LM3630A overcurrent abnormality detection problem

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LM3630A overcurrent abnormality detection problem [Copy link]

Question 1: I would like to ask a question about the use of LM3630A. When we use one LM3630A, two LED strings are driven at the same time, and the other string cannot detect a short circuit. Can the short-circuit detection of the IC work when both LED strings are turned on at the same time? Answer: See page 25 of the datasheet: The LM3630A features an LED short fault flag indicating if either of the LED strings have experienced a short. Follow-up question: But I can only detect one string of abnormalities, but not the other string. Is there any reference setting? Answer: I don't quite understand why you can't detect two paths. After enabling the short-circuit detection function of LM3630A, you can read bit3 and bit4 of register 0x0B to know which path is short-circuited. Is my understanding wrong? I'm sorry, but I want to ask if I can capture the data released by 0x0B if I use TI's test module, because I want to determine which LED string has a problem.

I have found the location where I can see the instructions, but I encountered a problem when testing. Can you help me solve my confusion? I am now using two LED lights to light up, but my short-circuit detection only detects the short circuit of LED1 and returns the short-circuit message. The part of LED2 has not been detected. If only LED2 is lit, the short-circuit message of LED2 can be seen. Is it true that only one group of short-circuit messages can be detected when both LEDs are turned on at the same time?

Question 2: LM3630 reads data incorrectly The LM3630A module has two LED strings, LED_A and LED_B. In the short-circuit test, when LED_A is short-circuited, the return value read by the test software is correct. However, when LED_B is short-circuited, the return value is wrong. Why? (1) What is the solution? (2) What are the test steps? As mentioned above, according to the LM3630 specification, when LED_B is short-circuited, the value 0x1C should be returned to be correct. Answer: You can try again, refresh the GUI interface or click the Read button again. Sometimes the GUI interface may not read back the status in time. This LED short-circuit test is only for production testing. This method of testing cannot read back. May I ask, when you said: [This LED short-circuit test is only for the production test stage], do you mean that when we actually design the circuit and use the LM3630 IC, there is no function to return the short-circuit value after a short circuit? This function does exist, but it is mentioned in the data sheet and is not recommended for normal operation. This material is relatively old. Can you explain your application requirements? We have new LM3697, LM36272, LM36923H. Can they meet your needs? We need an LED driver IC with OVP and OCP protection, We don't want the IC to burn out due to the current recharging after a short circuit. We see that this LM3630 (OVP and OCP) has met our needs. I just don't understand why it is not recommended to use it in normal operation? Short circuit detection should also be a way to improve circuit protection, allowing users to programmatically disconnect the power supply. The development board returns an error. Is there a solution at present? LM3697, LM36272, LM36923H, these three are references first, and I will ask you if I have any questions. Gavin Siew See if the chip itself can protect it. Don't look at the software, just use the chip directly. It may be a software problem.

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