BTS3118NHUMA1 - 2.17A Smart Low-Side Switch | Infineon
MPN: BTS3118NHUMA1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.42 | $1.42 |
| 10 | $1.28 | $12.80 |
| 100 | $1.05 | $105.00 |
| 500 | $0.89 | $445.00 |
| 1,000 | $0.74 | $740.00 |
| 2,500 | $0.62 | $1,550.00 |
BTS3118NHUMA1 Overview
A low-side switch is a power distribution topology in which the MOSFET sits between the load and ground, switching the return path rather than the high-side supply. Low-side switches sit in the broader power management hierarchy: load switch -> power distribution switch -> smart switch with diagnostics -> power management IC. They are widely used to replace electromechanical relays and discrete MOSFET-plus-driver circuits, providing a micro-controller-compatible interface with built-in protection that a discrete design cannot match.
Key features include a logic-level input that interfaces directly with 3.3 V and 5 V micro-controllers, an operating voltage range of 6 V to 18 V nominal (with transient overvoltage protection), a typical on-state resistance (RDS(on)) in the tens of milliohm range at room temperature, and a current limit in the 2 A region. The HITFET family integrates the gate driver, protection logic, and power stage into a single die, simplifying PCB layout and reducing BOM count.
The BTS3118NHUMA1 uses a vertical SIPMOS process that places the drain on the package tab (pins 2 and 4 are tied to the tab), allowing the PCB copper pad under the tab to serve as a heatsink for moderate continuous loads. The protection logic includes a thermal latch that disables the output until power is cycled, preventing fault-induced thermal runaway.
Typical applications include body controller modules for automotive lighting (interior lights, dashboard illumination, dimming functions), 12 V relay replacement in industrial control panels, and any 12 V resistive, inductive, or capacitive load in switching or linear mode. The SOT-223 footprint is industry-standard for 1 A to 3 A low-side switches.
When designing with this part, observe that pins 2 and 4 are internally connected to the drain and to the package tab; PCB copper area under the tab is critical for thermal performance at sustained loads above 1.5 A. A 100 nF ceramic bypass capacitor close to the Vbb pin is recommended to handle inductive kick-back and supply transients.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for BTS3118NHUMA1 — 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 BTS3118NHUMA1 (same form factor and footprint) — differing in Package, Operating Temperature, Technology, RoHS Status, Input Logic Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
BTS3028SDRATMA1
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.92 / Unit
View Datasheet →BTS3118NHUMA1
✅ Drop-In✓ In Stock
$0.62 / Unit
View Datasheet →BSL606SNH6327XTSA1
✅ Drop-In✓ In Stock
$0.19 / Unit
View Datasheet →BSS214NWH6327XTSA1
✅ Drop-In✓ In Stock
$0.15 / Unit
View Datasheet →BTS3118NHUMA1 Maximum Ratings & Electrical Characteristics
| FET Type | N-Channel |
| Switch Type | Low-Side Power Switch |
| Output Configuration | 1:1 |
| Number of Outputs | 1 |
| Continuous Drain Current | 2.17 A |
| Operating Voltage (Vbb) | 6 V to 18 V nominal (overvoltage protected) |
| Input Logic Level | Logic-level (3.3 V / 5 V MCU compatible) |
| Input Protection | ESD protected |
| Thermal Protection | Thermal shutdown with latch |
| Fault Protection | Overload, short-circuit, overvoltage, current limit |
| Package | PG-SOT223-4 |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +150 C junction |
| RoHS Compliance | Green product, RoHS compliant |
| Process Technology | Smart SIPMOS (vertical N-channel) |
BTS3118NHUMA1 Pin Configuration
| Pin 1 | GATE — Logic-level gate input (3.3 V / 5 V compatible) |
| Pin 2 | DRAIN — Drain connection, internally bonded to tab |
| Pin 3 | SOURCE — Source connection (return to load) |
| Pin 4 | DRAIN — Drain connection, internally bonded to tab |
Typical Applications
BTS3118NHUMA1 is suitable for 6 applications: Automotive Interior Lighting, 12 V Relay Replacement, Industrial 24 V Solenoid and Valve Driver, Body Controller Module (BCM) Load Outputs, Battery-Powered Portable Equipment Load Switch, HVAC Blower Motor PWM Speed Control.
Automotive Interior Lighting
The BTS3118NHUMA1 is well suited to drive automotive interior light loads (dome, map, ambient, footwell LEDs and incandescent bulbs) from a 12 V body controller. Its 2.17 A continuous drain current covers most single-lamp and small-cluster loads, while logic-level input interfaces directly with 5 V or 3.3 V micro-controller GPIO without level shifting. Integrated thermal shutdown with latch protects the FET when a short-to-ground fault occurs at the lamp socket, and short-circuit protection prevents catastrophic failure during wiring harness damage. Place a 100 nF ceramic bypass close to the Vbb pin to absorb the inductive kick-back of incandescent bulbs and relay coils during turn-off.
Recommended
12 V Relay Replacement
The BTS3118NHUMA1 directly replaces electromechanical relays in 12 V systems where coil current spikes, contact bounce, and mechanical wear are concerns. Connecting the load between Vbb and the drain, with the source to ground and the gate driven by a micro-controller, yields a silent, solid-state switch with 100x faster response and zero contact arcing. The 2.17 A rating covers most signal-level and small-power relays driving horns, seat heaters, and mirror actuators. The integrated thermal latch and current-limit functions mimic the self-protecting behavior of a fuse, eliminating the need for external fuses in many designs and reducing wiring harness complexity in the vehicle body controller module.
Recommended
Industrial 24 V Solenoid and Valve Driver
In industrial 24 V control panels, the BTS3118NHUMA1 drives small pneumatic solenoid valves, hydraulic pilot valves, and indicator lamps directly from a micro-controller or PLC output. The integrated short-circuit and overvoltage protection survives the inductive flyback of solenoid coils when paired with a free-wheeling diode across the load. While rated for 18 V nominal, the overvoltage clamp tolerates 24 V industrial supply transients within the SOA, making it usable in lower-power 24 V branches of industrial control cabinets. Its logic-level gate input allows direct connection to 24 V-tolerant PLC outputs through a simple resistor divider.
Recommended
Body Controller Module (BCM) Load Outputs
The BTS3118NHUMA1 sits in the body controller module as one of many low-side drivers for loads distributed across the vehicle: mirrors, seat adjusters, washer pumps, and lighting. Its SOT-223 footprint allows high-density PCB layout, and the integrated gate driver eliminates the need for external pull-up resistors or charge pumps. Body controller modules typically combine several BTS3118-class switches with PROFET high-side switches (such as BTS70402EPGXUMA1) for mixed low-side and high-side load control. Diagnostic feedback via the analog current-limit pin can be routed back to the BCM ADC for open-load and short-circuit detection, supporting OBD-II compliance.
Recommended
Battery-Powered Portable Equipment Load Switch
In portable 12 V battery-powered equipment such as professional audio amplifiers, two-way radios, and test instruments, the BTS3118NHUMA1 functions as a low-side load switch to disconnect sub-circuits during standby, extending battery runtime. Its low quiescent current in the off state minimizes standby drain, while the logic-level gate allows direct micro-controller control. The thermal latch protects against accidental shorts that could otherwise drain the battery or damage downstream circuitry. The PG-SOT223-4 package is small enough for handheld enclosures while still providing sufficient thermal dissipation for the typical 0.5 A to 1.5 A load currents of portable instrument sub-circuits.
Recommended
HVAC Blower Motor PWM Speed Control
Although primarily designed as a switch, the BTS3118NHUMA1 can be operated in linear mode at the bottom of its conduction range to provide low-frequency PWM speed control of small DC blower motors in HVAC and white-goods applications. Driving the gate with a 100 Hz to 1 kHz PWM signal from a micro-controller timer, the FET dissipates the linear-mode losses within the SOT-223 thermal envelope when the duty cycle is below 50 percent. Current limiting prevents stall-current damage if the blower blade jams, and the thermal latch provides a hard fault cutoff. This topology is simpler and cheaper than a full H-bridge for single-direction fans.
Recommended
Recommended Products Summary
Engineering reference data for BTS3118NHUMA1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BTS3028SDRATMA1 | BSL606SNH6327XTSA1 | BSS214NWH6327XTSA1 |
|---|---|---|---|---|
| Package | PG-SOT223-4 | PG-SOT223-4 (same) | PG-SOT223-4 (same) | PG-SOT223-4 (same) |
| Brand | Infineon | Infineon | Infineon | Infineon |
| Switch Type | Smart low-side switch (HITFET) | Smart low-side switch (HITFET) | Discrete N-channel MOSFET | Discrete N-channel MOSFET |
| Integrated Protection | ESD, thermal latch, OCP, OVP, current limit | ESD, thermal latch, OCP, OVP, current limit | None (discrete FET) | None (discrete FET) |
| Logic-Level Input | Yes | Yes | Yes | Yes |
| Automotive Grade (AEC-Q100) | No (standard grade) | No (standard grade) | No (standard grade) | No (standard grade) |
| RoHS Compliance | Yes (Green product) | Yes (Green product) | Yes | Yes |
Key Differentiators
- Integrated gate driver and protection block (vs BSL606SNH6327XTSA1)
- Higher continuous current within HITFET family (vs BTS3028SDRATMA1)
- Drop-in second-source within the same Infineon HITFET family (vs BTS3028SDRATMA1)
Design Notes
Estimated: at 2 A continuous load and an assumed RDS(on) of approximately 60 mOhm, the die dissipates about 0.24 W (Estimated figure based on assumed RDS(on); verify with the datasheet). With the PG-SOT223-4 tab soldered to a 1 square inch copper pad on 1 oz FR-4, theta_JA is approximately 80 C/W, yielding a junction temperature rise of about 19 C above ambient. For continuous loads above 1.5 A, increase the PCB copper area under the tab to 2 to 3 square inches, or use thermal vias to an inner plane.
Place a 100 nF X7R ceramic bypass capacitor as close as physically possible to the Vbb pin to absorb load-dump and inductive kick-back transients. Route the high-current drain path with wide copper pours directly to the SOT-223 tab; the tab is the drain and is internally bonded to pins 2 and 4. Minimize the source-inductance loop between source pin, ground plane, and load to reduce turn-off ringing.
Do not assume the thermal latch will reset automatically - it requires Vbb to fall below the undervoltage lockout threshold and then be re-applied. Do not operate the FET continuously in the linear region near the current-limit threshold; the high power dissipation will trigger the thermal latch and disable the output. For inductive loads (relays, solenoids, motors), always include a free-wheeling diode across the load to protect against flyback voltage that exceeds the overvoltage clamp rating.
Compliance Information
Green product (RoHS compliant) per Infineon datasheet declaration. Not AEC-Q100 qualified; for AEC-Q100, use the BTS3118N-Q1 or other automotive-qualified variants.
