NXP Semiconductors TDA3629T/N2,118

Overview

TDA3629T/N2,118 from NXP Semiconductors (formerly Philips) is a monolithic light position controller IC designed for automotive headlight elevation control in passenger cars. It implements an on-off motor control strategy with hysteresis, delivers up to 670 mA output current at 12.3 V supply, features broken-wire and short-circuit detection on the SET input, and integrates thermal protection up to 160 °C junction temperature.

For engineers reviewing the TDA3629T/N2,118 datasheet, TDA3629T/N2,118 pinout, TDA3629T/N2,118 application, or TDA3629T/N2,118 equivalent, this page provides verified functional context, validated SO16 pin mapping, confirmed automotive-grade transient immunity (±150 V), exact thermal resistance (105 K/W), and two manufacturer-validated alternative parts for headlight leveling systems.

Technical Context

The TDA3629T/N2,118 operates as a closed-loop analog controller using two potentiometers: one for driver-set elevation (SET input), the other for mechanical feedback (FB input). Its internal comparators and window detectors monitor VP1/VP2 supply rails (8–18 V operating range), enforce under-voltage lockout below 6 V, and trigger over-voltage shutdown above 18 V.

Motor drive is implemented via dual complementary output stages (OUT1/OUT2) that short-circuit the DC motor for braking. Hysteresis level is externally set via RSET, and fault detection includes SET input short-to-battery (VP threshold), short-to-ground (1 V threshold), and open-circuit (ΔVSET ≤ 160 mV detection margin).

Key Specifications

Pinout & Package

Package: SO16 - plastic small outline package, 16 leads, 3.9 mm body width, JEDEC MS-012AC / NXP SOT109-1 outline.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar light position controller applications.

Compared with TDA3629D/N2,118, the TDA3629T/N2,118 offers superior power density and surface-mount compatibility, while UC2637DW demands additional external circuitry and fails to replicate the integrated safety features essential for certified automotive headlight systems.

Availability

TDA3629T/N2,118 is available at Aetrix Electronics and suitable for automotive lighting control, headlight leveling modules, and OEM vehicle electronics requiring stable component supply across extended production lifecycles.

Supply support for TDA3629T/N2,118 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

NXP Semiconductors is a global semiconductor company specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with deep heritage in automotive analog ICs dating to Philips Semiconductor.

The TDA3629T/N2,118 belongs to NXP's automotive analog controller product line, engineered specifically for electromechanical headlight leveling systems requiring robust fault detection, thermal resilience, and ISO 7637-2 compliance without microcontroller dependency.

FAQ

What is the primary function of the TDA3629T/N2,118 in automotive systems?

The TDA3629T/N2,118 functions as a dedicated light position controller IC that automatically adjusts headlight beam elevation in passenger cars. It compares driver-set voltage (via dashboard potentiometer on SET pin) with mechanical feedback voltage (from motor-coupled potentiometer on FB pin) and drives a bidirectional DC motor via OUT1/OUT2 to minimize position error. Its on-off control strategy with hysteresis ensures high accuracy and noise immunity - a core requirement for ECE R48-compliant headlight leveling systems.

Does the TDA3629T/N2,118 support both 12 V and 24 V vehicle electrical systems?

The TDA3629T/N2,118 is specified for 8–18 V operating supply, making it suitable for standard 12 V automotive systems but not directly compatible with nominal 24 V commercial vehicle systems. While its absolute maximum non-operating voltage is +50 V, sustained operation above 18 V triggers over-voltage shutdown. For 24 V platforms, external regulation (e.g., DC-DC converter) is required to deliver ≤18 V to VP1/VP2 pins. The device's transient immunity (−150 V to +100 V) does cover 24 V system load-dump events, but steady-state operation remains limited to 18 V max.

How does the TDA3629T/N2,118 detect a broken wire on the SET input?

The TDA3629T/N2,118 detects SET input wire breakage by monitoring ΔVSET - the voltage difference between normal operation and open-circuit condition. With RSET = 20 kΩ and Vb = 16 V, the device guarantees ΔVSET ≤ 160 mV, meaning the voltage shift caused by an interrupted ground return is insufficient to exceed the motor switch-on threshold (6–12 µA). This design ensures the motor remains inactive during wiring faults. The internal broken-wire protection circuit actively holds the brake (short-circuiting the motor) when VSET falls outside the valid 1.5 V to 0.95×VP window.

Can the TDA3629T/N2,118 be used without external hysteresis components?

No - the TDA3629T/N2,118 requires an external resistor (RSET) to set hysteresis level, as stated in the datasheet: "Hysteresis level set externally." RSET connects between SET pin and VP, forming a voltage divider that defines the input current threshold (6–12 µA at VP = 12 V) for motor activation. Without RSET, the SET input lacks defined switching thresholds, rendering closed-loop control unstable. The datasheet specifies RSET > 2 kΩ and recommends optimization based on potentiometer value and desired positional resolution.

What thermal derating applies to the TDA3629T/N2,118 in SO16 package at 105 °C ambient?

At Tamb = 105 °C, the TDA3629T/N2,118 (SO16, Rth vj-amb = 105 K/W) must limit continuous motor current to approximately 220 mA when VP = 13 V, based on thermal modeling in the datasheet. This corresponds to a maximum allowable dissipated power of 0.67 W during motor-active periods. Exceeding this requires either reduced duty cycle (e.g., 4-step movement over 16 s with ≥300 s pause per Table 1) or enhanced PCB copper area to improve heat transfer - critical for under-hood placement where sustained high-current operation risks thermal shutdown.