Other Parts Discussed in Thread: LMC555,
Dear Specialists,
My customer is considering TLC555 and LMC555 for replacing from other maker.
Could you please advise to the customer's question.
-----The customer's question is listed below---
(1) According to the datasheet of TLC555 at 8.3.2 Astable Operation（p17） , between output pin(3) and VDD(8pin) is connected RL.
Is it necessary or not?
(2)In the meantime, the datasheet of LMC555 at 8.4.2 Astable Operation(P.10), it is not connected between output pin(3) and VDD(8pin).
Should it be connected RL?
-----My considerations are listed below---
I found a sentence concerned datasheet of TLC555 at 9.2.3.2 Detailed Design Procedure(P.24), says that RL improves VOH, but it is not required for TTL compatibility.
I think Vout is reduced by highside FET loss, so RL is for improving VOH.
The datasheet VOH is 4.1Vmin and 4.8Vmax, if RL is added, VOH close more with 5V.
I also think LMC555 is the same thing, because both devices are CMOS device, in addition 555 timer is very popular series and the circuit is almost same.
Are these considerations correct?
I appreciate your great help.
Best regards,
Shinichi
