MIC5233-3.3BM5 - 100mA 36V LDO Regulator 3.3V | Microchip
料号： MIC5233-3.3BM5 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.28 | $128.00 |
| 500 | $1.05 | $525.00 |
| 1,000 | $0.92 | $920.00 |
| 3,000 | $0.81 | $2,430.00 |
MIC5233-3.3BM5 概述
An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable, low-noise output voltage even when the input voltage is only marginally higher than the desired output - the dropout voltage defines this minimum headroom. LDOs belong to the broader class of linear regulators within power management ICs and are preferred over switching regulators in noise-sensitive analog and RF signal paths because they inject no switching ripple into the output rail. Compared with a discrete Zener-plus-pass transistor reference, an integrated LDO like the MIC5233 shrinks the BOM, removes trimming, and provides built-in current limit, thermal shutdown, and reverse-battery protection.
The MIC5233 uses a CMOS architecture with a P-channel pass transistor that intrinsically provides reverse-current blocking and zero reverse leakage when the input is shorted to ground. The 5-lead SOT-23 package adds an active-low enable (SHDN) pin, allowing the host MCU to turn off the regulator for power sequencing or to extend battery standby. The MIC5233 is a µCap LDO design, which means the output is stable with a single 2.2 µF ceramic capacitor - no tantalum or large ESR reservoir is required, simplifying PCB layout and shrinking the solution footprint compared to legacy LDOs that needed 10 µF tantalum output capacitors.
Typical applications include always-on battery rails in 12 V industrial sensors, USB dongles, multi-cell Li-Ion packs (3-4 cells giving 9-16 V nominal), handheld instruments, and post-regulation downstream of a switching converter to remove switching ripple. Because quiescent current is well under 1 mA even at no load, the MIC5233 suits sleep-mode and IoT endpoints that must minimize sleep current on coin-cell or Li-Ion primary cells.
When laying out the PCB, place the 2.2 µF ceramic output capacitor directly across the OUT and GND pins with the shortest trace possible; ESRs below 200 mΩ ensure loop stability. Avoid routing noisy switching traces near the feedback network, and ensure the input trace has sufficient copper width to handle the worst-case 100 mA continuous load without excessive voltage droop.
This page synthesizes MIC5233 family datasheet specifications, distributor pricing, drop-in SOT-23-5 alternatives, and practical design notes that are not available on a stock DigiKey or Mouser listing.
直接替换替代料： MIC5233-3.3BM5 ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
MIC5233-3.3YM5-TR
✅ 直接替换📋 参考替代料（不在目录中）
MIC5233-3.3YS
✅ 直接替换📋 参考替代料（不在目录中）
MIC5219-3.3BM5-TR
✅ 直接替换📋 参考替代料（不在目录中）
MIC5207BM5-TR
✅ 直接替换📋 参考替代料（不在目录中）
MIC5231-3.3BM5
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
MIC5201-3.3BM5
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
MIC5233-3.3BM5 最大额定值与电气特性
| Manufacturer | Microchip Technology (formerly Micrel) |
| Part Number | MIC5233-3.3BM5 |
| Output Voltage (Fixed) | 3.3 V |
| 输出类型 | Fixed |
| Output Current (Continuous) | 100 mA |
| Input Voltage Range (Max) | 36 V (maximum operating) |
| 压差电压 | 450 mV at 100 mA (typical, see datasheet) |
| Quiescent Current (Ground) | ~18 µA typical (ultra-low IQ) |
| Initial Output Accuracy | ±2.0% |
| Output Capacitor Requirement | 2.2 µF ceramic (µCap stable) |
| 封装 / 外壳 | 5-pin SOT-23 (M5) |
| 安装类型 | Surface Mount |
| 工作温度范围 | -40°C to +125°C (junction) |
| Protection Features | Thermal shutdown, current limit, reverse-battery protection, reverse leakage protection |
| Enable (SHDN) Input | Yes, active-low |
| 拓扑 | CMOS LDO with P-channel pass |
| Lead Free | Contains lead (per MIC5233-3.3BM5 TR datasheet listing) |
| RoHS 状态 | Non-Compliant (per MIC5233-3.3BM5 TR listing) |
MIC5233-3.3BM5 引脚配置
| 引脚 1 | IN — Input voltage supply (up to 36 V max) |
| 引脚 2 | GND — Ground |
| 引脚 3 | EN (SHDN) — Enable (active-low shutdown input) |
| 引脚 4 | NC — Not connected (per datasheet) |
| 引脚 5 | OUT — Regulated 3.3 V output (requires 2.2 µF ceramic capacitor) |
典型应用
MIC5233-3.3BM5 适用于 6 应用s: Multi-Cell Li-Ion Battery Power Rail, Industrial 12V/24V Sensor Power Rail, USB-Powered Peripherals and Dongles, Post-Stage Ripple Filtering for Switching Converters, Always-On IoT and Sleep-Mode Devices, Handheld Instruments and Portable Test Gear.
Multi-Cell Li-Ion Battery Power Rail
The MIC5233-3.3BM5's 36 V maximum input and 100 mA continuous output match multi-cell Li-Ion packs directly. The internal P-channel pass device provides reverse-battery protection, eliminating the need for an external blocking diode in 2-3S Li-Ion packs. Quiescent current of approximately 18 µA keeps standby drain below the self-discharge floor of typical Li-Ion cells, extending product shelf life for handheld instruments. Place the 2.2 µF ceramic output capacitor as close as possible to the OUT pin for noise-free 3.3 V supply rails to MCUs and BLE radios in this topology.
推荐
Industrial 12V/24V Sensor Power Rail
The MIC5233-3.3BM5 accepts 12 V or 24 V industrial inputs directly, simplifying power-tree designs for factory-automation sensors, PLC I/O modules, and field transmitters that need a 3.3 V rail for an MCU or wireless transceiver. The thermal-shutdown circuitry and current limit built into the regulator protect the part from shorted sensor loads and inductive kickback on long cable runs. The 5-pin SOT-23 footprint saves board space versus legacy TO-92 or SOT-223 industrial regulators, while the active-low SHDN pin allows a master controller to power-cycle the rail for fault recovery in field installations.
推荐
USB-Powered Peripherals and Dongles
The MIC5233-3.3BM5 operates from a 5 V USB bus rail directly with adequate headroom for the 3.3 V output and tolerates USB-supplied transients up to its 36 V absolute maximum. In USB dongles, BLE beacons, and HID peripherals, the regulator provides a clean 3.3 V rail from the VBUS line while its reverse-current blocking prevents the host from back-powering the dongle when USB is disconnected - useful for hot-swappable devices. Quiescent current of approximately 18 µA is below USB suspend-current thresholds, helping the dongle meet USB suspend current compliance when the host lowers VBUS to standby.
推荐
Post-Stage Ripple Filtering for Switching Converters
Linear regulators such as the MIC5233-3.3BM5 typically follow a switching front-end DC-DC converter to clean up ripple on the 3.3 V rail feeding an audio codec, RF PLL, or precision sensor. Because the LDO adds no switching noise of its own, the output ripple is limited by the upstream switcher's residual ripple filtered through the LDO's PSRR, yielding measurement-grade supply noise floor. The 450 mV dropout allows direct post-regulation from a 3.8 V intermediate rail without excessive dissipation at 100 mA - only ~50 mW of waste heat at full load, versus the several hundred milliwatts of a 12 V-to-3.3 V buck converter.
推荐
Always-On IoT and Sleep-Mode Devices
IoT endpoints - smart-home sensors, BLE beacons, environmental monitors - depend on sleep-mode regulators that draw tens of microamps to extend battery life on coin cells or Li-Ion primaries. The MIC5233-3.3BM5's 18 µA quiescent and active-low SHDN input let a low-power MCU shut down the regulator entirely between measurements, dropping system quiescent current to the MCU's RTC level. The 100 mA load capability is sufficient to power sub-GHz radios (LoRa, Sigfox) and BLE5 modules that consume 50-80 mA peak during transmit bursts.
推荐
Handheld Instruments and Portable Test Gear
The MIC5233-3.3BM5 supplies a clean 3.3 V rail for ADC references, op-amp signal chains, and MCU cores in handheld multimeters, oscilloscope probes, and portable gas analyzers. The 2.0% output accuracy suffices for MCU supplies, while the low dropout extends battery runtime when the Li-Ion pack falls into its lower state of charge. The 5-pin SOT-23 footprint simplifies handheld layouts where every square millimeter matters, and the small 2.2 µF output ceramic keeps the regulator layout footprint well under 25 mm² on the PCB.
推荐
推荐产品汇总
工程参考数据： MIC5233-3.3BM5 ——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 | MIC5233-3.3YM5-TR | MIC5233-3.3YS | MIC5219-3.3BM5-TR | MIC5207BM5-TR | MIC5231-3.3BM5 |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology (Micrel) | Microchip Technology (Micrel) | Microchip Technology (Micrel) | Microchip Technology (Micrel) | Microchip Technology (Micrel) | Microchip Technology (Micrel) |
| Package | 5-pin SOT-23 (M5) | 5-pin SOT-23 (M5) - same | 5-pin SOT-23 (M5) - same | 5-pin SOT-23 (M5) - same | 5-pin SOT-23 (M5) - same | 5-pin SOT-23 (M5) - same |
| Output Voltage | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed / adjustable | 3.3 V fixed |
| Output Current (Continuous) | 100 mA | 100 mA | 100 mA | 500 mA | 180 mA | 100 mA |
| Max Input Voltage | 36 V | 36 V | 36 V | 12 V - 16 V | 16 V | 36 V |
| Quiescent Current | ~18 µA | ~18 µA | ~18 µA | ~90 µA | ~170 µA | ~10-13 µA |
| Dropout (Full Load) | 450 mV at 100 mA | 450 mV at 100 mA | 450 mV at 100 mA | 500 mV at 500 mA | 300-500 mV at 180 mA | 320 mV at 100 mA |
| Enable Pin | Yes (active-low SHDN) | Yes (active-low) | Yes (active-low) | Yes (active-high or no) | Yes (active-low) | Yes (active-low) |
| RoHS Status | Non-compliant (lead-finish BM5) | RoHS Compliant | RoHS Compliant | RoHS Compliant | RoHS Compliant | RoHS Compliant |
关键差异点
- 36 V high-input-voltage capability （对比 MIC5219-3.3BM5-TR)
- Ultra-low quiescent current ~18 µA （对比 MIC5207BM5-TR)
- Reverse-battery and reverse-leakage protection on-chip （对比 MIC5231-3.3BM5)
设计说明
Estimated: at VIN=12 V, VOUT=3.3 V, IOUT=100 mA, the MIC5233-3.3BM5 dissipates (12-3.3) × 0.1 = 0.87 W. The 5-pin SOT-23 has a thermal resistance of approximately 200 °C/W on a standard JEDEC 1-square-inch copper pad, which yields a junction temperature rise of ~174 °C above ambient - well above the 125 °C junction limit. Either reduce input voltage to ~6 V max at full load, lower output current to ~50 mA, or expand the GND pin copper pour to keep Tj within the safe operating area of the datasheet.
The 5-pin SOT-23 (M5) requires careful layout. Place the 2.2 µF ceramic output capacitor as close to the OUT and GND pins as possible - within 3 mm - to keep the feedback loop stable. The input capacitor (1 µF ceramic minimum) should also be placed close to the IN pin to suppress input ripple. The SHDN pin traces must avoid coupling to noisy switcher traces; pull-up resistors for the active-low SHDN input must be kept under 100 kΩ to prevent false shutdown from leakage on long traces.
Do not place an external feedback resistor divider on a fixed-output variant - the internal trim network already sets VOUT. Operating the part above the 36 V absolute maximum can permanently damage the input ESD clamp. The MIC5233-3.3BM5 'BM5' suffix is non-RoHS lead-finish; for RoHS-compliant builds use the MIC5233-3.3YM5-TR variant from the same family. Output capacitance lower than 2.2 µF or with ESR outside the stability window defined in the datasheet can lead to oscillation.
合规信息
Per the digchip datasheet listing for the MIC5233-3.3BM5 TR variant, this part contains lead and is RoHS non-compliant. Use the MIC5233-3.3YM5-TR or other Y-suffix variants for RoHS-compliant builds.
