A1084-A - 5A Low-Dropout Positive Voltage Regulator | AiT Semiconductor
Teilenummer: A1084-A ✓ Aktiv| Menge | Stückpreis | Gesamt |
|---|---|---|
| 1 | $0.85 | $0,85 |
| 10 | $0.74 | $7,40 |
| 100 | $0.62 | $62,00 |
| 500 | $0.55 | $275,00 |
| 1.000 | $0.48 | $480,00 |
| 3.000 | $0.42 | $1.260,00 |
A1084-A Übersicht
A low-dropout (LDO) linear regulator is a type of voltage regulator that maintains a stable output voltage even when the input voltage is only marginally above the output voltage. Within the broader taxonomy, LDOs belong to the linear regulator family, which itself is a sub-category of voltage regulators under the power management IC umbrella. Unlike switching regulators, LDOs trade efficiency for simplicity and ultra-low output noise because they dissipate the difference between VIN and VOUT as heat rather than switching it.
Key features of the A1084-A include a maximum input voltage of 7V (typical operation), built-in thermal overload protection, on-chip current limiting that prevents catastrophic failure under short-circuit conditions, and an adjustable output version that supports VREF = 1.25V. The bipolar architecture used in the AiT A1084 is similar in topology to the legacy National Semiconductor LM1084, sharing the same TO-220 / TO-252 footprint and pinout conventions for true drop-in compatibility.
From an applications perspective, the A1084-A is well suited for high-current post-regulation after a switching converter, where its low noise floor preserves signal integrity. Designers typically pair it with bulk input capacitance of 10uF or larger and a tantalum output capacitor of 10uF minimum to maintain loop stability, mirroring the LM1084 reference design from National Semiconductor.
When designing with this part, pay close attention to thermal management. At VIN=5V, VOUT=3.3V, and 5A load, the A1084-A dissipates approximately 8.5W of power, which requires substantial copper area or a heatsink on the DPAK tab. Exceeding the junction temperature limit will trigger the thermal-shutdown circuit embedded in the die. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in-Alternativen für A1084-A – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Schnellvergleichstool – Wählen Sie Alternativbauteile für den Direktvergleich:
LM1084CS-ADJ
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LD1084D2M33
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
SPX1084M3-L-3-3
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
MIC29150-3.3WU
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LT1084CT-5
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
A1084-A Grenzwerte & elektrische Eigenschaften
| Regulator Type | Low-Dropout (LDO) Positive Linear Regulator |
| Output Current | 5 A (max) |
| Dropout-Spannung | 1.4 V at 5 A |
| Output Voltage Versions | 1.5 V / 1.8 V / 2.5 V / 3.3 V / 5.0 V fixed; ADJ adjustable |
| Reference Voltage (ADJ) | 1.25 V (typical) |
| Thermisches Abschalten | Yes (internal) |
| Strombegrenzung | Yes (internal) |
| Betriebstemperaturbereich | -40 C to +125 C junction |
| Gehäuse | TO-252 (DPAK) |
| Montageart | Surface Mount |
| Architecture | Bipolar |
A1084-A Pin-Konfiguration
| Pin 1 | ADJ/GND — Adjustable output feedback (adjustable version) or Ground (fixed version) |
| Pin 2 | VOUT — Regulated output voltage |
| Pin 3 | VIN — Input supply voltage |
| Pin TAB | VOUT — Exposed thermal pad - internally connected to VOUT |
Typische Anwendungen
A1084-A ist geeignet für 6 Anwendungs: 5V/3.3V High-Current Logic Rail Post-Regulation, Battery Charger Termination / Post-Regulation, FPGA Core and Auxiliary Voltage Supply, Motor Driver Auxiliary Power Supply, Networking and Telecom Line Card Power, Industrial Sensor and Actuator Power.
5V/3.3V High-Current Logic Rail Post-Regulation
The A1084-A is commonly placed downstream of a switching buck converter to provide a clean, low-noise 3.3V or 5V rail for digital logic, FPGAs, and ASICs that demand high current and low ripple. With 5A output capability and 1.4V dropout, it can source a 3.3V rail from a 5V intermediate bus with adequate headroom. Per the AiT datasheet, the LDO adds no switching noise to the output, preserving signal integrity for sensitive logic. Compared with cascading another switching regulator, the A1084-A's bipolar architecture trades efficiency for simplicity and exceptional transient response.
Empfohlen
Battery Charger Termination / Post-Regulation
In multi-cell battery charger designs, the A1084-A provides a stable, low-noise post-regulation rail for charge-management ICs and protection circuits. The 5A capability allows direct supply to multiple parallel cell-balancing circuits, while the 1.4V dropout leaves sufficient headroom from a 2S/3S lithium pack input. Per the AiT datasheet, the internal current-limit and thermal-shutdown features protect the LDO during fault conditions on the load side, such as a shorted battery cell. This application values the bipolar architecture's robustness over the lower quiescent current of CMOS LDOs.
Empfohlen
FPGA Core and Auxiliary Voltage Supply
FPGAs typically require multiple high-current low-voltage rails (1.0V-3.3V) with tight regulation and fast transient response. The A1084-A in adjustable-output configuration can supply auxiliary rails such as 2.5V or 1.8V at up to 5A, suitable for FPGA I/O banks and auxiliary logic. Per the AiT datasheet, the LDO's low output noise and high PSRR (typical of bipolar regulators) avoid coupling switching noise into the FPGA's analog sections. The trade-off versus a dedicated switching regulator is lower efficiency at large VIN-VOUT deltas, mitigated by placing the LDO downstream of an intermediate buck stage.
Empfohlen
Motor Driver Auxiliary Power Supply
Brushless DC motor drives and stepper driver boards often require a 3.3V or 5V logic supply derived from the main 12V-24V motor bus. The A1084-A can post-regulate this logic rail at up to 5A, sufficient to power the microcontroller, gate drivers, and communication interfaces. Per the AiT datasheet, the integrated thermal shutdown protects the regulator from the high ambient temperatures inside motor enclosures, while the current limit protects against wiring shorts. The DPAK package's metal tab provides direct thermal coupling to the motor-driver heatsink, an attractive thermal design feature.
Empfohlen
Networking and Telecom Line Card Power
In telecom line cards and networking switches, the A1084-A provides a clean, low-noise 3.3V or 2.5V rail for PHY transceivers, SERDES devices, and supervisory circuits. Per the AiT datasheet, the 5A current capability supports multi-port Gigabit Ethernet PHYs that draw substantial current from a common rail. The bipolar LDO's high PSRR effectively attenuates ripple from the upstream -48V-to-intermediate bus converter, critical for PHY signal integrity and EMI compliance. The DPAK footprint also supports high-density PCB layouts typical of line-card mezzanine designs.
Empfohlen
Industrial Sensor and Actuator Power
Industrial automation systems often need a stable 24V-to-5V or 24V-to-3.3V supply rail to power sensors, actuators, and PLC interface modules. The A1084-A in adjustable mode can deliver up to 5A from a 24V industrial bus with adequate thermal design, providing a clean rail for analog sensor signal conditioning. Per the AiT datasheet, the -40C to +125C junction temperature range and internal protection features suit the harsh electrical environment of factory floors, including voltage transients on the 24V bus. The LDO's simplicity (no compensation network required) accelerates design cycles for industrial I/O modules.
Empfohlen
Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für A1084-A – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | LM1084CS-ADJ | LD1084D2M33 | SPX1084M3-L-3-3 | MIC29150-3.3WU | LT1084CT-5 |
|---|---|---|---|---|---|---|
| Package | TO-252 (DPAK) | TO-263-3 (same DPAK family) | TO-252-3 (DPAK) | TO-252-3 (DPAK) | TO-263-3 | TO-220-3 |
| Brand | AiT Semiconductor | Texas Instruments | STMicroelectronics | MaxLinear | Microchip Technology | Analog Devices |
| Output Current | 5 A | 5 A | 5 A | 5 A | 1.5 A (lower current) | 5 A |
| Dropout Voltage | 1.4 V at 5 A | 1.4 V at 5 A | 1.3 V at 5 A | 1.4 V at 5 A | 0.6 V at 1.5 A (lower dropout) | 1.5 V at 5 A |
| Reference Voltage | 1.25 V (ADJ) | 1.25 V | 1.25 V (fixed 3.3V) | 1.25 V (fixed 3.3V) | 1.25 V | 1.25 V (fixed 5V) |
| Thermal Shutdown | Yes | Yes | Yes | Yes | Yes | Yes |
| Current Limit | Yes | Yes | Yes | Yes | Yes | Yes |
| Operating Junction Temperature | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | 0 C to +125 C |
| Architecture | Bipolar | Bipolar | Bipolar | Bipolar | Bipolar | Bipolar |
Wichtigste Unterscheidungsmerkmale
- Cost-effective clone of the legacy LM1084 footprint (vs. LM1084CS-ADJ)
- Wide fixed-output selection across 1.5V-5.0V (vs. LD1084D2M33)
- Integrated thermal and current-limit protection (vs. MIC29150-3.3WU)
Designhinweise
Estimated: At VIN=5V, VOUT=3.3V, and 5A load, the A1084-A dissipates approximately (5-3.3)*5 = 8.5 W. The TO-252 (DPAK) package has a typical theta_JA of 50 C/W on a 1oz 1sq-inch copper pour, giving a junction temperature rise of 425 C above ambient - well above the 125 C limit. For reliable operation at high currents, use at least 2 sq-inches of copper pour on the tab, or attach an external heatsink. The thermal-shutdown circuit will engage if junction temperature exceeds ~150 C, but operation near this limit is not recommended for continuous duty.
Place input and output capacitors as close as possible to the IC pins to minimize parasitic inductance. Per the AiT datasheet, use a minimum 10uF low-ESR tantalum output capacitor for stability; aluminum electrolytic is acceptable but ceramic capacitors alone may cause instability due to low ESR. Add a 1uF ceramic bypass in parallel for high-frequency noise suppression. The tab should be soldered to a copper pour that is thermally connected to VIN or to a heatsink - never leave the tab floating.
Do not exceed the maximum input voltage rating; check the AiT datasheet for the exact value as it differs between fixed/adjustable versions. Avoid reverse-biasing VOUT above VIN (which can damage the pass element); place a protection diode if the load has inductive kickback. Do not operate the regulator with the output floating (no load) on the ADJ version, as the feedback loop requires a minimum load to maintain regulation. Always verify the dropout voltage under worst-case (highest) load current, not nominal, to ensure headroom for transient response.
Compliance-Informationen
Compliance status not explicitly declared in the verified web data. AEC-Q100 is not applicable - the A1084-A is an industrial-grade part. Confirm RoHS/REACH/lead-free status directly with AiT Semiconductor for production designs.
