Playing around with the LT1228
You are viewing an old revision of this post, from November 3, 2012 @ 19:19:48. See below for differences between this version and the current revision.
At first, we’re just trying to build a simple DC-to-very-high-frequency VCA using the LT1228
Output is nice, very good colors, nice black, everything perfect…
but cv input has not our desired bandwidth. When feeding a video signal as CV it gets quite blurred. Measurements show that around 30-40khz CV gets too much damping (-3dB @ 40kHz ). Is it the protection diode D1 ? (somewhere (?) in the data sheet, Max saw that Iset (pin 5) never should be negative.)
We take it out to see if we’re able to grill the IC – or if frequency response improves.
On another note: we should buffer the output of the sk107 comparator module
Module Info
| Inputs: | |
|---|---|
| Outputs: | |
| Power Draw on +5V: | N/A |
| Power Draw on -5V: | N/A |
| Frequency Response: |
Schematic & PCB
Observations
No observations yet
Revisions:
- November 14, 2013 @ 16:12:11 [Current Revision] by Michael
- November 14, 2013 @ 16:12:11 by Michael
- November 3, 2012 @ 19:19:48 by Michael
Changes:
| November 3, 2012 @ 19:19:48 | Current Revision | ||
|---|---|---|---|
| Content | |||
| At first, we're just trying to build a simple DC-to-very-high-frequency VCA using the LT1228 | At first, we're just trying to build a simple DC-to-very-high-frequency VCA using the LT1228 | ||
| Output is nice, very good colors, nice black, everything perfect... | Output is nice, very good colors, nice black, everything perfect... | ||
| <a href="http:// synkie.net/wordpress/wp-content/ uploads/2012/ 11/Screen-Shot- 2012-11-03-at- 13.20.16.png"><img class="alignnone size-large wp-image-210" title="Screen Shot 2012-11-03 at 13.20.16" src="http://synkie.net/ wordpress/wp- content/uploads/ 2012/11/Screen-Shot-2012- 11-03-at-13.20.16- 1024x436.png | <a href="http:// synkie.net/wordpress/wp-content/ uploads/2012/ 11/Screen-Shot- 2012-11-03-at- 13.20.16.png"><img class="alignnone size-large wp-image-210" title="Screen Shot 2012-11-03 at 13.20.16" alt="" src="http://synkie.net/ wordpress/wp- content/uploads/ 2012/11/Screen-Shot-2012- 11-03-at-13.20.16- 1024x436.png" width="1024" height="436" /></a> | ||
| but cv input has not our desired bandwidth. When feeding a video signal as CV it gets quite blurred. Measurements show that around 30-40khz CV gets too much damping (-3dB @ 40kHz ). Is it the protection diode D1 ? (somewhere (?) in the data sheet, Max saw that Iset (pin 5) never should be negative.) | but cv input has not our desired bandwidth. When feeding a video signal as CV it gets quite blurred. Measurements show that around 30-40khz CV gets too much damping (-3dB @ 40kHz ). Is it the protection diode D1 ? (somewhere (?) in the data sheet, Max saw that Iset (pin 5) never should be negative.) | ||
| We take it out to see if we're able to grill the IC - or if frequency response improves. | We take it out to see if we're able to grill the IC - or if frequency response improves. | ||
| On another note: we should buffer the output of the sk107 comparator module | On another note: we should buffer the output of the sk107 comparator module | ||
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