TPS27081A - 8V 3A 44mΩ PFET High-Side Load Switch | Texas Instruments
MPN： TPS27081A ✓ 啟用中TPS27081A 概覽
A load switch is a discrete power-management component that sits between a system rail and a downstream load to provide controlled power-up, power-down, and protection functions. In the power-management hierarchy, load switches fall under the broader category of power distribution switches, which themselves belong to power management ICs. They are widely used to add sequencing, inrush control, and isolation to rails that would otherwise be permanently tied to the main supply. Compared with discrete PFET switches, integrated load switches save PCB area and provide consistent timing.
Key features include 1.2V to 8V input voltage, 3A continuous current, 44 mΩ typical on-resistance, integrated level shifter that accepts 1V GPIO logic and translates it to VIN levels, on-chip ESD protection on all pins, and a small SOT-23-6 package. The device supports active-high ON/OFF control via a single logic input. The level-shifter architecture lets a 1.2V, 1.8V, 3.3V, or higher MCU control a higher-voltage rail without external translators.
The TPS27081A uses TI's PFET/NFET integration to deliver a tiny footprint with low Rds(on). The ODT pin programs the gate slew rate, which directly controls dV/dt and therefore the inrush current when the load is a decoupling-bulk capacitor. Lower ODT resistance yields faster turn-on but higher peak inrush; higher resistance yields softer turn-on.
Typical applications include portable and battery-powered systems, SSDs, USB peripheral power rails, point-of-load isolation in multi-rail systems, embedded computing modules, and hot-swap interfaces for low-voltage subsystems. The device is also commonly used to provide sequenced power-up for sub-systems controlled by a host MCU.
When designing with this device, place the ODT resistor close to the ODT pin and ensure the input decoupling capacitor sits adjacent to VIN. Verify that peak inrush current does not exceed the upstream supply's transient capability, and derate for ambient temperature using the thermal metrics in the datasheet.
This page synthesizes verified distributor pricing, drop-in same-package alternatives from TI's portfolio, comparison parameters, and practical design notes not found in the manufacturer datasheet alone.
直接替換替代品，適用於 TPS27081A — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： TPS27081A （相同外形與佔位） — 差異在於 Function, Operating Temperature Range, Package.
TPS27081A 最大額定值與電氣特性
| Manufacturer | Texas Instruments |
| 功能 | High-Side Load Switch (PFET with integrated control NFET) |
| Input Voltage Range (VIN) | 1.2 V to 8 V |
| Maximum Continuous Load Current | 3 A |
| On-Resistance (Rds(on)) | 44 mΩ (typical) |
| On/Off Logic Input Voltage | 1 V to VIN (level-shifted) |
| Rise-Time Control | Adjustable via ODT resistor |
| ESD Protection | Industry-standard on all pins |
| 工作溫度範圍 | -40 C to +85 C |
| 封裝 | SOT-23-6 (DDC), 6-pin Thin |
| 安裝類型 | Surface Mount |
| Lead-Free / RoHS | Lead-free, RoHS compliant (per TI product page) |
| Logic Compatibility | 1 V GPIO and above (level-shifted ON input) |
TPS27081A 腳位配置
| 腳位 1 | ON — Active-high logic-level enable input; 1V-compatible GPIO, level-shifted to VIN |
| 腳位 2 | GND — Ground reference |
| 腳位 3 | VOUT — Switched output to load |
| 腳位 4 | VIN — Input supply, 1.2 V to 8 V |
| 腳位 5 | ODT — Adjustable rise-time / slew-rate control resistor to GND |
| 腳位 6 | NC — Not connected (per datasheet) |
典型應用
TPS27081A 適用於 6 應用s: USB VBUS Power Distribution, Portable and Battery-Powered Systems, SSD and Storage Power Rails, Point-of-Load Isolation in Multi-Rail Systems, Embedded Computing Modules, Hot-Swap Interface for Low-Voltage Subsystems.
USB VBUS Power Distribution
The TPS27081A is well suited for USB VBUS and downstream port power switching in portable and embedded systems. With a 44 mΩ Rds(on) and 3 A continuous rating it easily handles USB 3.0 peripheral loads while keeping conduction loss under 0.4 W. The ODT pin allows the designer to program soft-start so VBUS inrush stays within USB compliance limits and avoids triggering upstream current-limit thresholds.
推薦
Portable and Battery-Powered Systems
In battery-powered designs, the TPS27081A enables controlled power-up and power-down of sub-systems to extend runtime. Its wide 1.2 V to 8 V input range covers single-cell Li-ion, 2S/3S packs, and 5 V regulated rails. The integrated 1 V logic threshold lets a low-voltage MCU GPIO switch a higher-voltage rail directly, eliminating an external level shifter and reducing quiescent draw.
推薦
SSD and Storage Power Rails
Solid-state drives and removable storage subsystems benefit from the TPS27081A's low-loss PFET path and small SOT-23-6 footprint. The 44 mΩ Rds(on) minimizes voltage drop to NAND and controller rails, preserving margin during high-current write spikes. Programmable rise-time reduces inrush into bulk bypass capacitance during power-up, preventing supply sag on the host 3.3 V rail.
推薦
Point-of-Load Isolation in Multi-Rail Systems
In multi-rail embedded systems the TPS27081A acts as a point-of-load isolation switch, allowing the host processor to power down unused sub-systems independently. This dramatically reduces idle current and simplifies power-sequencing firmware. The 1 V GPIO compatibility means the switch can be controlled directly by modern low-voltage SoC pins without external translation.
推薦
Embedded Computing Modules
Industrial and consumer embedded modules often need controlled power-up for sub-circuits such as sensors, radios, or displays. The TPS27081A delivers that control in 2.9 mm x 1.6 mm of board area and integrates ESD protection on every pin. Designers can route the 1 V GPIO from the host MCU directly into the ON pin, simplifying schematics and lowering BOM count.
推薦
Hot-Swap Interface for Low-Voltage Subsystems
The TPS27081A can be used as a simple hot-swap interface for low-voltage subsystems where controlled inrush and reverse-current blocking are required. Programmable rise-time via ODT limits inrush into downstream bulk capacitance. Combined with upstream protection, it provides a robust and inexpensive solution for add-in card or peripheral power switching.
推薦
推薦產品摘要
工程參考資料，適用於 TPS27081A — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | TPS27082L | TPS22918 |
|---|---|---|---|
| Package | SOT-23-6 (DDC) | SOT-23-6 (DDC) - same | SOT-23-5 - smaller footprint |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Input Voltage (VIN) | 1.2 V to 8 V | Similar VIN range (per E2E) | 1 V to 5.5 V (lower VIN max) |
| Continuous Load Current | 3 A | Comparable 3 A | 2 A (lower) |
| On-Resistance (Rds(on)) | 44 mΩ typical | Similar Rds(on) class | ~60 mΩ typical |
| Logic Threshold on ON | 1 V (level-shifted) | Comparable 1 V logic | 1 V compatible |
| Adjustable Rise Time | Yes (ODT pin) | Yes | Yes (CT pin) |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
主要差異化特點
- Integrated level shifter accepts 1V GPIO directly (對比TPS22918)
- Higher VIN maximum supports 5V/6V Li-ion packs (對比TPS22918)
- Lower Rds(on) for less conduction loss (對比TPS22918)
設計說明
Place the ODT resistor as close as possible to the ODT pin and route the VIN decoupling capacitor (1 µF or larger ceramic) directly between VIN and GND adjacent to the device. Keep the high-current VOUT trace wide and short to minimize parasitic inductance. The NC pin may be left floating; do not tie it to a signal trace.
Do not exceed the 8 V absolute-maximum rating on VIN, including voltage transients from upstream hot-plug events. Ensure the upstream supply can source the programmed inrush current; large C_LOAD combined with low R_ODT may demand more current than the upstream rail can provide, causing sag.
Estimated: at 3 A continuous and 44 mΩ typical Rds(on), conduction loss is P = I² x R = 9 x 0.044 ≈ 0.40 W. Use the SOT-23-6 thermal metrics from the datasheet to derate for high-ambient enclosures or stacked PCB designs where the thermal path to ambient is poor.
合規資訊
RoHS and lead-free per TI product page. AEC-Q100 not qualified for this commercial variant.
