LTC2909 Datasheet, PDF (1/16 Pages) Linear Technology – Precision Triple/Dual Input UV, OV and Negative Voltage Monitor

FEATURES
■ _{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}
■ _{Ultralow Voltage Reset: VCC = 0.5V Guaranteed}
■ _{Space Saving 8-Lead TSOT-23 and 3mm × 2mm DFN}
Packages
U
APPLICATIO S
■ _{Desktop and Notebook Computers}
■ _{Handheld Devices}
■ _{Network Servers}
■ _{Core, I/O Monitor}
■ _Automotive
LTC2909
Precision Triple/Dual Input
UV, OV and Negative
Voltage Monitor
DESCRIPTIO
The LTC^®2909 is a dual input monitor intended for a variety
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
UVLO monitor on the part’s V_CC (also 1.5% accuracy) is
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.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
3.3V UV/OV (Window) Monitor Application with
200ms Internal Timeout (3.3V Logic Out)
3.3V
R_P6
453k
R_P5
10.7k
R_P4
76.8k
C_BYP
100nF
R_PU
V_CC
10k
ADJ1
RST
LTC2909-2.5
REF
SEL
ADJ2
TMR
GND
2909 TA01a
FAULT
OUTPUT
SEL Pin Connection for Input Polarity
Combinations
POLARITY
ADJ1
ADJ2
SEL PIN
+
+
V_CC
+
–
OPEN
–
–
GND
2909fa
1