LMZ22008: LMZ22008 vs LMZ31707

Khoi Nguyen83

Part Number: LMZ22008
Other Parts Discussed in Thread: LMZ31710, LMZ31704, , LMZ31707

I am looking at these two modules to drive 5V input of an Atom 1.44 GHz up to 1.92 GHzGHz processor board like Lattepanda or Up board .

From what I read, the LM31707 QFN module is the lower cost and better suited for instantaneous current application.

I need to shut down the module when running on low battery, and the LM31707 QFN also has 3uA standby vs 32uA of the TOMOD-11pin module.

In this same 10x10mm QFN package, I can also go with LMZ31704 (4A) or higher LMZ31710 (10A) so it is a plus.

Am I on the right path?

Thanks,

Khoi

over 6 years ago

0 Yangbo over 6 years ago

TI__Intellectual 1690 points

Hi Khoi,

I think you are right. LMZ31707 has much smaller standby current than LMZ22008. As is shown in the datasheet, the typical shut down current of LMZ22008 when VEN=0 is 32uA. And the typical standby current of LMZ31707 is 2uA, but it also could be 10uA maximum. And you can also go with LMZ31704 or LMZ31710 according to the current needed.

Regards!

Yangbo

0 Khoi Nguyen83 over 6 years ago in reply to Yangbo

Expert 1180 points

In term of transient response, does the QFN module perform better than TO module?

0 Yangbo over 6 years ago in reply to Khoi Nguyen83

TI__Intellectual 1690 points

Not really. For transient response, it depends on the amount of output capacitor and the bandwidth of the loop.

0 Yangbo over 6 years ago in reply to Khoi Nguyen83

TI__Intellectual 1690 points

Below is a blog about transient response, hope it helps.

e2e.ti.com/.../turbotrans-technology-one-resistor-dramatically-improves-transient-performance-and-reduces-solution-size

0 Khoi Nguyen83 over 6 years ago in reply to Yangbo

Expert 1180 points

Thanks for the info.

LMZ31707 is the lowest cost and easy for heatsink so we are going with it.

Thanks,

Khoi

0 Yangbo over 6 years ago in reply to Khoi Nguyen83

TI__Intellectual 1690 points

Great!

0 Khoi Nguyen83 over 6 years ago in reply to Yangbo

Expert 1180 points

We might use a 7.2V 2-cell li-ion for input and the Output is 5V.

VIN low is around 6V, would this be enough to for lmz31707?

0 Yangbo over 6 years ago in reply to Khoi Nguyen83

TI__Intellectual 1690 points

I am guessing your question is whether this device can support 6V input and 5V output. It depends on your switching frequency. What is the switching frequency in your design?

0 Khoi Nguyen83 over 6 years ago in reply to Yangbo

Expert 1180 points

Yes, you are correct.

This is a standalone design for intel Celeron processor.

We are probably using 1MHz for 5V as shown in table 2 of the datasheet.

Power management

Power management forum

LMZ22008: LMZ22008 vs LMZ31707