Other Parts Discussed in Thread: LM358, OPA313
Hi Sir
We need to test the frequency of the crystal oscillator, One design is count by MCU, Another design is LM231。
About LM231,Could you help to check the whole schematic? (some questions about 2-pole Filter, OPA U112B, Could we use LM358 for this Filter)
Because Figure 19 in the datasheet shows a negative voltage output, but we need to meet the ADC input spec:0<Input<5V, Could you help to check the schematic carefully
for this portion?.
Another question:
The test clock is 32.768Khz(From crystal oscillator)
Which design is better (Design1 or Design 2):
Design1 Without Frequency division(U119) :
>> Fin(Pin6)=4096Hz Rf=100K(R416)
Vout=4096Hz*2.09V*(100Kohm/14Kohm)*6.8K*0.01uF=4.158V
Design 2 (Frequency Factor=2^3=8):
>>Fin(Pin6)=32.768KHz Rf=12.4K(R416)
Vout=32768Hz*2.09V*(12.4Kohm/14Kohm)*6.8K*0.01uF=4.125V
LM231 footprint is PDIP, It is unpopular, and has few designs using it.
Why does Ti Still keep it, Could we use LM231/331 in a new design? (I am worried about if it will be EOL)
And does Ti have Plan to re-design a new footprint (For SMT)? I only can find another design about Freq-Voltage on the ADI website is AD650.
Foxconn Qin