HA16129FPJ Datasheet, PDF (1/23 Pages) Hitachi Semiconductor – Single Watchdog Timer

HA16129FPJ
Single Watchdog Timer
REJ03F0144-0300
(Previous: ADE-204-027B)
Rev.3.00
Jun 15, 2005
Description
The HA16129FPJ is a watchdog timer IC that monitors a microprocessor for runaway. In addition to the watchdog
timer function, the HA16129FPJ also provides a function for supplying a high-precision stabilized power supply to the
microprocessor, a power on reset function, a power supply voltage monitoring function, and a fail-safe function that
masks the microprocessor outputs if a runaway is detected.
Functions
• Watchdog timer (WDT) function
Monitors the P-RUN signal output by the microprocessor, and issues an auto-reset (RES) signal if a microprocessor
runaway is detected.
• Stabilized power supply
Provides power to the microprocessor.
• Power on and clock off functions
The power on function outputs a low level signal to the microprocessor for a fixed period when power is first
applied.
The clock off function outputs a RES signal to the microprocessor a fixed period after a runaway occurs.
• Power supply monitoring function
When the reference voltage (Vout) falls and becomes lower than the NMI detection voltage (4.63 V, Typ) or the
STBY detection voltage (3.0 V Typ), this function outputs either an NMI signal or an STBY signal, respectively.
Note that NMI detection can be set to monitor either V_CC or Vout.
• OUTE function^*1 (fail-safe function)
Outputs a signal used to mask microprocessor outputs when a microprocessor runaway has been detected.
• RES delay function
Sets the delay between the time the NMI signal is output and the time the RES signal is output.
• Protection functions
The HA16129FPJ incorporates both Vout overvoltage prevention and current limiter functions.
Note: 1. OUTE function: OUTE is an abbreviation for output enable.
Features
• High-precision output voltage: 5.0 V ± 1.5%
• The WDT supports both frequency and duty detection schemes.
• High-precision power supply monitoring function: 4.625 V ± 0.125 V
• Built-in OUTE function
• All functions can be adjusted with external resistors and/or capacitors.
Rev.3.00 Jun 15, 2005 page 1 of 22