IR21531DPBF - 600V Half-Bridge Gate Driver, 8-PDIP | Infineon
MPN: IR21531DPBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.2 | $3.20 |
| 10 | $2.88 | $28.80 |
| 100 | $2.55 | $255.00 |
| 500 | $2.21 | $1,105.00 |
| 1,000 | $1.92 | $1,920.00 |
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Request AlternativesIR21531DPBF Maximum Ratings & Electrical Characteristics
| Product Type | Self-oscillating half-bridge gate driver |
| Topology | Half-bridge (high-side + low-side) |
| High-side Offset Voltage (max) | 600 V |
| Vcc Supply Voltage (max) | 20 V (internally clamped at 15.6 V) |
| Vcc Undervoltage Lockout | Increased hysteresis (per datasheet) |
| Internal Deadtime (typical) | 0.6 µs |
| Deadtime Temperature Coefficient | Low (tightened initial deadtime) |
| Oscillator Type | CMOS 555-equivalent, external RT/CT |
| Shutdown Feature | Yes, on CT pin at 1/6 Vcc |
| Integrated Zener Clamp on Vcc | 15.6 V |
| Startup Behavior | True micropower startup |
| Propagation Delay Matching | Matched high-side / low-side (per datasheet) |
| Package | 8-Pin PDIP (through-hole) |
| Mounting Type | Through-hole (THT) |
| Lead-Free / RoHS | Lead-free (PBF suffix); RoHS compliant |
| MSL Level | Not applicable (through-hole) |
IR21531DPBF Pin Configuration
| Pin 1 | Vcc — Logic supply voltage (internally clamped at 15.6 V via integrated zener) |
| Pin 2 | RT — Timing resistor connection for oscillator (sets charging current with CT) |
| Pin 3 | CT — Timing capacitor / shutdown node (1/6 Vcc SD threshold) |
| Pin 4 | GND — Logic and low-side gate-drive return |
| Pin 5 | LO — Low-side gate-drive output (referenced to GND) |
| Pin 6 | VS — High-side floating supply return / switching node |
| Pin 7 | HO — High-side gate-drive output (referenced to VS) |
| Pin 8 | VB — High-side floating supply (bootstrap to VS) |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
IR21531DPBF is suitable for 6 applications: Fluorescent Electronic Ballast, HID Lamp Ballast (Automotive/Street Lighting), Low-Power SMPS Half-Bridge Converter, CCFL Backlight Inverter, Half-Bridge Motor Drive Stage (Low Power), Electronic Transformer for Low-Voltage Halogen.
Fluorescent Electronic Ballast
The IR21531DPBF is a canonical driver for fluorescent lamp electronic ballasts in both 120 V and 230 V AC mains designs. The 600 V high-side offset rating allows direct rectification of 230 V AC without an additional bootstrap clamp, and the integrated 15.6 V Vcc zener eliminates the external clamp diode/zener that discrete ballast drivers require. Designers program the oscillator above 20 kHz (typically 30-50 kHz) via the RT/CT network to push switching harmonics above the audible band and avoid lamp buzz, while the 0.6 µs deadtime with low temperature coefficient prevents shoot-through between the high-side and low-side MOSFETs that would otherwise stress the half bridge during lamp ignition transients.
Recommended
HID Lamp Ballast (Automotive/Street Lighting)
For high-intensity discharge (HID) lamp ballasts the IR21531DPBF's 600 V rating and micropower startup make it well-suited to the high ignition voltages (typically 4-5 kV via an igniter transformer) and long preheat cycles these lamps require. The 1/6 Vcc shutdown feature on the CT pin lets a supervisory MCU or timer circuit disable the half bridge cleanly when the lamp is removed or the ballast is in fault, while the matched high-side/low-side propagation delays keep the ignition arc stable. The 8-PDIP package also withstands the elevated ambient temperatures inside a sealed luminaire housing better than many SOIC equivalents.
Recommended
Low-Power SMPS Half-Bridge Converter
In low-to-medium power offline SMPS (typically below 200 W) the IR21531DPBF can replace a dedicated PWM controller plus separate half-bridge driver, reducing BOM count on the primary side. Its self-oscillating architecture is favored for simple resonant and quasi-resonant forward converters where closed-loop PWM complexity is not required, and the integrated Vcc clamp protects the auxiliary winding rectifiers during no-load bursts. The 600 V rating covers universal-input 85-265 V AC designs without an extra clamp network, and the micropower startup means the IC draws negligible quiescent current until Vcc reaches the UVLO turn-on threshold.
Recommended
CCFL Backlight Inverter
Cold-cathode fluorescent lamp (CCFL) backlight inverters for industrial LCD panels and early LED-backlit displays used Royer-topology oscillators that map directly onto the IR21531DPBF's 555-style oscillator and half-bridge output stage. The 0.6 µs deadtime prevents the cross-conduction that would otherwise burn the Royer transformer primary winding, while the high-side 600 V rating handles the transformer's reflected voltage during lamp striking. The CT-pin shutdown input also provides a clean interface to a brightness-control or fault-detection MCU that needs to disable the inverter on lamp failure.
Recommended
Half-Bridge Motor Drive Stage (Low Power)
For low-voltage brushless DC (BLDC) motor half-bridge stages and small induction-motor drives, the IR21531DPBF can drive the two switches of a half bridge with complementary gate signals derived from its on-chip oscillator. While it does not provide the commutation logic of a dedicated three-phase driver, it is useful for fixed-frequency or simple variable-frequency half-bridge motion where a single RT/CT pair sets the operating point. The matched high-side/low-side propagation delays limit the shoot-through window and improve EMI versus discrete gate-driver alternatives.
Recommended
Electronic Transformer for Low-Voltage Halogen
Electronic low-voltage halogen transformers rely on a self-oscillating half-bridge topology running at 30-60 kHz to drive a small ferrite transformer from the 230 V AC mains. The IR21531DPBF's 600 V rating, integrated 15.6 V Vcc zener, and programmable RT/CT oscillator fit this topology directly, with the 0.6 µs deadtime preventing the cross-conduction that can cause transformer saturation at high line. Its micropower startup also reduces standby loss, which is becoming important under tightening no-load energy regulations.
Recommended
Recommended Products Summary
Engineering reference data for IR21531DPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | IR21531SPBF |
|---|---|---|
| Brand | Infineon | Infineon |
| Package | 8-PDIP (through-hole) | SOIC-8 (SMD) - different footprint |
| High-side Offset Voltage (max) | 600 V | 600 V |
| Oscillator Type | CMOS 555-style (external RT/CT) | CMOS 555-style (external RT/CT) |
| Internal Deadtime (typical) | 0.6 µs | 0.6 µs |
| Vcc Clamp Voltage | 15.6 V (integrated) | 15.6 V (integrated) |
| Shutdown Feature | Yes (1/6 Vcc on CT) | Yes (1/6 Vcc on CT) |
| Mounting Type | Through-hole (THT) | Surface Mount (SMT) |
| Pinout vs IR21531DPBF | - | Pin-compatible logic, but SOIC-8 land pattern |
| Approx. qty-1 Price (USD, 2026-09-14) | ~$3.20 | ~$2.80 |
Key Differentiators
- Integrated 15.6 V Vcc zener clamp (vs Discrete 555 + external half-bridge driver design)
- Tightened initial deadtime with low temperature coefficient (vs Legacy IR2155 / IR2151 drivers)
- True micropower startup (vs Conventional high-Iq startup)
Design Notes
Place a 100 nF (minimum) low-ESR ceramic bypass capacitor directly on the IR21531DPBF Vcc pin (pin 1), within 2-3 mm of the package lead. The integrated 15.6 V zener clamps Vcc but is not designed to absorb the fast switching transients that propagate from the half-bridge node; without local bypassing the Vcc rail can ring above the zener during MOSFET switching edges and trigger premature UVLO. A 10 µF bulk capacitor from Vcc to GND is also recommended to absorb the energy delivered by the bootstrap diode during each high-side on-time.
Keep the high-current switching loop (Vcc -> HO -> high-side MOSFET -> low-side MOSFET -> GND) as small and tight as possible on the PCB, ideally directly under the IC's power pins. The 600 V high-side structure on the IR21531DPBF is sensitive to dV/dt coupling into the floating VB supply; a compact loop reduces radiated EMI and prevents the high-side from spuriously re-triggering due to capacitive coupling from the VS node. The bootstrap capacitor (typically 100 nF-1 µF ceramic from VB to VS) must be placed as close to pins 7 and 8 as layout allows.
Do not operate the IR21531DPBF with Vcc above its internal 15.6 V clamp for sustained periods - the integrated zener is sized for transient protection, not continuous dissipation. If your auxiliary winding can deliver more than ~50 mA continuous to Vcc, add a series resistor to limit current or use an external regulator. Also avoid running the oscillator below ~20 kHz in ballast applications, as the resulting acoustic resonance can shatter the lamp envelope; verify RT/CT against the manufacturer's curve in the datasheet before finalizing the BOM.
Compliance Information
PBF suffix indicates lead-free finish; RoHS status per Infineon product page. AEC-Q100 not applicable for this through-hole ballast driver. Halogen-free status not stated in the available distributor data.
