MCP1825S-3302E/AB - 500mA 3.3V LDO Regulator TO-220-3 | Microchip
Référence : MCP1825S-3302E/AB ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $1.83 | $1,83 |
| 10 | $1.65 | $16,50 |
| 100 | $1.42 | $142,00 |
| 500 | $1.2 | $600,00 |
| 1 000 | $1.05 | $1 050,00 |
MCP1825S-3302E/AB Présentation
An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable output voltage even when the input voltage approaches the output voltage - typically within a few hundred millivolts. LDOs are a subset of linear regulators, which in turn belong to the broader category of voltage regulators within power management ICs. Unlike switching regulators, an LDO dissipates the difference between input and output as heat, but in exchange it produces a clean, low-noise output with no switching ripple, making it ideal for noise-sensitive analog and digital loads.
Key specifications include 500 mA continuous output current, 210 mV typical dropout, only 1 microfarad (1 uF) ceramic output capacitance required for stability, low quiescent current, thermal-shutdown and current-limit protection, and an extended -40C to +125C junction operating temperature range. The TO-220-3 package with metal tab provides a very low thermal resistance (theta_JA around 35-40 C/W with proper PCB copper/heatsink), allowing sustained 500 mA output across the full input voltage range without additional thermal mitigation in typical through-hole designs.
Architecturally the MCP1825S uses a P-channel MOSFET pass element, which is the source of its low-dropout capability (P-channel FETs do not require a gate drive above VIN). The control loop combines a precision bandgap reference with a high-gain error amplifier and integrated soft-start, which controls inrush current at power-up. A separate SHDN input (if present on the variant) and internal protection features - current limit, thermal shutdown, and reverse-current blocking - protect both the regulator and downstream circuitry during fault conditions.
Typical applications include 3.3 V power rails for microcontrollers, ASICs, and FPGAs; USB peripheral and hub power; battery-powered portable devices; industrial sensor conditioning; and as post-regulation after switching converters to clean switching ripple from noise-sensitive analog blocks such as ADCs, DACs, and RF transceivers.
A key design consideration is the absolute maximum input voltage of 6.0 V - operation above this rating will damage the device. Although the device works without input capacitance, a 1 uF ceramic input cap placed close to VIN is strongly recommended to improve transient response to input steps. The TO-220 tab is electrically tied to the die substrate and normally connects to GND; depending on layout it can be left floating or connected to the ground plane to spread heat.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, giving the engineer an at-a-glance design reference for the MCP1825S-3302E/AB.
Alternatives de remplacement direct pour MCP1825S-3302E/AB — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
MCP1825S-3002E/AB
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
MCP1825S-3302E/AB Valeurs maximales et caractéristiques électriques
| Regulator Type | LDO (Low Dropout), Positive Fixed |
| Nombre de sorties | 1 |
| Output Voltage (Nominal) | 3.3 V |
| Output Voltage Accuracy | ±2.0% |
| Courant de sortie (max.) | 500 mA |
| Plage de tension d'entrée | 2.1 V to 6.0 V |
| Dropout Voltage (Typical) | 210 mV at 500 mA |
| Output Capacitor Requirement | 1 uF ceramic, ESR stable |
| Input Capacitor Recommendation | 1 uF ceramic (recommended) |
| Température de jonction en fonctionnement | -40C to +125C |
| Protection Features | Current Limit, Thermal Shutdown |
| Boîtier / Format | TO-220-3 (3 + Tab), through-hole |
| Type de montage | Through-Hole |
| Nombre de broches | 3 |
| Lead-Free / RoHS | Compliant (per Microchip product page, lead-free finish) |
| Niveau MSL | 1 (through-hole, not moisture-sensitive) |
Configuration des broches de MCP1825S-3302E/AB
| Broche 1 | VIN — Input supply voltage (2.1V to 6.0V) |
| Broche 2 | GND — Common ground / thermal tab (tab electrically tied to pin 2 internally) |
| Broche 3 | VOUT — Regulated 3.3V output (up to 500 mA) |
Applications typiques
MCP1825S-3302E/AB convient pour 6 applications: 3.3V Microcontroller / FPGA Core Rail, USB 5V to 3.3V Downstream Rail, Battery-Powered IoT Sensor Node, Post-Regulation After Switching Buck Converter, Industrial Sensor Conditioning Power, RF / Wireless Module Power.
3.3V Microcontroller / FPGA Core Rail
The MCP1825S-3302E/AB delivers a clean, fixed 3.3 V at up to 500 mA directly from a 5 V USB or 3.6 V Li-ion input, ideal for powering microcontrollers (PIC32, STM32, ESP32) and small FPGAs. With 210 mV dropout at full load it leaves comfortable margin on a 3.6 V battery rail, and 1 uF ceramic output capacitance keeps the BOM cost low and footprint small. The P-channel pass element produces no switching ripple, so the rail is clean enough to share directly with on-chip ADC references and high-speed GPIO. Recommended companions: PIC32MX series MCU, ESP32 module, ATmega328P.
Recommandé
USB 5V to 3.3V Downstream Rail
A 5 V USB bus can drop to 3.3 V cleanly with the MCP1825S-3302E/AB feeding hub or peripheral logic. The 2.1 V minimum input and 6.0 V maximum input bracket the USB range plus transient headroom, while the 210 mV dropout ensures regulation even on a sagging bus. A 1 uF MLCC at both input and output gives clean glitch-free power-up and steady-state noise below 50 uVrms. Recommended companions: USB hub controller, USB-UART bridge IC.
Recommandé
Battery-Powered IoT Sensor Node
In a 1- or 2-cell Li-ion / Li-Poly / 3x AA battery node the MCP1825S-3302E/AB delivers 3.3 V from 2.1 V up, stretching usable battery life where older LDOs would drop out. Its low-quiescent-current architecture (typical Iq around 120 uA) preserves standby endurance in duty-cycled sensor nodes. The TO-220 package supports through-hole assembly on compact sensor boards where hand-soldering or robust mechanical connections are preferred over SMT. Recommended companions: low-power MCU, BLE module.
Recommandé
Post-Regulation After Switching Buck Converter
Cascading an MCP1825S-3302E/AB after a buck converter produces an ultra-clean post-rail for ADC, DAC, VCO, or audio codec power. The switching converter handles the bulk step-down for efficiency; the LDO strips the switching ripple to a noise floor acceptable for sensitive analog blocks. Drop the buck's output to roughly 3.6 V and the LDO's 210 mV dropout keeps it in regulation while adding a clean 3.3 V output with negligible spurious content. Recommended companions: buck regulator, precision ADC.
Recommandé
Industrial Sensor Conditioning Power
Industrial analog front ends, 4-20 mA sensor signal chains, and bridge excitation benefit from the 3.3 V low-noise rail provided by the MCP1825S-3302E/AB. The -40C to +125C junction temperature range supports factory automation and outdoor instrumentation environments. The 500 mA capacity comfortably drives an instrumentation op-amp, an excitation reference, and a microcontroller ADC from a single LDO. The TO-220 footprint simplifies retrofits into existing through-hole layouts. Recommended companions: instrumentation amplifier, 24-bit sigma-delta ADC.
Recommandé
RF / Wireless Module Power
Sub-GHz, Bluetooth Low Energy, and Wi-Fi modules are notoriously sensitive to supply ripple; the MCP1825S-3302E/AB's low-noise output preserves the link budget. Dropping from a 5 V USB or 4.2 V Li-ion to 3.3 V with only 210 mV dropout keeps efficiency acceptable while giving the RF section a near-DC supply. The 1 uF ceramic output cap requirement allows tiny 0201/0402 capacitors near the module, keeping the supply loop area small and minimizing radiated noise. Recommended companions: BLE module, sub-GHz transceiver.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour MCP1825S-3302E/AB — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | MCP1825S-3302E/EB | MCP1825ST-3302E/DB | MCP1825S-3002E/AB |
|---|---|---|---|---|
| Package | TO-220-3 (3 + Tab) | SOT-223-3 | DDPAK-3 / TO-263 | TO-220-3 (3 + Tab) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Output Voltage | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed | 3.0 V fixed |
| Maximum Output Current | 500 mA | 500 mA | 500 mA | 500 mA |
| Input Voltage Range | 2.1 V to 6.0 V | 2.1 V to 6.0 V | 2.1 V to 6.0 V | 2.1 V to 6.0 V |
| Dropout Voltage | 210 mV at 500 mA | 210 mV at 500 mA | 210 mV at 500 mA | 210 mV at 500 mA |
| Output Capacitor | 1 uF ceramic | 1 uF ceramic | 1 uF ceramic | 1 uF ceramic |
| Mounting Type | Through-Hole | Surface Mount | Surface Mount | Through-Hole |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C |
Principaux différenciateurs
- Ceramic-output-cap stability (1 uF minimum) (vs LM1117-3.3 (in TO-220-3))
- P-channel pass element gives only 210 mV dropout (vs LM1117-3.3 (TO-220))
- Wide 2.1 V minimum input lets it work from 1-cell Li-ion after boost (vs MCP1700-3302E (TO-92))
Notes de conception
The MCP1825S-3302E/AB cannot operate above 6.0 V on VIN - connecting it directly to an unregulated 12 V supply will permanently damage the device. For higher-voltage rails, add a pre-regulator (buck or front LDO) that drops below 6.0 V, then use the MCP1825S for the final 3.3 V post-regulation. Although the datasheet shows the regulator will operate without input capacitance, adding a 1 uF ceramic input capacitor within a few millimeters of VIN significantly improves line-transient response and helps reject upstream switching noise.
Estimated: at VIN = 5 V, VOUT = 3.3 V, IOUT = 500 mA, dissipation is approximately (5.0 - 3.3) × 0.5 = 0.85 W. The TO-220 with a modest copper pad dissipates this in still air at 25C ambient, but at 60C ambient or with poor layout the junction can approach 125C. At VIN = 5.5 V the dissipation rises to 1.10 W; use a clip-on heatsink, larger copper pad, or forced airflow if VIN is consistently above 5.0 V at full load.
Keep the loop area formed by VIN → input cap → GND, and the loop formed by VOUT → output cap → GND, as small as practical. Place the 1 uF ceramic output cap immediately adjacent to VOUT and tie its ground pad through the shortest path to the GND plane - this minimizes high-frequency output impedance and improves load-step response. The TO-220 metal tab is electrically tied to GND internally; on the PCB either solder the tab to a copper pour for thermal spreading or leave it isolated, but never route a signal trace under or through the tab pad.
Do not assume dropout scales linearly - at lower load currents dropout drops proportionally, so a 100 mA load still regulates with only ~50 mV of headroom. Do not connect the output of a higher-voltage rail to VOUT while VIN is unpowered (reverse-current stress). The 'E/' suffix means lead-free Matte Tin finish suitable for Pb-free reflow through-hole pin - verify your socket/connector is compatible if you are wave-soldering.
Informations de conformité
RoHS compliant, lead-free finish. No AEC-Q100 automotive qualification on the base -AB variant; Microchip offers automotive-graded variants in this family with different suffixes. TO-220 is through-hole, MSL 1, no moisture-sensitivity handling required.
