HA16129AFPJ

Single Watchdog Timer

ADE-204-067 (Z)

Rev. 0

Mar. 2001

Description

The HA16129AFPJ is a watchdog timer IC that monitors a microprocessor for runaway. In addition to the

watchdog timer function, the HA16129AFPJ 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

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 HA16129AFPJ incorporates both Vout overvoltage prevention and short detection functions.

Note: 1. OUTE function: OUTE is an abbreviation for output enable.