That`s true for TL7705A.
For TL7705B and TLC7705 the reset line is at defined state for Vññ >= 1V.

I have used MAX1232:
+ adjustable watchdog timer;
+ power monitor with adj. tolerance for power-up, power-down, brown-out conditions;
+ manual reset input with debounce.
? 8 pin DIP.

As well, Atmel has published datasheet External Brown-out Protection for C51
Microcontrollers with Active High Reset Input where at the end of the document they indicate list of power supervisors and other ICs.

Regards,
Oleg