LM8364: Pls suggestion: Low power consumption comparator to replace LM2903DR2G on input undervoltage/overvoltage protection circuit

Hi Eric,

We can definitely help you find an undervoltage/overvoltage solution for your solution. Since you are using it for this purpose, I think it would be better here to use a voltage supervisor/reset IC that can monitor a rail for both UV and OV conditions, as these devices have integrated voltage references.

Please take a look at the TPS3703-Q1 (http://www.ti.com/lit/ds/symlink/tps3703-q1.pdf). This device has low current consumption (4.5 uA typ) and can achieve a very high threshold accuracy (+/-0.25% typ).

If you need me to take a look at your system requirements (voltage of rail monitored, thresholds, delay time, etc) let me know here and we can see if there is a better solution than this for your system.

Thanks,
Abhinav.

Hi Abhinav,

 Tks for your answers. 

 Here'are undervoltage/overvoltage levels:

 undervoltage: AC input: 170Vac (bus voltage 230Vdc), undervoltage protection and 8Vdc-10Vdc hysterisis

 Overvoltage AC input 270Vac (bus voltage 360Vdc), Overvoltage protection and 8Vdc-10Vdc hysterisis

 Plus: If the comparator could PIN TO PIN compatible with LM2903DR2G will be better. Tks, Abhinav.  

BR,

Xiaobing (Eric)

Hi Team,

 Any one can suggest me a comparator which are dual comparator and PIN TO PIN compatible with LM2903DR2G, also low power consumption is required. Tks. 

BR,

Xiaobing (Eric)

Hi teams,

Any one can helps? Tks a lot.

BR,

Xiaobing (Eric)

Hi Eric,

We do not have a pin to pin compatible device with the LM2903 in a voltage supervisor form, but please take a look at TPS3700 which may be able to accomplish your HV needs after voltage dividing down.

Please also take a look at this app note: http://www.ti.com/lit/an/snva849/snva849.pdf

Thanks,
Abhinav.

Hi Abhinav,

 Well noted with tks.

  By the way, can I have your suggestion for low power consumption comparator and PIN TO PIN compatible with LM2903DR2G, ON semiconductor have one low power consumption-NCS2220, but unfortunately, which package is UDFN8. Can I have your suggestion? Tks.

BR,

Xiaobing (Eric)

Eric,

I am not sure of a pin to pin part within our devices, but I will loop in the comparator team to see if they have any low-Iq options for you.

Thanks,
Abhinav.

Abhinav,

 Tks a lot. Any updating from comparator team? Tks. 

BR,

Xiaobing (Eric)

Eric

Sorry for the delayed response.  Your E2E thread was incorrectly assigned to the wrong group and was only transferred to the comparator team today.  I will address this internally to improve our customer support.

What is the supply voltage for the comparator?  We have several dual channel devices that would be pin compatible to the LM2903DR2G SOIC package.

For example, if your operating voltage is less than 15V, the LMC6772 may be an option for you to consider that has much lower quiescent current.

Also, if you have a schematic of your circuit that you can share that may helpful.  From the description of your circuit, are you resistor dividing down the ac-mains or using a transformer to divide them down to the comparator operating range?

Chuck

Chuck,

 Tks Chuck.

 The LM2903DR2G is powered +5V from bus+ by a regulator. During bus voltage lower than 220Vdc or greater than 3370Vdc, the comparator should trigger UC3844's COMP, also 10Vdc-15Vdc hysteresis function is necessary. 

 I'm tried to use a zener diode and LM2903DR2G to achieve above target, but I found the power dissipation on R16 is too higher, so I change the mind:

 1. Try to used NCP431BVSNT1G to replace D2,

 2. Replace transistor by a MOSFET,

 3. Would like to try a low power consumption comparator to replace LM2903DR2G. Also have other requirement for this comparactor: Low cost, general chip, industrial application, and pin to pin to replace LM2903DR2G. Can I have your suggestions? Tks.  

BR,

Xiaobing (Eric)

Hi Chuck, 

 Tks for your answer. 

 I don't know what happened during I submit my sch, questions and answer, I didn't find it on this topics. I'm typing again. 

 The schematic as following diagram:

 During bus+ voltage less than 260Vdc and greater than 380Vdc, the Q1 will be triggered. 

 I'm tried to use LM2903DR2G and zener diode and found power dissipation on R16 is too high, so I changed the mind:

 1. Change Zener diode to NCP431BVSNT1G (Any TI components suggestion? PIN TO PIN);

 2. Change low power consumption comparator to replace LM2903DR2G.

 Any suggestion for following diagram and compartor? Tks. 

BR,

Xiaobing (Eric)

Eric

Thanks for sharing the details.  I will review this further tomorrow but I have a few questions.  The circuit you show looks like the two comparators are part of a quad comparator since they are labeled C and D.  I want to make sure that you only need a dual and not a quad.  Also, the comparators in this circuit appear to have push-pull output stages while the 2903 is open-collector.  If you prefer open-collector, will you be modifying this circuit?  Lastly, you are asking for pin compatible with a D (SOIC) package.  Due to my other questions, I just wanted to make sure that is required and other packages such as VSSOP are not acceptable.  If you can comment on these, I will make a proper recommendation tomorrow.

Chuck

Tks, Chuck.

The question has been resolved. As learn on your website, I choose TLC3702IDR and LMV393 for a try. Tks again. 

BR,

Xiaobing (Eric)

Hi Marcoo,

 Tks.

 ATL432BQDBZR doesn't have similar Ika range compared with NCP431BVSNT1G. Does TL432BQDBZR is best options to replace NCP431BVSNT1G? Such IKA, tolerances, OP temp and etc.? Pls suggestion. Tks.

BR,

Xiaobing (Eric)

Tks, Marcoo. You gave a nice suggestion. By the way, what's difference between TL432BQDBZR  and ATL432BQDBZR? 

BR,

Xiaobing (Eric)