NXP Semiconductors UBA2024BT/N1,518

Overview

UBA2024BT/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 110 V mains. It integrates two MOSFETs (R_DS(on) = 2.0 Ω HS / 2.3 Ω LS), internal oscillator (41.32 kHz nominal), soft-start, and high-voltage level shifter (up to 300 V). It drives half-bridge configured loads up to 23 W in CFL ballast applications.

For engineers reviewing the UBA2024BT/N1,518 datasheet, UBA2024BT/N1,518 pinout, UBA2024BT/N1,518 application, or UBA2024BT/N1,518 equivalent, this device delivers integrated lamp ignition control, accurate 50 % duty cycle via internal divide-by-2 oscillator logic, minimum glow time management, and bootstrap diode integration - all critical for reliable CFL preheat and ignition in cost-sensitive lighting designs.

Technical Context

The UBA2024BT/N1,518 implements a self-oscillating 555-timer-based architecture with external R_OSC/C_OSC tuning, where the oscillator signal is internally divided to ensure precise 50 % bridge duty cycle. Its sweep mode uses pin SW charge current (280 nA typ.) and external capacitor to ramp frequency from 2.5× nominal down to resonance, enabling controlled filament preheating and high-voltage lamp ignition.

It features a fixed non-overlap time (1.35 μs typ.) between high-side and low-side drive signals, internal VDD regulation derived from HV supply (no external bias required), and undervoltage lockout on floating supply (V_float(UVLO) = 4.2 V typ.). The high-voltage level shifter supports operation up to 300 V transients at pin HV and 264 V at pin FS.

Key Specifications

Pinout & Package

UBA2024BT/N1,518 is housed in a plastic small outline package (SO14) with 14 leads, body width 3.9 mm (SOT108-1), optimized for surface-mount CFL ballast PCBs.

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 and UBA2026T/N1,518, the UBA2024BT/N1,518 offers lowest conduction loss and optimal 110 V compatibility, while avoiding PFC complexity - making it the most direct solution for cost-sensitive, non-PFC CFL ballasts up to 23 W.

Availability

UBA2024BT/N1,518 is available at Aetrix Electronics and suitable for electronic CFL ballast design, lamp ignition control, and energy-efficient lighting applications requiring stable component supply and long-term production continuity.

Supply support for UBA2024BT/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 secure connectivity solutions for automotive, industrial, and consumer applications.

The UBA2024 family was developed specifically for high-integration, low-cost electronic ballasts targeting compact fluorescent lamps - emphasizing reliability, thermal efficiency, and simplified system design for mass-market lighting.

FAQ

What is the maximum lamp power supported by UBA2024BT/N1,518?

The UBA2024BT/N1,518 is rated for half-bridge configured loads up to 23 W, provided the maximum junction temperature of +150 °C is not exceeded. Its 2.0 Ω high-side R_DS(on) and 2.3 Ω low-side R_DS(on) enable efficient operation within this power range when paired with appropriate heatsinking and resonant tank design. Thermal performance is validated per IEC 60747-1 with R_th(j-a) = 95 K/W in free air.

Does UBA2024BT/N1,518 require an external low-voltage supply?

No, the UBA2024BT/N1,518 does not require an external low-voltage supply. It derives its internal VDD (~12.5 V) directly from the HV pin connected to rectified mains, eliminating the need for auxiliary winding or external regulator. This feature simplifies board layout and reduces component count in CFL ballast designs using UBA2024BT/N1,518.

How is the 50 % duty cycle achieved in UBA2024BT/N1,518?

The UBA2024BT/N1,518 achieves an accurate 50 % duty cycle by passing the internal oscillator signal through a dedicated divide-by-2 circuit before routing it to the high-side and low-side output drivers. This hardware-level division ensures symmetrical conduction timing regardless of oscillator drift or external component tolerances - a key requirement for stable resonant operation in CFL ballasts using UBA2024BT/N1,518.

What is the purpose of the SW pin on UBA2024BT/N1,518?

The SW pin on UBA2024BT/N1,518 serves as the sweep timing input. An internal 280 nA current charges an external capacitor (CSW) connected to this pin, generating a linear voltage ramp that controls the frequency sweep duration - typically 350 ms with 33 nF. This sweep enables controlled filament preheating before high-voltage ignition, preventing electrode damage in CFLs driven by UBA2024BT/N1,518.

Can UBA2024BT/N1,518 be used in 230 V mains applications?

No, UBA2024BT/N1,518 is specifically optimized for 110 V mains operation, with a maximum HV pin rating of 300 V (transient) and 187 V (normal operation). Using it in 230 V systems risks exceeding absolute maximum ratings and premature failure. For 230 V applications, NXP specifies UBA2024T/N1,518 or UBA2024AT/N1,518 - both rated for 373 V HV transients and compatible with UBA2024BT/N1,518's pinout but differing in R_DS(on) and thermal specs.