LM2596SX-ADJ/NOPB - 3A 150kHz Buck Regulator | Texas Instruments
料号： LM2596SX-ADJ/NOPB ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.15 | $215.00 |
| 500 | $1.75 | $875.00 |
| 1,000 | $1.4 | $1,400.00 |
LM2596SX-ADJ/NOPB 概述
A buck converter, or step-down regulator, is a type of DC-DC switching voltage regulator that efficiently reduces a higher input voltage to a lower output voltage. It belongs to the power management IC family and uses a switching element, an inductor, and a freewheeling diode to transfer energy in controlled pulses, achieving far higher efficiency than linear regulators. The LM2596 is a non-synchronous buck, using an external Schottky diode for the freewheeling path, which keeps the design simple and low cost.
Key features include the wide 4.5V to 40V input range, adjustable output down to 1.2V via an external resistor divider, 3A output capability with excellent line and load regulation, and a fixed 150 kHz switching frequency that allows small inductors and low component count. Internal frequency compensation, thermal shutdown, and current limiting protect against fault conditions. Efficiency reaches up to roughly 90 percent depending on input-output differential and load.
Technically, the LM2596 uses voltage-mode PWM control with a nominal 150 kHz oscillator (110 kHz to 173 kHz range per datasheet). Only a few external parts are needed: an inductor, catch diode, and input/output capacitors, and TI documents standard inductor series for quick designs.
Typical applications include point-of-load supplies for microcontrollers, FPGAs, and DSPs, 12V and 24V industrial bus regulation, battery-powered equipment, automotive electronics, and popular adjustable DIY power modules.
Design tip: size the inductor for continuous conduction mode at full load, use a Schottky diode rated for peak current, and solder the exposed tab to adequate copper area to keep junction temperature within limits. Pricing references are as of 2026-08-30.
直接替换替代料： LM2596SX-ADJ/NOPB ——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： LM2596SX-ADJ/NOPB （相同外形与封装尺寸） ——差异在于 Switching Frequency, RoHS Status, Output Voltage Range, Package, Topology.
快速对比工具——选择替代料号进行并排对比：
LM2596SX-ADJ/NOPB-Q1
✅ 直接替换✓ 有现货
$1.02 / 个
查看数据手册 →LM2596S-ADJ/NOPB
✅ 直接替换📋 参考替代料（不在目录中）
LM2596SX-5.0/NOPB
⚡ 相同封装📋 参考替代料（不在目录中）
LM2596SX-12/NOPB
⚡ 相同封装📋 参考替代料（不在目录中）
LM2596HVS-ADJ
✅ 直接替换📋 参考替代料（不在目录中）
LM2596SX-ADJ/NOPB 最大额定值与电气特性
| 拓扑 | Step-Down (Buck), Non-Synchronous |
| 输出类型 | Adjustable |
| 输出电压范围 | 1.2 V to 37 V |
| 输入电压范围 | 4.5 V to 40 V |
| 最大输出电流 | 3 A |
| 开关频率 | 150 kHz nominal (110 kHz to 173 kHz) |
| 输出数量 | 1 |
| 静态电流 | 5 mA (typ) |
| Control Mode | Voltage-mode PWM |
| 效率 | Up to ~90% (typical, load dependent) |
| 工作温度 | -40C to +125C |
| 封装 | TO-263-5 (D2PAK, KTT), 5 leads + tab |
| 安装类型 | Surface Mount |
| Protection Features | Thermal shutdown, current limiting |
| Series | SIMPLE SWITCHER LM2596 |
| RoHS 状态 | Compliant (NOPB) |
LM2596SX-ADJ/NOPB 引脚配置
| 引脚 1 | VIN — Positive input supply, 4.5V to 40V |
| 引脚 2 | Output — Switch output to inductor/catch diode |
| 引脚 3 | Ground — Ground reference |
| 引脚 4 | Feedback — Feedback input from output divider (1.23V reference) |
| 引脚 5 | ON/OFF — Enable: ground or low = on; open/high = off (has internal pull-up) |
| 引脚 Tab | Tab (connects to Ground) — Exposed tab for thermal dissipation, tied to pin 3 ground |
典型应用
LM2596SX-ADJ/NOPB 适用于 6 应用s: Point-of-Load Supply for MCUs and FPGAs, Industrial 24V Bus Regulation, Adjustable Bench and DIY Power Supplies, Automotive 12V/24V Electronics, Battery-Powered Portable Equipment, LED Driver and Display Backlight Power.
Point-of-Load Supply for MCUs and FPGAs
The LM2596SX-ADJ/NOPB provides efficient local step-down regulation from 12V or 24V rails to the 3.3V or 5V supplies required by microcontrollers, FPGAs, and DSPs. Its 3A output covers most processor core and I/O rails, while the 150 kHz switching frequency keeps inductors small enough for dense boards. Placed near the load with 220uF output capacitance, it achieves fast transient response; efficiency near 90 percent minimizes heat compared to a linear regulator dropping 12V to 5V at 1A.
推荐
Industrial 24V Bus Regulation
Industrial control panels and PLC I/O run from 24V (or 12V) buses with wide tolerances; the LM2596SX-ADJ/NOPB's 40V maximum input provides margin for transients while regulating down to logic or analog rails. The adjustable output allows a single design to be retargeted from 3.3V to 15V via one resistor change, simplifying platform variants. Internal thermal shutdown and current limiting add robustness in electrically noisy factory environments, and the TO-263 tab handles the dissipation of medium-power rails without a heatsink.
推荐
Adjustable Bench and DIY Power Supplies
The LM2596SX-ADJ/NOPB is the classic heart of adjustable hobby and lab bench supplies: one potentiometer in the feedback divider sweeps the output from 1.2V to 37V at up to 3A. The 150 kHz fixed frequency yields quiet, easy-to-filter operation, and the low external component count (inductor, Schottky diode, two capacitors) makes the design forgiving for builders. Efficiency around 90 percent means minimal heatsinking even at full current, unlike linear regulator-based adjustable supplies.
推荐
Automotive 12V/24V Electronics
For automotive and heavy-vehicle electronics powered from 12V or 24V battery systems, the LM2596SX-ADJ/NOPB-Q1 variant offers AEC-Q100 qualification on the same die and TO-263-5 footprint. The 40V input rating absorbs load-dump-adjacent conditions with upstream protection, while the 3A output feeds infotainment, telematics, and sensor modules. The non-synchronous topology's simplicity aids automotive design reviews, and thermal shutdown protects against under-hood temperature extremes up to +125C.
推荐
Battery-Powered Portable Equipment
Portable instruments and battery packs benefit from the LM2596SX-ADJ/NOPB's high efficiency at moderate loads: converting a 12V battery to a 5V rail at 1-2A wastes only a fraction of the power a linear regulator would. The 5 mA typical quiescent current is acceptable for mains-rechargeable or vehicle-powered equipment where shutdown is periodic rather than continuous. The adjustable output supports multi-chemistry battery input ranges as the pack voltage sags, and the small TO-263 footprint fits compact enclosures.
推荐
LED Driver and Display Backlight Power
Fixed-voltage rails for LED lighting controllers, indicator drivers, and display backlights are a natural fit for the LM2596SX-ADJ/NOPB. The adjustable feedback lets designers set exact LED string supply voltages (for example 9V for three white LEDs in series), and the 3A capability supports high-brightness arrays. Efficiency near 90 percent keeps enclosure temperatures low for sealed fixtures, and the TO-263 exposed tab simplifies thermal design. Add an output resistor for basic current limiting in constant-voltage LED arrangements.
推荐
推荐产品汇总
工程参考数据： LM2596SX-ADJ/NOPB ——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 | LM2596SX-ADJ/NOPB-Q1 | LM2596S-ADJ/NOPB | LM2596SX-12/NOPB | LM2596HVS-ADJ |
|---|---|---|---|---|---|
| Package | TO-263-5 (D2PAK) | TO-263-5 - same | TO-263-5 - same | TO-263-5 - same | TO-263-5 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Umw |
| Input Voltage Range | 4.5 V to 40 V | 4.5 V to 40 V | 4.5 V to 40 V | 4.5 V to 40 V | 4.5 V to 40 V |
| Output Voltage | 1.2 V to 37 V adjustable | 1.2 V to 37 V adjustable | 1.2 V to 37 V adjustable | Fixed 12 V | 1.2 V to 37 V adjustable |
| Output Current | 3 A | 3 A | 3 A | 3 A | 3 A |
| Switching Frequency | 150 kHz (110-173 kHz) | 150 kHz (110-173 kHz) | 150 kHz (110-173 kHz) | 150 kHz (110-173 kHz) | 110-173 kHz |
| Quiescent Current | 5 mA typ | 5 mA typ | 5 mA typ | 5 mA typ | 5 mA typ |
关键差异点
- Adjustable output across full family range （对比 LM2596SX-12/NOPB)
- Automotive-qualified sibling on same footprint （对比 LM2596SX-ADJ/NOPB-Q1)
- Proven TI original vs clone （对比 LM2596HVS-ADJ)
设计说明
The TO-263 exposed tab (ground) must be soldered to a generous copper pour - at least 1 square inch - to achieve low junction-to-ambient thermal resistance. At VIN=24V, VOUT=5V, 2A load, dissipation is roughly 4-5W including switching losses; without adequate copper the junction will exceed 125C. Refer to the thermal considerations section of the TI LM2596 datasheet for derating curves.
Keep the loop formed by VIN capacitor, the IC, catch diode, and inductor as small as possible to minimize EMI. Place the input capacitor (470uF electrolytic plus 0.1uF ceramic) within 10mm of VIN. The feedback trace should be routed away from the inductor and switch node to avoid injecting switching noise into the FB pin.
Use a Schottky catch diode rated for the full load current (e.g., 1N5822, 3A/40V) - a standard silicon diode will overheat and destroy efficiency. Select the inductor using the datasheet charts for continuous conduction at full load; undersized inductance causes discontinuous mode, output ripple, and instability. The ON/OFF pin has an internal pull-up: tie it to ground for always-on operation.
合规信息
NOPB suffix indicates No Pb (lead-free) per TI ordering nomenclature. AEC-Q100 qualification applies only to the -Q1 variant.
