotive
applications, as well as for consumer products.
Functions
Features
Power-on reset
Watchdog timer (WDT)
Auto-reset
Supply voltage supervision
Low power consumption : Operating (ACC pin low) = 0.5 mW (Typ)
Watchdog timer on/off control by ACC input signal
Independent auto-reset high and low times (t
Watchdog monitoring by frequency filtering (independent of duty cycle)
High-precision low voltage detection ( 2%)
Space- and weight-saving 8-pin SOP package
Sends a RES signal to the MPU for a fixed time at power-on
Outputs RES signals to the MPU at clocked intervals while P-RUN remains abnormal
Outputs a low RES signal if the supply voltage (same as the MPU's V
Monitors a P-RUN signal from the MPU and sends the MPU a RES signal if P-RUN departs from a
set frequency range
level (V
matching system requirements (see ordering information)
TL
). The threshold differs for different ICs in the series, allowing designers to choose an IC
: Standby (ACC pin high) = 0.2 mW (Typ)
HA16117F Series
CMOS Watchdog Timer
RH
and t
RL
)
CC
) falls below a low threshold
ADE-204-018B (Z)
Dec. 2000
Rev. 2