LTC2921 - Power Supply Tracker with Input Monitors


  • 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

LTC2921 Typical Application
LTC2921 Typical Application


The LTC®2921 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.


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC2921CGN-2.5#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC2921CGN-2.5#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC2921CGN-3.3#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC2921CGN-3.3#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC2921CGN#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC2921CGN#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LTC2921IGN-2.5#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC2921IGN-2.5#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC2921IGN-3.3#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC2921IGN-3.3#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC2921IGN#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LTC2921IGN#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes

LTC2921 Package Drawing
LTC2921 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LTC2921CGN-2.5#PBF SSOP-16 C $4.20 $3.15 Yes
LTC2921CGN-2.5#TRPBF SSOP-16 C $3.21 Yes
LTC2921CGN-3.3#PBF SSOP-16 C $4.20 $3.15 Yes
LTC2921CGN-3.3#TRPBF SSOP-16 C $3.21 Yes
LTC2921CGN#PBF SSOP-16 C $4.20 $3.15 Yes
LTC2921CGN#TRPBF SSOP-16 C $3.21 Yes
LTC2921IGN-2.5#PBF SSOP-16 I $4.85 $3.65 Yes
LTC2921IGN-2.5#TRPBF SSOP-16 I $3.71 Yes
LTC2921IGN-3.3#PBF SSOP-16 I $4.85 $3.65 Yes
LTC2921IGN-3.3#TRPBF SSOP-16 I $3.71 Yes
LTC2921IGN#PBF SSOP-16 I $4.85 $3.65 Yes
LTC2921IGN#TRPBF SSOP-16 I $3.71 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Click here to view our complete list of demo boards


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