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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

onsemi NCP4688DSN25T1G

Name: NCP4688DSN25T1G
Brand: onsemi
SKU: NCP4688DSN25T1G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: NCP4688DSN25T1G

Manufacturer:: onsemi

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: SC-74A, SOT-753

Datasheet:: NCP4688DSN25T1G.pdf

Description:: IC REG LINEAR 2.5V 150MA SOT23-5

Quantity:: RFQ Add To RFQ list

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Product details

Overview

NCP4688DSN25T1G from onsemi is a 2.5 V, 150 mA CMOS low-dropout linear voltage regulator in SOT-23-5 package, featuring ±1% output voltage accuracy, 10 µV_RMS output noise, and 80 dB PSRR at 1 kHz - designed for powering noise-sensitive RF modules and portable communication equipment.

For engineers reviewing the NCP4688DSN25T1G datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage (0.25 V typ. at 150 mA), enable pin functionality (active-high CE), thermal performance (R_JA = 238 °C/W), and auto-discharge capability via internal NMOS.

Technical Context

The NCP4688DSN25T1G integrates a precision bandgap reference, error amplifier, and PMOS pass transistor with current-limit protection and thermal shutdown. Its active-high chip-enable input controls regulation state and activates an internal autodischarge NMOS (R_DS(ON) = 60 Ω) to rapidly discharge the output capacitor during disable.

Designed for low-noise operation, it achieves 10 µV_RMS integrated noise (10 Hz–100 kHz) and maintains high PSRR (80 dB @ 1 kHz, 75 dB @ 10 kHz) across its 2.0–5.25 V input range - critical for analog/RF subsystems where supply ripple directly impacts signal integrity.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 2.5 V ±1% over −40°C to +85°C - ensures stable biasing for ADC references and RF ICs without external feedback.
Max Output Current	150 mA continuous - supports moderate-power microcontrollers, sensors, and transceivers in space-constrained designs.
Dropout Voltage	0.25 V typical at 150 mA - enables operation from 2.75 V input while maintaining regulation, ideal for single-cell Li-ion or 3.3 V rail derivation.
Output Noise	10 µV_RMS (10 Hz–100 kHz) - minimizes phase noise in local oscillators and jitter in clocked data converters.
PSRR	80 dB at 1 kHz, 75 dB at 10 kHz - suppresses switching noise from upstream DC-DC converters feeding the LDO input.
Quiescent Current	75–100 µA - preserves battery life in always-on sensor nodes and standby circuits.
Enable Threshold	V_CEH = 1.0 V min, V_CEL = 0.4 V max - compatible with 1.8 V and 3.3 V logic-level control signals without level-shifting.

Pinout & Package

SOT-23-5 package (Case 1212), 2.9 × 2.8 × 1.15 mm body size with exposed pad (EP) - optimized for thermal dissipation in compact PCB layouts and compatible with standard pick-and-place assembly.

Pin/Terminal	Circuit Role	Design Meaning
1 - VIN	Input supply connection	Accepts 2.0–5.25 V input; requires 1.0 µF ceramic decoupling capacitor placed adjacent to pin for stability and transient response.
2 - GND	Ground reference	Common return path for input/output currents; must be connected to low-impedance ground plane to minimize noise coupling.
3 - CE	Chip enable input	Active-high logic control (V_IN-referenced); internal pull-down ensures safe default-off state if left floating.
4 - NC	No connect	Not internally bonded; must remain unconnected per datasheet - no routing or soldering allowed.
5 - VOUT	Regulated output	Delivers 2.5 V ±1% to load; requires 1.0 µF ceramic output capacitor near pin to maintain loop stability and reduce load-transient overshoot.
EP - Exposed Pad	Thermal and electrical ground	May be left floating or connected to GND plane; improves thermal resistance by up to 30% when soldered to copper area.

Key Features

Feature	Design Value
Low-noise regulation	10 µV_RMS output noise enables clean power for RF front-ends and precision analog circuitry without additional filtering.
Auto-discharge function	Integrated NMOS (60 Ω) discharges output capacitor during disable - prevents residual voltage hold-up in power sequencing-critical systems.
High PSRR across frequency	80 dB @ 1 kHz and 75 dB @ 10 kHz suppresses noise from noisy switchers, reducing need for multi-stage filtering.
Precision output accuracy	±1% over temperature and line/load ensures reliable operation of voltage-sensitive peripherals like ADCs and PLLs.
Ultra-low quiescent current	75 µA typical in active mode extends battery runtime in IoT edge nodes and wearable devices.

Applications

RF Module Power Supply	Portable Audio Codec Biasing
Use Scenario: Powers low-noise LNAs and mixers in Bluetooth/Wi-Fi modules where supply ripple directly degrades EVM and receiver sensitivity. IC Role / Device Role / Timing Role: Primary low-noise LDO delivering regulated 2.5 V to RF signal chain components. Use Value: 10 µV_RMS noise and 80 dB PSRR prevent baseband interference and preserve RF dynamic range.	Use Scenario: Supplies clean bias voltage to stereo audio codecs in cordless phones and smart speakers operating from single Li-ion cells. IC Role / Device Role / Timing Role: Fixed-output LDO providing stable 2.5 V reference for DAC/ADC sections and headphone amplifiers. Use Value: ±1% accuracy and low dropout ensure consistent audio fidelity across battery discharge curve.
Industrial Sensor Node Core Rail	Automotive Infotainment Display Interface
Use Scenario: Generates 2.5 V core supply for ultra-low-power microcontrollers and MEMS sensors in predictive maintenance gateways. IC Role / Device Role / Timing Role: Always-on LDO with 75 µA IQ supporting wake-on-event operation and rapid system startup. Use Value: Low quiescent current extends 10-year battery life; CE pin enables synchronized power gating with host MCU.	Use Scenario: Powers LVDS timing controllers and display driver ICs in automotive LCD instrument clusters requiring stable, low-noise rails. IC Role / Device Role / Timing Role: Secondary LDO deriving 2.5 V from 5 V domain for display interface logic and gamma correction circuitry. Use Value: High PSRR rejects noise from display backlight drivers; auto-discharge prevents ghosting during power-down transitions.

RF Module Power Supply

Portable Audio Codec Biasing

Use Scenario: Powers low-noise LNAs and mixers in Bluetooth/Wi-Fi modules where supply ripple directly degrades EVM and receiver sensitivity.

IC Role / Device Role / Timing Role: Primary low-noise LDO delivering regulated 2.5 V to RF signal chain components.

Use Value: 10 µV_RMS noise and 80 dB PSRR prevent baseband interference and preserve RF dynamic range.

Use Scenario: Supplies clean bias voltage to stereo audio codecs in cordless phones and smart speakers operating from single Li-ion cells.

IC Role / Device Role / Timing Role: Fixed-output LDO providing stable 2.5 V reference for DAC/ADC sections and headphone amplifiers.

Use Value: ±1% accuracy and low dropout ensure consistent audio fidelity across battery discharge curve.

Industrial Sensor Node Core Rail

Automotive Infotainment Display Interface

Use Scenario: Generates 2.5 V core supply for ultra-low-power microcontrollers and MEMS sensors in predictive maintenance gateways.

IC Role / Device Role / Timing Role: Always-on LDO with 75 µA IQ supporting wake-on-event operation and rapid system startup.

Use Value: Low quiescent current extends 10-year battery life; CE pin enables synchronized power gating with host MCU.

Use Scenario: Powers LVDS timing controllers and display driver ICs in automotive LCD instrument clusters requiring stable, low-noise rails.

IC Role / Device Role / Timing Role: Secondary LDO deriving 2.5 V from 5 V domain for display interface logic and gamma correction circuitry.

Use Value: High PSRR rejects noise from display backlight drivers; auto-discharge prevents ghosting during power-down transitions.

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MCP1700T-2502E/TT	250 mA output, 6 µV_RMS noise, no auto-discharge, SOT-23-5	Lacks active discharge; better noise but lower current headroom	Select when ultra-low noise (<6 µV_RMS) is prioritized over fast turn-off discharge.
TLC7605CDR	250 mA output, 40 µV_RMS noise, no CE pin, SOIC-8	Higher noise, no enable control, larger footprint	Choose only if board layout permits SOIC-8 and enable functionality is unnecessary.

Compared with MCP1700T-2502E/TT and TLC7605CDR, the NCP4688DSN25T1G uniquely combines 150 mA capability, 10 µV_RMS noise, active-high CE, and integrated auto-discharge in SOT-23-5 - making it optimal for RF and portable systems requiring fast, controlled power sequencing and minimal board area.

Availability

NCP4688DSN25T1G is available at Aetrix Electronics and suitable for RF modules, portable audio systems, and industrial sensor nodes requiring stable component supply, long-term lifecycle support, and Pb-free compliance.

Supply support for NCP4688DSN25T1G 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, and cloud infrastructure markets.

The NCP4688DSN25T1G belongs to onsemi's NCP4688 family of low-noise, auto-discharge LDOs - engineered specifically for noise-sensitive applications in portable communications, RF modules, and battery-powered instrumentation.

FAQ

What is the maximum input voltage rating for the NCP4688DSN25T1G?

The NCP4688DSN25T1G has an absolute maximum input voltage rating of 6 V. Operation above 5.25 V is not recommended per datasheet specifications, as exceeding the recommended operating range may impact reliability and output accuracy. The device is designed for 2.0–5.25 V input operation, with optimal PSRR and dropout performance within this window. Always observe derating guidelines for thermal management at higher input-to-output differentials.

Does the NCP4688DSN25T1G require external capacitors, and what values are specified?

Yes, the NCP4688DSN25T1G requires both input and output ceramic decoupling capacitors. The datasheet specifies 1.0 µF for C_IN (between VIN and GND) and 1.0 µF for C_OUT (between VOUT and GND), placed as close as possible to their respective pins. These values ensure stability, adequate line/load transient response, and optimal PSRR. Tantalum capacitors are discouraged due to ESR-related instability risks documented in Figures 42–44 of the datasheet.

How does the auto-discharge feature work in the NCP4688DSN25T1G?

The NCP4688DSN25T1G integrates an NMOS transistor between VOUT and GND that activates automatically when the CE pin is driven low. This provides a 60 Ω discharge path, enabling rapid depletion of the output capacitor charge during shutdown - critical for preventing voltage hold-up in power-sequenced systems. Unlike external discharge circuits, this function requires no additional components and operates independently of load conditions.

Is the NCP4688DSN25T1G pin-compatible with other variants in the NCP4688 family?

Yes, all NCP4688 variants in SOT-23-5 packaging - including NCP4688DSN12T1G, NCP4688DSN15T1G, and NCP4688DSN25T1G - share identical pinout, package dimensions, and thermal characteristics. Only the marked output voltage differs (e.g., L25 marking denotes 2.5 V). This allows drop-in replacement across voltage options without PCB redesign, provided input voltage and load requirements remain within spec.

What is the thermal resistance (R_JA) of the NCP4688DSN25T1G in its SOT-23-5 package?

The NCP4688DSN25T1G in SOT-23-5 package has a junction-to-air thermal resistance (R_JA) of 238 °C/W, as specified in Table 3 of the datasheet. This value assumes standard JEDEC test conditions (single-layer 1 in² copper pad). Actual R_JA can improve significantly with enhanced PCB copper area, multiple thermal vias under the exposed pad, and airflow - enabling continuous 150 mA operation even at +70°C ambient with proper layout.

NCP4688DSN25T1G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: SC-74A, SOT-753

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):: 2.5V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.31V @ 150mA

Current - Output:: 150mA

Current - Quiescent (Iq):: 100 µA

Current - Supply (Max):: -

PSRR:: 80dB ~ 65dB (1kHz ~ 100kHz)

Control Features:: Enable

Protection Features:: Over Current

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-5

NCP4688DSN25T1G FAQ

1.How can I place an order for NCP4688DSN25T1G through Aetrix?

Please submit a Request for Quotation (RFQ) for NCP4688DSN25T1G 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 NCP4688DSN25T1G reliable?

The price and inventory of NCP4688DSN25T1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NCP4688DSN25T1G is usually 5 days.

3.What payment methods are accepted for NCP4688DSN25T1G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NCP4688DSN25T1G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for NCP4688DSN25T1G?

NCP4688DSN25T1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your NCP4688DSN25T1G 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 NCP4688DSN25T1G?

For technical support, including NCP4688DSN25T1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NCP4688DSN25T1G requirements.

6.How does Aetrix verify that NCP4688DSN25T1G is sourced from the original manufacturer or authorized distributors?

All NCP4688DSN25T1G 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 NCP4688DSN25T1G meets industry standards.

7.What is the process for return or replacement of NCP4688DSN25T1G?

All NCP4688DSN25T1G units undergo pre-shipment inspection (PSI). If there is an issue with NCP4688DSN25T1G, 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 NCP4688DSN25T1G part is unused and in its original packaging.

Return procedure for NCP4688DSN25T1G:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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