Protection IC for ringing SLICs

The LCP12 has been developed to protect SLICs operating on both negative and positive battery supplies, as well as high voltage SLICs. It provides crowbar mode protection for both TIP and RING lines. The surge suppression is assumed for each wire by two thyristor structures, one dedicated to positive surges the second one for negative surges. Both positive and negative threshold levels are programmable by two gates.

LCP12 can be used to help equipment to meet various standards such as UL1950, IEC 60950 / CSAC22.2, UL1459 and TIA-968-A. LCP12 pinout and clearance is compatible with UL60950. Resin meets UL94 V0.

LCP12 is UL497B approved - file: E136224.

The LCP12 associated with Epcos PTC model B59173C1130A151 is compliant with ITU TK20/K21 (4 kV lightning and AC power fault tests).

Key Features

  • Protection IC recommended for ringing SLICs
  • Wide firing voltage range: -120 V to +120 V
  • Low gate triggering current: IG = 5 mA max
  • Peak pulse current: IPP = 50 A (10/1000 μs)
  • Holding current: IH = 150 mA min.


Technical Documentation

Product Specifications
Description Version Size
DS6834 DS6834: Protection IC for ringing SLICs 4.0 209 KB
Application Notes
Description Version Size
AN2064 AN2064: Compliance of series/parallel protections for Telecom CO 1.2 420 KB
AN579 AN579: Protection concepts in telecommunications equipment 3.0 150 KB
AN2456 AN2456: Protection of single battery voltage SLICs for new networks in US market 1.1 611 KB
AN2266 AN2266: SLIC based system protection for European and Asian markets 2.1 241 KB
AN2053 AN2053: SLIC protection for both classical and new networks 2.1 317 KB
Technical Notes & Articles
Description Version Size
TN1173 TN1173: Packing information for IPAD™, protection, rectifiers, thyristors and AC Switches 5.0 1 MB

HW Model, CAD Libraries & SVD

HW Model, CAD Libraries & SVD
Description Version Size
LCP12 PSpice model (.lib) and symbols (.olb) 1.0 3 KB

Publications and Collaterals

Description Version Size
ST Protection Finder - The new app for Android and iOS 1.0 1 MB

Tools and Software

Design Tools
Smart selectors
Support & Community

Sample & Buy

Part Number Marketing Status Stand-off voltage (V) (nom) Directionality Package Packing Type Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors
LCP12-150B1RL Active - Bi-Directional SO-8W Tape And Reel 0.902 100 NEC EAR99 CHINA MORE INFO DISTRIBUTOR AVAILABILITY

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors

Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
LCP12-150B1RL ActiveSO-8WIndustrialEcopack2 0 0

(**) The Material Declaration forms available on may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.