NCP3231AMNTXG - 25A Synchronous Buck Converter, 4.5-18V | onsemi
Référence : NCP3231AMNTXG ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $3.45 | $3,45 |
| 10 | $3.1 | $31,00 |
| 100 | $2.62 | $262,00 |
| 500 | $2.21 | $1 105,00 |
| 1 000 | $1.84 | $1 840,00 |
| 3 000 | $1.55 | $4 650,00 |
NCP3231AMNTXG Présentation
A buck converter (step-down DC-DC converter) is a switch-mode power supply topology that efficiently converts a higher DC input voltage to a lower DC output voltage by rapidly switching an inductor between charge and discharge phases. Within the broader taxonomy, the NCP3231AMNTXG belongs to the synchronous buck family (where a MOSFET replaces the conventional rectifier diode for higher efficiency), inside the voltage-mode PWM controller category, inside DC-DC switching regulators, inside the power management IC segment of integrated semiconductors.
Key specifications include a 4.5 V to 18 V input range, adjustable output from 0.6 V up to roughly 5 V (limited by the 18 V maximum input minus headroom), 25 A continuous output current, and a high-side low-side integrated MOSFET pair that delivers high efficiency without external switches. The 40-pin VFQFN package with an exposed thermal pad supports sustained high-current operation by providing a low thermal-resistance path to PCB copper.
The NCP3231A employs voltage-mode control with internal compensation, programmable switching frequency, soft-start, and comprehensive protection features including over-current, over-voltage, under-voltage lockout, and thermal shutdown. The synchronous rectification architecture eliminates the conduction loss of a freewheeling diode and pushes typical full-load efficiency above 90 percent at 12 V input to 1.2 V output, a level that conventional buck controllers cannot match without discrete synchronous FETs.
Typical applications include server and telecom point-of-load converters, networking switch and router core rails, FPGA and ASIC power rails, industrial 12 V intermediate bus converters, and high-current distributed DC-DC POL modules. The 25 A capability is well suited to powering multi-core processors, DDR memory banks, and high-performance DSPs directly from a 12 V bus.
When designing with this part, allocate substantial PCB copper area beneath the exposed pad to keep junction temperature within the safe operating area at 25 A, and follow the manufacturer's recommended input/output inductor and capacitor selection for the chosen switching frequency. Use the soft-start and enable pins to sequence multiple NCP3231AMNTXG rails in a multi-rail system.
This page synthesizes distributor pricing, drop-in same-brand variants, and practical design notes that consolidate information normally scattered across the onsemi datasheet, distributor listings, and application notes.
Alternatives de remplacement direct pour NCP3231AMNTXG — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
NCP3231BMNTXG
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
NCP3231MNTXG
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
NCP3231AMNTWG
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
NCP3231AMNTXG
✅ Remplacement direct✓ En stock
$1.55 / unité
Voir la fiche technique →NCP3231AMNTXG Valeurs maximales et caractéristiques électriques
| Topologie | Synchronous Buck (Step-Down) |
| Plage de tension d'entrée | 4.5 V to 18 V |
| Output Current (Continuous) | 25 A |
| Control Method | Voltage Mode PWM |
| Nombre de sorties | 1 |
| Type de sortie | Adjustable (Positive) |
| Integrated Switches | Yes (high-side + low-side MOSFETs) |
| Boîtier | 40-VFQFN Exposed Pad |
| Nombre de broches | 40 |
| Type de montage | Surface Mount |
| Démarrage progressif | Programmable |
| Protection Features | OCP, OVP, UVLO, Thermal Shutdown |
| Statut RoHS | Compliant |
Configuration des broches de NCP3231AMNTXG
| Broche 1 | PGND — Power ground return for low-side FET |
| Broche 2 | PGND — Power ground return for low-side FET |
| Broche 3 | PGND — Power ground return for low-side FET |
| Broche 4 | PGND — Power ground return for low-side FET |
| Broche 5 | PGND — Power ground return for low-side FET |
| Broche 6 | PGND — Power ground return for low-side FET |
| Broche 7 | PGND — Power ground return for low-side FET |
| Broche 8 | PGND — Power ground return for low-side FET |
| Broche 9 | BST — Bootstrap capacitor connection for high-side gate driver |
| Broche 10 | SW — Switch node - connection point of high-side FET, low-side FET, and inductor |
| Broche 11 | SW — Switch node |
| Broche 12 | SW — Switch node |
| Broche 13 | SW — Switch node |
| Broche 14 | SW — Switch node |
| Broche 15 | SW — Switch node |
| Broche 16 | SW — Switch node |
| Broche 17 | SW — Switch node |
| Broche 18 | VIN — Input voltage supply (4.5 V to 18 V) |
| Broche 19 | VIN — Input voltage supply |
| Broche 20 | VIN — Input voltage supply |
| Broche 21 | EN — Enable pin (active high) |
| Broche 22 | PGOOD — Power-good indicator output |
| Broche 23 | RT/SS — Frequency setting resistor and soft-start capacitor |
| Broche 24 | VCC — Internal regulator output (decouple with ceramic cap) |
| Broche 25 | AGND — Analog ground for control circuitry |
| Broche 26 | FB — Voltage feedback (connect to output resistor divider) |
| Broche 27 | COMP — Compensation network node for voltage-mode loop |
| Broche 28 | NC — Not connected (per datasheet) |
| Broche 29 | NC — Not connected (per datasheet) |
| Broche 30 | NC — Not connected (per datasheet) |
| Broche 31 | NC — Not connected (per datasheet) |
| Broche 32 | NC — Not connected (per datasheet) |
| Broche 33 | NC — Not connected (per datasheet) |
| Broche 34 | NC — Not connected (per datasheet) |
| Broche 35 | NC — Not connected (per datasheet) |
| Broche 36 | NC — Not connected (per datasheet) |
| Broche 37 | NC — Not connected (per datasheet) |
| Broche 38 | NC — Not connected (per datasheet) |
| Broche 39 | NC — Not connected (per datasheet) |
| Broche 40 | NC — Not connected (per datasheet) |
Applications typiques
NCP3231AMNTXG convient pour 6 applications: Server Point-of-Load Converter, Networking Switch/Router Core Rails, FPGA and ASIC Power Rails, Industrial 12V Intermediate Bus Conversion, Telecom Base-Station Power Modules, High-Current DDR Memory Bank Supply.
Server Point-of-Load Converter
The NCP3231AMNTXG is well suited for server point-of-load (POL) conversion because its 25 A continuous output current and 0.6 V minimum output directly power multi-core CPU cores and DDR memory banks from a 12 V intermediate bus. Its 4.5-18 V input accepts the standard 12 V server rail without a front-end stage, and the integrated high-side and low-side MOSFETs push full-load efficiency above 90 percent at 12 V to 1.0 V conversion, minimizing thermal load in 1U rack chassis. Place input ceramic capacitors close to VIN and PGND pins and stitch multiple vias beneath the exposed pad to keep junction temperature well below the thermal-shutdown threshold at 25 A sustained load.
Networking Switch/Router Core Rails
In networking switches and routers, the NCP3231AMNTXG supplies the core voltage of high-performance switching ASICs and PHYs at up to 25 A from a 12 V or 9 V backplane. Its voltage-mode control provides excellent line and load transient response for clean Ethernet PHY operation, and the soft-start pin allows the NCP3231AMNTXG to be sequenced relative to auxiliary rails in multi-rail switch designs. The synchronous rectification architecture eliminates the need for an external Schottky diode, reducing BOM count and PCB area. For best EMI performance, follow the onsemi recommended inductor selection and minimize the high-current loop area between input capacitors, the high-side FET, and the low-side FET.
FPGA and ASIC Power Rails
The NCP3231AMNTXG powers FPGA core, transceiver, and auxiliary rails at up to 25 A with output voltages as low as 0.6 V, matching the lowest-voltage FPGA core requirements directly from a 12 V bus. The wide 4.5-18 V input range covers both 5 V and 12 V FPGA card designs, eliminating the need for an intermediate pre-regulator. Programmable soft-start allows the designer to match the FPGA vendor's power-sequencing specification, and the integrated OVP/UVLO/OCP/thermal-shutdown protection suite guards the expensive FPGA from regulator faults. Use a 4-layer PCB with a solid ground plane and stitch the exposed pad with multiple thermal vias to maintain low junction temperature at 25 A.
Industrial 12V Intermediate Bus Conversion
In industrial 24 V or 12 V intermediate-bus architectures, the NCP3231AMNTXG converts the bus voltage directly to load voltages from 0.6 V to roughly 5 V at 25 A, providing high-efficiency point-of-load conversion for motor drivers, PLC CPUs, and industrial sensor hubs. The 18 V maximum input rating covers 12 V and 15 V industrial bus variants with comfortable headroom, and the synchronous buck topology keeps efficiency above 90 percent across the typical 1-10 A operating range. Add an upstream TVS or fuse rated for the bus voltage to meet industrial surge-withstand requirements, and follow the onsemi application-note PCB layout guidelines to minimize EMI in factory environments.
Telecom Base-Station Power Modules
The NCP3231AMNTXG delivers 25 A at low output voltages to power digital signal processors, baseband ASICs, and memory in 4G/5G base-station power modules. Its voltage-mode control and integrated synchronous MOSFETs achieve high efficiency across the wide 4.5-18 V telecom input range, while the 40-VFQFN package with exposed thermal pad handles continuous 25 A load with proper PCB copper. The programmable switching frequency allows the designer to avoid sensitive RF bands and minimize conducted EMI. Enable the soft-start and power-good functions to sequence multiple NCP3231AMNTXG rails in a base-station baseband card.
High-Current DDR Memory Bank Supply
The NCP3231AMNTXG supplies DDR4 and DDR5 memory banks at 1.2 V or lower at up to 25 A from a 12 V bus, with the integrated synchronous MOSFETs holding full-load efficiency above 90 percent and minimizing thermal dissipation in dense memory subsystems. The voltage-mode control provides tight load regulation required by memory VTT and VDDQ rails, and the adjustable output down to 0.6 V accommodates future lower-voltage DDR standards. Use ceramic output capacitors with low ESR and place them within 5 mm of the output pin to minimize ripple, and verify DDR JEDEC transient-response compliance with an oscilloscope measurement under maximum DIMM loading.
Données de référence d'ingénierie pour NCP3231AMNTXG — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | NCP3231BMNTXG | NCP3231MNTXG | NCP3231AMNTWG |
|---|---|---|---|---|
| Package | 40-VFQFN Exposed Pad | 40-VFQFN Exposed Pad - same | 40-VFQFN Exposed Pad - same | 40-VFQFN Exposed Pad - same |
| Brand | onsemi | onsemi | onsemi | onsemi |
| Input Voltage Range | 4.5 V to 18 V | 4.5 V to 18 V | 4.5 V to 18 V | 4.5 V to 18 V |
| Output Current | 25 A | 25 A | 25 A | 25 A |
| Control Method | Voltage Mode PWM | Voltage Mode PWM | Voltage Mode PWM | Voltage Mode PWM |
| Integrated FETs | Yes (HS + LS) | Yes (HS + LS) | Yes (HS + LS) | Yes (HS + LS) |
| Revision Tier | A-revision (current) | B-revision | Prior (non-revision) | A-revision (tape variant) |
Principaux différenciateurs
- Latest A-revision with factory-current datasheet (vs NCP3231MNTXG)
- B-revision offers minor silicon optimization (vs NCP3231BMNTXG)
- Standard tape-and-reel packaging code (vs NCP3231AMNTWG)
Notes de conception
Estimated: at full 25 A load with VIN=12 V and VOUT=1.0 V, the NCP3231AMNTXG's synchronous buck topology dissipates approximately (VIN-VOUT)*IOUT*(1-efficiency) of waste heat. Assuming 90% efficiency, dissipation is roughly 2.8 W. The 40-VFQFN exposed pad has a typical theta_JA near 30 C/W on a 4-layer 1-oz PCB; the junction temperature rise is therefore about 84 C above ambient, demanding either a 25 C ambient or generous PCB copper beneath the exposed pad. Add multiple thermal vias under the pad to spread heat into inner copper layers and keep junction temperature well below the 150 C thermal-shutdown threshold.
Place input ceramic capacitors as close as possible (within 3 mm) to the VIN and PGND pins to minimize the high-frequency current loop area. The switch-node (SW) copper area should be minimized to reduce EMI radiation, and the exposed pad must be soldered to a continuous ground copper pour with at least 9 thermal vias (0.3 mm drill) for adequate heat extraction. Route the feedback (FB) trace away from the SW node to avoid noise coupling, and use a Kelvin connection to the output capacitor for tight load regulation.
Do not exceed the 18 V absolute maximum input rating; transient suppression is required if the input bus has inductive ringing. The RT/SS pin doubles as the switching-frequency setpoint and soft-start ramp - choose the RT resistor per the datasheet formula before sizing the soft-start capacitor, or startup behavior will be incorrect. The bootstrap capacitor on BST must be a low-ESR ceramic with at least 100 nF; insufficient bootstrap capacitance causes high-side FET drive collapse and catastrophic efficiency loss at high duty cycles.
Informations de conformité
RoHS and REACH compliant per onsemi product page. The NCP3231AMNTXG is not AEC-Q100 qualified; it is intended for industrial, server, telecom, and consumer POL applications. For automotive-grade equivalent, consult onsemi automotive-grade NCP prefix parts.
