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NXP Semiconductors MC34726BFCR2
- Part No.:
- MC34726BFCR2
- Manufacturer:
- NXP Semiconductors
- Package:
- 8-UFDFN
- Datasheet:
-
MC34726BFCR2.pdf
- Description:
- IC REG BUCK 1.8V 300MA 8USON
- Quantity:
- Payment:
- Shipping:
Inventory:3,488
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Product details
Overview
MC34726BFCR2 from Freescale Semiconductor is a 300 mA synchronous buck regulator with Z-mode architecture, designed for single-cell Li-Ion systems requiring high efficiency at light loads. It operates from 2.7–5.5 V input, delivers fixed 1.8 V output, switches at 2.0 MHz, and achieves 65 μA quiescent current in Sleepy Z-mode - enabling long battery life in portable medical sensors and low-power IoT endpoints.
For engineers reviewing the MC34726BFCR2 datasheet, MC34726BFCR2 pinout, MC34726BFCR2 application, or MC34726BFCR2 equivalent, key selection criteria include its factory-preset 1.8 V output, ultra-thin 2×2 UDFN-8 package, Z-mode ripple suppression below 10 mA load, thermal shutdown at 140°C, and compatibility with 4.7 μF ceramic input/output capacitors and 4.7 μH inductors.
Technical Context
The MC34726BFCR2 implements voltage-mode control with feed-forward compensation and Freescale's proprietary Z-mode architecture, which dynamically reduces switching frequency below 85% CCM duty cycle to minimize light-load switching losses. Its internal block includes dual power MOSFETs (250 mΩ high-side, 350 mΩ low-side), integrated soft-start timer (2.0 ms), and UVLO with 2.5 V falling / 2.7 V rising thresholds.
It supports three operational modes: continuous conduction mode (CCM) above ~10 mA, Z-mode (pulse-skipping) between ~1–10 mA, and Sleepy Z-mode (<1 mA) with oscillator throttling to 250 kHz and low-side FET disablement. Over-current protection triggers at 450 mA peak inductor current, and short-circuit recovery uses output-voltage detection below 0.5 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8 V - eliminates external feedback resistors and ensures stable rail for 1.8 V logic or RF front-end biasing. |
| Max Output Current | 300 mA continuous - sufficient for microcontrollers, BLE radios, and sensor signal chains without external boost stages. |
| Input Voltage Range | 2.7–5.5 V - matches single-cell Li-Ion (3.0–4.2 V nominal) and USB-powered systems with margin. |
| Quiescent Current | 65 μA in Sleepy Z-mode - extends battery runtime in always-on wake-on-event applications like smoke detectors. |
| Switching Frequency | 2.0 MHz ±20% - enables use of compact 4.7 μH inductors and 4.7 μF X5R ceramics, reducing PCB area by >40% vs. 500 kHz designs. |
| Efficiency Peak | 94% - achieved at mid-load (e.g., 150 mA @ 3.6 V → 1.8 V), minimizing thermal stress in sealed enclosures. |
| Thermal Shutdown | 140°C junction temperature with 10°C hysteresis - prevents latch-up during sustained overload while allowing safe recovery. |
| Package | 2×2 mm UDFN-8 (FC suffix, Pb-free) - ultra-low profile (0.55 mm max height) for space-constrained wearables and hearing aids. |
Pinout & Package
MC34726BFCR2 is housed in an 8-pin, 2×2 mm ultra-thin UDFN package with exposed pad omitted (non-EP). Pin 1 is VIN; pins 2 and 3 are GND (low-noise and power ground); pin 4 is EN (active-high enable); pin 5 is FB (feedback input, internally connected to fixed 1.8 V divider); pin 6 is NC (must be externally tied to GND); pins 7 and 8 are SW (dual-switching node outputs, paralleled internally).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Power Input | 2.7–5.5 V DC supply input; requires local 4.7 μF ceramic bypass capacitor to minimize high-frequency noise injection. |
| GND (Pins 2, 3) | Ground Reference | Dual ground pins separate noisy power return (Pin 2) from low-noise analog reference (Pin 3) to reduce FB sensing error. |
| EN (Pin 4) | Enable Control | Active-high logic input; drives high (>1.6 V) to enable regulation, low (<0.4 V) to enter 0.1 μA shutdown state. |
| FB (Pin 5) | Feedback Node | Internally connected to fixed 1.8 V resistor divider; no external components required - simplifies layout and improves stability. |
| NC (Pin 6) | No Connection | Internally unconnected; must be externally tied to GND to prevent floating node coupling noise into sensitive analog blocks. |
| SW (Pins 7, 8) | Switching Node | Paralleled high/low-side MOSFET drain connection; routes to inductor; requires tight loop layout to minimize EMI and voltage spikes. |
Key Features
| Feature | Design Value |
|---|---|
| Z-mode pulse-skipping | Reduces switching frequency under light load (e.g., 1–10 mA), cutting ripple by >50% vs. fixed-frequency operation while maintaining 65 μA IQ. |
| Sleepy Z-mode | Disables low-side FET and throttles oscillator to 250 kHz below 1 mA load, achieving lowest possible quiescent consumption for multi-year battery life. |
| Integrated soft-start | 2.0 ms internal ramp limits inrush current during power-up, preventing input rail collapse and avoiding false brown-out resets. |
| Over-current protection | 450 mA peak inductor current limit provides cycle-by-cycle shutdown, protecting both IC and external inductor from saturation damage. |
| Short-circuit recovery | Detects VOUT < 0.5 V and initiates auto-restart cycles until fault clears - avoids thermal runaway during accidental output shorts. |
| UVLO with hysteresis | 2.7 V turn-on / 2.5 V turn-off threshold prevents oscillation near battery depletion, ensuring clean shutdown before system instability. |
Applications
| Wearable Health Monitor | Smart Home Sensor Node |
|---|---|
|
Use Scenario: Continuous ECG/PPG sensing in wrist-worn device powered by 3.7 V Li-Po cell. IC Role / Device Role / Timing Role: Primary 1.8 V power rail generator for analog front-end and ultra-low-power MCU. Use Value: Sleepy Z-mode extends battery life to >12 months on 120 mAh cell by drawing only 65 μA during sleep intervals between sensor reads. |
Use Scenario: Battery-operated door/window contact sensor with Zigbee radio and reed switch. IC Role / Device Role / Timing Role: Efficient 1.8 V supply for radio transceiver and microcontroller during periodic wake-up and transmission bursts. Use Value: 2.0 MHz switching allows full BOM with < 3 mm² footprint - critical for coin-cell-sized PCBs where board area is premium. |
| Portable Diagnostic Tool | Industrial Wireless Transmitter |
|
Use Scenario: Handheld blood glucose meter using disposable test strips and LCD display. IC Role / Device Role / Timing Role: Single-stage step-down regulator powering 1.8 V digital core and analog measurement circuitry. Use Value: Fixed 1.8 V output eliminates calibration drift from external resistor tolerances, improving ADC accuracy over temperature. |
Use Scenario: Remote pressure/temperature transmitter in oil-field equipment powered by primary lithium battery. IC Role / Device Role / Timing Role: High-reliability 1.8 V supply for low-power MCU and 4–20 mA DAC, operating across -25°C to +85°C ambient. Use Value: Thermal shutdown at 140°C and guaranteed operation to +85°C ambient ensure robustness in unventilated enclosures exposed to solar heating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62231DRYR | 300 mA, 2.0–6.0 V input, adjustable output (0.6–5.5 V), 17 μA IQ in DCS-Control™ eco-mode - lacks Z-mode ripple optimization. | Requires external feedback resistors; better for multi-rail systems needing flexibility, but higher light-load ripple than MC34726BFCR2. | Select when output voltage programmability outweighs lowest possible light-load noise; verify layout for DCS-Control stability. |
| MAX17222ELT+T | 400 mA, 2.0–5.5 V input, fixed 1.8 V output, 0.9 μA IQ in shutdown - uses hysteresis-based constant-on-time control, not Z-mode. | Lower shutdown IQ, but no Sleepy Z-mode; peak efficiency 92% (vs. 94%) and no thermal shutdown hysteresis spec. | Prefer for ultra-deep sleep applications where 0.1 μA shutdown matters more than 2.0 ms soft-start or 140°C thermal protection. |
Compared with TPS62231DRYR and MAX17222ELT+T, the MC34726BFCR2 uniquely combines factory-fixed 1.8 V, Z-mode ripple suppression, and integrated thermal hysteresis - making it optimal for cost-sensitive, space-constrained, and noise-sensitive Li-Ion devices where design simplicity and light-load performance are prioritized.
Availability
MC34726BFCR2 is available at Aetrix Electronics and suitable for wearable health monitors, smart home sensor nodes, portable diagnostic tools, and industrial wireless transmitters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for MC34726BFCR2 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
Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in embedded processing and analog power solutions, specializing in automotive, industrial, and consumer ICs with emphasis on reliability and system-level integration.
The MC34726BFCR2 belongs to Freescale's Power Management IC family, engineered specifically for ultra-low-power, single-cell battery-powered applications where efficiency across the full load range - especially sub-10 mA - is critical to product lifetime.
FAQ
What is the output voltage of the MC34726BFCR2, and is it adjustable?
The MC34726BFCR2 has a factory-preset fixed output voltage of 1.8 V. It is not adjustable - the feedback divider is internal and permanently configured for 1.8 V, eliminating external resistors and associated tolerance errors. This ensures consistent regulation across temperature and time without calibration, making MC34726BFCR2 ideal for applications where output stability and BOM simplicity are essential.
Does the MC34726BFCR2 require external components for basic operation?
Yes, the MC34726BFCR2 requires three external components for stable operation: a 4.7 μF ceramic input capacitor (CIN), a 4.7 μF ceramic output capacitor (COUT), and a 4.7 μH low-DCR inductor (L1). No feedback resistors or compensation networks are needed due to its fixed 1.8 V output and internally optimized control loop - significantly reducing design risk and layout complexity compared to adjustable buck regulators.
How does Z-mode improve efficiency at light loads in the MC34726BFCR2?
Z-mode in the MC34726BFCR2 reduces switching frequency via pulse-skipping when load drops below ~10 mA, directly lowering switching losses that dominate at light loads. For example, at 1 mA load, MC34726BFCR2 may operate at ~250 kHz instead of 2.0 MHz - cutting switching losses by nearly 10× while maintaining 65 μA quiescent current. This preserves high efficiency across the entire 0–300 mA range without sacrificing low-noise performance.
What protection features are built into the MC34726BFCR2?
The MC34726BFCR2 integrates five key protections: (1) over-current limit at 450 mA peak inductor current, (2) thermal shutdown at 140°C junction temperature with 10°C hysteresis, (3) UVLO with 2.5 V/2.7 V thresholds, (4) short-circuit detection below 0.5 V output triggering auto-restart, and (5) 0.1 μA shutdown current. These ensure robust operation in real-world conditions without external supervision circuits - a critical advantage for MC34726BFCR2 in unattended battery-powered systems.
Is the MC34726BFCR2 compatible with lead-free reflow processes?
Yes, the MC34726BFCR2 carries the FC suffix, indicating Pb-free packaging compliant with JEDEC J-STD-020C reflow standards. Its 2×2 mm UDFN-8 package supports peak reflow temperatures up to 260°C for 10 seconds and is rated for Moisture Sensitivity Level 3 (MSL3), requiring bake-out only if exposed to ambient >30°C/60% RH for >168 hours - fully compatible with standard SMT assembly lines handling MC34726BFCR2.
MC34726BFCR2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 8-UFDFN
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.7V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Current - Output:
- 300mA
- Frequency - Switching:
- 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -25°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-USON (2x2)
MC34726BFCR2 FAQ
1.How can I place an order for MC34726BFCR2 through Aetrix?
Please submit a Request for Quotation (RFQ) for MC34726BFCR2 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 MC34726BFCR2 reliable?
The price and inventory of MC34726BFCR2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC34726BFCR2 is usually 5 days.
3.What payment methods are accepted for MC34726BFCR2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC34726BFCR2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC34726BFCR2?
MC34726BFCR2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC34726BFCR2 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 MC34726BFCR2?
For technical support, including MC34726BFCR2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC34726BFCR2 requirements.
6.How does Aetrix verify that MC34726BFCR2 is sourced from the original manufacturer or authorized distributors?
All MC34726BFCR2 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 MC34726BFCR2 meets industry standards.
7.What is the process for return or replacement of MC34726BFCR2?
All MC34726BFCR2 units undergo pre-shipment inspection (PSI). If there is an issue with MC34726BFCR2, 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 MC34726BFCR2 part is unused and in its original packaging.
Return procedure for MC34726BFCR2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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