Have a look at this:
SSM2529 Datasheet and Product Info | Analog Devices
There a few issues:
1. converting binary digital codes to pulse width modulation.
This can be a DAC and analog PWM or ~2.89GHz counter for 16 bits at 44KHz
2. gain control
3. Power supply noise rejection
SSM2529 Datasheet and Product Info | Analog Devices
There a few issues:
1. converting binary digital codes to pulse width modulation.
This can be a DAC and analog PWM or ~2.89GHz counter for 16 bits at 44KHz
2. gain control
3. Power supply noise rejection