100kW

TLV803S

V

DD

3.3V

RESET

GND

47kW RST

Microprocessor

V

CC

RESET

V

DD

t

d

V

+V

IT

HYS

-

1.1V

ValidOutput

TLV803, TLV853, TLV863

SBVS157C – APRIL 2011 – REVISED SEPTEMBER 2015

www.ti.com

Feature Description (continued)

8.3.2 Reset During Power Up and Power Down

turns off and becomes high impedance. The voltage on the RESET pin rises to the voltage level connected to the

pull-up resistor. Figure 9 shows a typical waveform for power-up, assuming the RESET pin has a pull-up resistor

Figure 9. Power-Up Response

8.3.3 Bidirectional Reset Pins

Some microcontrollers have bidirectional reset pins that act as both inputs and outputs. In a situation where the

TLV803 is pulling the RESET line low while the microcontroller is trying the force the RESET line high, a series

resistor should be placed between the output of the TLV803 and the RESET pin of the microcontroller to protect

against excessive current flow. Figure 10 shows the connection of the TLV803 to a microcontroller using a series

resistor to drive a bidirectional RESET line.

Figure 10. Connection To Bidirectional Reset Pin

8.4 Device Functional Modes

8.4.1 Normal Operation (VDD > Power-Up Reset Voltage)

8.4.2 Power On Reset (VDD < Power-Up Reset Voltage)

When the voltage on VDD is lower than the required voltage to internally pull the asserted output to GND (power-

up reset voltage), both outputs are in a high-impedance state.

8

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