I am doing a CD player project using an old CDROM. For the digital output I am using a Sharp optical transmitter. Here is the datasheet for it.
http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp1fav51tk_e.pdf
I am a little lost about the implementation. The data sheet says I need to put an 0.1uF capacitor across the Vcc and ground which I understand but also says to put a 4.7uF capacitor across the supply line which I don't know exactly what that means.
The CDROM digital output is TTL and the optical module requires a TTL input. Would I just connect this directly or do I need some circuitry before the connecting to the Vin?
http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp1fav51tk_e.pdf
I am a little lost about the implementation. The data sheet says I need to put an 0.1uF capacitor across the Vcc and ground which I understand but also says to put a 4.7uF capacitor across the supply line which I don't know exactly what that means.
The CDROM digital output is TTL and the optical module requires a TTL input. Would I just connect this directly or do I need some circuitry before the connecting to the Vin?
The 4.7uf and 0.1uf are in parallel across the supply. The 0.1uf should be up close to the pins of the transmitter, for the 4.7uf that requirement is less strict.
Should be no problem connecting the two units together.
Should be no problem connecting the two units together.
The 0.1uF is for local high-frequency decoupling - only for the GP1FAV51TK0F
This needs to be mounted very close to the GP1FAV51TK0F, and should preferably be a SMD part, with NPO or X7R dielectric.
The 4.7uF is a lower frequency decoupler that should be mounted nearby, but is expected to be shared with other devices.
For DIY, you can use a larger value, and get better LF decoupling.
The GP1FAV51TK0F input has Vih of 2.0V min, so the interface can be direct - but you can use a resistor near the "sending end" - 43 to 68 ohm, to damp the waveform edges a little, if needed.
This needs to be mounted very close to the GP1FAV51TK0F, and should preferably be a SMD part, with NPO or X7R dielectric.
The 4.7uF is a lower frequency decoupler that should be mounted nearby, but is expected to be shared with other devices.
For DIY, you can use a larger value, and get better LF decoupling.
The GP1FAV51TK0F input has Vih of 2.0V min, so the interface can be direct - but you can use a resistor near the "sending end" - 43 to 68 ohm, to damp the waveform edges a little, if needed.
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