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Replacement of Exar XRP7724

Markus Mueller12
Prodigy 30 points
Other Parts Discussed in Thread: TPS650861, LM2665, TPS65023, LP87561-Q1, TPS5130

I'm in search of an adequate replacement of our power supply with the EXAR XRP7724.

It's key features are:
- 4 external switches
- programmable power sequence
- Programming/Configuration through PC Application

The configuration to replace works from 5V and powers a x86 CPU VortexDX3 with DDR3 memory
- 1V/6A
- 1.2V/0.8A
- 1.5A/2.6A
- 1.8V/0.8A

An additional DC/DC powers
- 3.3V/5A
(would be nice to be integrated)

The main tasks the PMIC should fulfill are
- flexible configuration of the 4 (better 5) rails regarding voltage/current
- programmable power sequence regarding delay/rise time

The TI power management products i found yet are either much to oversized (external components count / complexity e.g. the PMIC section) or not flexible enough (non-isolated DC/DC)

Any hints are welcome! Thx!

  • 0
    TI__Genius 17380 points

    Hi Markus,

    We do not have an equivalent 4 controller device but what about using the TPS650861? This is our only released software programmable non-volatile memory multi-rail PMIC, though we are expanding our selection. It would be able to power the 4 main supplies with BUCK2 (controller), BUCK3/4/5 (converters) as well as integrate the 3.3 V supply (BUCK1 - controller). It also has a termination LDO if your DDR needs termination.

    If the other LDOs or load switches provide any value then it's even better, but they can also be left unused without losing too much value since they are relatively small. The downside is that it has a UVLO of 5.6 V, so if there isn't a higher voltage supply available, it would require a small boost to power the VSYS pin (~1 mA DC, with some inrush during start-up). In the datasheet, section 6.2.2 (VIN 5-V Application) has details on this.

    Basically instead of XRP7724 + 4 FETs + 3.3V Buck, it could be TPS650861 + 2 FETs + LM2665; looking at the 1k web price, the XRP7724 is much more expensive than the TPS650861.

    We have a few device which could support hardware configuring (TPS5130 for example) but not many that support 6A; our more popular TPS65023 for example only goes up to 1.8 A. If you had an microcontroller that could write the the volatile memory, there would be a few more options (LP87561-Q1 family for example) but my understanding is that you are looking for programming the non-volatile memory.