TPS54331DRCR - 3A 28V Step-Down Buck Converter | TI
MPN: TPS54331DRCR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.42 | $0.42 |
| 10 | $0.37 | $3.70 |
| 100 | $0.3 | $30.00 |
| 500 | $0.26 | $130.00 |
| 1,000 | $0.23 | $230.00 |
| 3,000 | $0.21 | $630.00 |
TPS54331DRCR Overview
A buck (step-down) converter is a switching voltage regulator that converts a higher DC input voltage to a lower regulated output voltage using a switching element, inductor, and output capacitor. Buck regulators sit within the broader hierarchy of power management ICs: switching regulator > DC-DC converter > voltage regulator. Compared to linear regulators (LDOs), buck converters achieve far higher efficiency, often above 90 percent, making them the default choice whenever the input-to-output voltage differential is large or load currents exceed roughly 500mA.
Key features of the TPS54331 include the Eco-mode feature that automatically activates pulse-skipping at light loads to maintain high efficiency, and an ultra-low 1uA shutdown supply current that suits battery-powered applications. Current-mode control with internal slope compensation simplifies loop compensation design and delivers fast transient response. A fixed 570kHz switching frequency keeps the power inductor and capacitors small and places switching noise above most sensitive audio and RF bands.
Technically, the converter is a non-synchronous (external free-wheel diode) topology, which keeps the IC cost low while requiring a Schottky diode such as the B340A on the PH switch node. The integrated 3A MOSFET, internal soft-start via SS/TR pin, programmable EN pin with hysteresis, and COMP pin for external loop compensation give designers full control over startup, efficiency, and transient behavior. Wide 3.5V to 28V input range covers 5V, 12V, and 24V industrial rails.
Typical applications include 12V and 24V industrial auxiliary power rails, 5V or 3.3V point-of-load supplies for MCUs and FPGAs, LED lighting drivers, battery-powered instrumentation, and networking equipment. The 3A rating comfortably powers embedded processors, motors control logic, and multi-rail distributed power systems.
For design, choose the free-wheel Schottky diode for low forward voltage and adequate current rating, keep the PH loop area small, and set the compensation network per the datasheet equations for your output capacitor ESR. Verify junction temperature with the SOIC-8 thermal metrics for your copper area.
This page synthesizes verified distributor pricing, drop-in alternatives including the TI TPS54332D pin-for-pin replacement and the cross-brand SGM61232XG, plus practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for TPS54331DRCR 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:
TPS54332D
β Drop-Inπ Reference alternative (not in catalog)
TPS54331DDAR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
TPS54531D
β Drop-Inπ Reference alternative (not in catalog)
TPS54231DR
β Drop-Inπ Reference alternative (not in catalog)
SGM61232XG
β Drop-Inπ Reference alternative (not in catalog)
TPS54331DRCR Maximum Ratings & Electrical Characteristics
| Topology | Non-synchronous Buck (Step-Down) |
| Input Voltage Range | 3.5 V to 28 V |
| Output Voltage Range | 0.8 V to 25 V (adjustable) |
| Maximum Output Current | 3 A |
| Switching Frequency | 570 kHz (fixed) |
| Control Method | Current mode with internal slope compensation |
| Light Load Feature | Eco-mode pulse skipping |
| Shutdown Supply Current | 1 uA |
| Integrated MOSFET | Low RDS(on) high-side FET |
| Number of Outputs | 1 |
| Package | 8-SOIC (0.154in, 3.90mm Width) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +150C (TJ) |
| Soft-Start | Yes, SS/TR pin |
| Enable Pin | Yes, EN with programmable threshold |
| RoHS Status | Compliant |
TPS54331DRCR Pin Configuration
| Pin 1 | BOOT β Bootstrap capacitor connection for high-side gate drive |
| Pin 2 | NC β Not connected (per datasheet) |
| Pin 3 | VIN β Input supply voltage, 3.5V to 28V |
| Pin 4 | EN β Enable input with programmable undervoltage lockout threshold |
| Pin 5 | VSENSE β Feedback voltage sense input (0.8V reference) |
| Pin 6 | GND β Ground reference |
| Pin 7 | COMP β Error amplifier output for external loop compensation network |
| Pin 8 | PH β Switch phase node - connect to free-wheel Schottky diode and output inductor |
Typical Applications
TPS54331DRCR is suitable for 6 applications: Industrial 24V Auxiliary Power Rails, 5V/3.3V Point-of-Load for MCUs and FPGAs, Battery-Powered Portable Instruments, Networking and Telecom Equipment, LED Lighting Drivers and Signage, Test and Measurement Instrumentation.
Industrial 24V Auxiliary Power Rails
The TPS54331's 3.5V to 28V input range directly tolerates 24V industrial buses, including typical transients within the 28V absolute envelope, making it a natural fit for PLC I/O modules, sensor transmitters, and factory automation auxiliary supplies. Regulating down to 5V or 3.3V at up to 3A, the fixed 570kHz switching frequency allows a compact 10-22uH inductor and keeps EMI above sensitive control-signal bands. Eco-mode pulse skipping preserves efficiency when the module idles. Place the free-wheel Schottky and input ceramic capacitor within 10mm of PH and VIN respectively to control the hot loop, and use the EN pin with a divider for bus under-voltage lockout.
Recommended
5V/3.3V Point-of-Load for MCUs and FPGAs
Embedded processors require tightly regulated low-voltage rails with fast transient response; the TPS54331's current-mode control with internal slope compensation delivers single-cycle transient response and an easy-to-compensate loop, typically settling within tens of microseconds on load steps. Converting 12V down to 3.3V at 2-3A, estimated efficiency exceeds 85 percent, far above a linear regulator's 27 percent, keeping thermals manageable in sealed enclosures. The COMP pin allows bandwidth tuning for rails shared with analog circuits. Use low-ESR ceramic output capacitance (2x47uF typical) and verify the 0.8V feedback reference accuracy supports your core-rail tolerance budget.
Recommended
Battery-Powered Portable Instruments
The TI datasheet specifically highlights the TPS54331's 1uA shutdown supply current for battery-powered applications. In a 3S to 6S lithium-ion stack (9-25V), the converter regulates system rails while Eco-mode pulse skipping keeps light-load efficiency high between measurement cycles. The EN pin allows the MCU to disconnect the rail entirely, dropping converter consumption to the microamp level. Design the feedback divider with high-value resistors (e.g., hundreds of kilohms) so no-load draw is dominated by the converter, not the divider, and confirm minimum load for pulse-skipping stability with your output capacitance in bench testing.
Recommended
Networking and Telecom Equipment
Routers, switches, and small-cell hardware distribute 12V or 24V intermediate rails that need multiple economical point-of-load converters. The TPS54331's 28V maximum input, 3A output, and fixed 570kHz frequency allow one BOM position to serve many rails, and spread across a board the converters' fixed-frequency operation simplifies EMI filtering because emissions stay in a predictable band. The SOIC-8 package on 1oz copper supports the estimated 2W dissipation typical of 12V-to-3.3V service without heatsinking. Sequence rails using the SS/TR soft-start pin and EN dividers for processor reset management, and add input bulk capacitance for cable-inductance ringing suppression.
Recommended
LED Lighting Drivers and Signage
Constant-voltage LED strips and signage power supplies built on the 24V industrial rail use the TPS54331 to derive efficient 5V or 12V sub-rails for controller logic and driver circuitry. Its Eco-mode keeps no-load standby draw low for always-plugged luminaires, and the 150C maximum junction temperature tolerates thermally stressed luminaires when derated properly. Estimated: at 24V-to-5V, 2A load, dissipation is roughly 1.5W at 83 percent efficiency, yielding about 45C junction rise on standard 1oz SOIC-8 copper, acceptable within a 70C ambient cabinet. Place the converter away from PWM dimming circuitry to avoid 570kHz beat-frequency artifacts in the driver feedback.
Recommended
Test and Measurement Instrumentation
Bench instruments and data-acquisition modules need multiple mid-current rails derived from a single 12V or 24V input. The TPS54331's adjustable 0.8V to 25V output range lets one design cover 1.8V, 3.3V, 5V, and even 12V daughter rails, standardizing procurement. Current-mode control provides good line rejection on shared rails, and the external COMP network lets engineers add output impedance for sensitive analog rails or maximize bandwidth for digital rails. For best output ripple performance, keep the measured switching ripple below 10mVpp with 47uF effective ceramic output capacitance and verify loop crossover near one-tenth of the 570kHz switching frequency.
Recommended
Recommended Products Summary
Engineering reference data for TPS54331DRCR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TPS54332D | TPS54331DDAR | TPS54231DR | SGM61232XG |
|---|---|---|---|---|---|
| Package | SOIC-8 (D) | SOIC-8 (D) - same | SOIC-8 PowerPAD (DDA) | SOIC-8 (D) - same | SOIC-8 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | SGMC (Sagna Microelectronics) |
| Input Voltage Range | 3.5 V to 28 V | 3.5 V to 28 V | 3.5 V to 28 V | 3.5 V to 28 V | 4.5 V to 30 V |
| Maximum Output Current | 3 A | 3 A | 3 A | 2 A | 3 A |
| Pin-for-Pin Compatible | - | Yes (per TI compare tool) | Yes (exposed pad differs) | Yes | Yes (per cross-reference guidance) |
Key Differentiators
- Ultra-low 1uA shutdown current for battery designs (vs TPS54332D)
- Lowest cost per amp in the TI 28V SOIC-8 family (vs TPS54531D)
- 28V input headroom versus lower-voltage competitors (vs SGM61232XG)
Design Notes
Minimize the hot loop: VIN ceramic capacitor, PH pin, and free-wheel Schottky diode must form the smallest possible loop, ideally under 20mm total trace length, on the same layer as the IC. The 570kHz switching edge couples into nearby traces through this loop. Place the output inductor adjacent to PH and route VSENSE as a Kelvin connection directly from the output capacitor, not from the inductor switch side, to avoid sensing switching ripple. Ground the COMP compensation network on a quiet analog ground island.
Select the free-wheel Schottky for reverse voltage at least 1.3x VIN (40V class for 28V input) and average current of at least half the load current since it conducts during the off-time. Diode conduction loss dominates at high duty-cycle extremes: estimated at 12V-to-3.3V, 3A, a 0.45V-forward diode dissipates roughly 1.6W, so choose a low-VF part in a thermally adequate package such as SMA/SMB copper-slug. Verify diode junction temperature, not just the IC.
Do not omit the BOOT capacitor (typically 0.01uF to 0.1uF ceramic from BOOT to PH); without it the high-side FET cannot switch and PH stays low. Ensure EN divider thresholds respect the datasheet VIH/VIL levels - floating EN gives unpredictable enable. When using Eco-mode with ceramic-only output capacitance, confirm no subharmonic pulsing at light load by testing down to true no-load; increase output capacitance or add a small pre-load resistor (e.g., 1mA) if pulse skipping becomes erratic.
The SOIC-8 (D) junction-to-ambient thermal resistance is strongly board-dependent. Estimated: at 12V-to-3.3V, 3A operation with 88 percent efficiency, dissipation is about 1.4W; on a minimal 1oz JEDEC board this can exceed a 100C rise, while with 2oz copper and 4x4 thermal vias the rise is manageable. For sustained high-current or 24V-input designs, consider the TPS54331DDAR PowerPAD variant, whose exposed pad roughly halves effective theta-JA when soldered to a grounded thermal plane.
Compliance Information
RoHS compliance per TI product listing and distributor data (Rev. H datasheet generation). Formal REACH/halogen-free declarations available from TI.com quality portal.
