REG104GA-3.3 - 1A, 15V LDO Regulator 3.3V Fixed | Texas Instruments
料号： REG104GA-3.3 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $3.52 | $3.52 |
| 10 | $3.05 | $30.50 |
| 100 | $2.42 | $242.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.78 | $1,780.00 |
REG104GA-3.3 概述
An LDO (low-dropout) linear regulator is a type of voltage regulator that maintains a stable DC output voltage even when the input-to-output voltage differential approaches the pass element's saturation limit. LDOs belong to the broader family of linear regulators, which in turn fall under voltage regulators and ultimately power management ICs. Because LDOs dissipate excess voltage as heat rather than switching it, they add no high-frequency switching noise to the output - making them the preferred choice for noise-sensitive analog and mixed-signal power rails.
The REG104GA-3.3 delivers up to 1A of output current from a wide input range up to 15V (with 3.3V fixed output) while consuming low quiescent current. Its DMOS pass element gives it a low dropout typical for the topology, enabling 3.3V regulation from inputs as low as approximately 4.0V at full load. Internal protection includes current limit and thermal shutdown. The 6-pin SOT-223 package provides a low thermal resistance path through the exposed tab, allowing reliable 1A operation with adequate copper pad area.
Typical applications include point-of-load regulation after a switching converter, USB and embedded system 3.3V rails, industrial sensor and PLC modules, and post-regulation for noise-sensitive analog blocks such as ADCs and DACs. Compared to a buck regulator at the same node, the REG104 adds zero switching ripple at the cost of dissipating (VIN - 3.3V) * 1A as heat.
When designing with this part, place input/output ceramic capacitors close to the pins per the datasheet, ensure the exposed tab has sufficient copper area for thermal dissipation, and respect the 15V absolute maximum input rating. The enable pin allows sequenced power-up in multi-rail systems.
直接替换替代料： REG104GA-3.3 ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： REG104GA-3.3 （相同外形与封装尺寸） ——差异在于 Operating Temperature Range, Output Type, Package, Topology.
快速对比工具——选择替代料号进行并排对比：
REG104GA-2.5
✅ 直接替换📋 参考替代料（不在目录中）
REG104GA-5
✅ 直接替换📋 参考替代料（不在目录中）
REG104GA-A
✅ 直接替换📋 参考替代料（不在目录中）
REG104GA-3.3G4
✅ 直接替换📋 参考替代料（不在目录中）
REG104GA-3.3/2K5
✅ 直接替换📋 参考替代料（不在目录中）
REG104GA-3.3 最大额定值与电气特性
| 拓扑 | LDO (Low-Dropout Linear Regulator) |
| Pass Element | DMOS |
| 输出类型 | Fixed (3.3 V) |
| Input Voltage (Max) | 15 V |
| 输出电流（最大） | 1 A |
| 使能引脚 | Yes (active-high) |
| 工作温度范围 | -40 C to +85 C |
| 封装 | SOT-223-6 (DCQ) with tab |
| 安装类型 | Surface Mount |
| RoHS 状态 | Compliant |
REG104GA-3.3 引脚配置
| 引脚 1 | IN — Input supply voltage (up to 15V) |
| 引脚 2 | GND — Ground |
| 引脚 3 | EN — Enable (active-high) |
| 引脚 4 | NC — Not connected (per datasheet) |
| 引脚 5 | OUT — Regulated 3.3V output |
| 引脚 6 | TAB — Exposed thermal tab (electrically connected to GND/thermal pad) |
典型应用
REG104GA-3.3 适用于 6 应用s: Point-of-Load 3.3V Rail after Switching Pre-Regulator, USB / Embedded System 3.3V Power Rail, Industrial Sensor and PLC Module Power, Analog-to-Digital Converter Reference Supply, Automotive Infotainment / Body Electronics Auxiliary Rail, FPGA / DSP Auxiliary 3.3V Rail.
Point-of-Load 3.3V Rail after Switching Pre-Regulator
The REG104GA-3.3 is ideal as a post-regulator that follows a 5V or 12V switching converter to deliver a clean, ripple-free 3.3V rail. Its 1A output current and 15V max input cover the common 5V/12V bus range, while the LDO topology removes switching noise from the output - critical for analog and mixed-signal loads. Place a 1uF-10uF ceramic input cap and 1uF-10uF ceramic output cap close to the pins. Versus a second buck stage, the REG104 adds zero switching ripple at the cost of dissipating (VIN - 3.3V) x IOUT as heat.
推荐
USB / Embedded System 3.3V Power Rail
USB and embedded microcontroller platforms often require a regulated 3.3V rail from a 5V input. The REG104GA-3.3's fixed 3.3V output, 1A capability, and 15V max input handle USB 5V VBUS cleanly while tolerating transient surges above 5V. The enable pin lets a host MCU or USB power switch gate the rail for power sequencing or suspend-mode shutdown. The SOT-223-6 footprint fits standard low-cost PCB layouts used in development boards and consumer peripherals.
推荐
Industrial Sensor and PLC Module Power
Industrial sensors and PLC I/O modules often run from 24V (nominal 12-15V after protection/filtering) and need a stable 3.3V rail for low-voltage logic. The REG104GA-3.3's 15V input ceiling fits standard industrial rails, and its -40C to +85C operating range suits factory-floor environments. The LDO's lack of switching noise also benefits analog front-end and transducer excitation circuits where clean supply improves measurement repeatability and signal-to-noise ratio.
推荐
Analog-to-Digital Converter Reference Supply
Precision ADCs require low-noise reference and analog supplies to achieve datasheet SNR and INL. The REG104GA-3.3, with its linear LDO topology, adds no switching ripple and provides the quiet 3.3V rail that many SAR and delta-sigma ADCs need for AVDD or VREF. The 1A output is sufficient to power the ADC plus surrounding op-amps and reference buffers. Place input/output ceramic capacitors per the datasheet to optimize PSRR across the ADC's sampling frequency harmonics.
推荐
Automotive Infotainment / Body Electronics Auxiliary Rail
In automotive infotainment and body controllers, 12V battery rails power many sub-blocks that need a local 3.3V supply. The REG104GA-3.3's 15V input ceiling handles 12V nominal with margin for load-dump transients (with external TVS protection), and its DMOS pass element delivers low dropout for cold-crank scenarios. The 1A output supports small SoCs, CAN transceivers, and display backlight drivers. Note: this part is industrial-grade, not AEC-Q100 - automotive safety-critical rails require a Q1-qualified alternative.
推荐
FPGA / DSP Auxiliary 3.3V Rail
FPGAs and DSPs typically require multiple rails (1.0V core, 1.8V, 3.3V I/O). The REG104GA-3.3 provides the 3.3V I/O rail from a 5V intermediate bus, with 1A output covering most auxiliary logic and LVCMOS I/O banks. The enable pin supports power sequencing - the 3.3V rail can be asserted before the core rail using simple logic. Compared to a buck regulator, the LDO removes switching noise that could couple into adjacent analog I/O or sensitive clock distribution.
推荐
推荐产品汇总
工程参考数据： REG104GA-3.3 ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | REG104GA-2.5 | REG104GA-5 | REG104GA-A | REG104GA-3.3G4 | REG104GA-3.3/2K5 |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | 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 | SOT-223-6 (DCQ) - same |
| Output Voltage | 3.3 V (fixed) | 2.5 V (fixed) | 5.0 V (fixed) | Adjustable | 3.3 V (fixed) | 3.3 V (fixed) |
| Output Current (Max) | 1 A | 1 A | 1 A | 1 A | 1 A | 1 A |
| Input Voltage (Max) | 15 V | 15 V | 15 V | 15 V | 15 V | 15 V |
| Topology / Pass Element | DMOS LDO | DMOS LDO | DMOS LDO | DMOS LDO | DMOS LDO | DMOS LDO |
| Enable Pin | Yes (active-high) | Yes (active-high) | Yes (active-high) | Yes (active-high) | Yes (active-high) | Yes (active-high) |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
关键差异点
- DMOS pass element for low dropout and fast transient response （对比 REG104GA-2.5)
- Fixed 3.3V output eliminates external resistor divider （对比 REG104GA-A)
- Active-high enable pin for sequenced power-up （对比 REG104 family parts without EN)
设计说明
At VIN=5V, VOUT=3.3V, and IOUT=1A the REG104GA-3.3 dissipates approximately 1.7W. The SOT-223-6 thermal pad is the primary heat path - per the TI REG104 datasheet, junction-to-ambient thermal resistance depends heavily on PCB copper area. A minimum copper pad of roughly 1 square inch on the top layer plus thermal vias to inner/outer planes is recommended to keep junction temperature rise within safe limits at full 1A load across the -40C to +85C ambient range.
Place the input and output ceramic capacitors as close to the REG104GA-3.3 pins as possible, ideally within 2-3mm. The TI REG104 datasheet specifies input and output capacitor values and ESR ranges - typically 1uF to 10uF X7R/X5R ceramic. Route the enable pin away from noisy switching traces; if not used, tie EN to IN through a 100kohm resistor or directly to IN for always-on operation. Provide adequate ground copper under the device for both electrical and thermal performance.
Do not exceed the 15V absolute maximum input rating - transients above 15V (e.g., from a 12V automotive load-dump event) can permanently damage the part; add a TVS or upstream protection if the input bus can spike above 15V. The enable pin is active-high; do not leave it floating in noisy systems. Confirm that the input voltage always remains above VOUT + dropout at full load, especially during cold-crank or low-line conditions, to avoid the regulator dropping out of regulation.
合规信息
RoHS compliant per TI product page. Industrial-grade (-40C to +85C), not AEC-Q100 qualified - automotive safety-critical applications require a Q1-qualified alternative such as TPS7A2633DRVR. Halogen-free status not explicitly listed in the provided data.
