Infineon Technologies IR2156SPBF

Overview

IR2156SPBF from Infineon Technologies is a high-voltage ballast control IC integrating a half-bridge gate driver, programmable oscillator, and state-machine logic for fluorescent lamp electronic ballasts. It delivers programmable preheat frequency (49–60 kHz), run frequency (36–44 kHz), preheat time (via RPH/CPH), internal ignition ramp, and over-current threshold (1.1–1.44 V). Used in 2D/4-pin CFL and T5/T8 linear lamp drivers with integrated protection.

For engineers reviewing the IR2156SPBF datasheet, IR2156SPBF pinout, IR2156SPBF application, or IR2156SPBF equivalent, key selection criteria include preheat/run frequency tuning range, CT/RT/CPH/RPH timing component dependencies, VCC zener clamp (15.6 V), shutdown hysteresis (450 mV), and current-sense propagation delay (160 ns).

Technical Context

The IR2156SPBF implements a three-state lamp control sequence-PREHEAT, IGNITION RAMP, and RUN-governed by CPH voltage ramping (4.3 µA typical charging current) and CT-based oscillator timing. Preheat mode uses RPH/CPH to set duration; ignition ramps frequency from fPH to fRUN when CPH exceeds 10 V; RUN mode disables RPH and locks oscillator to RT/CT.

Protection is hardware-automated: undervoltage lockout (UVLO+ = 11.5 V, UVLO− = 9.5 V, 2 V hysteresis), over-current detection (CS > 1.25 V, 160 ns delay), shutdown latch (SD > 5.1 V), and automatic restart after fault clearance. The internal 15.6 V zener on VCC requires external current limiting to avoid regulation failure.

Key Specifications

Pinout & Package

IR2156SPBF is housed in a 14-pin SOIC (SOICN14) package with exposed pad thermal enhancement per Infineon's standard outline.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ballast control applications.

Compared with IRS2156DSPBF, IR2156SPBF lacks the integrated bootstrap diode but offers identical timing accuracy and protection; versus UCC3895DW, it delivers complete ballast functionality out-of-box but less general-purpose configurability.

Availability

IR2156SPBF is available at Aetrix Electronics and suitable for compact fluorescent lamp ballasts, T5/T8 linear lighting systems, LED retrofit modules, and industrial lighting control requiring stable component supply and long-term lifecycle support.

Supply support for IR2156SPBF 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

Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive, and industrial control ICs with global manufacturing and quality certification (IATF 16949, ISO 9001).

The IR2156 product line targets electronic ballast design for fluorescent lighting, delivering integrated timing, driver, and protection functions to replace multi-chip solutions in cost- and space-constrained fixtures.

FAQ

What is the purpose of the CPH pin and how does it affect lamp starting?

The CPH pin integrates a 4.3 µA current source that charges an external capacitor to generate a controlled preheat duration. When CPH voltage reaches ~10 V, the IC transitions from PREHEAT to IGNITION RAMP mode, sweeping frequency toward RUN. This ensures consistent filament heating before high-voltage ignition, reducing electrode sputtering and extending lamp life.

Can IR2156SPBF drive 600 V-rated MOSFETs directly?

Yes - its high-side driver supports VB up to 625 V and VS offset up to 600 V, enabling direct drive of 600 V MOSFETs in half-bridge configurations. However, gate resistor selection must account for Miller effect-induced peak currents (±500 mA max), and layout must minimize parasitic inductance on HO/VS paths to prevent false triggering.

How does the VDC pin contribute to system reliability?

The VDC pin monitors DC bus voltage via an external resistor divider (RVDC = 10 kΩ typical). If VDC falls below the internal threshold during operation, the IC resets into UVLO mode, halting switching and preventing unstable lamp operation or MOSFET overstress due to insufficient bus voltage - a critical safeguard in unregulated rectifier supplies.

Is external timing capacitor (CT) required for basic operation?

Yes - CT is mandatory for oscillator function in all modes (PREHEAT, IGNITION, RUN). A 470 pF capacitor is specified for nominal 40 kHz RUN frequency with RT = 40 kΩ. Omitting CT disables the oscillator entirely, forcing the IC into UVLO mode regardless of VCC or SD status.