LTC4420 - 18V Dual Input Micropower PowerPath Prioritizer with Backup Supply Monitoring


  • Selects Highest Priority Valid Supply from Two Inputs
  • Wide 1.8V to 18V Operating Range
  • Internal Dual 2Ω, 0.5A Switches
  • Low 3.6µA Operating Current
  • Low 320nA V2 Current When V1 Connected to OUT
  • Blocks Reverse and Cross Conduction Currents
  • Reverse Supply Protection to –15V
  • Built-In V2 Test with Optional V2 Disconnect
  • V2 Freshness Seal/Ship Mode
  • ±1.5% Accurate Adjustable Switchover Threshold
  • ±2.3% Accurate V2 Monitor and Comparator
  • Overcurrent and Thermal Protection
  • Thermally Enhanced 12-Pin 3mm × 3mm DFN and 12-Lead Exposed Pad MSOP Packages

Typical Application

LTC4420 Typical Application
LTC4420 Typical Application


The LTC®4420 is a dual input monolithic PowerPath™ prioritizer, with low operating current, that provides backup switchover for keeping critical circuitry alive during brownout and power loss conditions. Unlike diode-OR products, little current is drawn from the inactive supply even if its voltage is greater than the active supply.

Internal 2Ω, current limited PMOS switches provide power path selection from a primary input (V1) or a backup input (V2) to the output. Two adjustable voltage monitors set via external resistive dividers provide flexibility in setting V1 to V2 switchover and V2 undervoltage thresholds. V1 is monitored continuously while V2 supply monitoring includes controllable low duty cycle UV monitoring. When primary input V1 drops, the ADJ monitor causes OUT to be switched to V2. When V2 drops, it is disconnected from OUT if V2DIS is low. Fast non-overlap switchover circuitry prevents reverse and cross conduction while minimizing output droop.

Auxiliary voltage monitor CMP1 provides flexible voltage monitoring and output V2OK provides V2 undervoltage status. Freshness seal mode prevents V2 battery discharge during storage or shipment.


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

Part Number Package Code Temp Package
LTC4420CDD#PBF 3x3 DFN-12 DD C 05-08-1725 Yes
LTC4420CDD#TRPBF 3x3 DFN-12 DD C 05-08-1725 Yes
LTC4420CMSE#PBF MS-12E MSE C 05-08-1666 Yes
LTC4420CMSE#TRPBF MS-12E MSE C 05-08-1666 Yes
LTC4420IDD#PBF 3x3 DFN-12 DD I 05-08-1725 Yes
LTC4420IDD#TRPBF 3x3 DFN-12 DD I 05-08-1725 Yes
LTC4420IMSE#PBF MS-12E MSE I 05-08-1666 Yes
LTC4420IMSE#TRPBF MS-12E MSE I 05-08-1666 Yes

LTC4420 Package Drawing
LTC4420 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
LTC4420CDD#PBF 3x3 DFN-12 C $4.21 $2.95 Yes
LTC4420CDD#TRPBF 3x3 DFN-12 C $4.27 $3.01 Yes
LTC4420CMSE#PBF MS-12E C $4.21 $2.95 Yes
LTC4420CMSE#TRPBF MS-12E C $4.27 $3.01 Yes
LTC4420IDD#PBF 3x3 DFN-12 I $4.85 $3.39 Yes
LTC4420IDD#TRPBF 3x3 DFN-12 I $4.91 $3.45 Yes
LTC4420IMSE#PBF MS-12E I $4.85 $3.39 Yes
LTC4420IMSE#TRPBF MS-12E I $4.91 $3.45 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.

Part Number Description Price Documentation
DC2208A LTC4420CDD Demo Board | 18V Dual Input Micropower PowerPath Prioritizer with Backup Supply Monitoring $75.00
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  • Low Power Battery Backup
  • Portable Equipment
  • Point-of-Sale (POS) Equipment

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