Voltage Detector IC?
The attached photo is of a component from the logic board of a Toshiba hard disk drive (probably over 30 years old, ST412 interface). It's a 3-lead TO92 package, this one is dead if only because the middle pin has now dropped off.
The writing on the device reads
<logo that looks like SWS> 74
T520D
I can find nothing about it with Google.
I'll put the device in 'context'. There's an 8049 microcontroller on the board too. The reset/ pin has the standard circuit of a capacitor to ground and a resistor + diode in parallel to +5V. The 3 pins of this device are connected to ground, +5V, and the reset line.
My guess is that the last pin is an open-collector or open-drain output It holds the reset line low until the 5V line reaches a particular voltage (say around 4.75V), then releases it, the capacitor charges via the resistor and then the microcontroller starts up.
Anyway, any ideas about it, and what I could replace it with?
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