Hello,
I accidentally broke (at least) this chip on a small wind/temperature/433MHz sensor module (though the power consumption was horrid before I broke it).
As far as I can tell, the package is SOT-23-6.
The VCC comes from two D battery cells, so VCC_max is going to be 3.0 volts or so. It seems to stop functioning at around 1.85 volts, so VCC_min is somewhere around 1.85 volts.
The part number is 7A50a.
The part is connected directly to the battery via pin 6.
The part is connected to the battery through an inductor via pin 5.
Pin 4 is used by the micro (labeled CLCK1).
Pin 3 is a test point.
Pin 2 is connected directly to ground.
Pin 1 is connected to a "J26.000" (26 MHz) crystal oscillator.