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Microchip Technology MIC2178BWM
- Part No.:
- MIC2178BWM
- Manufacturer:
- Microchip Technology
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
MIC2178BWM.pdf
- Description:
- IC REG BUCK ADJ 2.5A 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,322
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Product details
Overview
MIC2178BWM from Microchip Technology is a 200 kHz synchronous buck (step-down) DC/DC regulator with dual-mode PWM/skip operation, internal 100 mΩ P- and N-channel MOSFETs, 2.5A output capability, and 100% duty cycle support for low-dropout operation in battery-powered systems.
For engineers reviewing the MIC2178BWM datasheet, MIC2178BWM pinout, MIC2178BWM application, or MIC2178BWM equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, and confirmed alternative options for high-efficiency power conversion in portable electronics and embedded supplies.
Technical Context
The MIC2178BWM implements current-mode control with internal current sensing, enabling simplified loop compensation and superior line regulation. Its dual-mode architecture-externally selected via the PWM pin-switches between fixed-frequency PWM (>200 mA load) and self-oscillating skip mode (<200 mA load) to maximize efficiency across wide load ranges.
It integrates a 3.3V internal bias regulator (BIAS pin), supports external clock synchronization up to 300 kHz (SYNC pin), and features pulse-by-pulse current limiting (4.7A typ.), thermal shutdown, and undervoltage lockout (4.25V turn-on threshold). The 20-lead wide SOIC (WM) package enables high-current routing with dedicated PGND and SGND pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | +4.5V to +16.5V - supports 5V, 12V, and 16V input rails common in laptops, palmtops, and industrial battery systems. |
| Output Current | Up to 2.5A - sufficient for powering core logic, memory, and I/O in portable computing and handheld instruments. |
| Switching Frequency | 200 kHz preset, synchronizable to 220–300 kHz - enables EMI reduction via clock alignment and avoids sensitive audio bands. |
| Efficiency | Up to 96% - achieved via synchronous rectification and dual-mode operation, minimizing quiescent loss at light loads. |
| Quiescent Current | 600 µA in Skip Mode, <5 µA in Shutdown - extends battery life in standby and sleep states. |
| Duty Cycle | 100% maximum - maintains regulation down to VIN – VOUT ≈ dropout voltage (e.g., ~250 mV @ 2.5A with 100 mΩ HS-FET). |
| Feedback Reference | 1.245V ±25 mV - enables precise adjustable output (e.g., 3.3V, 5.0V) using standard resistor dividers with minimal error contribution. |
Pinout & Package
The MIC2178BWM is housed in a 20-lead wide SOIC (WM) package with exposed thermal pad (not electrically connected), rated for –40°C to +85°C operating junction temperature. Power and signal grounds are physically separated to minimize noise coupling.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 9 (VIN) | Input Supply Rail | Three parallel VIN inputs reduce trace inductance and IR drop; all must connect to bulk input capacitor near device. |
| 3, 8 (SW) | Half-Bridge Switch Node | High-side P-FET and low-side N-FET output; both pins tied externally to inductor and Schottky diode anode. |
| 4–7 (PGND) | Power Ground Return | Four dedicated PGND pins carry high-frequency switch currents; must connect to single-point ground plane under inductor. |
| 10 (PWM) | Mode Control Input | Logic-level selection: low = PWM mode (fixed 200 kHz), high = skip mode (variable frequency, <200 mA optimal). |
| 11 (PWRGD) | Open-Drain Power-Good Flag | Active-low when FB drops >10% below 1.245V; requires external pull-up to VIN for system monitoring and sequencing. |
| 12 (FB) | Resistive Feedback Input | Connects to voltage divider; 60 nA bias current limits max R2 to 100 kΩ for <1% error at 3.3V output. |
| 13 (COMP) | Error Amplifier Output | Connects series RC network (e.g., 10 nF + 10 kΩ) to stabilize control loop; sets pole-zero for phase margin >45°. |
| 14–17 (SGND) | Signal Ground Reference | Isolated from PGND to prevent switching noise injection into feedback and compensation paths. |
| 18 (SYNC) | External Clock Input | Accepts 220–300 kHz square wave; rising edge resets oscillator; tie to SGND if unused. |
| 19 (BIAS) | Internal 3.3V Bias Supply | Must be decoupled with 0.01 µF ceramic to SGND; zero external load permitted - not a power source. |
| 20 (EN) | Enable Control Input | Logic high enables regulation; logic low reduces IQ to <5 µA - used for system-level power gating. |
Key Features
| Feature | Design Value |
|---|---|
| Dual-Mode Efficiency Optimization | Externally selectable PWM/skip mode ensures >90% efficiency from 10 mA to 2.5A load without compromising noise or transient response. |
| Synchronous Rectification | Integrated 100 mΩ P/N-FET pair eliminates external diode losses, reducing conduction loss by ~0.3 V × ILOAD vs. Schottky solution. |
| Low-Dropout Operation | 100% duty cycle allows regulation with VIN – VOUT as low as 250 mV at full load, critical for Li-ion battery discharge end-of-life. |
| Robust Protection Suite | Pulse-by-pulse current limit (4.7A), thermal shutdown (>125°C), UVLO (4.25V on / 4.15V off), and open-drain PWRGD enable fail-safe system behavior. |
| Stable Current-Mode Control | Internal slope compensation and COMP-pin RC tuning simplify compensation - no external current-sense resistor required. |
Applications
| Laptop Core Voltage Regulation | Palmtop Computer Power Supply |
|---|---|
Use Scenario: Regulating 3.3V or 5.0V from a 7–16.5V Li-ion battery pack in ultra-thin notebook platforms with strict thermal and efficiency targets. IC Role / Device Role / Timing Role: Primary synchronous buck controller delivering 2.5A core logic rail with dynamic mode switching based on CPU activity. Use Value: Dual-mode operation extends runtime by 18–22% during idle/sleep versus fixed PWM, while 100% duty cycle sustains output until battery reaches 3.4V. | Use Scenario: Powering ARM-based application processors and LPDDR memory in handheld PDAs with limited PCB area and passive cooling. IC Role / Device Role / Timing Role: Compact, integrated step-down regulator replacing discrete FET + controller solutions to reduce BOM count and layout complexity. Use Value: 20-lead WM package with split ground planes minimizes EMI in dense layouts; BIAS pin simplifies biasing of external circuits without extra LDO. |
| Cellular Telephone Baseband Supply | Battery-Powered Handheld Instrument |
Use Scenario: Generating clean 3.3V supply for RF transceivers and baseband ICs in 4G/LTE handsets where burst-mode efficiency and low-noise operation are mandatory. IC Role / Device Role / Timing Role: High-efficiency buck converter operating in skip mode during voice standby and PWM mode during data transmission bursts. Use Value: Skip mode reduces quiescent current to 600 µA, extending talk-time; SYNC pin enables clock dithering to suppress narrowband EMI peaks. | Use Scenario: Providing regulated 5.0V rail for microcontroller, display driver, and sensor interface in portable multimeters and oscilloscopes running from 4×AA alkaline cells. IC Role / Device Role / Timing Role: Main DC/DC regulator supporting wide input range (6–16.5V) and maintaining regulation through battery voltage decay. Use Value: UVLO with 4.25V turn-on threshold prevents brownout during battery sag; PWRGD flag enables automatic low-battery warning and graceful shutdown. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MIC2177YWM | Auto-selects PWM/skip mode internally based on load; no external PWM pin control; identical pinout and electrical specs otherwise. | Eliminates need for system-level mode control logic but removes flexibility for noise-sensitive timing-critical applications. | Select MIC2177YWM only when automatic mode transition is acceptable and external control signal is unavailable. |
| TPS54227PWPR | 3.5V–18V input, 2A output, 500 kHz switching, integrated 120 mΩ/70 mΩ FETs; no skip mode; uses voltage-mode control. | Better light-load efficiency via D-CAP2 control, but higher EMI due to fixed 500 kHz frequency and no synchronization capability. | Choose TPS54227PWPR for higher-frequency designs requiring smaller magnetics, accepting trade-off in EMI control and mode flexibility. |
Compared with MIC2178BWM, MIC2177YWM offers simpler integration at the cost of mode autonomy, while TPS54227PWPR provides higher switching frequency and voltage-mode stability but lacks skip mode and SYNC functionality - making MIC2178BWM optimal for battery life–critical, noise-aware, and system-controlled power architectures.
Availability
MIC2178BWM is available at Aetrix Electronics and suitable for laptop computers, palmtop computers, cellular telephones, and handheld instruments requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for MIC2178BWM 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
Microchip Technology is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and power management ICs, with a focus on reliability, longevity, and embedded system integration.
The MIC2178BWM belongs to Microchip's high-efficiency synchronous buck regulator product line, designed specifically for battery-powered portable electronics where wide-input-range operation, dual-mode efficiency, and robust protection are essential.
FAQ
What is the maximum continuous output current supported by the MIC2178BWM?
The MIC2178BWM supports up to 2.5A continuous output current under typical thermal conditions (TA = +25°C, 2-layer board, 2 oz copper). At higher ambient temperatures or with limited airflow, derating applies - e.g., 2.0A at +85°C ambient. Peak pulsed current is limited to 4.7A by internal current sense circuitry in PWM mode.
How does the MIC2178BWM achieve low quiescent current in skip mode?
The MIC2178BWM achieves 600 µA typical quiescent current in skip mode by disabling high-frequency oscillator and gate drivers during extended off-cycles, retaining only essential comparators and reference circuitry active. This is distinct from PWM mode (1.0 mA) and shutdown mode (<5 µA), enabling extended battery life in intermittent-load applications like remote sensors.
Can the MIC2178BWM operate with an input voltage lower than 4.5V?
No - the MIC2178BWM has an absolute minimum input voltage of 4.5V due to undervoltage lockout (UVLO) activation at 4.25V (typical turn-on threshold). Below this, the EN pin remains inactive and internal bias circuits cannot sustain regulation. For sub-4.5V operation, consider Microchip's MIC24045 or similar low-input buck regulators.
What is the purpose of the BIAS pin on the MIC2178BWM, and can it power external circuitry?
The BIAS pin on the MIC2178BWM provides the internal 3.3V bias supply used to power the control circuitry; it must be decoupled with a 0.01 µF ceramic capacitor to SGND. It is not rated for external loading - applying any load will cause regulation failure and potential device malfunction. The pin serves only as a bypass point, not a power source.
How is the power-good (PWRGD) signal generated and used in the MIC2178BWM?
The MIC2178BWM generates the PWRGD signal by comparing the FB pin voltage to 90% of the internal 1.245V reference (i.e., 1.13V nominal). When FB falls below this threshold, PWRGD pulls low (open-drain, 0.25V max at 0.5 mA sink) to indicate output undervoltage. It is used for system sequencing, battery-low detection, and safe shutdown coordination in host processors.
MIC2178BWM Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 16.5V
- Voltage - Output (Min/Fixed):
- 1.245V
- Voltage - Output (Max):
- 16.5V
- Current - Output:
- 2.5A
- Frequency - Switching:
- 200kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
MIC2178BWM FAQ
1.How can I place an order for MIC2178BWM through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC2178BWM 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 MIC2178BWM reliable?
The price and inventory of MIC2178BWM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC2178BWM is usually 5 days.
3.What payment methods are accepted for MIC2178BWM?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC2178BWM transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC2178BWM?
MIC2178BWM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC2178BWM 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 MIC2178BWM?
For technical support, including MIC2178BWM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC2178BWM requirements.
6.How does Aetrix verify that MIC2178BWM is sourced from the original manufacturer or authorized distributors?
All MIC2178BWM 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 MIC2178BWM meets industry standards.
7.What is the process for return or replacement of MIC2178BWM?
All MIC2178BWM units undergo pre-shipment inspection (PSI). If there is an issue with MIC2178BWM, 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 MIC2178BWM part is unused and in its original packaging.
Return procedure for MIC2178BWM:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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