onsemi NCP571SN09T1G

Overview

NCP571SN09T1G from onsemi is a fixed-output, low-dropout linear voltage regulator delivering 0.9 V at up to 150 mA with ultra-low 4.0 µA typical quiescent current, PMOS pass transistor architecture, and ±3% output voltage accuracy over 25°C - designed for battery-powered handheld instruments requiring stable low-voltage bias under light-load conditions.

For engineers reviewing the NCP571SN09T1G datasheet, pinout, applications, or equivalent options, key selection criteria include dropout voltage (max 750 mV at 10 mA), enable threshold (1.3 V logic-high turn-on), thermal shutdown protection, TSOP-5 package compatibility, and support for 0.1 µF ceramic output capacitors without stability concerns.

Technical Context

The NCP571SN09T1G implements a PMOS-based LDO topology with integrated error amplifier, voltage reference, current limit, and thermal shutdown circuits. It operates across 0.9 V to 12 V input range and maintains regulation down to 0.9 V output with dropout as low as 650 mV (typ) at 10 mA load.

Enable functionality is implemented via a dedicated logic-controlled input (V_TH(EN) = 1.3 V min for turn-on), and the device supports industrial temperature operation from −40°C to +85°C. No internal connection pins (NC) are present on both TSOP-5 and DFN6 variants and must be tied to GND per design guidance.

Key Specifications

Pinout & Package

Package: TSOP-5 (Case 483), 3.00 × 1.50 × 0.95 mm, Pb-free, surface-mount. Exposed pad not present. Thermal resistance R_JA = 250°C/W (1 oz Cu, 100 mm²).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-I_Q LDO applications.

Compared with MCP1700T-0902E/TT and TCS2117-0900Y5R, the NCP571SN09T1G offers balanced performance: higher I_Q than TCS2117 but includes full thermal shutdown, and adds enable control missing in MCP1700 - making it optimal for sequenced, battery-sensitive portable systems requiring robust fault handling.

Availability

NCP571SN09T1G is available at Aetrix Electronics and suitable for battery-powered instrumentation, hand-held test equipment, and wearable health monitors requiring stable component supply, long-lifecycle assurance, and Pb-free compliance.

Supply support for NCP571SN09T1G 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 NCP571 series belongs to onsemi's precision analog LDO portfolio, engineered specifically for ultra-low-power portable electronics where quiescent current, small footprint, and ceramic-capacitor compatibility are primary design constraints.

FAQ

What is the maximum input voltage rating for the NCP571SN09T1G?

The NCP571SN09T1G has an absolute maximum input voltage rating of 12 V, as specified in the Maximum Ratings table. Operation above this voltage risks permanent damage. For reliable long-term use, design input rails to remain ≤12 V under all conditions including transients and ripple - especially important when deriving input from unregulated sources like battery chargers or DC-DC outputs.

Does the NCP571SN09T1G require an external capacitor on the Enable pin?

No, the NCP571SN09T1G does not require an external capacitor on the Enable pin. The Enable input is CMOS-compatible and functions as a digital control signal. If unused, it must be tied directly to V_IN - not left floating - to ensure predictable regulator behavior. Adding capacitance could slow enable/disable transitions and is unnecessary per the datasheet.

Can the NCP571SN09T1G operate with a 0.1 µF ceramic output capacitor?

Yes, the NCP571SN09T1G is explicitly characterized and guaranteed stable with a minimum 0.1 µF ceramic output capacitor, as confirmed in the Applications Information section and Figure 2 schematic. Larger values improve load transient response and noise rejection but are not required for stability - simplifying layout and reducing BOM count compared to older LDOs needing specific ESR ranges.

What is the thermal shutdown threshold of the NCP571SN09T1G?

The NCP571SN09T1G activates thermal shutdown at a junction temperature of +150°C, as stated in the Maximum Ratings table. This protection is internal and non-latching - the device resumes normal operation once junction temperature falls below the hysteresis threshold (~140°C). Board-level thermal design must ensure R_JA ≤ 250°C/W (TSOP-5) to avoid repeated cycling under sustained 150 mA loads.

Is the NCP571SN09T1G pin-compatible with other NCP571 variants in TSOP-5 package?

Yes, all NCP571 variants in TSOP-5 package (e.g., NCP571SN08T1G, NCP571SN10T1G, NCP571SN12T1G) share identical pinout, package dimensions, and thermal characteristics. Only the marked output voltage differs - enabling drop-in replacement across 0.8 V to 1.2 V versions without PCB redesign, provided the new voltage meets downstream circuit requirements.