OPA858: Regarding PD and supply product

Weiyu Leng

Part Number: OPA858

To whom it may concern,

I have a single-ended input signal range of 0V~0.5V and a single-ended output range of 0V to 3V, and I need a bandwidth of more than 800MHz for a capacitive load <2pF.

Based on simulation and reading, I find OPA858 to be very suitable.

Signal 1: analog low swing

Signal 2: digital high swing

Now I have two questions:

1. I find that I need an unbalanced split supply of -1V and 4V for non-inverting amplification. Thus, is there any recommended TI LDO that can generate -1V and 4V together conveniently?

2. If the amplifier is in power down mode, with Vin+ still connected to a voltage within the input range, and supplies still connected to -1V and 4V, can I short the output to 0V?

Please advice.

Thank you.

Weiyu

over 6 years ago

0 Hasan Babiker31 over 6 years ago

TI__Genius 15605 points

Hello Weiyu,

To answer your second question, you can short the output when it is in power-down. The reason for this is the output is placed in a high-impedance state when the power-down pin is low.

I will move this thread to the LDO product group so they can help you with a part recommendation.

Best,

Hasan Babiker

0 Weiyu Leng over 6 years ago in reply to Hasan Babiker31

Intellectual 360 points

Hi Hasan,

Thank you for your explanation.

Please pin me when the thread in LDO group gets replied, because I didn't receive any extra notification email.

Weiyu

0 Hasan Babiker31 over 6 years ago in reply to Weiyu Leng

TI__Genius 15605 points

Hello Weiyu,

It may be better to start a new thread under the LDO group.

Best,

Hasan Babiker

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OPA858: Regarding PD and supply product