REG104GA-3.3/2K5 - 1A 15V DMOS LDO, 3.3V Fixed, SOT-223-6 | TI
MPN: REG104GA-3.3-2K5 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.1 | $2.10 |
| 10 | $1.89 | $18.90 |
| 100 | $1.62 | $162.00 |
| 500 | $1.38 | $690.00 |
| 1,000 | $1.18 | $1,180.00 |
REG104GA-3.3-2K5 Overview
An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable output voltage even when the input voltage is very close to the output voltage. Within the broader power management hierarchy, LDOs sit under linear regulators -> voltage regulators -> power management ICs (PMICs). LDOs are valued for low noise, simplicity, and fast transient response because no switching element is present, unlike a switching DC-DC converter.
Key features of the REG104GA-3.3/2K5 include fast transient response, very low 33 µVrms output noise, ±2% maximum output accuracy, a low 1.7 mA quiescent ground-pin current at full load, and stable operation without an output capacitor. An active-high enable pin supports power-sequencing in multi-rail systems. Internal current limit and thermal shutdown protection safeguard the regulator under fault conditions.
Architecturally, the REG104 employs a DMOS pass transistor rather than a conventional bipolar or PMOS device, achieving much lower dropout at high current while preserving analog-style low-noise operation. The reference and error amplifier are trimmed at the wafer stage for tight output accuracy.
Typical applications include post-regulation after a switching DC-DC converter (FPGA, DSP, or microcontroller rails), industrial 5 V/3.3 V point-of-load supplies, battery-powered portable equipment, and noise-sensitive analog circuits. A heatsink or adequate copper area on the tab is required at high VIN-VOUT differential and full 1 A load.
When designing with the REG104GA-3.3/2K5, observe the tab-land thermal layout guidelines in the datasheet, since at 1 A the device can dissipate 1-7 W depending on dropout. The enable pin allows inrush control via a small RC delay.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for REG104GA-3.3-2K5 — 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 REG104GA-3.3-2K5 (same form factor and footprint) — differing in Operating Temperature Range, Output Type, Package, Topology.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
REG104GA-3.3G4
✅ Drop-In📋 Reference alternative (not in catalog)
REG104GA-3.3
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →REG104GA-5/2K5
✅ Drop-In📋 Reference alternative (not in catalog)
REG104GA-2.5/2K5
✅ Drop-In📋 Reference alternative (not in catalog)
REG104GA-A/2K5
✅ Drop-In📋 Reference alternative (not in catalog)
REG104GA-3.3-2K5 Maximum Ratings & Electrical Characteristics
| Manufacturer | Texas Instruments |
| Series | REG104 |
| Product Type | LDO Linear Voltage Regulator |
| Topology | DMOS Low-Dropout |
| Number of Outputs | 1 |
| Output Type | Fixed |
| Output Voltage | 3.3 V |
| Maximum Output Current | 1 A |
| Absolute Maximum Input Voltage | 15 V |
| Dropout Voltage | 230 mV typical at 1 A, 3.3 V |
| Output Noise | 33 uVrms |
| Output Accuracy | ±2% max |
| Quiescent (Ground Pin) Current | 1.7 mA at IOUT=1 A |
| Enable Pin | Yes (active-high) |
| Output Capacitor Required | No (stable without output cap) |
| Protection Features | Current limit, thermal shutdown |
| Operating Temperature Range | -40C to +85C |
| Package | SOT-223-6 (DCQ), 6 pins (5+Tab) |
| Mounting Type | Surface Mount |
| MSL Level | 2 (per TI datasheet) |
| RoHS Status | Compliant |
| Packaging | Tape & Reel (2,500/reel, /2K5 suffix) |
REG104GA-3.3-2K5 Pin Configuration
| Pin 1 | EN — Enable input (active high) |
| Pin 2 | VIN — Input supply voltage |
| Pin 3 | GND — Ground |
| Pin 4 | NC — Not connected (per datasheet) |
| Pin 5 | VOUT/SENSE — Regulated output (fixed 3.3 V part) |
| Pin 6 | TAB / VOUT — Output / thermal pad (must be soldered to copper pour) |
Typical Applications
REG104GA-3.3-2K5 is suitable for 6 applications: FPGA/DSP/Microcontroller Core Supply Post-Regulation, Industrial 12 V / 24 V Bus Point-of-Load Supply, Noise-Sensitive Analog / Audio / RF Circuit Power, Battery-Powered Portable Equipment, USB / Peripheral Power Distribution, Test & Measurement Instrument Rails.
FPGA/DSP/Microcontroller Core Supply Post-Regulation
The REG104GA-3.3/2K5 is commonly used as a post-regulator after a switching DC-DC converter to provide a clean 3.3 V rail for FPGA, DSP, or microcontroller cores. Its 33 µVrms output noise and fast transient response eliminate switching ripple that would otherwise couple into PLL supplies and ADC references. With 230 mV typical dropout at 1 A and a 15 V input rating, it accepts the output of a 5 V or 12 V intermediate bus while delivering full 1 A continuous current. Place the LDO close to the load with its tab land soldered to a generous copper pour for thermal dissipation.
Recommended
Industrial 12 V / 24 V Bus Point-of-Load Supply
The REG104GA-3.3/2K5 operates directly from industrial 12 V or 24 V buses (after derating) to deliver a clean 3.3 V rail at 1 A for sensors, isolators, and interface ICs. Its 15 V absolute-maximum input allows direct connection to 12 V rails without pre-regulation. The active-high enable pin supports power sequencing, while internal current limit and thermal shutdown protect against fault conditions on rugged factory-floor equipment. The SOT-223-6 footprint and tab land keep the solution footprint compact for dense PLC backplanes.
Recommended
Noise-Sensitive Analog / Audio / RF Circuit Power
The REG104GA-3.3/2K5 provides a clean 3.3 V rail for audio codecs, RF transceivers, PLLs, VCOs, and precision ADC references where supply noise directly degrades performance. The 33 µVrms output noise and absence of switching ripple preserve dynamic range in audio paths and phase noise in RF synthesizers. Stable operation with or without an output capacitor simplifies analog PCB layout. Place the LDO as close as possible to the analog supply pin with a star-ground return to minimize coupling from digital return currents.
Recommended
Battery-Powered Portable Equipment
The REG104GA-3.3/2K5 delivers up to 1 A from a battery input down to its dropout limit, making it suitable for portable devices that need a regulated 3.3 V rail as the battery discharges. The 1.7 mA typical quiescent ground-pin current at full load preserves battery life, while the active-high enable pin allows the host MCU to switch off the LDO in sleep modes. The DMOS pass element achieves much lower dropout than bipolar alternatives, extending usable battery runtime. Tab-land layout keeps the package cool in handheld enclosures.
Recommended
USB / Peripheral Power Distribution
The REG104GA-3.3/2K5 is well suited to derive a clean 3.3 V rail from a 5 V USB or peripheral supply in hubs, dongles, and embedded peripherals. Its 15 V absolute-maximum input tolerates transients on USB VBUS, while current limit and thermal shutdown guard against short-circuit faults on the downstream rail. The 1 A capability easily covers typical MCU + Wi-Fi/BLE radio loads. A small 1 µF input ceramic capacitor placed near the VIN pin is sufficient for stable operation.
Recommended
Test & Measurement Instrument Rails
The REG104GA-3.3/2K5 provides a low-noise 3.3 V rail for ADCs, DACs, and precision analog front-ends inside bench-top instruments. The 33 µVrms output noise floor and ±2% accuracy contribute negligible error to high-resolution measurement chains. The wide -40C to +85C operating range supports laboratory and field environments. With 1 A continuous current, the regulator can power an entire analog sub-board including references, op-amps, and a precision ADC.
Recommended
Recommended Products Summary
Engineering reference data for REG104GA-3.3-2K5 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | REG104GA-3.3G4 | REG104GA-3.3 | REG104GA-5/2K5 | REG104GA-2.5/2K5 |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | SOT-223-6 (DCQ) | SOT-223-6 (DCQ) - same | SOT-223-6 (DCQ) - same | SOT-223-6 (DCQ) - same | SOT-223-6 (DCQ) - same |
| Output Voltage | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed | 5.0 V fixed | 2.5 V fixed |
| Maximum Output Current | 1 A | 1 A | 1 A | 1 A | 1 A |
| Dropout Voltage (typ @ 1 A) | 230 mV | 230 mV | 230 mV | 230 mV | 230 mV |
| Output Noise | 33 uVrms | 33 uVrms | 33 uVrms | 33 uVrms | 33 uVrms |
| Enable Pin | Yes (active high) | Yes (active high) | Yes (active high) | Yes (active high) | Yes (active high) |
| Quiescent Current (IGND @ 1 A) | 1.7 mA | 1.7 mA | 1.7 mA | 1.7 mA | 1.7 mA |
Key Differentiators
- Drop-in compatible with all REG104 fixed-output SOT-223-6 variants (vs REG104GA-3.3G4)
- Stable without output capacitor (vs Standard PMOS LDOs requiring ESR-specified output caps)
- 15 V absolute-maximum input (vs Lower-VIN LDOs (e.g. 6 V or 7 V max))
Design Notes
Estimated: at VIN=5 V, VOUT=3.3 V, IOUT=1 A the REG104GA-3.3/2K5 dissipates P = (5-3.3) * 1 = 1.7 W. With SOT-223 theta_JA around 60 C/W on a 1 sq inch copper pour, junction temperature rise is roughly 100 C above ambient. For VIN=12 V applications dissipation rises to 8.7 W, requiring substantial copper area, thermal vias to an internal plane, or a small clip-on heatsink to keep Tj below 125 C.
The SOT-223-6 tab is the primary thermal path and must be soldered to a copper pour that exceeds 1 square inch for rated thermal performance. Place a 1 µF or larger ceramic input capacitor as close as possible to the VIN pin to dampen high-frequency ringing. Use a star-ground topology tying the REG104 GND pin directly to the load's ground return to avoid ground-loop noise coupling into the 3.3 V rail.
Do not exceed the absolute maximum input voltage of 15 V, even during transient events - add a TVS or input capacitor snubber if the upstream supply is inductive. Verify the EN pin logic level against the system MCU; driving EN below VIH disables the regulator. For adjustable REG104 variants, never leave the feedback resistor divider open - the output will rise to VIN and damage downstream components.
Compliance Information
RoHS and lead-free per TI product page; not AEC-Q100 qualified - use REG104-Q1 variant for automotive.
