TPS62136: Chaging swiching frequency

Y.Ottey

Part Number: TPS62136

Dear all,

Our customer is evaluating a sample to consider the TPS62361.
Among them, when we confirmed the load characteristics from our customers,
As shown below, when the load was increased, the switching frequency became faster.
Iout=1A→fsw=1.17MHz
Iout=2.6A→fsw=1.25MHz

Although the switching frequency is described as Typ 1MHz in the data sheet, is this the original operation of the device?

*By the way, they are investigating the load characteristics under the following conditions. ‥
Vin=5-6V
Vout=3V

Best Regards,

Y.Ottey

over 5 years ago

0 JohnTucker over 5 years ago

TI__Guru**** 191445 points

The TPS62136 does not use an internal oscillator. DCS control uses adaptive on time with hysteric off time, so frequency will vary with input voltage output voltage and output current. Looking at the data sheet, Figure 68 is closest to your condition. You can see for input voltages between 5 and 6 V, the switching frequency will increase as the output current increases. I would deem what you observe as normal operation.

0 Amod Vaze over 5 years ago

TI__Mastermind 26790 points

Y.Ottey,

This is normal behavior for the device. Please check https://www.ti.com/lit/an/slyt646/slyt646.pdf for frequency variation in DCS control topology specifically "moderate duty cycles" section.

Regards,
Amod

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TPS62136: Chaging swiching frequency