MIC5209-3.3YS - 500mA 3.3V Fixed LDO Regulator SOT-223 | Microchip
料号： MIC5209-3.3YS ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.42 | $1.42 |
| 10 | $1.18 | $11.80 |
| 100 | $0.92 | $92.00 |
| 500 | $0.74 | $370.00 |
| 1,000 | $0.58 | $580.00 |
MIC5209-3.3YS 概述
An LDO (Low-Dropout) regulator is a type of linear voltage regulator that maintains a stable, accurate output voltage even when the input-to-output voltage differential is very small. Within the broader power-management integrated circuit (PMIC) hierarchy, LDOs sit beneath DC-DC converters and switching regulators as the low-noise, fast-transient alternative used when the input voltage is only slightly above the desired rail. LDOs add no switching ripple, but dissipate the voltage difference as heat.
Key features of the MIC5209-3.3YS include reversed-battery protection, internal current limiting, overtemperature shutdown, and an ultra-low-noise reference architecture. The SOT-223-3 package exposes a metal tab that doubles as both pin 4 (connected to VOUT) and a thermal pad, allowing the part to sustain its 500 mA continuous rating without external heatsinking on typical 1 oz copper PCB pours.
The internal architecture is a classic P-channel pass-MOSFET LDO with a bandgap reference and error amplifier. The P-channel element is why the dropout voltage is so low and why the device can survive reversed battery polarity (input more negative than ground). Stability is maintained with a small 1 µF ceramic output capacitor, simplifying BOM cost and board area versus older LDO generations that required tantalum or large electrolytic output caps.
Typical applications include USB peripherals, microcontroller core or I/O rails, GSM modem power supplies, post-regulation after a switching converter, battery chargers, and instrumentation. The 3.3 V fixed output makes the MIC5209-3.3YS a natural fit for 3.3 V MCUs, Bluetooth/Wi-Fi modules, and low-power sensor interfaces where 5 V or 12 V inputs must be dropped down cleanly.
A key design tip: keep trace lengths short between the output pin tab and the load, because the SOT-223 tab is the primary power and thermal path. For applications above ~250 mA continuous, increase copper area under the tab to keep junction temperature below 125 °C. Per the Microchip datasheet, the derating begins around 1 W dissipation in free air.
This page synthesizes distributor pricing, same-package drop-in alternatives, and design notes drawn from the Microchip datasheet - information not collected in one place on the manufacturer product page.
直接替换替代料： MIC5209-3.3YS ——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： MIC5209-3.3YS （相同外形与封装尺寸） ——差异在于 Output Type, Output Voltage Accuracy, Package, Protection Features, RoHS Status.
快速对比工具——选择替代料号进行并排对比：
MIC5209-3.3YU
✅ 直接替换📋 参考替代料（不在目录中）
MIC5209-3.3YS-TR
✅ 直接替换✓ 有现货
$0.29 / 个
查看数据手册 →MIC5209-3.0BU
✅ 直接替换📋 参考替代料（不在目录中）
MIC5205-3.3YD5
✅ 直接替换📋 参考替代料（不在目录中）
MIC5201-3.0YS
✅ 直接替换📋 参考替代料（不在目录中）
MIC5209-3.3YS 最大额定值与电气特性
| 输出类型 | Fixed |
| 输出电压 | 3.3 V |
| Output Voltage Accuracy | ±1 % |
| 最大输出电流 | 500 mA |
| 输入电压范围 | 2.5 V to 16 V |
| Dropout Voltage (typical @ light load) | 10 mV |
| Dropout Voltage (maximum @ 500 mA) | 500 mV |
| 输出噪声 | Low noise (LDO architecture) |
| 工作温度范围 | -40 °C to +125 °C |
| 封装 | SOT-223-3 (TO-261-4) |
| 安装类型 | Surface Mount |
| Protection Features | Reverse-battery, current limit, overtemperature shutdown |
| RoHS 状态 | Compliant |
| Lead-Free Status | Lead Free |
MIC5209-3.3YS 引脚配置
| 引脚 1 | VOUT — Regulated output voltage (3.3 V); also connected to the metal tab internally |
| 引脚 2 | VIN — Input supply voltage (2.5 V to 16 V) |
| 引脚 3 | GND — Ground reference; tie to system ground |
| 引脚 4 (Tab) | VOUT — Same as Pin 1 (VOUT) - exposed thermal pad; solder to copper pour for current/thermal path |
典型应用
MIC5209-3.3YS 适用于 6 应用s: USB Peripheral 3.3 V Power Rail, Microcontroller Core / I/O Voltage Rail, Post-Regulation After Switching Converter, Handheld / Battery-Powered Device Rail, Wireless Module Power (Wi-Fi / Bluetooth / Sub-GHz), Industrial Sensor / Instrumentation Power.
USB Peripheral 3.3 V Power Rail
The MIC5209-3.3YS is well suited as a fixed 3.3 V rail for USB peripherals, hubs, and dongles that must derive logic-level power from a 5 V USB VBUS or a downstream 5 V switching regulator. Its 10 mV typical dropout at light loads means the part regulates cleanly even when VBUS sags to 4.0 V during USB suspend. The SOT-223-3 tab dissipates up to 1.5 W on a small copper pour, supporting 500 mA continuous load for downstream PHY or LED drivers. Per the Microchip datasheet, internal reversed-battery and short-circuit protection guard USB ports against mis-wired cables. Compared to a buck regulator, the LDO produces a quieter rail for USB audio and high-speed data PHYs without an inductor in the BOM.
推荐
Microcontroller Core / I/O Voltage Rail
The MIC5209-3.3YS makes a robust 3.3 V core or I/O supply for low-power microcontrollers and SoCs that cannot tolerate supply ripple. With ±1 % output accuracy, a 1 µF ceramic output cap, and P-channel pass-element architecture, it stabilizes any 5 V, 9 V, or 12 V input down to a clean 3.3 V at up to 500 mA for ARM Cortex-M0/M4 parts and ESP32 modules. Its 16 V input rating lets it share a wide 6-12 V wall-adapter bus with other peripherals without extra protection. The ±1 % accuracy over temperature holds the MCU below brownout, while the 65 °C/W thermal resistance on standard 1 oz copper keeps the junction cool at typical MCU loads under 200 mA.
推荐
Post-Regulation After Switching Converter
Placed downstream of a switching DC-DC converter, the MIC5209-3.3YS cleans switching ripple from a sensitive 3.3 V analog, RF, or sensor signal chain where the residual ripple of even a good buck regulator would couple into the signal. Designers typically feed the LDO with the buck's output - say, 3.6 V - and let it drop ~300 mV to a clean 3.3 V at hundreds of milliamps. The P-channel LDO architecture adds no switching noise of its own. Per the Microchip datasheet, the very low dropout at light loads (10 mV typical) keeps the LDO outside its high-dissipation regime during sensor sleep intervals, preserving the efficiency of the upstream buck at light load.
推荐
Handheld / Battery-Powered Device Rail
Designed for hand-held, battery-powered devices, the MIC5209-3.3YS excels as the system rail for portable instruments, handheld scanners, and wearables powered from a 2-cell Li-ion or 4-cell NiMH pack. The 10 mV dropout at light loads extends usable battery life by keeping regulation intact as the cell voltage drops toward the cutoff. Quiescent current in the microamp range preserves standby life between measurement bursts. The reversed-battery and overtemperature protections allow direct connection to a 2-cell Li-ion pack without external protection circuitry, while the small SOT-223-3 footprint fits inside tight wearable enclosures.
推荐
Wireless Module Power (Wi-Fi / Bluetooth / Sub-GHz)
Many Wi-Fi, Bluetooth, and sub-GHz wireless modules require a tightly-regulated 3.3 V to meet their RF output power and EVM specifications. The MIC5209-3.3YS, with its low output noise and P-channel architecture, supplies this rail from USB VBUS, a 5 V supply, or a 2-cell Li-ion pack. At 500 mA continuous, it supports transmit bursts of common Wi-Fi/BLE SoCs without sagging the rail. Per the Microchip datasheet, the LDO's high PSRR at audio-relevant frequencies prevents switching ripple from a host 5 V rail from coupling into the RF chain, simplifying PCB layout versus a buck-only solution.
推荐
Industrial Sensor / Instrumentation Power
In industrial 24 V systems, an upstream switching converter steps the bus down to a 5 V or 6 V intermediate rail, and the MIC5209-3.3YS creates the final low-noise 3.3 V for sensor signal conditioning, 4-20 mA loop interfaces, or instrumentation amplifiers. The regulator's 16 V maximum input comfortably accommodates the intermediate rail plus transient margin, while its current limit and overtemperature shutdown protect against field wiring faults. Per the Microchip datasheet, the ±1 % accuracy over -40 °C to +125 °C holds measurement calibration stable across outdoor and factory-floor temperature swings, supporting calibrated sensor products that must hold accuracy in harsh environments.
推荐
推荐产品汇总
工程参考数据： MIC5209-3.3YS ——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 | MIC5209-3.3YU | MIC5209-3.3YS-TR | MIC5209-3.0BU | MIC5205-3.3YD5 | MIC5201-3.0YS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOT-223-3 (TO-261-4) | SOT-223-3 (TO-261-4) | SOT-223-3 (TO-261-4) | SOT-223-3 (TO-261-4) | SOT-223-5 (extended) | SOT-223-3 (TO-261-4) |
| Output Voltage (Fixed) | 3.3 V | 3.3 V | 3.3 V | 3.0 V (not 3.3 V) | 3.3 V | 3.0 V (not 3.3 V) |
| Output Current | 500 mA | 500 mA | 500 mA | 500 mA | 500 mA | 500 mA |
| Input Voltage Range | 2.5 V to 16 V | 2.5 V to 16 V | 2.5 V to 16 V | 2.5 V to 16 V | 2.5 V to 16 V | ~2.5 V to ~6 V (lower rating) |
关键差异点
- Widest 16 V input range in its SOT-223 family （对比 MIC5201-3.0YS)
- P-channel architecture with reversed-battery protection built-in （对比 MIC5205-3.3YD5)
- 10 mV typical dropout at light load （对比 MIC5201-3.0YS)
设计说明
Estimated: with VIN = 5 V, VOUT = 3.3 V and IOUT = 500 mA, the MIC5209-3.3YS dissipates (5 - 3.3) * 0.5 = 0.85 W. On a JEDEC 1 oz copper board giving a typical θJA around 50 °C/W, that produces a 42 °C temperature rise above ambient, leaving substantial margin to the 125 °C junction limit. For designs at higher VIN or higher current, expand the copper area under the tab or add a small thermal via array. In free air with no copper, the same dissipation approaches the thermal limit, so do not omit the tab soldering for >250 mA continuous loads.
Per the Microchip datasheet, place a 1 µF (or larger) low-ESR ceramic bypass capacitor on the VOUT pin within 5 mm of the package, and a similar cap on the VIN pin. Connect the SOT-223 tab to the VOUT copper pour with at least two thermal vias or a direct solder connection - this is the dominant current path. Do NOT connect the tab to ground: shorting the tab to GND destroys the regulator. Keep AGND and PGND separated if your downstream analog section is noise-sensitive.
Estimated: omitting the output capacitor causes oscillation or unstable VOUT under load steps, since the loop relies on COUT for pole compensation. Another common pitfall is exceeding 16 V VIN during load-dump transients on automotive 12 V rails - add a TVS or series resistor if the upstream bus has long inductive runs. For very low-noise analog loads, the SOT-223-3 (no enable pin) cannot be put into standby - you must switch the input upstream if you need <1 µA shutdown current.
合规信息
RoHS compliant and Lead Free per DigiKey and DigChip data. AEC-Q100 qualification not stated in the verified data - not recommended for automotive safety applications without further qualification. Halogen-free and conflict-minerals status not directly stated - mark as unknown unless proven via manufacturer declaration.
