BSP77E6433HUMA1 - 42V 2.17A Smart Low-Side Switch | Infineon
MPN: BSP77E6433HUMA1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.92 | $0.92 |
| 10 | $0.83 | $8.30 |
| 100 | $0.69 | $69.00 |
| 500 | $0.58 | $290.00 |
| 1,000 | $0.49 | $490.00 |
BSP77E6433HUMA1 Overview
A low-side switch is a semiconductor power switch placed between the load and ground, in contrast to a high-side switch placed between the supply and the load. Low-side switches are widely used for cost-sensitive, ground-referenced loads such as solenoids, relays, lamps, heaters, and small DC motors where the wiring return path can tolerate being switched. Within the broader semiconductor taxonomy, the BSP77 sits in the hierarchy: low-side switch → power distribution switch → load driver → power management IC → semiconductor. Infineon's HITFET family adds integrated protection features—overload, overtemperature, ESD, and active current limiting—that discrete N-channel MOSFETs require external circuitry to provide.
Key features include a 42 V drain-to-source breakdown voltage providing substantial transient headroom above 12 V automotive rails, an active current limit, thermal shutdown with auto-restart, and ESD protection on the input pin. The logic-level input accepts standard 3.3 V or 5 V microcontroller GPIO signals directly, simplifying firmware-driven load control. The 4-pin SOT-223 (PG-SOT223-4) footprint exposes the drain tab for both electrical connection and thermal dissipation, with a low junction-to-ambient thermal resistance that supports sustained 2.17 A operation on minimum copper area.
Architecturally, the BSP77 uses Infineon's Smart SIPMOS technology, integrating a vertical N-channel DMOS output stage with CMOS-compatible control logic and bandgap-referenced protection comparators on a single die. This co-integration allows the protection thresholds to track the output MOSFET's safe operating area, giving precise overload and short-circuit behavior across temperature. The monolithic approach reduces parasitic inductance compared to discrete solutions, improving switching performance and EMC.
Typical applications include automotive body electronics such as LED drivers, small motor control (window lifters, mirror adjusters, door locks), relay and solenoid replacement, resistive heating elements (seat heaters), and general 12 V load switching in industrial 24 V systems with adequate derating. The integrated protection makes it especially suitable for applications where load faults (short to battery, stuck relay contacts) must not damage the ECU.
When designing with this device, observe the Safe Operating Area in the manufacturer datasheet and ensure the tab is soldered to a copper area sized for the worst-case dissipation. Bypass the input pin with a 100 nF ceramic capacitor placed close to the IC to suppress ESD-induced transients. For inductive loads, add a freewheeling diode; the BSP77 does not include internal avalanche clamping for inductive turn-off.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on the manufacturer datasheet.
Drop-in alternatives for BSP77E6433HUMA1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with BSP77E6433HUMA1 (same form factor and footprint) — differing in Output Configuration, Package.
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BSP76E6433HUMA1
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BSP77E6433HUMA1 Maximum Ratings & Electrical Characteristics
| Manufacturer | Infineon Technologies |
| Product Family | Classic HITFET™ 12V |
| Function | Smart Low-Side Power Switch |
| Output Configuration | 1:1 N-Channel |
| Drain-to-Source Voltage (Vds max) | 42 V |
| Continuous Drain Current | 2.17 A |
| Input Voltage Range | -0.2 V to 10 V (logic input) |
| Operating Temperature Range | -40 °C to +150 °C (junction) |
| Package | PG-SOT223-4 (4-Pin SOT-223 with Tab) |
| Mounting Type | Surface Mount |
| ESD Protection | Yes (integrated, per datasheet) |
| Overload Protection | Yes (active current limit) |
| Thermal Shutdown | Yes (with auto-restart) |
| Automotive Qualified | Yes |
| RoHS Status | Compliant |
| Packing | Tape & Reel |
BSP77E6433HUMA1 Pin Configuration
| Pin 1 | IN — Logic-level gate input (3.3 V / 5 V compatible) |
| Pin 2 | SOURCE — Source / ground return (pin 2) |
| Pin 3 | SOURCE — Source / ground return (pin 3) |
| Pin 4 | DRAIN (TAB) — Drain output to load; tab is internally connected to drain and provides thermal path |
Typical Applications
BSP77E6433HUMA1 is suitable for 6 applications: Automotive LED Lighting Drivers, Relay and Solenoid Replacement, Small DC Motor Control, Resistive Heating Element Drivers, Industrial 24V PLC Load Switching, Body Electronics ECU Outputs.
Automotive LED Lighting Drivers
The BSP77E6433HUMA1's 42 V drain breakdown and 2.17 A continuous current make it well suited for driving 12 V automotive LED strings for interior lighting, daytime running lights, and tail-light clusters. Its logic-level input accepts 3.3 V or 5 V microcontroller GPIO directly, eliminating the need for a level shifter. Placed on the low side of the LED string, the integrated thermal shutdown protects against LED-string shorts while the active current limiter prevents inrush damage during PWM dimming transitions.
Recommended
Relay and Solenoid Replacement
The BSP77E6433HUMA1 directly replaces automotive relays and solenoids in body-control modules, providing silent, bounce-free switching with built-in fault protection. With 2.17 A continuous rating it handles most 12 V relays and small solenoids including door-lock actuators and mirror-adjust motors. The integrated thermal shutdown and active current limit protect the ECU when contacts stick or wiring faults occur, replacing the need for fuses and snubbers required by mechanical relays.
Recommended
Small DC Motor Control
The BSP77E6433HUMA1 provides efficient low-side PWM control for small 12 V brushed DC motors such as those used in window lifters, mirror adjusters, and seat-position actuators. Its 42 V breakdown absorbs inductive flyback spikes when paired with an external freewheeling diode, while the logic-level input allows direct connection to MCU timer PWM outputs at frequencies up to several kHz. The integrated current limit protects against stall conditions without requiring external shunt resistors.
Recommended
Resistive Heating Element Drivers
The BSP77E6433HUMA1 controls resistive heating loads such as seat heaters, mirror heaters, and steering-wheel heaters in 12 V automotive platforms. Its 2.17 A continuous rating supports up to ~26 W at 12 V (parallel heating elements) with the tab soldered to adequate copper. The thermal-shutdown auto-restart prevents thermal runaway under fault conditions, while the active current limit isolates shorted heater elements without blowing fuses.
Recommended
Industrial 24V PLC Load Switching
Beyond automotive, the BSP77E6433HUMA1 operates in industrial 24 V PLC and process-control applications as a rugged low-side output driver. The 42 V drain breakdown provides comfortable headroom above 24 V rails with inductive load transients. The logic-level input interfaces directly with 3.3 V or 5 V PLC logic outputs, while the integrated protections eliminate external fusing and current-sense circuitry in distributed I/O modules and remote terminal units (RTUs).
Recommended
Body Electronics ECU Outputs
The BSP77E6433HUMA1 is widely deployed in body-control modules (BCMs) and central electrical units as a per-pin driver for mixed-load outputs. Its compact SOT-223 footprint and monolithic protection enable high-density PCB layouts where space is at a premium, while its AEC-Q100 qualification ensures reliable operation across the full automotive temperature range. The active current limit provides per-pin diagnostics via the MCU ADC when paired with a small sense resistor, supporting ISO 26262 functional-safety requirements.
Recommended
Recommended Products Summary
Engineering reference data for BSP77E6433HUMA1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BSP77 | BSP77E6327 | BSP77E6433 | BSP76E6433HUMA1 |
|---|---|---|---|---|---|
| Brand | Infineon | Infineon | Infineon | Infineon | Infineon |
| Package | PG-SOT223-4 | PG-SOT223-4 | PG-SOT223-4 | PG-SOT223-4 | PG-SOT223-4 |
| Drain-to-Source Voltage (Vds max) | 42 V | 42 V | 42 V | 42 V | 42 V |
| Continuous Drain Current | 2.17 A | 2.17 A | 2.17 A | 2.17 A | 1 A (lower class) |
| Function | Smart low-side switch | Smart low-side switch | Smart low-side switch | Smart low-side switch | Smart low-side switch |
| Integrated Current Limit | Yes | Yes | Yes | Yes | Yes |
| Thermal Shutdown | Yes (auto-restart) | Yes | Yes | Yes | Yes |
| Automotive Qualified | Yes (AEC-Q100) | Yes | Yes | Yes | Yes |
Key Differentiators
- Active current limit with auto-restart thermal shutdown (vs Discrete N-channel MOSFET + external fuse)
- 42 V drain breakdown for 12 V automotive transients (vs BSP75N (lower-class HITFET))
- 4-pin SOT-223 with exposed drain tab (vs BTS3018TC in PG-TO263-3-2 (DPAK))
Design Notes
Estimated: at Vds=12 V and Id=2.17 A continuous, the BSP77 dissipates roughly 1 W assuming Rds(on) around 50 mOhms at Tj=25 °C. The PG-SOT223-4 package with the tab soldered to a 1-square-inch copper pour keeps theta_JA below 50 °C/W. For continuous operation at 2 A, provide at least 1 square inch of copper on the drain tab; without adequate copper, thermal shutdown will engage prematurely at currents well below 2.17 A.
Place a 100 nF ceramic bypass capacitor as close as possible to the IN pin (Pin 1) to suppress ESD-induced transients from coupling into the logic input. Route the SOURCE pins (2 and 3) to a low-impedance ground plane; do not rely on the tab for ground return current. Use a star-ground topology where the BSP77 source connects directly to the system ground at the load return, not at the MCU ground, to avoid ground loops in analog feedback paths.
Do not drive inductive loads without an external freewheeling diode reverse-biased across the load; the BSP77 does not include internal avalanche clamping for inductive turn-off energy and will fail if the flyback voltage exceeds Vds max. For PWM dimming of LEDs, keep switching frequency above 100 Hz to avoid visible flicker, and below 1 kHz to keep switching losses negligible. Do not exceed 10 V on the IN pin or apply voltages below -0.2 V, which can damage the gate oxide.
Compliance Information
AEC-Q100 automotive qualified per Infineon product family datasheet. RoHS and REACH compliant. Lead-free and halogen-free per modern Infineon manufacturing standards.
