TPS50601A-SP: TPS50601A-SP Load and Line regulation; Vsense voltage not constant, it varies

Thomas Gati

Part Number: TPS50601A-SP

Test results (24 degrees C case is shown) indicate load and line regulation issues.

Voltages are measured with respect to analog return. In particular, the Vsense pin voltage is expected to remain constant (within micro volts) as load current and input voltage are varied.

Test results indicate undue magnitudes of voltage variation of the Vsense pin.

MHP50601A			TPS50601A-SP
EM319


		Load	Vout1	Vsense	Vss	PG	EN	Vin	Tsink	Iin	Pin	Pout	Ploss	efficiency
			ch1	ch2	ch3	ch4	ch5	ch8	ch9	ch10
Test Date	UNIT	amp	volt	volt	volt	volt	volt	volt	°C	amp	watt	watt	watt
2/6/2020	SN1	0.101	0.886	0.809	1.486	1.647	1.345	3.292	26.2	0.037	0.1	0.1	0.0	72.6%
2/6/2020	SN1	6.004	0.802	0.798	1.447	1.658	1.319	3.268	25.9	2.532	8.3	4.8	3.5	58.2%
2/6/2020	SN1	0.101	0.887	0.809	1.497	3.001	1.761	5.997	26.2	0.031	0.2	0.1	0.1	47.8%
2/6/2020	SN1	6.004	0.727	0.785	1.429	3.006	1.753	5.985	26.4	1.270	7.6	4.4	3.2	57.4%
2/6/2020	SN1	0.101	4.385	0.810	1.495	2.501	1.655	4.996	28.1	0.106	0.5	0.4	0.1	83.6%
2/6/2020	SN1	6.004	4.410	0.814	1.498	2.525	1.639	4.939	28.2	6.060	29.9	26.5	3.5	88.5%


2/5/2020	SN1-16	0.101	0.884	0.809	1.517	1.646	1.347	3.289	28.5	0.037	0.1	0.1	0.0	73.1%
2/5/2020	SN1-16	6.004	0.802	0.798	1.484	1.512	1.321	3.264	28.4	2.610	8.5	4.8	3.7	56.5%
2/5/2020	SN1-16	0.101	0.883	0.809	1.528	2.999	1.760	5.994	28.5	0.031	0.2	0.1	0.1	47.7%
2/5/2020	SN1-16	6.004	0.721	0.784	1.453	3.005	1.752	5.982	28.7	1.282	7.7	4.3	3.3	56.5%
2/5/2020	SN1-16	0.101	4.381	0.809	1.526	2.499	1.655	4.993	30.4	0.106	0.5	0.4	0.1	84.0%
2/5/2020	SN1-16	6.004	4.406	0.814	1.528	2.524	1.639	4.935	30.3	6.057	29.9	26.5	3.4	88.5%


2/6/2020	SN2	0.101	0.889	0.809	1.449	1.649	1.344	3.295	22.3	0.039	0.1	0.1	0.0	70.6%
2/6/2020	SN2	6.004	0.808	0.798	1.405	1.659	1.318	3.271	22.4	2.559	8.4	4.9	3.5	58.0%
2/6/2020	SN2	0.101	0.889	0.809	1.458	3.002	1.762	5.999	23.1	0.032	0.2	0.1	0.1	47.3%
2/6/2020	SN2	6.004	0.734	0.786	1.376	3.007	1.754	5.987	23.6	1.294	7.7	4.4	3.3	56.9%
2/6/2020	SN2	0.101	4.387	0.810	1.456	2.501	1.655	4.997	25.7	0.107	0.5	0.4	0.1	82.8%
2/6/2020	SN2	6.004	4.412	0.815	1.455	2.526	1.639	4.940	26.0	6.068	30.0	26.5	3.5	88.4%


2/5/2020	SN2-16	0.101	0.874	0.807	1.503	1.646	1.347	3.289	28.6	0.037	0.1	0.1	0.0	73.1%
2/5/2020	SN2-16	6.004	0.792	0.796	1.465	1.603	1.320	3.265	28.1	2.518	8.2	4.8	3.5	57.8%
2/5/2020	SN2-16	0.101	0.873	0.807	1.514	2.999	1.760	5.994	28.3	0.031	0.2	0.1	0.1	48.0%
2/5/2020	SN2-16	6.004	0.720	0.784	1.437	3.005	1.752	5.982	28.5	1.267	7.6	4.3	3.3	57.1%
2/5/2020	SN2-16	0.101	4.371	0.807	1.511	2.499	1.655	4.993	29.8	0.106	0.5	0.4	0.1	83.9%
2/5/2020	SN2-16	6.003	4.404	0.814	1.515	2.524	1.639	4.935	30.0	6.048	29.8	26.4	3.4	88.6%


2/6/2020	SN3-16	0.101	0.866	0.806	1.496	1.646	1.342	3.288	28.7	0.037	0.1	0.1	0.0	72.0%
2/6/2020	SN3-16	6.004	0.764	0.791	1.458	1.656	1.315	3.265	28.2	2.481	8.1	4.6	3.5	56.6%
2/6/2020	SN3-16	0.100	0.866	0.806	1.507	2.999	1.758	5.994	28.5	0.031	0.2	0.1	0.1	47.4%
2/6/2020	SN3-16	6.004	0.696	0.780	1.432	3.005	1.750	5.982	28.7	1.262	7.5	4.2	3.4	55.4%
2/6/2020	SN3-16	0.101	4.364	0.806	1.505	2.499	1.652	4.993	30.1	0.106	0.5	0.4	0.1	83.8%
2/6/2020	SN3-16	6.003	4.394	0.812	1.508	2.524	1.636	4.936	30.1	6.056	29.9	26.4	3.5	88.3%


2/6/2020	SN4	0.101	0.877	0.808	1.466	1.648	1.349	3.292	25.8	0.037	0.1	0.1	0.0	72.3%
2/6/2020	SN4	6.004	0.802	0.797	1.428	1.659	1.323	3.268	25.5	2.607	8.5	4.8	3.7	56.5%
2/6/2020	SN4	0.101	0.878	0.808	1.476	3.001	1.762	5.997	25.9	0.031	0.2	0.1	0.1	48.1%
2/6/2020	SN4	6.004	0.727	0.785	1.402	3.007	1.755	5.985	26.2	1.320	7.9	4.4	3.5	55.3%
2/6/2020	SN4	0.101	4.376	0.808	1.474	2.501	1.657	4.996	28.0	0.106	0.5	0.4	0.1	83.5%
2/6/2020	SN4	6.004	4.396	0.812	1.476	2.526	1.641	4.938	28.0	6.074	30.0	26.4	3.6	88.0%


2/5/2020	SN8	0.101	0.889	0.809	1.485	1.646	1.346	3.289	29.1	0.037	0.1	0.1	0.0	73.2%
2/5/2020	SN8	6.004	0.812	0.799	1.453	1.501	1.319	3.263	28.8	2.745	9.0	4.9	4.1	54.5%
2/5/2020	SN8	0.101	0.889	0.809	1.495	2.999	1.759	5.994	28.8	0.031	0.2	0.1	0.1	47.8%
2/5/2020	SN8	6.004	0.733	0.786	1.421	3.005	1.751	5.981	29.1	1.363	8.1	4.4	3.7	54.0%
2/5/2020	SN8	0.101	4.386	0.810	1.492	2.499	1.654	4.993	30.6	0.106	0.5	0.4	0.1	83.4%
2/5/2020	SN8	6.003	4.387	0.811	0.987	0.032	1.638	4.935	30.8	6.094	30.1	26.3	3.7	87.6%


2/5/2020	SN14	0.102	0.883	0.808	1.505	1.646	1.349	3.290	27.6	0.038	0.1	0.1	0.0	72.6%
2/5/2020	SN14	6.004	0.797	0.796	1.469	1.657	1.323	3.265	27.8	2.562	8.4	4.8	3.6	57.2%
2/5/2020	SN14	0.101	0.883	0.808	1.516	3.000	1.761	5.995	28.4	0.032	0.2	0.1	0.1	46.9%
2/5/2020	SN14	6.004	0.729	0.785	1.443	3.005	1.753	5.983	28.5	1.300	7.8	4.4	3.4	56.3%
2/5/2020	SN14	0.101	4.380	0.809	1.513	2.499	1.656	4.994	29.9	0.106	0.5	0.4	0.1	83.9%
2/5/2020	SN14	6.004	4.405	0.814	1.516	2.524	1.640	4.936	29.9	6.070	30.0	26.4	3.5	88.3%

over 5 years ago

0 Christian Yots over 5 years ago

TI__Genius 14540 points

Hi,

I can look into this but will need more information from you. The variation on the regulated output, and therefore, Vsense is highly dependent on the external circuitry of the converter. Could you please provide schematic for each scenario (target VOUT) including the ESR of the output capacitance being used. Also, please provide what regulation ripple you have designed for. You can send to me privately if you prefer not to post on this public forum.

Thanks

Christian

0 Thomas Gati over 5 years ago in reply to Christian Yots

Prodigy 20 points

simulation POL Hybrid 1-0.pdf

0 Christian Yots over 5 years ago in reply to Thomas Gati

TI__Genius 14540 points

Hi,

From the schematic provided it appears you are targeting the following applications:

VIN=3.3, 5V, 6V

IOUT = 100mA, 6A

Fswitching = 300kHz

VOUT = 2.515V

Can you confirm these are the target applications.

The VOUT measured is not 2.5V as it should be indicating a gross problem.

The compensation circuit in the schematic does not look correct for me. I estimate the following comp circuit.

R9=12kohms

C3=22nF

C6=650pF

Thanks

Christian

0 Christian Yots over 5 years ago in reply to Christian Yots

TI__Genius 14540 points

Discussion has moved to email so I'm closing this thread.

Thanks

Christian

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TPS50601A-SP: TPS50601A-SP Load and Line regulation; Vsense voltage not constant, it varies