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Microchip Technology MIC5249-1.8BMM
- Part No.:
- MIC5249-1.8BMM
- Manufacturer:
- Microchip Technology
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MIC5249-1.8BMM.pdf
- Description:
- IC REG LINEAR 1.8V 300MA 8MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,318
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Product details
Overview
MIC5249-1.8BMM from Micrel is a 300mA, 1.8V fixed-output CMOS low-dropout regulator with programmable power-on-reset delay, ±1.0% initial output accuracy, 340mV dropout at full load, and ultra-low 85µA quiescent current. It integrates an open-drain RESET output, CMOS-compatible ENABLE pin, and noise-reduction bypass input-designed for noise-sensitive battery-powered applications including cellular handsets and fiber optic modules.
For engineers reviewing the MIC5249-1.8BMM datasheet, MIC5249-1.8BMM pinout, MIC5249-1.8BMM application, or MIC5249-1.8BMM equivalent, key selection criteria include adjustable POR delay via external capacitor, stability with 2.2µF ceramic output capacitance, thermal shutdown protection, and MSOP-8 footprint compatibility in space-constrained portable designs.
Technical Context
The MIC5249-1.8BMM implements a precision bandgap reference with active feedback control to maintain 1.8V output under varying line (2.7–6V VIN), load (0–300mA), and temperature (–40°C to +125°C) conditions. Its internal architecture includes a dedicated DELAY pin current source (0.55µA) and threshold comparator (1.4V) enabling accurate, capacitor-programmed reset timing.
It features an open-drain RESET output that asserts low only when both undervoltage detection (VOUT < 89–91% of nominal) and fault condition (overcurrent/thermal/dropout) co-occur-preventing false triggering. The device remains stable with zero load and supports fast transient response due to high-bandwidth CMOS pass element and optimized compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8V ±1.0% initial accuracy ensures reliable core logic supply for 1.8V microcontrollers and RF ICs. |
| Dropout Voltage | 340mV @ 300mA enables operation from 2.14V minimum input-critical for single-cell Li-ion or dual-cell NiMH systems. |
| Quiescent Current | 85µA typical supports >1-year battery life in always-on standby circuits without compromising regulation. |
| PSRR | 65dB @ 120Hz suppresses switching noise from upstream DC/DC converters feeding the LDO input. |
| RESET Threshold | Active-low flag triggers when VOUT falls below 89–91% of 1.8V (≈1.60–1.64V), providing precise brown-out detection. |
| Enable Logic | CMOS-compatible ENABLE (VIH ≥1.6V, VIL ≤0.4V) allows direct interfacing with 1.8V/3.3V GPIO without level-shifting. |
| Thermal Protection | Internal thermal shutdown activates at TJ ≥125°C and recovers automatically upon cooling-no latch-up or manual reset required. |
Pinout & Package
Package: 8-pin MSOP (MM), 3.0mm × 3.0mm × 1.0mm body, 0.65mm pitch, exposed pad optional (not electrically connected per datasheet).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - CBYP | Reference bypass node | Connects 0.01µF capacitor to GND to reduce output voltage noise and improve PSRR; optional but recommended for RF/ADC applications. |
| 2 - DELAY | POR delay timing input | Sinks 0.55µA constant current; external capacitor to GND sets RESET assertion delay (TDELAY = CDELAY × 1.4V / 0.55µA). |
| 3 - GND | Analog and power ground | Common return path for regulator, reference, and RESET driver; must be low-impedance connection to minimize noise coupling. |
| 4 - VIN | Main power input | Accepts 2.7V–6V input; requires ≥1.0µF ceramic bypass capacitor to GND for stability and high-frequency noise rejection. |
| 5 - VOUT | Regulated output | Delivers up to 300mA at 1.8V; stable with ≥2.2µF ceramic output capacitor (ESR ≤300mΩ); no minimum load required. |
| 6 - NC | No-connect terminal | Internally unconnected; must remain floating-no PCB trace or component allowed. |
| 7 - RESET | Open-drain fault indicator | Drives low only during combined undervoltage + fault condition; requires external pull-up resistor to VIN or VOUT. |
| 8 - ENABLE | Active-high enable control | Logic high (≥1.6V) enables regulation; logic low (≤0.4V) disables output and reduces ground current to ≤1µA. |
Key Features
| Feature | Design Value |
|---|---|
| Programmable POR Delay | External capacitor on DELAY pin sets precise power-on reset timing-enables deterministic system boot sequencing without external timers. |
| Ultra-Low Noise Operation | CBYP pin + 0.01µF capacitor reduces output ripple and improves PSRR by >15dB-essential for analog/RF signal chains. |
| Zero-Current Shutdown | ENABLE-driven shutdown draws ≤1µA total supply current-preserves battery charge in deep-sleep modes. |
| Active Output Discharge | Integrated N-channel clamp discharges VOUT capacitor when disabled-prevents residual voltage from interfering with downstream logic states. |
| No-Load Stability | Maintains regulation with 0mA load-supports CMOS RAM keep-alive and other ultra-low-power retention circuits. |
Applications
| Cellular Handset Power | Fiber Optic Transceiver Bias |
|---|---|
Use Scenario: Supplying 1.8V core voltage to baseband processor and RF transceiver in GSM/UMTS smartphones with tight battery voltage margins. IC Role / Device Role / Timing Role: Primary LDO delivering clean, regulated 1.8V with POR-controlled reset to synchronize processor boot after battery insertion or cold start. Use Value: 340mV dropout enables operation down to 2.14V input-extending usable battery range by ~12% versus higher-dropout alternatives. | Use Scenario: Providing low-noise bias to laser diode drivers and post-amplifiers in SFP+ and XFP optical modules. IC Role / Device Role / Timing Role: Low-PSRR, low-noise LDO with CBYP filtering to minimize jitter-inducing supply noise on high-speed data paths. Use Value: 65dB PSRR at 120Hz and 0.01µF CBYP support reduce RMS output noise to <15µVrms-meeting SONET OC-48 jitter specs. |
| PDA Application Processor Core | Portable Medical Sensor Node |
Use Scenario: Powering ARM-based application processors requiring tightly regulated 1.8V I/O and core rails in handheld diagnostic devices. IC Role / Device Role / Timing Role: Main system LDO with ENABLE-controlled power gating and RESET-synchronized firmware initialization. Use Value: ±1.0% output accuracy ensures consistent timing margins across voltage/temperature; ENABLE pin enables dynamic power management. | Use Scenario: Supplying 1.8V to ultra-low-power ADCs, Bluetooth LE SoCs, and MEMS sensors in wearable ECG monitors. IC Role / Device Role / Timing Role: Always-on LDO maintaining regulation during sleep cycles, with RESET signaling brown-out before data corruption occurs. Use Value: 85µA quiescent current extends coin-cell battery life beyond 2 years in intermittent-sampling mode. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MCP1700-1802E/TO | 250mA output, 600mV dropout @ 250mA, no RESET or DELAY pins, TO-92 package. | Lacks POR delay and fault flag; suitable only for basic regulation where sequencing and monitoring are handled externally. | Select when board space permits through-hole mounting and system-level reset generation is available. |
| TLS850F0TESK | 500mA output, integrated watchdog timer, AEC-Q100 qualified, PG-SSOP-14 package. | Automotive-grade with extended temp range (–40°C to +150°C) and functional safety features not present in MIC5249-1.8BMM. | Select for automotive infotainment or ADAS modules requiring ISO 26262 support and higher current capability. |
Compared with MCP1700-1802E/TO and TLS850F0TESK, the MIC5249-1.8BMM uniquely combines 300mA capability, programmable POR delay, and ultra-low noise in a compact MSOP-8-making it optimal for portable electronics where board area, sequencing control, and signal integrity are jointly constrained.
Availability
MIC5249-1.8BMM is available at Aetrix Electronics and suitable for cellular handsets, fiber optic modules, PDAs, portable medical sensors, and battery-powered IoT edge nodes requiring stable component supply with guaranteed long-term availability.
Supply support for MIC5249-1.8BMM includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Micrel Inc. was a U.S.-based analog and mixed-signal semiconductor company founded in 1978, acquired by Microchip Technology in 2015. Known for high-performance power management and timing solutions.
The MIC5249 family was designed specifically for noise-critical, space-constrained portable electronics-delivering precision regulation, integrated power sequencing, and low-ESR ceramic capacitor compatibility in sub-3mm² packages.
FAQ
What is the maximum input voltage for MIC5249-1.8BMM?
The absolute maximum input voltage for MIC5249-1.8BMM is +7V. However, the recommended operating range is +2.7V to +6V. At 300mA load and ambient temperature of 50°C in MSOP-8 package, maximum safe input is 4.56V to avoid thermal shutdown-calculated using θJA = 160°C/W and TJ(max) = 125°C. Exceeding this limit risks thermal foldback.
Does MIC5249-1.8BMM require an external capacitor on the CBYP pin?
The CBYP pin on MIC5249-1.8BMM is optional but strongly recommended for noise-sensitive applications. A 0.01µF capacitor to GND reduces output voltage noise and improves PSRR. Without it, PSRR drops significantly-especially below 1kHz-and output noise increases by ~3×. For RF, ADC, or precision analog circuits, the CBYP capacitor is essential.
How is the power-on-reset delay time calculated for MIC5249-1.8BMM?
The POR delay time for MIC5249-1.8BMM is set by an external capacitor on the DELAY pin: TDELAY = (CDELAY × 1.4V) / 0.55µA. For example, a 100nF capacitor yields ~255ms delay. The DELAY pin sources a precise 0.55µA current, and the internal comparator trips at 1.4V-ensuring predictable, temperature-stable timing without external resistors or clocks.
Can MIC5249-1.8BMM operate without any load connected to VOUT?
Yes, MIC5249-1.8BMM remains stable and in regulation with zero load-unlike many older LDO architectures. This no-load stability is confirmed in the datasheet and critical for applications like CMOS RAM keep-alive, real-time clock backup, or sensor biasing during deep sleep. Output voltage accuracy and dropout behavior are fully specified down to 0mA.
What is the function of the NC pin on MIC5249-1.8BMM?
Pin 6 on MIC5249-1.8BMM is marked NC (No Connect) and is internally unconnected. It must remain electrically floating-no trace, solder, or component should be attached. Routing a trace to this pin may introduce parasitic coupling or contamination risk. The MSOP-8 footprint accommodates this unused pin without modification, and its presence does not affect thermal or electrical performance.
MIC5249-1.8BMM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Bulk
- Product Status:
- Discontinued at Digi-Key
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 6V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.6V @ 300mA
- Current - Output:
- 300mA
- Current - Quiescent (Iq):
- 200 µA
- Current - Supply (Max):
- -
- PSRR:
- 65dB (120Hz)
- Control Features:
- Enable, Reset
- Protection Features:
- Over Current, Over Temperature, Under Voltage Lockout (UVLO)
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-MSOP
MIC5249-1.8BMM FAQ
1.How can I place an order for MIC5249-1.8BMM through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC5249-1.8BMM on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MIC5249-1.8BMM reliable?
The price and inventory of MIC5249-1.8BMM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC5249-1.8BMM is usually 5 days.
3.What payment methods are accepted for MIC5249-1.8BMM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC5249-1.8BMM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC5249-1.8BMM?
MIC5249-1.8BMM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC5249-1.8BMM order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MIC5249-1.8BMM?
For technical support, including MIC5249-1.8BMM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC5249-1.8BMM requirements.
6.How does Aetrix verify that MIC5249-1.8BMM is sourced from the original manufacturer or authorized distributors?
All MIC5249-1.8BMM products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MIC5249-1.8BMM meets industry standards.
7.What is the process for return or replacement of MIC5249-1.8BMM?
All MIC5249-1.8BMM units undergo pre-shipment inspection (PSI). If there is an issue with MIC5249-1.8BMM, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MIC5249-1.8BMM part is unused and in its original packaging.
Return procedure for MIC5249-1.8BMM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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