LM337: About Ripple Rejection Ratio

Hello Hide, 

Do you have specific output currents to look at?

Best,

Juliette

Hi Juliette-san,

Thank you for your response.

We use LM337KVURG3 at the following conditions.

And, we need those data ta all output conditions(0A to 1.5A).

Because, we would like to know the conditions that can produce the maximum effect of Ripple Rejection.

[LM337KVURG3]

VIN=-18V

VOUT=-15V

IOUT=90mA

Regards,

Hide

Hello Hide,

                 Just to clarify, you require Ripple Rejection vs frequency graph only for the below listed condition?

[LM337KVURG3]

VIN=-18V

VOUT=-15V

IOUT=90mA

                Would you like the PSRR at any other ILOAD? Do you have a specific CIN and COUT at which the PSRR graph needs to be generated? Finally, what is the frequency range (10Hz - 10MHz?) over which you need the ripple rejection? Thanks!

Regards,

Srikanth

Hi Juliette-san,

Thank you for your response.

We have presented our use conditions.

However, we need the following graph like a Figure20 of LP5907.

<Our requests>

-We don’t have spec(Value) of CIN and COUT so your select value.

-Frequency range is form 10Hz to 10MHz

-All load current (20mA /step etc.)

* Please be within the range that can be confirmed.

<LP5907 datasheet Figure20>

Regards,

Hide

Hello Hide, 

Thank you for clarifying, Srikanth Lolla Venkata should be able to help take the PSRR measurements for you. 

Best,

Juliette

Hi Juliette-san, Srikanth-san,

Thank you for always support.

Could you please let us know the measurement completion date?

I’d greatly appreciate your verification.

Regards,

Hide

Hello Hide-San,

                         LM337 is a relatively old part released in 1981, and hence we don't have much data on it. May I recommend TPS7A33 as a possible substitute which has Specs similar to LM337? This device is less than 10 years old and will be an improved design over LM337. Thanks!

Regards,

Srikanth 

Hi Srikanth-san,

Thank you for a recommended device.

However, our customer has already decided to use LM337KVURG3.

Therefore, we need those data.

Is it possible to measure it?

Regards,

Hide

Hello Hide-San,

                         We can make the measurement, we will have to request samples and design a setup. This may take a couple weeks. I will aim to provide you the data by April 2nd, but hopefully sooner than that. 

Regards,

Srikanth

Hi Srikanth-san,

Thank you for always kind support.

I greatly appreciate your cooperation.

I would appreciate your continued support.

Regards,

Hide

Hello Hide-San,

                          The samples arrived only today. I will aim to provide you with the Data for this part by end of next week. 

Regards,

Srikanth

Srikanth-san,

Thank you for the information and kind support.

I would appreciate if you could handle this as soon as possible.

Regards,

Hide

Hi Srikanth-san,

How is the investigation after than going?

I’m looking forward to hearing from you.

Regards,

Hide

Hello Hide-San,

                        Please find attached the PSRR plot for LM337 for the following test condition: Vin -18V, Vout -15V and Iout 90mA.

Regards,

SrikanthPSRR -18V Vin -15V Vout 90mA Iout Cout EVM.pdf

Hi Srikanth-san,

Thank you for your response.

However, it is different from the data I requested.

We would like to know the conditions that can produce the maximum effect of Ripple Rejection.

Therefore, we need All load current condition like a Figure20 of LP5907.

Is it possible to evaluate it?

Regards,

Hide

Hi Srikanth-san,

Thank you for your prompt reply and information.

I greatly appreciate your cooperation.

Regards,

Hide