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

onsemi NCP5661MN12T2G

Name: NCP5661MN12T2G
Brand: onsemi
SKU: NCP5661MN12T2G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: NCP5661MN12T2G

Manufacturer:: onsemi

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

Package:: 6-VDFN Exposed Pad

Datasheet:: NCP5661MN12T2G.pdf

Description:: IC REG LINEAR 1.2V 1A 6DFN

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Product details

Overview

NCP5661MN12T2G from onsemi is a fixed-output, 1.2 V, 1.0 A ultra-low-dropout linear regulator in a thermally robust DFN6 3×3.3 mm package. It features 0.9 V internal reference, 1.0 V typical dropout at 1.0 A, 26 µV_rms output noise without bypass capacitor, and integrated Enable and Error Flag functions-designed for post-regulation in server power supplies and ASIC core rails.

For engineers reviewing the NCP5661MN12T2G datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed 1.2 V ±1% accuracy over −40°C to +125°C, ultra-fast load transient response (1–3 µs settling), low ground current independent of load (≤3.0 mA), and AEC-Q100-compliant NCV variants for automotive use.

Technical Context

The NCP5661MN12T2G implements a high-current LDO architecture with a precision 0.9 V bandgap reference and low-impedance output stage, enabling stable 1.2 V regulation down to 2.0 V input. Its error amplifier drives an NPN pass transistor with current-limit and thermal shutdown protection, while the dedicated Error Flag pin (Pin 6) asserts logic-low when output falls below 88% of nominal voltage.

It operates with minimal external components: only input (≥150 µF OSCON) and output (≥10 µF, ESR <300 mΩ) capacitors are required. The DFN6 package provides 18 °C/W junction-to-lead thermal resistance, supporting continuous 1.0 A operation with appropriate PCB copper area per Figure 18.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 1.2 V ±1% at TJ = 25°C; ±1.5% over −40°C to +125°C - ensures tight core rail tolerance for ASICs and FPGAs.
Max Output Current	1.0 A continuous - supports high-current digital loads without derating under typical thermal conditions.
Dropout Voltage	1.0 V typical at I_OUT = 1.0 A - enables operation from 2.2 V input, critical for multi-rail systems with tight voltage margins.
Ground Current	≤3.0 mA at I_OUT = 1.0 A - remains constant across load, simplifying power budgeting and improving light-load efficiency.
Output Noise	26 µV_rms (10 Hz–100 kHz) - eliminates need for external bypass capacitor, reducing BOM count and board space.
PSRR	≥65 dB at 1 kHz - suppresses switching noise from upstream DC/DC converters in hybrid power architectures.
Error Flag Threshold	88% of V_OUT (1.056 V) - provides early fault detection before system-level brownout, with 50 µs blanking time to ignore transients.
Enable Threshold	V_EN(HI) ≥1.3 V, V_EN(LO) ≤0.3 V - compatible with standard 1.8 V/3.3 V GPIOs for precise sequencing control.

Pinout & Package

Package: DFN6 (3.0 × 3.3 mm, 0.95 mm pitch), exposed thermal pad (Pin 4), RoHS-compliant Pb-free.

Pin/Terminal	Circuit Role	Design Meaning
1	Enable (EN)	Active-high digital control input; tie to VIN for always-on operation or drive with microcontroller GPIO for power sequencing.
2	VIN	Main input supply (2.0–9.0 V); requires ≥150 µF low-ESR input capacitor placed near pin for stability and transient immunity.
3	GND	Power ground reference; must be connected to large copper pour tied to thermal pad (Pin 4) for optimal heat dissipation.
4	Thermal Pad (EPAD)	Internally connected to GND; soldered to PCB thermal plane to achieve R_θJL = 18 °C/W and sustain full 1.0 A load.
5	VOUT	Regulated 1.2 V output; requires ≥10 µF output capacitor with ESR <300 mΩ; place ceramic cap within 3 mm of pin.
6	Error Flag (EF)	Open-drain output asserting logic-low when V_OUT < 1.056 V; requires external 100 kΩ pull-up to VIN for monitoring.

Key Features

Feature	Design Value
Ultra-fast transient response	1–3 µs settling time enables stable operation during sudden 0.1–1.0 A load steps common in CPU/GPU burst modes.
Low-noise operation without bypass cap	26 µV_rms noise floor eliminates need for dedicated 10 nF bypass capacitor, saving board area and cost.
Load-independent ground current	3.0 mA max quiescent current regardless of output load - simplifies standby power estimation and improves light-load efficiency.
Integrated error flag with blanking	50 µs blanking window prevents false triggers during normal load transients while providing reliable undervoltage detection.
Thermally optimized DFN6 package	18 °C/W junction-to-lead resistance with EPAD allows 1.0 A continuous operation using 1 in² 1 oz copper PCB area.
AEC-Q100 qualified variant available	NCV5661MN12T2G meets automotive grade 1 (−40°C to +125°C) and PPAP requirements for infotainment and ADAS power rails.

Applications

Server VRM Post-Regulation	ASIC Core Power Supply
Use Scenario: Secondary regulation stage after a primary 5 V or 12 V DC/DC converter supplying power to high-performance server CPUs and memory controllers. IC Role / Device Role / Timing Role: Low-noise, fast-response LDO delivering clean 1.2 V to sensitive digital cores while rejecting ripple from upstream switching stages. Use Value: 26 µV_rms noise and ≥65 dB PSRR prevent timing jitter and bit errors; 1–3 µs transient response maintains voltage within ±3% during 500 mA/µs load steps.	Use Scenario: Point-of-load regulation for FPGA or ASIC core voltages where tight tolerance and rapid load tracking are mandatory. IC Role / Device Role / Timing Role: Precision 1.2 V reference-stabilized regulator with ±1% accuracy and integrated enable for power-domain sequencing. Use Value: 1.0 V dropout enables use with 2.2 V intermediate bus; ±1% output accuracy over temperature ensures reliable logic operation at maximum frequency.
Networking Equipment Power Rail	Gaming/STB Module Regulation
Use Scenario: Dedicated 1.2 V rail for packet processing ASICs and SerDes PHYs in switches and routers operating in thermally constrained enclosures. IC Role / Device Role / Timing Role: High-current LDO with thermal shutdown and current limit, mounted directly on dense multilayer PCBs with limited airflow. Use Value: DFN6 package with EPAD achieves 1.0 A continuous rating at +85°C ambient; 160°C thermal shutdown prevents catastrophic failure during sustained overload.	Use Scenario: Main SoC core supply in set-top boxes and gaming consoles requiring low standby power and fast wake-up response. IC Role / Device Role / Timing Role: Enable-controlled LDO enabling deep-sleep mode with <300 µA disabled-state current, then instant reactivation. Use Value: 300 µA max disable current extends battery-backed standby time; 1.3 V enable threshold ensures compatibility with 1.8 V I/O domains.

Server VRM Post-Regulation

ASIC Core Power Supply

Use Scenario: Secondary regulation stage after a primary 5 V or 12 V DC/DC converter supplying power to high-performance server CPUs and memory controllers.

IC Role / Device Role / Timing Role: Low-noise, fast-response LDO delivering clean 1.2 V to sensitive digital cores while rejecting ripple from upstream switching stages.

Use Value: 26 µV_rms noise and ≥65 dB PSRR prevent timing jitter and bit errors; 1–3 µs transient response maintains voltage within ±3% during 500 mA/µs load steps.

Use Scenario: Point-of-load regulation for FPGA or ASIC core voltages where tight tolerance and rapid load tracking are mandatory.

IC Role / Device Role / Timing Role: Precision 1.2 V reference-stabilized regulator with ±1% accuracy and integrated enable for power-domain sequencing.

Use Value: 1.0 V dropout enables use with 2.2 V intermediate bus; ±1% output accuracy over temperature ensures reliable logic operation at maximum frequency.

Networking Equipment Power Rail

Gaming/STB Module Regulation

Use Scenario: Dedicated 1.2 V rail for packet processing ASICs and SerDes PHYs in switches and routers operating in thermally constrained enclosures.

IC Role / Device Role / Timing Role: High-current LDO with thermal shutdown and current limit, mounted directly on dense multilayer PCBs with limited airflow.

Use Value: DFN6 package with EPAD achieves 1.0 A continuous rating at +85°C ambient; 160°C thermal shutdown prevents catastrophic failure during sustained overload.

Use Scenario: Main SoC core supply in set-top boxes and gaming consoles requiring low standby power and fast wake-up response.

IC Role / Device Role / Timing Role: Enable-controlled LDO enabling deep-sleep mode with <300 µA disabled-state current, then instant reactivation.

Use Value: 300 µA max disable current extends battery-backed standby time; 1.3 V enable threshold ensures compatibility with 1.8 V I/O domains.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TPS7A4700RGWR	20 V input, 1 A, 4 µV_rms noise, adjustable only, no Error Flag	Higher PSRR (≥70 dB) and lower noise ideal for analog/RF sections; lacks fault reporting for digital rails	Select when ultra-low noise is prioritized over fault monitoring and fixed-voltage simplicity.
MCP1826-1202E/DB	1.2 V fixed, 1 A, 65 µV_rms noise, no Error Flag, SOT-223 package	Larger thermal footprint, higher noise, no fault signaling - suitable for cost-sensitive non-critical rails	Choose for legacy designs with SOT-223 footprints or where Error Flag is not required and noise <50 µV_rms is acceptable.

Compared with TPS7A4700RGWR and MCP1826-1202E/DB, the NCP5661MN12T2G uniquely combines fixed 1.2 V output, integrated Error Flag with blanking, ultra-low 26 µV_rms noise without bypass cap, and thermally efficient DFN6 packaging-making it optimal for high-reliability digital core regulation where fault visibility and compact layout are essential.

Availability

NCP5661MN12T2G is available at Aetrix Electronics and suitable for server VRM post-regulation, ASIC core power supplies, and networking equipment requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant alternatives.

Supply support for NCP5661MN12T2G 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 NCP5661 series was designed specifically for high-current, low-noise, ultra-fast transient response LDO applications in datacenter, networking, and high-performance computing infrastructure-emphasizing thermal robustness, precision regulation, and system-level fault awareness.

FAQ

What is the minimum input voltage required for stable 1.2 V output from the NCP5661MN12T2G?

The NCP5661MN12T2G requires a minimum input voltage of 2.0 V to maintain regulation. With a typical dropout voltage of 1.0 V at 1.0 A, a 2.2 V input is recommended to ensure margin across temperature and load variations. Operation below 2.0 V risks loss of regulation and activation of the Error Flag output.

Does the NCP5661MN12T2G require an external bypass capacitor to achieve its specified 26 µV_rms noise performance?

No, the NCP5661MN12T2G achieves 26 µV_rms output noise (10 Hz–100 kHz) without any external bypass capacitor. This is enabled by its internal low-noise architecture and precision reference design. Adding a bypass capacitor does not improve noise performance and is unnecessary for meeting datasheet specifications.

How is the Error Flag pin on the NCP5661MN12T2G configured and used in a system?

The Error Flag (Pin 6) is an open-drain output that pulls low when V_OUT drops below 88% of nominal (1.056 V). It requires an external 100 kΩ pull-up resistor to VIN. The 50 µs blanking time prevents false triggering during normal load transients. In system monitoring, this signal can feed a microcontroller interrupt or supervisor IC to initiate graceful shutdown or fault logging.

Can the NCP5661MN12T2G be used in automotive applications, and what qualification does it hold?

The NCP5661MN12T2G itself is not AEC-Q100 qualified; however, its automotive-grade counterpart NCV5661MN12T2G is fully AEC-Q100 Grade 1 qualified (−40°C to +125°C) and PPAP capable. For automotive infotainment or ADAS power rails requiring qualification, NCV5661MN12T2G must be selected instead of NCP5661MN12T2G.

What thermal design considerations are critical for sustaining 1.0 A output current with the NCP5661MN12T2G in its DFN6 package?

To sustain 1.0 A continuously, the NCP5661MN12T2G's DFN6 package requires the exposed thermal pad (Pin 4) to be soldered to a ≥1 in² copper area on the PCB using ≥4 thermal vias to inner ground planes. Per datasheet Figure 18, this achieves R_θJA ≈ 82 °C/W and limits junction temperature rise to <80°C at +25°C ambient-ensuring reliable operation within the −40°C to +150°C TJ range.

NCP5661MN12T2G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: 6-VDFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 9V

Voltage - Output (Min/Fixed):: 1.2V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 1.3V @ 1A

Current - Output:: 1A

Current - Quiescent (Iq):: 3 mA

Current - Supply (Max):: -

PSRR:: 70dB ~ 65dB (120Hz ~ 1kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 6-DFN (3x3.3)

NCP5661MN12T2G FAQ

1.How can I place an order for NCP5661MN12T2G through Aetrix?

Please submit a Request for Quotation (RFQ) for NCP5661MN12T2G 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 NCP5661MN12T2G reliable?

The price and inventory of NCP5661MN12T2G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NCP5661MN12T2G is usually 5 days.

3.What payment methods are accepted for NCP5661MN12T2G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NCP5661MN12T2G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for NCP5661MN12T2G?

NCP5661MN12T2G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your NCP5661MN12T2G 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 NCP5661MN12T2G?

For technical support, including NCP5661MN12T2G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NCP5661MN12T2G requirements.

6.How does Aetrix verify that NCP5661MN12T2G is sourced from the original manufacturer or authorized distributors?

All NCP5661MN12T2G 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 NCP5661MN12T2G meets industry standards.

7.What is the process for return or replacement of NCP5661MN12T2G?

All NCP5661MN12T2G units undergo pre-shipment inspection (PSI). If there is an issue with NCP5661MN12T2G, 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 NCP5661MN12T2G part is unused and in its original packaging.

Return procedure for NCP5661MN12T2G:

1.Submit a request within 90 days.

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

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