MCP1700T-2802E/MB - 250mA, 2.8V CMOS LDO | Microchip
MPN： MCP1700T-2802E/MB ✓ 啟用中MCP1700T-2802E/MB 概覽
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, removing the need for large switching inductors. LDOs are sub-class of linear regulators, which in turn sit under the broader category of voltage regulators and power management ICs used to deliver clean, low-noise supply rails to downstream analog, digital, and mixed-signal blocks.
Key features include ±2% output voltage accuracy, short-circuit current limiting, and thermal shutdown protection. The SOT-89-3 package's tab is the ground/output pin, providing a low thermal resistance path to the PCB copper pour and supporting up to 250 mA continuous output without external heatsinking in most battery-powered designs.
The MCP1700 uses a CMOS pass element rather than a PNP transistor, achieving the low quiescent current that makes it ideal for battery-powered systems. Its low dropout also means more usable energy can be extracted from a Li-Ion cell as it discharges toward 3.0 V, while its stable output regulator with 1.6 mA Iq typically extends standby time on coin-cell or two-cell alkaline supplies.
Typical applications include microcontroller core/logic supply (PIC, AVR, ARM Cortex-M0/M4) in battery-powered IoT nodes, single-cell Li-Ion post-regulation following a switching converter, real-time clock (RTC) and SRAM backup rails, and wireless sensor nodes such as BLE, LoRa, and Sub-GHz remotes that sleep most of the time.
When designing with this device, always observe the minimum 1uF ceramic output capacitor requirement for ESR between 0.2 ohm and 2 ohm, and reserve adequate input copper below the tab. The MCP1700 leads on quiescent current and dropout voltage set by Microchip's CMOS architecture.
This page synthesizes distributor pricing, drop-in same-family alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 MCP1700T-2802E/MB — 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。
MCP1700T-3302E/MB
✅ 直接替換📋 參考替代品（不在目錄中）
MCP1700T-1802E/MB
✅ 直接替換📋 參考替代品（不在目錄中）
MCP1700T-2502E/MB
✅ 直接替換📋 參考替代品（不在目錄中）
MCP1700T-3002E/MB
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MCP1700T-1202E/MB
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MCP1700T-5002E/MB
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MCP1700T-2802E/MB 最大額定值與電氣特性
| Manufacturer | Microchip Technology |
| Product Type | LDO Linear Voltage Regulator (CMOS) |
| 輸出類型 | Fixed Positive |
| 輸出電壓 | 2.8 V |
| Output Voltage Accuracy | ±2% |
| 最大輸出電流 | 250 mA |
| 輸入電壓範圍 | 2.3 V to 6.0 V |
| 壓降電壓 | 178 mV (typical at 250 mA) |
| 靜態電流 | 1.6 mA (typical) |
| 工作溫度範圍 | -40 C to +125 C (Extended, 'E' suffix) |
| 封裝 | SOT-89-3 (3-pin + tab, MB suffix) |
| 安裝類型 | Surface Mount |
| Pin/Package Code | SOT-89 |
| Pbfree / RoHS | Yes / Yes |
| 生命週期狀態 | Active |
| AEC-Q100 Automotive | Yes (per DigiKey parametric catalog) |
| 過熱關機 | Yes (internal) |
| Short Circuit Protection | Yes (current limit) |
MCP1700T-2802E/MB 腳位配置
| 腳位 1 | VIN — Input voltage supply (2.3 V to 6.0 V) |
| 腳位 2 | GND — Ground (also the metal tab on package bottom) |
| 腳位 3 | VOUT — Regulated output voltage (fixed 2.8 V) |
典型應用
MCP1700T-2802E/MB 適用於 6 應用s: Microcontroller Core/Logic Supply (Battery-Powered IoT), Single-Cell Li-Ion Post-Regulation (after Buck Converter), RTC and SRAM Backup Rail, Wireless Sensor Node Power (LoRa / Sub-GHz / Zigbee), Two-Cell Alkaline / Three-Cell Alkaline Powered Toys and Remotes, Automotive Accessory and Aftermarket Modules.
Microcontroller Core/Logic Supply (Battery-Powered IoT)
The MCP1700T-2802E/MB is a near-perfect match for low-power MCU rails in IoT endpoints. Its 1.6 mA typical quiescent current is dominated by the MCU sleep current itself, so the regulator adds negligible overhead in always-on battery budgets. With 178 mV dropout at 250 mA, the part stays in regulation down to roughly 2.98 V on VIN, extracting the maximum usable energy from a single Li-Ion cell before brownout. The fixed 2.8 V output is suitable for many PIC16/18, AVR, and Cortex-M0 parts configured for low-voltage operation, and is also compatible with sub-GHz and BLE radio rails that prefer 2.7-2.8 V for improved PA efficiency. Place a 1uF X5R/X7R ceramic on VOUT within 5 mm of pin 3 and a 1uF ceramic on VIN to ensure stability across the 0.2-2 ohm ESR window.
推薦
Single-Cell Li-Ion Post-Regulation (after Buck Converter)
Following a switching converter with a clean low-noise LDO is a common mixed-signal power architecture, and the MCP1700T-2802E/MB excels as the post-regulator stage. The 2.8 V fixed output is ideal for image sensors, audio codecs, or precision ADCs that need a low-ripple analog rail but can tolerate the linear regulator's dropout at the higher load current. Its 1.6 mA Iq adds negligible drain even when the upstream buck is enabled, and the SOT-89-3 package with thermal tab keeps the junction temperature within limits at 250 mA and modest VIN-VOUT differential. Compared to a second buck stage, this solution removes one inductor and one set of feedback components, reducing BOM cost and PCB area by roughly 30%.
推薦
RTC and SRAM Backup Rail
Real-time clocks and battery-backed SRAMs need a continuous, ultra-low-quiescent rail that survives main power removal. The MCP1700T-2802E/MB's 1.6 mA Iq and 178 mV dropout make it well-suited to supply these devices from a coin cell or supercap backup when the main rail collapses. Many RTCs (such as MCP79410) and SRAMs accept 2.7-3.3 V, so the 2.8 V fixed output is in the sweet spot. The internal short-circuit current limit and thermal shutdown protect the backup battery from damage during fault conditions. A 1uF ceramic output capacitor ensures hold-up time during transient main-rail drops.
推薦
Wireless Sensor Node Power (LoRa / Sub-GHz / Zigbee)
Long-range wireless sensor nodes spend 99%+ of their life in deep sleep, waking briefly to transmit. The MCP1700T-2802E/MB's 1.6 mA quiescent current is small relative to typical transmit currents of 50-120 mA for sub-GHz radios, so efficiency is dominated by the LDO's dropout at full TX load. The 178 mV dropout at 250 mA allows the node to operate down to ~3.0 V on a fresh Li-Ion cell, maximizing deployment life. The SOT-89-3 tab provides adequate heat spreading for the brief transmit bursts without requiring a dedicated heatsink. Pair with a low-power MCU and a sensor front-end for a complete 2-3 year battery node.
推薦
Two-Cell Alkaline / Three-Cell Alkaline Powered Toys and Remotes
Many low-cost consumer products still run from 2 or 3 alkaline cells (nominal 3.0 V or 4.5 V). The MCP1700T-2802E/MB's 2.3 V to 6.0 V input range accommodates this directly. As the cells discharge from fresh (3.2 V or 4.8 V) toward end-of-life (2.0 V or 3.0 V), the LDO maintains a stable 2.8 V output until VIN reaches about 2.98 V, giving 80-90% usable cell capacity. The regulator's low cost and small SOT-89-3 footprint suit the BOM constraints of toy and remote-control designs where every fraction of a cent matters.
推薦
Automotive Accessory and Aftermarket Modules
The MCP1700T-2802E/MB is AEC-Q100 qualified and rated for -40 C to +125 C operation, making it suitable for non-safety automotive accessory applications such as interior lighting controllers, dash-cam power boards, OBD-II dongles, and aftermarket infotainment modules. The 6.0 V absolute-maximum input voltage tolerates load-dump transients below 6 V on the 12 V battery rail when used after a pre-regulator or TVS clamp. The CMOS pass element's low quiescent current keeps parasitic battery drain under the 100 mA-hour/year threshold mandated by many OEMs for accessories that plug into the OBD-II port.
推薦
推薦產品摘要
工程參考資料，適用於 MCP1700T-2802E/MB — 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 | MCP1700T-3302E/MB | MCP1700T-1802E/MB | MCP1700T-2502E/MB | MCP1700T-3002E/MB | MCP1700T-1202E/MB |
|---|---|---|---|---|---|---|
| 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) - same |
| Output Voltage | 2.8 V | 3.3 V | 1.8 V | 2.5 V | 3.0 V | 1.2 V |
| Output Current | 250 mA | 250 mA | 200-250 mA | 250 mA | 250 mA | 250 mA |
| Dropout Voltage (typ @ full load) | 178 mV | 178 mV | 178 mV | 178 mV | 178 mV | 178 mV |
| Quiescent Current (typ) | 1.6 mA | 1.6 mA | 1.6 mA | 1.6 mA | 1.6 mA | 1.6 mA |
| Input Voltage Range | 2.3 V to 6.0 V | 2.3 V to 6.0 V | 2.3 V to 6.0 V | 2.3 V to 6.0 V | 2.3 V to 6.0 V | 2.3 V to 6.0 V |
| Operating Temperature | -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 |
| AEC-Q100 Automotive | Yes | Yes | Yes | Yes | Yes | Yes |
主要差異化特點
- Industry-leading low quiescent current for the 250 mA class (對比MCP1700T-3302E/MB)
- CMOS pass element with bipolar-class dropout (對比MCP1700T-1802E/MB)
- Single-MB package solution covers 2.3-6.0 V inputs (對比MCP1700T-1202E/MB)
設計說明
Per the Microchip datasheet, place a 1uF X5R or X7R ceramic output capacitor within 5 mm of the VOUT pin with ESR between 0.2 ohm and 2 ohm for stability. The SOT-89-3 tab is the GND pin and must be soldered to a copper pour of at least 100 mm² to achieve rated thermal performance at 250 mA continuous load. Place VIN decoupling (1uF) within 3 mm of the VIN pin to suppress high-frequency input ripple from upstream sources.
Estimated: at VIN = 5.0 V, VOUT = 2.8 V, and IOUT = 250 mA, power dissipation is (5.0 - 2.8) * 0.25 = 0.55 W. With the SOT-89-3 thermal pad soldered to a 100 mm² copper pour, theta_JA is approximately 75 C/W, yielding a 41 C junction temperature rise above ambient - well within the 125 C maximum. At VIN = 6.0 V worst case, dissipation rises to 0.80 W and temperature rise to 60 C, still acceptable. Avoid VIN above 6.5 V to prevent exceeding absolute-maximum ratings.
Common pitfall: do not use the SOT-23-3 version (MCP1700T-2802E/TT) and the SOT-89-3 version (MCP1700T-2802E/MB) interchangeably - the land patterns differ and the pin assignments do NOT match between packages despite similar marking codes. Also avoid tantalum or polymer output capacitors without verifying ESR falls within the 0.2-2 ohm window specified for stability. The 2.8 V fixed output cannot be trimmed; if adjustable output is needed, choose a different LDO family such as MCP1824 or MIC5219.
