Page History

...

Low

...

Dropout Linear Regulator

The low-dropout (LDO)  provides an easy-to-use robust power management  solution for a wide variety of applications. User programmable soft-start minimizes stress on the input power

The microprocessor supervisory circuits monitor system voltages from 0.4 V to 5 V, asserting an open-drain RESET signal when the SENSE voltage drops below a preset threshold or when the manual reset (MR) pin drops to a logic low. The RESET output remains low for the user adjustable delay time after the SENSE voltage and MR return above their thresholds. Datasheet is available in Texas Instruments website.

Low Dropout Linear Regulator

The low-dropout (LDO)  provides an easy-to-use robust power management  solution for a wide variety of applications. User programmable soft-start minimizes stress on the input power source by reducing capacitive inrush current on start-up. The soft-start is monotonic and well- suited for powering many different types of Monitoring or Provides a Sequencing Signal processors and ASICs. The enable input and power for Other Supplies good output allow easy sequencing with external regulators. This complete flexibility permits the user to configure a solution that meets the sequencing Voltage Startup requirements of FPGAs, DSPs, and other applications with special start-up requirements.

...

The PS and PL power supplies are fully independent. PS power supplies (VCCPINT, VCCPAUX, VCCPLL, VCCO_DDR, VCCO_MIO0, and VCCO_MIO1) can be powered before or after any PL power supplies. The PS and PL power regions are isolated to prevent damage. The recommended power-on sequence is VCCPINT, then VCCPAUX and VCCPLL together, then the PS VCCO supplies (VCCO_MIO0, VCCO_MIO1, and VCCO_DDR) to achieve minimum current draw and ensure that the I/Os are 3-stated at power-on. The PS_POR_B input is required to be asserted to GND during the power-on sequence until VCCPINT, VCCPAUX and VCCO_MIO0 have reached minimum operating levels to ensure PS eFUSE integrity. 

...

The PS and PL power supplies are fully independent. PS power supplies (VCCPINT, VCCPAUX, VCCPLL, VCCO_DDR, VCCO_MIO0, and VCCO_MIO1) can be powered before or after any PL power supplies. The PS and PL power regions are isolated to prevent damage. The recommended power-on sequence is VCCPINT, then VCCPAUX and VCCPLL together, then the PS VCCO supplies (VCCO_MIO0, VCCO_MIO1, and VCCO_DDR) to achieve minimum current draw and ensure that the I/Os are 3-stated at power-on. The PS_POR_B input is required to be asserted to GND during the power-on sequence until VCCPINT, VCCPAUX and VCCO_MIO0 have reached minimum operating levels to ensure PS eFUSE integrity.

Voltage Monitor Circuit

The microprocessor supervisory circuits monitor system voltages from 0.4 V to 5 V, asserting an open-drain RESET signal when the SENSE voltage drops below a preset threshold or when the manual reset (MR) pin drops to a logic low. The RESET output remains low for the user adjustable delay time after the SENSE voltage and MR return above their thresholds. Datasheet is available in Texas Instruments website.

When the U8 and U9 generates PWRGD signal, it turns on the U4 which generates PWRGD_3.3V, it turns on the U6 and it generates PWROK signal which is connected to MR. Whenever the supply voltage for U12 drops down below the threshold it resets the system. Actually it resets the system when all regulators are working.

Power Rails

...