1 Features

• 3-pin SOT-23 package

• Supply current of 9 μA (typical)

• Precision supply voltage monitor

2.5 V, 3 V, 3.3 V, 5 V

• Pin-for-pin compatible with MAX 809

• Temperature range: –40°C to +85°C

2 Applications

• Factory automation

• Wireless speakers

• Motor drives

• Servers

• Appliances

• Electricity meters

• Building automation

3 Description

The TPS3809 family of supervisory circuits provides

circuit initialization and timing supervision, primarily

for DSPs and processor-based systems. The newer

TLV809E device is an alternative with the same pins,

functions and electrical parameters.

During power-on, RESET is asserted when the supply

voltage VDD becomes higher than 1.1 V. Thereafter,

the supervisory circuit monitors VDD and keeps

RESET active as long as VDD remains below the

threshold voltage VIT. An internal timer delays the

return of the output to the inactive state (high) to

ensure proper system reset. The delay time, td(typ) =

200 ms, starts after VDD has risen above the threshold

voltage VIT. When the supply voltage drops below the

threshold voltage VIT, the output becomes active (low)

again. No external components are required. All the

devices of this family have a fixed sense-threshold

voltage VIT set by an internal voltage divider.

The product spectrum is designed for supply voltages

of 2.5 V, 3 V, 3.3 V, and 5 V. The circuits are available

in a 3-pin SOT-23. The TPS3809 devices are

characterized for operation over a temperature range

of –40°C to 85°C.