SLG46811 datasheet(92/171 Pages) DIALOG

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Datasheet

14-Apr-2021

CFR0011-120-00

Revision 3.0

92 of 171

SLG46811

GreenPAK Programmable Mixed-Signal Matrix

Power-On Reset

The SLG46811 has a Power-On Reset (POR) macrocell to ensure correct device initialization and operation of all macrocells in

the device. The purpose of the POR circuit is to have consistent behavior and predictable results when the VDD power is first

ramping to the device, and also while the VDD is falling during power-down. To accomplish this goal, the POR drives a defined

sequence of internal events that trigger changes to the states of different macrocells inside the device, and finally to the state of

the IOs.

14.1 GENERAL OPERATION

The SLG46811 is guaranteed to be powered down and non-operational when the VDD voltage (voltage on PIN1) is less than

Power-Off Threshold (see in Table 6), but not less than -0.6 V. Another essential condition for the chip to be powered down is that

no voltage higher (Note) than the VDD voltage is applied to any other PIN. For example, if VDD voltage is 0.3 V, applying a voltage

higher than 0.3 V to any other PIN is incorrect, and can lead to incorrect or unexpected device behavior.

Note: There is a 0.6 V margin due to forward drop voltage of the ESD protection diodes.

To start the POR sequence in the SLG46811, the voltage applied on the VDD should be higher than the Power-On threshold

(Note). The full operational VDD range for the SLG46811 is 2.3 V to 5.5 V. This means that the VDD voltage must ramp up to the

operational voltage value, but the POR sequence will start earlier, as soon as the VDD voltage rises to the Power-On threshold.

After the POR sequence has started, the SLG46811 will have a typical period of time to go through all the steps in the sequence

(noted in the datasheet for that device), and will be ready and completely operational after the POR sequence is complete.

Note: The Power-On threshold is defined in Table 6.

To power down the chip the VDD voltage should be lower than the operational and to guarantee that chip is powered down it

should be less than Power-Off Threshold.

All PINs are in high impedance state when the chip is powered down and while the POR sequence is taking place. The last step

in the POR sequence releases the IO structures from the high impedance state, at which time the device is operational. The pin

configuration at this point in time is defined by the design programmed into the chip. Also, as it was mentioned before, the voltage

on PINs can’t be bigger than the VDD, this rule also applies to the case when the chip is powered on.

SLG46811 Datasheet(PDF) 92 Page - Dialog Semiconductor