MCP1703AT-3302E/MB - 250mA, 16V LDO Regulator, 3.3V Fixed | Microchip
料号： MCP1703AT-3302E/MB ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0.42 | $0.42 |
| 10 | $0.38 | $3.80 |
| 100 | $0.34 | $34.00 |
| 500 | $0.3 | $150.00 |
| 1,000 | $0.27 | $270.00 |
| 3,000 | $0.24 | $720.00 |
MCP1703AT-3302E/MB 概述
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 - it drops only a small headroom (dropout voltage) between VIN and VOUT. LDOs sit within the broader hierarchy of linear regulators -> voltage regulators -> power management ICs -> analog semiconductors. They are valued for simplicity, low quiescent current, no switching noise, and small PCB area, trading efficiency for noise performance at moderate current levels.
Key specifications include 250 mA maximum output current, 178 mV typical dropout voltage at 250 mA load, 2.0 µA typical quiescent current, and ±2% output voltage accuracy. The MCP1703A family provides short-circuit protection and thermal shutdown. The 3-pin SOT-89 package is a thermally enhanced surface-mount format that dissipates up to about 800 mW at the 25 C ambient reference condition.
The internal architecture uses a CMOS pass element and a low-current bandgap reference, which together minimize ground current across load. Unlike a PNP-based regulator, this P-MOSFET topology keeps quiescent current essentially constant over load, a critical advantage for sleep-current dominated IoT and battery-backed designs. Stability is achieved with only 1 µF ceramic output capacitance.
Typical applications include 2-6 cell alkaline battery power supplies, 9V wall-adapter powered systems, single- or dual-cell Li-Ion powered devices, IoT sensor nodes, MCU auxiliary rails, and metering/instrumentation power. It is well-suited wherever long battery life, a small PCB footprint, and clean DC rails are required.
When designing with this part, observe the minimum input-to-output headroom to keep the LDO in regulation. Use a 1 µF X7R ceramic bypass capacitor on the output placed as close as possible to the VOUT pin, and an optional 1 µF on VIN to suppress source transients. Verify thermal dissipation in continuous 250 mA load because the SOT-89 PCB copper area drives thermal resistance.
This page synthesizes distributor pricing, verified SOT-89-3 drop-in alternatives, and practical battery-application design notes not consolidated on the manufacturer product page.
直接替换替代料： MCP1703AT-3302E/MB ——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： MCP1703AT-3302E/MB （相同外形与封装尺寸） ——差异在于 MSL Level, Output Type, Package.
快速对比工具——选择替代料号进行并排对比：
MCP1703AT-5002E/MB
✅ 直接替换📋 参考替代料（不在目录中）
MCP1703AT-4002E/MB
✅ 直接替换📋 参考替代料（不在目录中）
MCP1703AT-2502E/MB
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
MCP1703T-3302E/MB
✅ 直接替换✓ 有现货
$0.2 / 个
查看数据手册 →MCP1703AT-3302E/CB
✅ 直接替换📋 参考替代料（不在目录中）
MCP1703AT-3302E/MB 最大额定值与电气特性
| Manufacturer | Microchip Technology |
| Part Family | MCP1703A |
| 输出类型 | Fixed (Positive) |
| Nominal Output Voltage | 3.3 V |
| 最大输出电流 | 250 mA |
| 输入电压范围 | 2.7 V to 16.0 V |
| Quiescent Current (Typical) | 2.0 µA |
| Dropout Voltage (Typical @ 250 mA) | 178 mV |
| Output Capacitor | 1 µF ceramic minimum |
| 工作温度范围 | -40 C to +125 C |
| 封装 | SOT-89-3 (MB) |
| 安装类型 | Surface Mount |
| 引脚数量 | 3 |
| Protection Features | Short-Circuit Current Limit, Thermal Shutdown |
| MSL 等级 | 1 |
| RoHS 状态 | Compliant |
| Lead-Free | Yes |
MCP1703AT-3302E/MB 引脚配置
| 引脚 1 | VIN — Unregulated input supply voltage (2.7 V to 16.0 V) |
| 引脚 2 | GND — Ground reference; exposed tab internally tied to GND |
| 引脚 3 | VOUT — Regulated 3.3 V output, up to 250 mA |
典型应用
MCP1703AT-3302E/MB 适用于 6 应用s: Multi-Cell Alkaline Battery Power Supply, 9V Wall-Adapter Powered Devices, Single-Cell Li-Ion Powered IoT Sensor Nodes, MCU Auxiliary / Sensor Power Rail, Remote Control and Battery-Backed Devices, Test and Measurement Handheld Instruments.
Multi-Cell Alkaline Battery Power Supply
The MCP1703AT-3302E/MB is a natural fit for 2-6 cell alkaline battery packs because it accepts up to 16V input per the Microchip 22049f datasheet and consumes only 2.0 µA quiescent current, preserving shelf life. Placed between the battery stack and a 3.3V MCU rail with 1 µF X7R ceramic caps on VIN and VOUT, it supplies clean DC without an upstream preregulator. Unlike a switching regulator it generates zero switching EMI, critical for adjacent RF receivers. At end-of-life (battery near 3.5V), the 178 mV dropout keeps the LDO in regulation at 250 mA - a 30%+ battery-life extension over a 0.5V-dropout alternative.
推荐
9V Wall-Adapter Powered Devices
Industrial sensors and household appliances powered from a 9V DC adapter use the MCP1703AT-3302E/MB to drop directly to 3.3V without a preregulator. The Microchip 22049f datasheet's 16V max VIN tolerates adapter overvoltage transients. Placed after a bridge rectifier and bulk cap, the LDO rejects line ripple and supplies a clean 3.3V at 250 mA. Its P-MOSFET pass element draws nearly constant ground current across load, simplifying thermal budgets. Designers benefit from no inductors, no EMI shielding, and no compensation-network tuning - just 1 µF ceramic input/output capacitors.
推荐
Single-Cell Li-Ion Powered IoT Sensor Nodes
Battery-powered IoT sensor nodes running from a single Li-Ion cell (3.0-4.2V) use the MCP1703AT-3302E/MB to generate a stable 3.3V rail that exceeds the cell voltage during the upper half of the discharge curve. Per the Microchip 22049f datasheet, the part delivers up to 250 mA, sufficient for short transmit bursts of sub-GHz radios such as LoRa or Sigfox. The 2 µA quiescent current contributes negligibly to standby drain, which is dominated by the radio and MCU sleep currents. Add a 1 µF X7R output cap placed within 5 mm of VOUT for stability.
推荐
MCU Auxiliary / Sensor Power Rail
Main boards with a 5V or 12V intermediate bus use the MCP1703AT-3302E/MB to derive a quiet 3.3V auxiliary rail for sensors, op-amps, or low-power companion MCUs. Because the LDO adds no switching noise, it can sit adjacent to analog signal-chain ICs without filtering. The 22049f datasheet specifies 1 µF ceramic output capacitance minimum for stability, with X7R dielectric recommended for temperature stability. Designers use this rail to power temperature sensors, MEMS microphones, and low-speed ADCs that demand a low-ripple supply.
推荐
Remote Control and Battery-Backed Devices
Infrared remote controls, garage-door openers, and battery-backed alarm sensors rely on the MCP1703AT-3302E/MB to maximize battery life. The Microchip 22049f datasheet quotes 2 µA quiescent current, often less than the MCU's sleep current, so the LDO is virtually transparent to the standby budget. At 250 mA peak load the LDO drops only 178 mV, so even near end-of-discharge the 3.3V rail stays in regulation. The SOT-89-3 footprint simplifies hand-soldered prototypes while supporting automated assembly in volume.
推荐
Test and Measurement Handheld Instruments
Handheld multimeters, oscilloscope probes, and field-installable sensor calibrators use the MCP1703AT-3302E/MB to power analog front-ends from a 9V battery or USB supply. Per the Microchip 22049f datasheet, the LDO's PSRR rejects ripple from boost converters upstream, keeping ADC reference noise low. Its low 2 µA quiescent current preserves battery life when the meter's display and backlight are off. The SOT-89-3 footprint also tolerates the higher internal temperatures of an enclosed handheld case with adequate copper pour.
推荐
推荐产品汇总
工程参考数据： MCP1703AT-3302E/MB ——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 | MCP1703AT-5002E/MB | MCP1703AT-4002E/MB | MCP1703AT-2502E/MB | MCP1703T-3302E/MB | MCP1703AT-3302E/CB |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOT-89-3 (MB) | SOT-89-3 (MB) - same | SOT-89-3 (MB) - same | SOT-89-3 (MB) - same | SOT-89-3 (MB) - same | SOT-89-3 (MB) footprint - pinout differs (TO-220 package variant) |
| Output Voltage | 3.3 V | 5.0 V | 4.0 V | 2.5 V | 3.3 V | 3.3 V |
| Maximum Output Current | 250 mA | 250 mA | 250 mA | 250 mA | 250 mA | 250 mA |
| Input Voltage Range | 2.7 V to 16.0 V | 2.7 V to 16.0 V | 2.7 V to 16.0 V | 2.7 V to 16.0 V | 2.7 V to 16.0 V | 2.7 V to 16.0 V |
| Quiescent Current (Typical) | 2.0 µA | 2.0 µA | 2.0 µA | 2.0 µA | 2.0 µA | 2.0 µA |
| Dropout Voltage (Typical @ 250 mA) | 178 mV | 178 mV | 178 mV | 178 mV | 178 mV | 178 mV |
| Operating Temperature Range | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C |
| Drop-In Compatibility | Reference | Drop-in (different Vout) | Drop-in (different Vout) | Drop-in (different Vout) | Drop-in (identical Vout, T&R variant) | Footprint-only (TO-220 package) |
关键差异点
- 16V max input voltage enables direct 9V adapter and multi-cell alkaline operation without a preregulator （对比 MCP1700T-3302E/TT)
- 2.0 µA quiescent current - flat across load due to P-MOSFET pass element （对比 MCP1703AT-5002E/MB)
- Compact SOT-89-3 package with thermally enhanced tab （对比 MCP1703AT-3302E/CB (TO-220))
设计说明
At VIN=9V, VOUT=3.3V, and 250 mA continuous load, the MCP1703AT-3302E/MB dissipates approximately (9V - 3.3V) * 0.25A = 1.43W. With SOT-89-3 thermal resistance of roughly 60-90 C/W on a 1-square-inch copper pour (datasheet-typical PCB), junction temperature rises 86-129 C above ambient. For continuous full-load operation above 60 C ambient, increase copper area or use the TO-220 (CB) variant. Estimated: assumes 1 sq-inch copper pour and 25 C reference ambient; consult Microchip 22049f thermal curves for verified numbers.
Place the 1 µF X7R ceramic output capacitor within 5 mm of the VOUT pin and the input capacitor within 5 mm of VIN. Use wide, short copper pours connecting the GND pin and the package thermal tab to a continuous ground plane; the SOT-89 tab is the primary heat path. Keep high-current switching nodes (DC-DC converters, motor drivers) away from the LDO input/output traces to avoid conducted noise coupling. Reference Microchip 22049f Section 4 'Application Circuits' for the canonical 1 µF X7R BOM.
Do not use Y5V or Z5U ceramic output capacitors - their capacitance drops 50-80% over temperature and bias, destabilizing the regulator. The MCP1703A requires a minimum 1 µF effective output capacitance, per Microchip 22049f. Also avoid reverse-polarity battery input - although the LDO tolerates a brief surge, sustained reverse voltage damages the die. Finally, do not operate below 2.7V VIN; the LDO falls out of regulation and output ripple increases near dropout.
合规信息
RoHS and REACH compliance per Microchip product page; lead-free / halogen-free per Microchip 22049f datasheet. Not AEC-Q100 qualified - for automotive applications consult Microchip's automotive-grade portfolio.
