LMR14050-Q1: LMR14050SQDPRTQ1

Hi Singh,

Can you please describe the behavior of the part when increasing load from .1A to 1A? Please also send me:

1. oscilloscope traces of the affected signals as well. SW node voltage, output voltage, and inductor current may be helpful depending on the problem you're seeing

2. schematic diagram and pcb layout

Regards,

Ryan

Hello

Please Find picture circuit and layout.

When Power on No load condition output voltage coming 3.305VDC and increase load 0.4A Output Voltage is constant.

When increase more load then LMR14050SQDPRTQ1 has gone bad condition.

I have seen IC input terminal is short and some time burn IC input pin

That time I have no seen oscilloscope graph

Please see circuit any issue in circuit.

Suggest me.

Hi Vishwanath,

I will review your circuit and return with suggestions as soon as possible

Best,

Ryan

Okay

Please as soon as possible

Hi Vishwanath,

I don't see anything immediately problematic with your schematic. However, can you please clarify how 3V3_enable operates? What is the input source and is it open drain? Additionally, is the 3V3 rail with R31 used to pull up PGOOD? Are you using the signal PGOOD in your system?

Can you please isolate the LMR14050SQDPRTQ1 from the other IC's and run the test conditions that cause the circuit to fail? What do you mean when the circuit is in bad condition? Does the output voltage stop regulating at 3.3V? Which IC input do you observe burning sometimes?

Best,

Ryan

Hello

1. However, can you please clarify how 3V3_enable operates -  I am useing 2 seperatue PCB in my Project. This singal is open in This Board.This Signal 3V3_enable is connect only berg Strip connector

2. What is the input source - Input Source 3 Phase 115VAC

Input Source 3 Phase 115VAC------ Rectifier Circuit-------Holdup capacitor--------DCM4623TD2H31E0T70(28VDC)------ LMR14050SQDPRTQ1

3.Are you using the signal PGOOD in your system?- No

As per datasheet I am connection output voltage through resistance PGOOD Pin

4.Can you please isolate the LMR14050SQDPRTQ1 from the other IC's and run the test conditions-  Which  IC

I am on this IC only LMR14050SQDPRTQ1 other IC connection removed

when I am increase load(atleast 0.6A) IC start heated.

5. What do you mean when the circuit is in bad condition- IC is going damage condition.Input Pin is shorting

6.Which IC input do you observe burning sometimes-Yes

Please find wavefrom SW Pin and Output voltage graph with Noload,100mA and 300mA Load.

Increase Load IC temperature increase.

inductors are not saturating.- No Inductor is not saturating

Other Point I will work and update on Monday

Tie 3V3_Enable to ground so R27(100K),R28(0E) and R34(10K) form a resistor divider from Vin to EN.LMR14050SQDPRTQ1 is starting heat after approx 2Min

Can you explain to me by drawing a schematic or graph?