LTC2922 - Power Supply Tracker with Input Monitors

The LTC2921 and LTC2922 monitor up to five supplies and force them to track on power-up in multiple supply systems. Using external N-channel pass transistors, the supplies can be ramped up at an adjustable rate. Automatic remote sense switching allows the DC/DC converters to compensate for series voltage drops in the wiring. An incorrect level on one or more of the supplies triggers disconnect of all supplies. Tight 1% accuracy and glitch immunity on the low 0.5V monitoring level ensure no false error disconnects.

The LTC2921 and LTC2922 each feature an adjustable electronic circuit breaker to protect the VCC supply against short circuits. Capacitance at the TIMER pin programs the delays in the monitoring sequence.

The LTC2921 includes three remote sense switches in a 16-pin narrow SSOP package, while the LTC2922 includes five remote sense switches in a 20-pin TSSOP package. Both parts are available for VCC supply voltages of 5V, 3.3V, and 2.5V.

Features
  • Tracks Multiple Supplies with MOSFET Switches
  • Monitors 5 Input Voltages Including VCC
  • Guaranteed Threshold Accuracy: ±1% at 0.5V
  • Automatic Remote Sense Switching
  • Adjustable Supply Ramp Rate
  • Overvoltage Monitor
  • Adjustable Electronic Circuit Breaker
  • Adjustable Power-Good Delay
  • Available for VCC Supply Voltages of 5V, 3.3V and 2.5V
  • Available in 16-Pin Narrow SSOP (LTC2921 Series) and 20-Pin TSSOP (LTC2922 Series)
Typical Application

Applications
  • Desktop Computers
  • Plug-In Cards
  • Telecom Infrastructure
  • Supply Sequencing
  • Instruments
Packaging

Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC2922CF-2.5#PBFTSSOP-20C$4.50$3.40
LTC2922CF-2.5#TRPBFTSSOP-20C$3.50
LTC2922CF-3.3#PBFTSSOP-20C$4.50$3.40
LTC2922CF-3.3#TRPBFTSSOP-20C$3.50
LTC2922CF#PBFTSSOP-20C$4.50$3.40
LTC2922CF#TRPBFTSSOP-20C$3.50
LTC2922IF-2.5#PBFTSSOP-20I$5.20$3.90
LTC2922IF-2.5#TRPBFTSSOP-20I$4.00
LTC2922IF-3.3#PBFTSSOP-20I$5.20$3.90
LTC2922IF-3.3#TRPBFTSSOP-20I$4.00
LTC2922IF#PBFTSSOP-20I$5.20$3.90
LTC2922IF#TRPBFTSSOP-20I$4.00
Demo Boards
Part NumberDescriptionPrice
DC740A-ALTC2922IF | Tracker/Sequencer Demo Board, VCC = 5V$100.00
DC740A-BLTC2922IF-3.3 | Tracker/Sequencer Demo Board, VCC = 3.3V$100.00
DC740A-CLTC2922IF-2.5 | Tracker/Sequencer Demo Board, VCC = 2.5V$100.00
Datasheet
Reliability Data
LT Journal
Related Product
LTC2921/LTC2922 - Power Supply Tracker with Input Monitors
LTC2921/LTC2922 - 具有输入监控器的电源跟踪器
LTC2922 Package Drawing LTC2922
R493 Reliability Data
April 2010 - Dual 500mA µPower LDO Features Independent 1.8V–20V Inputs and Easy Sequencing in a 4mm × 3mm DFN
May 2004 Single Device Tracks and Monitors Five Supplies
LTC2922 Footprints and Symbols