LTC2909

1

2909fa

SEL Pin Connection for Input Polarity

Combinations

POLARITY

ADJ1

ADJ2

SEL PIN

++

+–

OPEN

––

GND

Precision Triple/Dual Input

UV, OV and Negative

Voltage Monitor

■

Desktop and Notebook Computers

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Handheld Devices

■

Network Servers

■

Core, I/O Monitor

■

Automotive

■

Two Low Voltage Adjustable Inputs (0.5V)

■

Pin Selectable Input Polarity Allows Negative

and OV Monitoring

■

Guaranteed Threshold Accuracy: ±1.5%

■

6.5V Shunt Regulator for High Voltage Operation

■

Low 50µA Quiescent Current

■

Buffered 1V Reference for Negative Supply Offset

■

Input Glitch Rejection

■

Adjustable Reset Timeout Period

■

Selectable Internal Timeout Saves Components

■

Open-Drain

⎯R⎯S⎯T Output

■

Accurate UVLO for 2.5V, 3.3V, 5V Systems

■

■

Space Saving 8-Lead TSOT-23 and 3mm × 2mm DFN

Packages

3.3V UV/OV (Window) Monitor Application with

200ms Internal Timeout (3.3V Logic Out)

ADJ1

LTC2909-2.5

REF

ADJ2

RST

SEL

10k

FAULT

OUTPUT

2909 TA01a

453k

3.3V

10.7k

76.8k

100nF

TMR

GND

of system monitoring applications. Polarity selection and

a buffered reference output allow the LTC2909 to monitor

positive and negative supplies for undervoltage (UV) and

overvoltage (OV) conditions.

The two inputs have a nominal 0.5V threshold, featuring

tight 1.5% threshold accuracy over the entire operating

temperature range. Glitch filtering ensures reliable reset

operation without false triggering. A third fixed-threshold

available for standard logic supplies.

The common reset output has a timeout that may use

a preset 200ms, be set by an external capacitor or be

disabled. A three-state input pin sets the input polarity

of each adjustable input without requiring any external

components.

The LTC2909 provides a highly versatile, precise, space-

conscious, micropower solution for supply monitoring.

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.