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onsemi NCP4681HMX35TCG
- Part No.:
- NCP4681HMX35TCG
- Manufacturer:
- onsemi
- Package:
- 4-XFDFN Exposed Pad
- Datasheet:
-
NCP4681HMX35TCG.pdf
- Description:
- IC REG LINEAR 3.5V 150MA 4XDFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,056
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Product details
Overview
NCP4681HMX35TCG from onsemi is a 150 mA ultra-low-quiescent-current CMOS linear voltage regulator with 3.5 V fixed output, 1 µA typical supply current, and enable (CE) functionality for standby mode control. It operates from 1.40 V to 5.25 V input, delivers ±1.0% output accuracy, and features 0.25 V dropout at 150 mA (VOUT = 3.5 V), making it suitable for battery-powered portable electronics requiring stable low-power rail generation.
For engineers reviewing the NCP4681HMX35TCG datasheet, pinout, applications, or equivalent options, this device is selected for its combination of sub-1-µA quiescent current in active mode, integrated soft-start to prevent output overshoot, current fold-back protection, and compatibility with 0.1 µF ceramic output capacitors in space-constrained designs.
Technical Context
The NCP4681HMX35TCG uses a CMOS pass transistor architecture with a built-in constant-slope soft-start circuit that controls output ramp rate independently of load capacitance. Its CE pin enables high-level active logic control, with VCEH = 1.0 V minimum and ICEPD = 0.3 µA pull-down current - critical for minimizing leakage in always-on subsystems.
It integrates current fold-back protection and an internal reference with ±100 ppm/°C temperature coefficient. The regulator remains stable with ≥0.1 µF ceramic output capacitors and achieves 25 dB PSRR at 1 kHz (VOUT = 1.5 V), supporting noise-sensitive analog and RF supply domains.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.5 V ±1.0% over −40°C to +85°C - ensures consistent biasing for 3.3 V–3.6 V logic and analog circuits. |
| Quiescent Current | 1 µA typical (excluding CE pull-down) - enables multi-year battery life in IoT sensors and wearable standby modes. |
| Dropout Voltage | 0.25 V at 150 mA (VOUT = 3.5 V) - supports operation down to 3.75 V input, compatible with single-cell Li-ion under discharge. |
| Input Voltage Range | 1.40 V to 5.25 V - accommodates coin cells, Li-ion, and regulated intermediate rails without external pre-regulation. |
| Line Regulation | 0.02%/V typical - maintains tight output stability across wide input transients common in battery or USB-powered systems. |
| Output Capacitor | Stable with ≥0.1 µF ceramic - eliminates need for tantalum or large electrolytics, reducing board area and cost. |
| Thermal Resistance | RJA = 350 °C/W (XDFN0808) - requires minimal copper pour for thermal management in compact PCB layouts. |
Pinout & Package
Package: XDFN4 0.8 mm × 0.8 mm, 0.48 mm pitch, exposed thermal pad connected to GND. Compact footprint ideal for wearables and ultra-thin modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VOUT) | Regulated output node | Delivers 3.5 V to load; must be decoupled with ≥0.1 µF ceramic capacitor placed adjacent to pin. |
| 2 (GND) | Power ground reference | Primary return path for load and IC bias currents; connects to exposed thermal pad for improved heat dissipation. |
| 3 (CE) | Enable control input | Active-high logic input (VCEH ≥ 1.0 V); pulls down 0.3 µA when low to enter standby mode (<1 µA total IQ). |
| 4 (VIN) | Unregulated input supply | Accepts 1.40–5.25 V; requires local 0.1 µF ceramic decoupling to suppress high-frequency noise and line transients. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low quiescent current | 1 µA typical active-mode supply current - extends battery runtime in always-on sensor nodes and remote controls. |
| Integrated soft-start | Constant-slope output ramp prevents inrush current and overshoot into large output capacitors without external components. |
| Current fold-back protection | Reduces output current and voltage during overload, limiting power dissipation and preventing thermal shutdown during short-circuit events. |
| CE-controlled standby mode | Reduces total supply current to ≤1.0 µA (including CE pull-down), enabling rapid wake-up from deep sleep states. |
| Pb-free XDFN0808 package | 0.8 mm × 0.8 mm footprint with 0.48 mm pitch - supports high-density layout and automated reflow assembly per JEDEC J-STD-020. |
Applications
| Battery-Powered Wearables | IoT Sensor Nodes |
|---|---|
Use Scenario: Powering BLE SoCs and MEMS accelerometers in smart wristbands with coin-cell or rechargeable Li-ion batteries. IC Role / Device Role / Timing Role: Primary 3.5 V LDO supplying core logic and analog front-end; enabled/disabled via host MCU GPIO. Use Value: 1 µA quiescent current preserves >95% of battery capacity during multi-week idle periods between motion-triggered measurements. |
Use Scenario: Regulating supply for ultra-low-power environmental sensors (temperature/humidity) transmitting data every 10 minutes via LoRaWAN. IC Role / Device Role / Timing Role: Standby-mode LDO delivering stable 3.5 V to sensor and transceiver; CE pin synchronized with transmission duty cycle. Use Value: Fold-back current limiting protects against transient faults during antenna coupling events while maintaining system reliability. |
| Portable Medical Monitors | USB-Powered Diagnostic Tools |
Use Scenario: Providing clean 3.5 V rail to analog signal chain (ECG amplifier, ADC) in handheld ECG recorders powered by CR2032. IC Role / Device Role / Timing Role: Low-noise, low-dropout regulator with 100 µVRMS output noise and 25 dB PSRR at 1 kHz. Use Value: Stable output voltage and minimal ripple ensure <1 LSB error in 12-bit medical-grade ADC conversions. |
Use Scenario: Supplying 3.5 V to FPGA configuration logic and interface buffers in field-deployable USB oscilloscopes. IC Role / Device Role / Timing Role: Input-tolerant LDO accepting 4.5–5.25 V USB VBUS with 0.25 V dropout to maintain regulation during cable voltage drop. Use Value: Operates reliably across full USB voltage range without brown-out, eliminating need for upstream buck converter. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-quiescent-current LDO applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MCP1700T-3502E/MB | 250 mA output, 1.6 µA IQ, no CE pin, SOT-23 package | Lacks enable control; higher quiescent current reduces battery life in duty-cycled systems | Select when CE functionality is unnecessary and higher output current margin is required. |
| Torex XC6210B352MR-G | 200 mA output, 1 µA IQ, CE pin, SOT-25 package, 0.35 V dropout at 150 mA | Slightly higher dropout limits usable input range with aging Li-ion cells below 3.8 V | Prefer when board space allows SOT-25 and lower thermal resistance (RJA = 238 °C/W) is needed. |
Compared with MCP1700T-3502E/MB and XC6210B352MR-G, the NCP4681HMX35TCG offers the smallest footprint (0.64 mm²), lowest active-mode IQ, and integrated soft-start - making it optimal for miniaturized, battery-constrained designs where controlled startup and minimal leakage are mandatory.
Availability
NCP4681HMX35TCG is available at Aetrix Electronics and suitable for battery-powered wearables, IoT sensor nodes, portable medical monitors, and USB-powered diagnostic tools requiring stable component supply with long-term lifecycle assurance.
Supply support for NCP4681HMX35TCG 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 specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The NCP4681 series belongs to onsemi's ultra-low-IQ linear regulator product line, designed specifically for extended-battery-life portable electronics where micropower operation and small form factor are critical.
FAQ
What is the maximum input voltage rating for the NCP4681HMX35TCG?
The absolute maximum input voltage for the NCP4681HMX35TCG is 6.0 V. However, the recommended operating maximum is 5.25 V per electrical characteristics. Operation up to 5.50 V is permitted only for cumulative durations ≤500 hours - exceeding this risks reliability degradation and is not advised for continuous-use applications.
Does the NCP4681HMX35TCG require an external capacitor on the CE pin?
No, the NCP4681HMX35TCG does not require an external capacitor on the CE pin. The CE input has internal hysteresis and is designed for direct connection to a digital GPIO. Adding external capacitance may slow enable/disable timing and is unnecessary for noise immunity given the 1.0 V VCEH threshold and 0.4 V VCEL specification.
Can the NCP4681HMX35TCG be used with a 0.01 µF output capacitor?
No - the NCP4681HMX35TCG requires a minimum 0.1 µF ceramic output capacitor for guaranteed stability. Using 0.01 µF violates the stability condition stated in the datasheet and may cause oscillation, especially under load transients. Always use ≥0.1 µF X5R/X7R ceramic with low ESR placed adjacent to VOUT and GND pins.
What is the thermal performance of the NCP4681HMX35TCG in its XDFN0808 package?
The NCP4681HMX35TCG in XDFN0808 has a junction-to-air thermal resistance (RJA) of 350 °C/W. With 150 mA output at 0.25 V dropout (37.5 mW dissipation), junction temperature rise is ~13.1 °C above ambient - well within safe limits. For sustained high-load operation, connecting the exposed thermal pad to a ≥25 mm² internal GND plane further improves thermal performance.
How does the soft-start function behave during repeated enable/disable cycles of the NCP4681HMX35TCG?
The soft-start circuit in the NCP4681HMX35TCG activates on every rising edge of the CE pin. Each enable event initiates a new constant-slope output ramp - independent of prior state or output capacitor voltage. This ensures consistent, overshoot-free startup even during rapid toggling (e.g., burst-mode sensor sampling), with no user-configurable timing or external components required.
NCP4681HMX35TCG 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)
NCP4681HMX35TCG FAQ
1.How can I place an order for NCP4681HMX35TCG through Aetrix?
Please submit a Request for Quotation (RFQ) for NCP4681HMX35TCG 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 NCP4681HMX35TCG reliable?
The price and inventory of NCP4681HMX35TCG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NCP4681HMX35TCG is usually 5 days.
3.What payment methods are accepted for NCP4681HMX35TCG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NCP4681HMX35TCG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for NCP4681HMX35TCG?
NCP4681HMX35TCG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your NCP4681HMX35TCG 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 NCP4681HMX35TCG?
For technical support, including NCP4681HMX35TCG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NCP4681HMX35TCG requirements.
6.How does Aetrix verify that NCP4681HMX35TCG is sourced from the original manufacturer or authorized distributors?
All NCP4681HMX35TCG 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 NCP4681HMX35TCG meets industry standards.
7.What is the process for return or replacement of NCP4681HMX35TCG?
All NCP4681HMX35TCG units undergo pre-shipment inspection (PSI). If there is an issue with NCP4681HMX35TCG, 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 NCP4681HMX35TCG part is unused and in its original packaging.
Return procedure for NCP4681HMX35TCG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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