LM61440-Q1 - 36V, 4A Automotive Low-Noise Buck | Texas Instruments
MPN: LM61440Q-Q1 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.55 | $4.55 |
| 10 | $4.1 | $41.00 |
| 100 | $3.55 | $355.00 |
| 500 | $3.1 | $1,550.00 |
| 1,000 | $2.78 | $2,780.00 |
Drop-in alternatives for LM61440Q-Q1 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
LM61440
β Drop-Inβ In Stock
$1.82 / Unit
View Datasheet βLM61460
β Drop-Inπ Reference alternative (not in catalog)
LM61460-Q1
β Drop-Inπ Reference alternative (not in catalog)
LM61440Q-Q1 Maximum Ratings & Electrical Characteristics
| Topology | Synchronous Step-Down (Buck) |
| Input Voltage Range | 3 V to 36 V |
| Input Transient Tolerance | 42 V |
| Maximum Output Current | 4 A |
| Number of Outputs | 1 |
| Output Type | Adjustable |
| Integrated MOSFETs | Yes (high-side and low-side) |
| Light Load Mode | Pin Selectable |
| EMI Performance | Low EMI, optimized for automotive |
| Functional Safety | Functional-Safety-Capable documentation available |
| Package | 14-Pin PowerVFQFN (VQFN-HR, HotRod, RJR) |
| Mounting Type | Surface Mount |
| Qualification | AEC-Q100 (automotive) |
| Switching Frequency | [DATA_NEEDED: switching frequency range] |
| Operating Temperature | [DATA_NEEDED: operating temperature range] |
| RoHS Status | [DATA_NEEDED: RoHS status] |
LM61440Q-Q1 Pin Configuration
| Pin 1 | PVIN β Power input voltage, parallel input path |
| Pin 2 | PVIN/SW β Power input / switch node path |
| Pin 3 | SW β Switch node - connect to inductor |
| Pin 4 | BOOT β Bootstrap for high-side gate driver |
| Pin 5 | EN β Enable pin |
| Pin 6 | RT/SYNC β Frequency set / synchronization |
| Pin 7 | FB β Feedback input for output regulation |
| Pin 8 | AGND β Analog ground |
| Pin 9 | PGND β Power ground |
| Pin 10 | VCC β Internal LDO output / bias |
| Pin 11 | SS/TR β Soft-start / tracking |
| Pin 12 | MODE β Light-load mode selection |
| Pin 13 | PWRGD β Power good indicator (open drain) |
| Pin 14 | PGND/PAD β Power ground / thermal pad |
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
LM61440Q-Q1 is suitable for 6 applications: ADAS Domain Controller Power, Automotive Infotainment, Automotive Gateway and Body Electronics, Industrial 24 V Bus Point-of-Load, Automotive Lighting and LED Drivers, Test and Measurement Instruments.
ADAS Domain Controller Power
The LM61440-Q1 fits ADAS domain controllers where sensor processors need clean, efficient mid-current rails from a 12 V automotive battery. Its 3 V to 36 V input with 42 V transient tolerance survives load-dump without front-end clampers, and AEC-Q100 qualification plus functional-safety documentation supports ISO 26262 system arguments. Placed as a first-stage 5 V or 3.3 V rail feeding downstream point-of-load regulators, its low-EMI HotRod package with parallel input path minimizes switch-node ringing that could interfere with radar and camera signal chains.
Recommended
Automotive Infotainment
Infotainment head units and displays draw several amps at 5 V from a noisy 12 V battery rail shared with RF tuners and audio amplifiers. The LM61440-Q1's low-EMI switching and pin-selectable light-load mode keep conducted/radiated emissions within CISPR-class limits while maintaining efficiency at standby loads. The 4 A capacity directly powers display backplane or audio power stages, and the 36 V input covers jump-start and load-dump transients that would damage commercial-grade converters.
Recommended
Automotive Gateway and Body Electronics
Gateway modules and body control units run continuously, so light-load efficiency matters. The LM61440-Q1's pin-selectable light-load mode keeps quiescent losses low during sleep states while providing 4 A bursts for CAN/LIN transceiver banks and microcontroller rails. Its 42 V transient tolerance eases input surge protection against ISO pulse events in harsh body-electronics environments. The AEC-Q100 qualification and functional-safety-capable documentation align with typical gateway reliability targets.
Recommended
Industrial 24 V Bus Point-of-Load
Industrial PLC and factory automation systems distribute a 24 V bus that must be stepped down to 5 V or 3.3 V for I/O and sensors. The LM61440-Q1's 36 V maximum input covers 24 V rails plus surge margin, while its 4 A output feeds multiple I/O cards. The low-EMI design prevents interference with nearby analog measurement front ends, and adjustable switching frequency lets designers steer switching harmonics away from sensitive ADC bands used in industrial data acquisition.
Recommended
Automotive Lighting and LED Drivers
Exterior and interior LED lighting modules in vehicles demand stable current rails from a battery subject to cold-crank dips (down near 3-4 V) and load-dump surges (up to 36-42 V). The LM61440-Q1 spans this entire envelope natively. Its 4 A capacity supports high-power LED strings via constant-voltage feeding of linear LED drivers, and the pin-selectable light-load mode enables PWM-dimming-friendly continuous conduction for low output ripple and uniform light output.
Recommended
Test and Measurement Instruments
Bench instruments and data acquisition modules need efficient, low-noise intermediate rails from 12 V or 24 V wall adapters. The LM61440-Q1's 36 V input accepts both adapter standards, and its adjustable frequency plus spread of harmonics simplify compliance testing. The HotRod package reduces switch-node overshoot, improving radiated emissions margins in plastic-enclosed instruments without shielding, while 4 A covers DSP and FPGA I/O rail demands in compact designs.
Recommended
Recommended Products Summary
Engineering reference data for LM61440Q-Q1 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM61440 | LM61460 | LMR61440-Q1 |
|---|---|---|---|---|
| Package | 14-Pin VQFN-HR (RJR, HotRod) | 14-Pin VQFN-HR (RJR) - same | 14-Pin VQFN-HR (RJR) - same | QFN-9 2.5x2 mm - different |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Input Voltage Range | 3 V to 36 V (42 V transient) | 3 V to 36 V | 3 V to 36 V | 3 V to 36 V (42 V transient) |
| Output Current | 4 A | 4 A | 6 A | 4 A |
| Qualification | AEC-Q100 (Q1) | Commercial grade | Commercial grade | AEC-Q100 (Q1) |
| Pin Compatible | Yes (family) | Yes | Yes | No (different package) |
| Light Load Mode | Pin selectable | Pin selectable | Pin selectable | Pin selectable |
| Price (1 pc, approx, as of 2026-08-29) | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- 42 V transient tolerance without external surge protection (vs LM61440)
- Proprietary HotRod package lowers EMI (vs LMR61440-Q1)
- Pin-compatible current scaling path (vs LM61460)
Design Notes
Exploit the HotRod parallel input path by placing the input ceramic capacitor loop as tight as possible across PVIN and PGND. The package eliminates bond wires specifically to minimize parasitic inductance - long traces negate this benefit and raise switch-node ringing, degrading the low-EMI advantage. Follow the layout section of datasheet SNVSBE4C for recommended land pattern and via stitching to the ground plane.
Use the RT/SYNC pin to set the switching frequency away from sensitive bands (e.g., AM radio band 530-1700 kHz for automotive) and enable synchronization to a clean system clock when multiple converters operate nearby. The HotRod package already minimizes switch-node ringing, but snubber-free EMI compliance still requires a compact power stage and shielded or tightly-coupled inductor selection.
Use the MODE pin strap deliberately: light-load mode improves standby efficiency but introduces larger output ripple and variable frequency, which can upset sensitive analog rails downstream. For ADC/DAC analog supplies, force continuous conduction. Also confirm the BOOT capacitor is rated above the internal driver voltage and never leave EN floating in safety-critical rails - tie it through a divider for defined startup.
Compliance Information
AEC-Q100 automotive qualification confirmed per TI product page. RoHS/REACH/lead-free status not stated in provided data - verify on TI quality pages.
