NXP Semiconductors UBA2024AT/N1,518

Overview

UBA2024AT/N1,518 from NXP Semiconductors is a monolithic high-voltage half-bridge power IC designed for electronically self-ballasted compact fluorescent lamps (CFLs) operating from 230 V mains. It integrates dual MOSFETs (R_DS(on) = 7.0–8.0 Ω HS, 6.2–6.9 Ω LS), an adjustable internal oscillator (40–43 kHz nominal), and a high-voltage level shifter rated to 550 V. The device delivers accurate 50 % duty cycle via internal divide-by-2 logic and supports up to 23 W lamp loads with soft-start and minimum glow time control.

For engineers reviewing the UBA2024AT/N1,518 datasheet, UBA2024AT/N1,518 pinout, UBA2024AT/N1,518 application, or UBA2024AT/N1,518 equivalent, this page provides verified functional context, SO14 package mapping, confirmed sweep-mode timing behavior (t_sweep = 0.28–0.45 s with C_SW = 33 nF), thermal resistance (R_th(j-a) = 95 K/W), and validated alternatives for CFL ballast redesigns.

Technical Context

The UBA2024AT/N1,518 implements a self-oscillating 555-timer-based architecture with external R_OSc/C_OSc tuning (e.g., 110 kΩ/180 pF yields 41.3 kHz). Its internal oscillator signal is divided by two before driving the half-bridge output stage, ensuring precise 50 % duty cycle independent of component tolerances.

Start-up initiates when V_HV exceeds V_DD(startup) (10–12 V), charging C_FS and C_VDD while holding the high-side transistor off. Sweep mode begins once V_DD > V_DD(startup), ramping frequency from 2.5× nominal down to resonance-enabling controlled filament preheat and reliable lamp ignition without external timing controllers.

Key Specifications

Pinout & Package

UBA2024AT/N1,518 is housed in a plastic small outline package (SO14, SOT108-1) with 14 leads and 3.9 mm body width. Pin numbering follows JEDEC MS-012 standard, with pin 1 located at the top-left corner adjacent to the index notch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar half-bridge CFL driver applications.

Compared with UBA2024AT/N1,518, the UBA2024T/N1,518 offers identical functionality in through-hole form but increases layout area and assembly cost, while UBA2024AT/F,118 provides identical electrical and mechanical behavior with different packaging logistics - making the /N1,518 variant optimal for new SMT-based CFL designs requiring 2,500-unit reels.

Availability

UBA2024AT/N1,518 is available at Aetrix Electronics and suitable for compact fluorescent lamp ballasts, 230 V mains-powered lighting systems, and low-component-count electronic ballast designs requiring stable component supply and long-lifecycle support.

Supply support for UBA2024AT/N1,518 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 headquartered in Eindhoven, Netherlands, specializing in high-performance analog, mixed-signal, and power management ICs for automotive, industrial, and consumer applications.

The UBA2024 family was developed specifically for integrated electronic CFL ballast solutions - combining high-voltage power switching, precision timing, and thermal resilience to replace multi-chip discrete implementations in energy-efficient lighting.

FAQ

What is the maximum continuous voltage rating on the HV pin of the UBA2024AT/N1,518?

The UBA2024AT/N1,518 supports a maximum continuous voltage of 373 V on the HV pin under normal operation, as specified in Table 3 of the datasheet. This rating is sufficient for rectified 230 V AC mains (≈325 V DC peak) with margin for line variations. Transient rating remains 550 V for ≤0.5 s, enabling robustness against mains surges per IEC 61000-4-5. The UBA2024AT/N1,518 must not be used with sustained HV voltages exceeding 373 V.

Does the UBA2024AT/N1,518 require an external low-voltage power supply?

No, the UBA2024AT/N1,518 does not require an external low-voltage supply. It derives its internal VDD (11.4–13.3 V) directly from the HV pin via an integrated charge pump, as described in Section 7.1. This self-powering capability eliminates the need for an external linear regulator or auxiliary winding, reducing component count and simplifying the UBA2024AT/N1,518-based ballast design.

How is the 50 % duty cycle achieved in the UBA2024AT/N1,518 half-bridge output?

The UBA2024AT/N1,518 achieves an accurate 50 % duty cycle by routing its internal oscillator signal through a dedicated divide-by-2 circuit before feeding it to the high-side and low-side output drivers. This hardware-level division ensures symmetry independent of external R/C component tolerances or temperature drift - a key differentiator from externally timed half-bridge controllers where duty cycle accuracy depends on matching passive components.

What is the function of the SW pin on the UBA2024AT/N1,518, and how is it used?

The SW pin on the UBA2024AT/N1,518 serves as the sweep timing input, controlling the duration of the filament preheat phase before lamp ignition. An external capacitor (C_SW) is connected to this pin; its value (e.g., 33 nF) sets the sweep time to 0.28–0.45 s, as defined by the internal 280 nA charge current. This programmable sweep ensures consistent electrode heating across temperature and line-voltage variations in the UBA2024AT/N1,518 application.

Can the UBA2024AT/N1,518 be used in 120 V mains applications?

No, the UBA2024AT/N1,518 is optimized for 230 V mains operation and rated for 550 V HV transients. For 120 V mains, NXP specifies the UBA2024B-series variants (e.g., UBA2024BT), which feature lower R_DS(on) (2.0–2.35 Ω) and reduced HV ratings (187 V continuous / 300 V transient) to match the lower bus voltage and higher current requirements. Using UBA2024AT/N1,518 in 120 V designs risks overcurrent stress and thermal runaway due to mismatched MOSFET sizing.