Trying to add a digital output to a Laserdisc player. The datasheet for the chipset says pin 56 is DOUT. So I ran a wire from pin 56 to a TTL=>Coax circuit, however when I use a multimeter the voltage coming from the chip is only like 2.9V....shouldn't it be ~5.00V?
Needless to say I'm not getting any output.
I didn't do anything to the chip, as I don't see like a DOUT enable pin or anything.
Any ideas?
Needless to say I'm not getting any output.
I didn't do anything to the chip, as I don't see like a DOUT enable pin or anything.
Any ideas?
hi, you may try the following which I have done to my Onkyo LD player.
LC78621 75ohm coax CS8412/4
pin56-DOUT ---------------------------> pin9-RXP
common gnd ---------------------------> pin10-RXN
(find any gnd jumper next to LC78621)
I suppose you must have missed out the gnd
LC78621 75ohm coax CS8412/4
pin56-DOUT ---------------------------> pin9-RXP
common gnd ---------------------------> pin10-RXN
(find any gnd jumper next to LC78621)
I suppose you must have missed out the gnd
It would probably be something like that measured by a multimeter even if it was working so it really don't indicate anything.the voltage coming from the chip is only like 2.9V....shouldn't it be ~5.00V?
Dout can be muted, details in the datasheet. The other issue could be how you've connected things, dout is made to drive a transformer direct again see the datasheet.
A 8 said:Dout can be muted, details in the datasheet. The other issue could be how you've connected things, dout is made to drive a transformer direct again see the datasheet.
hi A8, do you mind sharing how could I disable the MUTE function in this chip....I know very little in digital world
Thanks in advance!
PS : I connected the DOUT to CS8414 via 1:1 Pulse Trans in my external DAC.
A 8 said:Dout can be muted, details in the datasheet. The other issue could be how you've connected things, dout is made to drive a transformer direct again see the datasheet.
Heres the inspiration I used. The only thing I could think of was the mute pin.
The datasheet says 0.5vpp for dout so it is probably too low for your 74hc04 to detect any pulses.Heres the inspiration I used. The only thing I could think of was the mute pin.
For testing you could connect dout via a cap directly to spdif in and see what happens.
why do you need 74hc04 in the first place?
I connected the DOUT from LC78621 with coax cable directly to my digital receiver CS8414 via a 0.1uF wima mkp cap and 1:1 pulse trans (all in my DIY DAC). No problem with the output level.
coax
LC78621 pin56 (Dout) --------->0.1uF---->pulse trans--->cs8414
LC78612 gnd -------------------->DAC gnd
coax schield
I connected the DOUT from LC78621 with coax cable directly to my digital receiver CS8414 via a 0.1uF wima mkp cap and 1:1 pulse trans (all in my DIY DAC). No problem with the output level.
coax
LC78621 pin56 (Dout) --------->0.1uF---->pulse trans--->cs8414
LC78612 gnd -------------------->DAC gnd
coax schield
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