ssm2164_getting_started
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ssm2164_getting_started [2018/04/26 17:03] phatline [Class A] |
ssm2164_getting_started [2018/04/26 19:28] (current) phatline |
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| seppomans building information;[[ssm2164_pcb]]\\ | seppomans building information;[[ssm2164_pcb]]\\ | ||
| the following informations are take from the midibox forum, its a collection of infos, without the claim to be 100% true, i will try to test the given information. | the following informations are take from the midibox forum, its a collection of infos, without the claim to be 100% true, i will try to test the given information. | ||
| + | |||
| + | ====== Shematic ====== | ||
| + | not found anywhere... m( \\ | ||
| + | also reverse engeniering/understanding/troubleshooting/moding is nearly impossible when the pcbs are stuffed, because most of the traces are on the component site... or hidden behind the black paint\\\ | ||
| + | --- first i want to know for what are those POTs? Input Gain of Audio? or of CV? or some BIAS? seppoman said nothing...\\ | ||
| + | POT P1 middle & right Pin connected to VCC-\\ | ||
| + | POT P1 left Pin connected to a 27K Resistor and this resistor to a nother 27K Resistor which is connected to CV1+ Input. the middle point of this2xresistors is going to the TL74-OP-Amp Pin1 which is a inverting input...\\ | ||
| + | The Output of this TL74 Stage is Pin1: its connected to Pin 6 SSM2164, which is the CV-Input\\ | ||
| + | When i measure Pin6 to Ground, and Turn P1 most left:1,8V... Turn P1 most right: 2,47V\\ | ||
| + | so what does it? no one said: its a zero offset for bipolar cv? or is it gain-control? FIXME m( \\ | ||
| + | |||
| ====== Power ====== | ====== Power ====== | ||
| Line 73: | Line 84: | ||
| SSM2164 Pin 1 (the first pin) sets the "Mode" | SSM2164 Pin 1 (the first pin) sets the "Mode" | ||
| ==== Class AB ==== | ==== Class AB ==== | ||
| - | Pin is Open, no Resistor to +12V (PCB Default)\\ | + | Pin 1 is Open, no Resistor to +12V (PCB Default)\\ |
| Lower current results in higher distortion/lower noise.\\ | Lower current results in higher distortion/lower noise.\\ | ||
| + | ---i do want distortion and dont care about noise--- so i do not change anything, the pcb is fine. | ||
| ==== Class A ==== | ==== Class A ==== | ||
| - | Pin is Connected to +12V via a Resistor\\ | + | Pin 1 is Connected to +12V via a Resistor\\ |
| Higher current results in lower distortion/higher noise\\ | Higher current results in lower distortion/higher noise\\ | ||
| lets look in the datasheet:\\ | lets look in the datasheet:\\ | ||
| {{:phatline:ssm2164-ab-a.png?600|}}\\ | {{:phatline:ssm2164-ab-a.png?600|}}\\ | ||
| Figures 11 and 12 show the THD and noise performance of the | Figures 11 and 12 show the THD and noise performance of the | ||
| - | SSM2164 as the bias current is adjusted. Notice the two | + | SSM2164 as the bias current is adjusted\\ |
| - | characteristics have an inverse characteristic.\\ | + | |
| - | The quiescent current in the core is set by adding a single | + | |
| - | resistor from the positive supply to the MODE pin.\\ the formula for the | + | |
| - | MODE current is:\\ | + | |
| I_MODE = ( (V+)−0.6V )/ RB\\ | I_MODE = ( (V+)−0.6V )/ RB\\ | ||
| 1,52mA = (12V-0.6V) / 7,5K\\ | 1,52mA = (12V-0.6V) / 7,5K\\ | ||
| Leaving the MODE pin open sets the SSM2164 in Class AB with 30 μA in the Gain-Core\\ | Leaving the MODE pin open sets the SSM2164 in Class AB with 30 μA in the Gain-Core\\ | ||
ssm2164_getting_started.1524762226.txt.gz · Last modified: 2018/04/26 17:03 by phatline
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