onsemi NCP561SN28T1

Overview

NCP561SN28T1 from onsemi is a fixed 2.8 V, 150 mA CMOS low-dropout linear regulator in TSOP-5 package, featuring 3.0 µA typical quiescent current, 170 mV dropout at full load, and ±2.0% output voltage accuracy - designed for battery-powered handheld instruments requiring ultra-low standby power.

For engineers reviewing the NCP561SN28T1 datasheet, pinout, applications, or equivalent options, key selection criteria include dropout performance at 150 mA, enable-controlled shutdown capability, ceramic capacitor compatibility (≥1.0 µF), and industrial temperature operation from –40°C to +85°C.

Technical Context

The NCP561SN28T1 integrates a PMOS pass transistor with internal voltage reference, error amplifier, thermal shutdown, and current limit protection. Its enable input supports logic-level control (V_TH(H) = 1.3 V, V_TH(L) = 0.2 V) and requires connection to VIN if unused.

It operates with minimal external components: only 1.0 µF input and output ceramic capacitors are required. Dropout voltage is specified at 140 mV (typical) and 230 mV (max) at 150 mA over temperature, with output voltage stability maintained across line (±10–20 mV), load (≤60 mV), and temperature (±100 ppm/°C).

Key Specifications

Pinout & Package

The NCP561SN28T1 is housed in a 3.0 mm × 1.5 mm × 0.95 mm TSOP-5 surface-mount package (Case 483), with exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-2802E/TT and TCS2102-2800V, the NCP561SN28T1 uniquely balances ultra-low I_Q, integrated enable, TSOP-5 compactness, and proven 140 mV dropout - making it optimal for space- and battery-limited handhelds where all three attributes are simultaneously required.

Availability

NCP561SN28T1 is available at Aetrix Electronics and suitable for battery-powered instruments, hand-held test equipment, and camcorder power management requiring stable component supply, long-term lifecycle support, and Pb-free compliance.

Supply support for NCP561SN28T1 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, and sensor solutions for automotive, industrial, and portable electronics.

The NCP561 series belongs to onsemi's low-power linear regulator product line, engineered specifically for ultra-low-quiescent-current operation in battery-critical portable applications - emphasizing extended runtime, small footprint, and ceramic-capacitor compatibility.

FAQ

What is the maximum input voltage rating for the NCP561SN28T1?

The NCP561SN28T1 has an absolute maximum input voltage (VIN) rating of 6.0 V. Exceeding this voltage may cause permanent damage. For reliable operation, the recommended input range is 2.94 V to 6.0 V - ensuring sufficient headroom above the 2.8 V output while staying within safe limits. The device includes internal protection against overvoltage stress on the VIN pin, but sustained operation beyond 6.0 V is not guaranteed.

Does the NCP561SN28T1 require an external resistor network to set the output voltage?

No, the NCP561SN28T1 does not require external resistors. It is a fixed-output regulator with factory-trimmed 2.8 V output voltage, achieved via internal resistor divider and voltage reference. This eliminates component count, layout complexity, and tolerance drift associated with external feedback networks - simplifying design and improving long-term output accuracy to ±2.0% over temperature and load.

Can the NCP561SN28T1 be used with ceramic output capacitors smaller than 1.0 µF?

No - the NCP561SN28T1 requires a minimum 1.0 µF ceramic output capacitor for stability, as confirmed in the datasheet's Applications Information section. Using smaller values risks oscillation or poor transient response. The device is optimized for ceramic capacitors with ESR from a few mΩ up to 3.0 Ω, and larger values (e.g., 2.2–10 µF) further improve noise rejection and load-step performance without compromising stability.

What happens to the output when the Enable pin is left floating on the NCP561SN28T1?

If the Enable pin is left floating on the NCP561SN28T1, the device behavior is undefined and may result in erratic turn-on/turn-off cycling or partial conduction due to noise coupling. The datasheet explicitly states that the Enable pin must be tied to VIN if not actively controlled. Leaving it unconnected violates the recommended operating conditions and can lead to increased ground current, output instability, or premature device failure in noisy environments.

Is the NCP561SN28T1 RoHS-compliant and halogen-free?

Yes, the NCP561SN28T1 is RoHS-compliant and halogen-free. The "G" suffix variant (NCP561SN28T1G) is explicitly designated as Pb-free per JEDEC J-STD-609, and the standard NCP561SN28T1 also meets RoHS Directive 2011/65/EU requirements. Both variants use halogen-free molding compounds and conform to IPC-4101D/126 specifications - verified through onsemi's material declarations and certified test reports.