TL431: Difference between TL431/2 and ATL431/2

Part Number: TL431

Tool/software:

Hi,

Q1. Difference between TL431/2 and ATL431/2
The reference voltage Typ for TL431/432 is 2.495V, while the reference voltage Typ for ATL431/432 (including LI) is 2.500V. Could you tell me the reason for this change?

Q2. Package lineup
While TL431/432 has a wide range of lineups, TL431/432 (including LI) has a narrower lineup. Could you tell me the reason for this?

Q3. About TL431 SOT-23-5
It is recommended that the 2 pins of SOT-23-3 be used at anode potential or open, but if they are connected to anode potential, will the substrate be at a stable potential, which will improve noise immunity?

Thanks,

Conor

  • Hi Conor,

    1. The TL431 2.495V was typical of competition devices when it was released. I am not 100% as to why when the ATL431 was created that design swapped it to 2.5V, but I can speculate that it was to accommodate for a more standard reference voltage.

    2. I assume by lineups you mean packages. The TL431 is an older device and has a wider variety of application use cases due to the higher operating current, therefore there are more requested package options.

    3. Pin 2 can either be connected to the anode or left floating, both configurations have the same noise immunity. 

    Thanks,
    Joshua