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LP87322E-Q1: question about LDO regulator output flow from startup

Part Number: LP87322E-Q1

Hi TI,

When the moment the device power up, does the output voltage value of LDO or BUCK will be the value defined as the defult registor set(for 0x0A [4:0])?   flow 1: device power up-->read OTP register set-->regulator ouput enable. flow 2:device power up-->read OTP register set-->modify VSET registor-->regulator ouput enable. which flow is right? Could you pls kindly tell me the right startup flow from power up to regulator output? Thank you so much.

BR

jason_koo

  • As the device operation mode block diagram described in device Spec. Figure 18 . regulator output value reset will be executed after the default value is enabled.
  • Jason,

    The LP8732x devices do not wait for the user to set the voltages; it will start up with the default voltages once the power on conditions are met. However, for the LP87322E-Q1 the BUCK regulators won't turn on until the EN signal is set high, and the LDOs won't turn on until enabled via I2C, so by holding the EN signal low you should be able to modify the output voltages before any rails are turned on.

    If you need to make a lot of changes to the default settings then I would also take a look at the LP873200-Q1, which is the same device, but with all of the regulators disabled by default so that it is easy to re-configure all of the settings. It also has a lot of other settings at easy default values, like 0ms startup and shutdown delays.