STMicroelectronics TSI220B1RL

Overview

TSI220B1RL from STMicroelectronics is a monolithic Application Specific Discrete (ASD™) device integrating a diode bridge and crowbar overvoltage protection in a single SO-8 package, designed for telecom line interface stages. It provides 220 V stand-off voltage (VRM), 330 V breakover voltage (VBO), 150 mA holding current (IH), 50 mA breakover current (IBO), and withstands 30 A peak pulse current (10/1000 µs), enabling polarity guard and transient protection in telephone sets and fax machines.

For engineers reviewing the TSI220B1RL datasheet, TSI220B1RL pinout, TSI220B1RL application, or TSI220B1RL equivalent, key selection criteria include VRM–VBO margin for AC ringing + battery superposition, IH > line operating current to ensure automatic recovery, IBO compatibility with series PTC/fuse coordination, and SO-8 thermal resistance (170 °C/W) for sustained telecom duty cycles.

Technical Context

The TSI220B1RL implements a bidirectional crowbar-triggered protection architecture combined with full-wave diode bridge rectification on a single silicon die. Its internal Trisil-based crowbar activates when both VBO ≥ 330 V and IBO ≥ 50 mA are simultaneously exceeded, ensuring reliable short-circuit clamping during lightning surges (CCITT K17 10/700 µs ±1.5 kV) and AC power induction events (240/600 V RMS).

It operates in two distinct functional modes: normal polarity-guard rectification (VF ≈ 0.9–1.1 V per diode at 20–100 mA), and transient-triggered crowbar mode where junction voltage collapses to <5 V after triggering, diverting surge current away from downstream circuitry while relying on external PTC or fuse for open-circuit recovery.

Key Specifications

Pinout & Package

TSI220B1RL is housed in an industry-standard SO-8 surface-mount package (4.8–5.0 mm × 5.8–6.2 mm, 1.27 mm pitch), with exposed pad not electrically connected. Thermal performance relies on PCB copper area and solder joint quality due to high Rth(j-a) = 170 °C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar telecom line interface protection applications.

Compared with TSI200B1RL and TSI265B1RL, TSI220B1RL offers optimal balance for modern analog telecom terminals: sufficient VRM margin above 100 V RMS ringing + 48 V battery (220 V), robust 330 V VBO for noise immunity, and unchanged crowbar timing and thermal behavior - simplifying redesigns from TSI200B1RL without over-engineering.

Availability

TSI220B1RL is available at Aetrix Electronics and suitable for telephone sets, fax machines, cordless base stations, and Caller ID equipment requiring stable component supply across long-lifecycle telecom deployments.

Supply support for TSI220B1RL includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in automotive, industrial, and power discrete solutions with broad IP in protection and interface devices.

The TSIxxB1 series belongs to ST's Application Specific Discretes (ASD™) portfolio, engineered specifically to replace multi-component telecom line interface protection circuits with monolithic, standards-compliant alternatives.

FAQ

What is the role of the NC pins (7 and 8) on TSI220B1RL?

Pins 7 and 8 are unconnected internally and serve no electrical function. They must remain un-routed and un-soldered to avoid parasitic capacitance or unintended coupling into the sensitive crowbar trigger path. ST's mechanical drawings confirm zero bond wire or metallization to these terminals.

Can TSI220B1RL be used without an external PTC or fuse?

No - a series PTC (e.g., 10 Ω PolySwitch) or fast-blow fuse is mandatory for AC power contact tests (FCC Part 68, CNET). Without it, the device latches in crowbar mode during 240 V RMS contact and cannot self-reset, risking permanent short-circuit failure.

How does TSI220B1RL behave during simultaneous surge and normal line current?

It maintains normal diode bridge operation until surge voltage exceeds VBO (330 V) AND surge current exceeds IBO (50 mA). Below those thresholds, leakage remains <1 µA at 220 V; above them, it transitions to low-impedance crowbar mode within <2 µs, clamping voltage to <5 V while diverting surge current.

Is TSI220B1RL compliant with RoHS and REACH?

Yes - TSI220B1RL is manufactured per STMicroelectronics' qualified green process: lead-free (Pb-free) terminations, halogen-free molding compound, and fully compliant with EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, as documented in ST's official material declarations.