onsemi NCP585DSN12T1G

Overview

NCP585DSN12T1G from onsemi is a tri-mode 300 mA CMOS low-dropout (LDO) regulator with enable and ECO pin for mode selection, delivering a fixed 1.2 V output voltage in SOT-23-5 package. It supports CE (chip enable), Fast Transient (FT), and Low Power (LP) modes, features 310 mV dropout at 300 mA (1.2 V output), ±2% output accuracy in FT mode, and 70 dB PSRR at 1 kHz - optimized for portable battery-powered systems requiring stable low-voltage rail generation.

For engineers reviewing the NCP585DSN12T1G datasheet, pinout, applications, or equivalent options, this page provides verified technical context, mode-specific quiescent current values (60 µA FT mode, 3.5 µA LP mode), dropout behavior across temperature, load regulation (15 mV FT mode), and real-world transient response data for handheld instrumentation and camera power design.

Technical Context

The NCP585DSN12T1G implements a CMOS-based LDO architecture with three configurable operating modes controlled via the ECO pin: CE mode (standard enable), FT mode (VECO = Vin, prioritizing transient response), and LP mode (VECO = GND, minimizing I_q). Its internal reference and error amplifier maintain tight output regulation under varying line (0.01%/V FT mode) and load (15 mV, 1–300 mA) conditions.

It integrates fold-back current limiting, auto-discharge capability (active-high variant with discharge path), and operates across −40°C to +85°C ambient. Input voltage range is 1.4 V to 6.0 V, supporting single-cell Li-ion, multi-cell alkaline, or regulated intermediate rails - with shutdown current limited to 0.1 µA when CE is inactive.

Key Specifications

Pinout & Package

SOT-23-5 package (Case 1212), surface-mount, Pb-free, with 1.0 mm pitch and exposed pad not present. Pin 2 is NC (no connect); pin 3 is Vout; pin 4 is ECO (mode control); pin 5 is GND; pin 6 does not exist - this is a 5-pin device.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1804T-1202I/OT and XC6209B122MR-G, the NCP585DSN12T1G uniquely delivers 300 mA drive with selectable transient performance (FT) or ultra-low I_q (LP) via a single external pin - enabling adaptive power management unattainable with fixed-mode alternatives.

Availability

NCP585DSN12T1G is available at Aetrix Electronics and suitable for portable medical sensors, handheld test meters, and digital camcorders requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for NCP585DSN12T1G 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 sensing solutions for automotive, industrial, and portable electronics.

The NCP585 series belongs to onsemi's precision LDO portfolio, designed specifically for battery-constrained portable equipment demanding high accuracy, low dropout, and intelligent power-state control - not general-purpose regulation.

FAQ

What is the maximum input voltage rating for the NCP585DSN12T1G?

The NCP585DSN12T1G has an absolute maximum input voltage (Vin) rating of 6.5 V. The recommended operating input voltage range is 1.4 V to 6.0 V. Exceeding 6.5 V may cause permanent damage. For reliable operation with a 1.2 V output, minimum input is 1.51 V (accounting for 310 mV typical dropout), making it compatible with single-cell Li-ion (2.7–4.2 V) and two-cell alkaline (2.0–3.2 V) sources. Always include input capacitance per datasheet guidelines.

How does the ECO pin affect the NCP585DSN12T1G's quiescent current and performance?

The ECO pin configures the NCP585DSN12T1G's operating mode: tying ECO to Vin activates Fast Transient (FT) mode (60 µA I_q for 1.2 V output), while grounding ECO enables Low Power (LP) mode (3.5 µA I_q). FT mode improves load regulation (15 mV) and PSRR; LP mode degrades regulation (40 mV load, 0.05%/V line) but maximizes battery life. The NCP585DSN12T1G must never float ECO - it must be actively driven high or low.

Does the NCP585DSN12T1G support active discharge of the output capacitor?

Yes, the NCP585DSN12T1G (active-high variant, as indicated by "DSN" suffix) includes an internal NMOS discharge switch that activates when the CE pin is driven low. This discharges the output capacitor through a ~60 Ω path, collapsing Vout rapidly to prevent back-powering downstream circuitry or violating reset timing requirements. Discharge is automatic and requires no external components - a key differentiator from basic CE-only LDOs like the XC6209B122MR-G.

What are the recommended input and output capacitors for stable operation of the NCP585DSN12T1G?

The NCP585DSN12T1G requires a 1.0 µF ceramic capacitor between Vin and GND, placed as close as possible to pins 1 and 5. For output, a 1.0 µF ceramic capacitor with low ESR is recommended at Vout (pin 3), also placed adjacent to the device. Larger values (e.g., 2.2 µF) improve transient response but do not compromise stability. Tantalum capacitors are acceptable but require careful ESR selection per Figure 32–35 in the datasheet to avoid oscillation in FT mode.

Is the NCP585DSN12T1G pin-compatible with other devices in the NCP585 family?

The NCP585DSN12T1G uses the SOT-23-5 package and shares identical pinout (Vin, NC, Vout, ECO, GND) with all other "DSN" and "HSN" variants in the NCP585 family, including NCP585DSN09T1G and NCP585HSN12T1G. However, voltage variants differ in output setting and marking; mode behavior (FT/LP thresholds) is consistent across the family. No PCB redesign is needed when substituting same-package NCP585 variants - only firmware or ECO routing may require review for optimal mode selection.