Part Number: LM317
Tool/software:
Hi,
I have an old design in which LM317KCS (TO-220) is used for supplying 14.2V output from 24V input to charge lead acid battery in constant voltage mode. There is an external circuit on battery which monitors voltages of each cell and cut-off the charging supply to battery when total battery voltage reaches 11.8V.
As input is 24V, this supply circuit is dissipating lot of power in LM317 and hence additional heat sink is used with chip for heat management. Is it possible to replace LM317 in this application with some other switch mode supply so as to avoid external heat sink and big package of LM317? As the load here is battery and hence I am not clear if this is possible or not. Also, if it is possible then do we have to take any additional care for this battery as load?
Thanks,
Pradeep
Part Number: LM317
Tool/software:
Hi everyone,
I'm working on a design where I replaced an LM317HVK STEEL (TO-3) with an LM317S/NOPB (TO-263). I'm seeing higher-than-expected temperatures on the TO-263.
Here's the situation:
As I understand it, the junction temperature should be the same for both solutions, and the TO-3 package should be closer to the junction temperature (Rjc = 2.3°C/W). However, observed TO-263 temperature is significantly higher.
Appreciate if you could shed some light on be contributing to the higher temperature on the TO-263 and why does TO-3 based solution experience significantly lower temperature?
Part Number: LM317
Hi,
We are currently reviewing the detailed specifications of the LM317DCY.
However, we noticed that the datasheet available on the TI website contains conflicting information between different pages. Could you please confirm which specification is correct?
Thanks,
Conor
Part Number: LM317
Tool/software:
Hello,
I have a question related to the adjustable linear regulators LM317 and/or LM338. I purchased these two components to build a constant current source. My idea was to create a source that maintains a constant current of 1,5~2A with a load of 0~10Ω.
I limited the short-circuit current of one circuit to approximately 1.5A, but when I reach a resistance value of around 6Ω, the current value starts to drop. I placed two regulators in parallel, but their output currents are not summed; they seem to be divided.
I would like to know if it is possible to increase the current. I performed SPICE simulations, and according to the simulation, the currents should be summed. I also built some circuits demonstrated in the datasheets of both components, but the current remained the same as with one regulator, even with two in use.
BR,
Felipe.
Part Number: LM317
Tool/software:
Need to have a reference circuit for using LM317 as constant current of 1mA.
application - will be use to sense temperature from PT100 sensor. (3 wire)
Voltage used is AA battery - 3V.
Part Number: LM317
Tool/software:
I am figuring out a design to Charge a E-Cap with constant current limiting using LM317 .. currently using 27V input I am charging a E-cap Bank at 1A using the precision current limiter circuit in Datasheet
Now I want to handle higher current say 1.5A-2.0 A In that case can I go with the below approach ?
Part Number: LM317
Tool/software:
Hi
Based on MPN LM317DCYR. Our Package is SOT-223 (DCY)
From given datasheet, Kindly refer the page no.5 (Figure 5-1, DCY package 4-Pin SOT-223 (Top View))
Then refer page no.35 - DCY(R-PDSO-G4)
In both pages, Pin number sequence 1,2,3,4 are not aligned with each other which means orientation is different in both pages for same package.
Also refer the below given image.
Kindly review and align both the pin numbering sequence for package drawing (page 35) as well as pin configuration and functions (page 5).
Awaiting your response.
Website: https://www.ti.com/product/LM317/part-details/LM317DCYR
Datasheet: https://www.ti.com/lit/ds/symlink/lm317.pdf?ts=1751379021183&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252Fko-kr%252FLM317%252Fpart-details%252FLM317DCYR%253Futm_source%253Dgoogle%2526utm_medium%253Dcpc%2526utm_campaign%253Dapp-null-null-OPN_EN-cpc-storeic-google-kr_kr_pur%2526utm_content%253DDevice%2526ds_k%253DLM317DCYR%2526DCM%253Dyes%2526gad_source%253D1%2526gad_campaignid%253D22524984210%2526gclid%253DEAIaIQobChMImrauneubjgMVp9sWBR2SYSaeEAAYASAAEgLXD_D_BwE%2526gclsrc%253Daw.ds
Regards
Vishal Sharma
Keysight Technologies
Part Number: LM317
Tool/software:
Requesting for LM317 revision Y datasheet for cross check the thermal difference between the rev Y & Z
Part Number: LM317
Tool/software:
Hello,
Following the PCN# 20250618000.1, I have a question about the pinout in SOT223 package.
In top view i can see a difference in the pinout if i do a rotation with the old drawing to be like the new one.
Could you confirm if there is a mistake or not ? could you confirm that there is no inversion between Adjust pin and Input pin with the new silicon?
I think it is a mistake because in the layout example there is no difference between the new and old chip but i need confirmation.
BR
Part Number: LM317
Hello TI Team,
I have a question regarding LDO regulators. For example, let’s assume an input voltage of 24V and an output of 3.3V at 300 mA. In this case, the power dissipation would be approximately:
(24V−3.3V)×0.3A=6.21W
My first question is: although the device is specified to support up to 1.5A output current, it seems that from a power dissipation perspective, the device cannot handle 24V to 3.3V at 300 mA without overheating. Is that correct? Could you explain why the datasheet lists 1.5A as the maximum output current?
My second question: under conditions like 24V to 3.3V at 300 mA (around 6.21W dissipation), should I use a DC-DC converter instead of an LDO? I would like to understand the exact criteria for choosing between LDO and DC-DC in such cases. (If a heatsink is used, would this LDO still be feasible? I would appreciate TI engineers’ opinion on this.)
Thank you for your support.