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onsemi NCP4681DMX35TCG
- Part No.:
- NCP4681DMX35TCG
- Manufacturer:
- onsemi
- Package:
- 4-XFDFN Exposed Pad
- Datasheet:
-
NCP4681DMX35TCG.pdf
- Description:
- IC REG LINEAR 3.5V 150MA 4XDFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,989
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Product details
Overview
NCP4681DMX35TCG from onsemi is a 150 mA ultra-low-quiescent-current CMOS linear voltage regulator with fixed 3.5 V output, 0.25 V dropout at 150 mA, ±1.0% output accuracy, and integrated auto-discharge functionality. It operates from 1.40 V to 5.25 V input and delivers stable power to low-power microcontrollers in portable battery-powered equipment.
For engineers reviewing the NCP4681DMX35TCG datasheet, pinout, applications, or equivalent options, key selection criteria include its 1 µA quiescent current, XDFN0808 0.8 × 0.8 mm package, enable-controlled startup/shutdown behavior, and guaranteed stability with ≥0.1 µF ceramic output capacitors.
Technical Context
The NCP4681DMX35TCG implements a CMOS-based LDO architecture with a built-in constant-slope soft-start circuit that prevents output overshoot and limits inrush current during power-up. Its internal N-channel pass transistor enables low dropout and supports fast output discharge via an integrated VOUT-to-GND switch when disabled.
It features fold-back current limiting for short-circuit protection, 25 dB PSRR at 1 kHz (VOUT = 1.5 V), and operates across −40°C to +85°C ambient temperature. The device is specified for use with ceramic output capacitors ≥0.1 µF and requires no external compensation components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.5 V ±1.0% over −40°C to +85°C - ensures precise rail generation for 3.3 V–compatible logic with margin. |
| Dropout Voltage | 0.25 V at IOUT = 150 mA - enables regulation down to VIN = 3.75 V, extending battery runtime in single-cell Li-ion or 3×AA systems. |
| Quiescent Current | 1 µA typical - minimizes standby power loss in always-on sensor nodes or real-time clock backup supplies. |
| Input Voltage Range | 1.40 V to 5.25 V - supports direct connection to LiFePO₄, Li-ion, or regulated 5 V rails without pre-regulation. |
| Output Capacitor | Stable with ≥0.1 µF ceramic - eliminates need for tantalum or electrolytic capacitors, reducing BOM cost and board area. |
| Thermal Resistance | RJA = 350°C/W (XDFN0808) - requires minimal PCB copper pour for thermal management at full load in ambient ≤60°C. |
| Enable Threshold | VCEH = 1.0 V min - compatible with 1.8 V GPIOs and open-drain controllers without level-shifting. |
Pinout & Package
The NCP4681DMX35TCG is housed in a Pb-free XDFN4 0.8 × 0.8 mm package (Case 711AB) with an exposed thermal pad connected to GND. The package has four terminals and is optimized for high-density portable designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VOUT) | Regulated output | Delivers fixed 3.5 V; connects directly to load and output capacitor (≥0.1 µF ceramic). |
| 2 (GND) | Ground reference | Common return path for input/output currents; ties to exposed thermal pad for thermal conduction. |
| 3 (CE) | Chip enable input | Active-high control: ≥1.0 V enables regulation; ≤0.4 V disables output and activates auto-discharge. |
| 4 (VIN) | Input supply | Accepts 1.40–5.25 V; requires local 0.1 µF ceramic decoupling placed adjacent to this pin. |
Key Features
| Feature | Design Value |
|---|---|
| Auto-discharge function | Integrated VOUT-to-GND switch discharges output capacitor rapidly upon disable - prevents residual voltage from powering downstream circuits. |
| Constant-slope soft-start | Internally controlled ramp limits inrush current and eliminates output overshoot - no external timing components required. |
| Fold-back current limit | Reduces output current and voltage under overload or short-circuit - protects IC and source while maintaining safe junction temperature. |
| Pb-free XDFN0808 package | 0.8 × 0.8 mm footprint with 0.48 mm pitch - enables ultra-compact layouts in space-constrained wearables and IoT sensors. |
| Ultra-low IQ operation | 1 µA supply current in active mode - extends shelf life and operational time in coin-cell or energy-harvesting applications. |
Applications
| Wearable Health Sensors | Smart Home Motion Detectors |
|---|---|
Use Scenario: Continuous ECG/PPG monitoring powered by CR2032 coin cell with multi-year battery life requirement. IC Role / Device Role / Timing Role: Primary 3.5 V LDO supplying ultra-low-power MCU, analog front-end, and BLE radio. Use Value: 1 µA quiescent current and auto-discharge prevent parasitic drain during sleep cycles, enabling >3 years of operation. |
Use Scenario: PIR-based occupancy sensor with wake-on-motion and wireless reporting via sub-GHz RF transceiver. IC Role / Device Role / Timing Role: Regulator for 3.3 V logic domain, enabling fast wake-from-sleep (<100 µs) with stable rail recovery. Use Value: Constant-slope soft-start ensures clean power-up without MCU reset glitches during frequent motion-triggered activations. |
| Industrial Wireless Node Transceivers | Portable Diagnostic Handhelds |
Use Scenario: LoRaWAN end-node operating from 2×AA alkaline cells across −25°C to +70°C industrial environments. IC Role / Device Role / Timing Role: Input-stage LDO buffering battery voltage before DC-DC conversion for RF subsystem. Use Value: 0.25 V dropout preserves usable battery range down to 3.75 V, increasing effective capacity by ~18% vs. higher-dropout alternatives. |
Use Scenario: Battery-powered ultrasound probe requiring clean, low-noise 3.5 V supply for analog signal chain and FPGA core. IC Role / Device Role / Timing Role: Low-noise post-regulator stabilizing switched-mode supply output for sensitive ADC drivers. Use Value: 100 µVrms output noise (10 Hz–100 kHz) and 25 dB PSRR suppress switching artifacts from upstream DC-DC converters. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MCP1700T-3502E/MB | 3.5 V fixed, 250 mA, 1.6 µA IQ, SOT-23-3 - no enable pin or auto-discharge. | Lacks CE control and output discharge; suitable only for always-on, non-interruptible loads. | Select when board space allows SOT-23 and system-level discharge is handled externally. |
| Torex XC6219B352MR-G | 3.5 V fixed, 150 mA, 1 µA IQ, SOT-25 - includes CE but no auto-discharge; RDS(on) = 250 mΩ. | Higher dropout (0.35 V @ 150 mA); requires larger output cap for same transient response. | Choose if SOT-25 compatibility is mandatory and discharge is managed by system controller. |
Compared with MCP1700T-3502E/MB and XC6219B352MR-G, the NCP4681DMX35TCG uniquely combines ultra-low IQ, enable control, and integrated auto-discharge in a 0.8 × 0.8 mm XDFN package - critical for compact, battery-gated IoT endpoints where residual voltage must be eliminated between wake cycles.
Availability
NCP4681DMX35TCG is available at Aetrix Electronics and suitable for wearable health sensors, smart home motion detectors, industrial wireless node transceivers, and portable diagnostic handhelds requiring stable component supply with long-term lifecycle assurance.
Supply support for NCP4681DMX35TCG 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The NCP4681DMX35TCG belongs to onsemi's ultra-low-IQ LDO family designed specifically for battery-powered edge devices where micropower operation, small size, and reliable power sequencing are essential.
FAQ
What is the maximum input voltage rating for the NCP4681DMX35TCG?
The absolute maximum input voltage for the NCP4681DMX35TCG is 6.0 V. However, per the datasheet, continuous operation above 5.25 V is limited to ≤500 hours total lifetime. For reliable long-term use, VIN must remain within 1.40 V to 5.25 V under all operating conditions. Exceeding 5.25 V risks accelerated parametric drift or failure.
Does the NCP4681DMX35TCG require an external pull-up resistor on the CE pin?
No, the NCP4681DMX35TCG does not require an external pull-up on the CE pin. It includes an internal pull-down current source (0.3 µA typical). To enable the regulator, drive CE to ≥1.0 V using a GPIO or open-drain driver; to disable it, drive CE to ≤0.4 V or leave it floating (which defaults to disable due to internal pull-down).
How does the auto-discharge function operate in the NCP4681DMX35TCG?
When the CE pin is driven low (≤0.4 V), the NCP4681DMX35TCG disables regulation and activates an internal N-channel transistor between VOUT and GND. This provides a low-impedance discharge path, rapidly collapsing the output voltage - critical for preventing back-powering of downstream circuitry during sleep modes.
Can the NCP4681DMX35TCG be used with a 0.047 µF ceramic output capacitor?
No. The NCP4681DMX35TCG requires a minimum output capacitance of 0.1 µF ceramic (X5R/X7R) for guaranteed stability across all load and temperature conditions. Using 0.047 µF may cause oscillation or poor transient response, especially under dynamic load changes. Always use ≥0.1 µF placed within 2 mm of VOUT and GND pins.
What is the thermal performance of the NCP4681DMX35TCG in its XDFN0808 package?
In the XDFN0808 package, the NCP4681DMX35TCG has a junction-to-air thermal resistance (RJA) of 350°C/W. At 150 mA load and 3.5 V output, power dissipation is ~37.5 mW; this yields a worst-case junction rise of ~13°C above ambient - well within the −40°C to +150°C rating, provided the PCB includes adequate GND copper area under the exposed pad.
NCP4681DMX35TCG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- 4-XFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 5.25V
- Voltage - Output (Min/Fixed):
- 3.5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.35V @ 150mA
- Current - Output:
- 150mA
- Current - Quiescent (Iq):
- 2 µA
- Current - Supply (Max):
- -
- PSRR:
- 25dB (1kHz)
- Control Features:
- Enable
- Protection Features:
- Over Current
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 4-XDFN (0.8x0.8)
NCP4681DMX35TCG FAQ
1.How can I place an order for NCP4681DMX35TCG through Aetrix?
Please submit a Request for Quotation (RFQ) for NCP4681DMX35TCG 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 NCP4681DMX35TCG reliable?
The price and inventory of NCP4681DMX35TCG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NCP4681DMX35TCG is usually 5 days.
3.What payment methods are accepted for NCP4681DMX35TCG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NCP4681DMX35TCG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for NCP4681DMX35TCG?
NCP4681DMX35TCG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your NCP4681DMX35TCG 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 NCP4681DMX35TCG?
For technical support, including NCP4681DMX35TCG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NCP4681DMX35TCG requirements.
6.How does Aetrix verify that NCP4681DMX35TCG is sourced from the original manufacturer or authorized distributors?
All NCP4681DMX35TCG 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 NCP4681DMX35TCG meets industry standards.
7.What is the process for return or replacement of NCP4681DMX35TCG?
All NCP4681DMX35TCG units undergo pre-shipment inspection (PSI). If there is an issue with NCP4681DMX35TCG, 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 NCP4681DMX35TCG part is unused and in its original packaging.
Return procedure for NCP4681DMX35TCG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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