onsemi CAT6219-285TDGT3

Overview

CAT6219-285TDGT3 from onsemi is a fixed-output 2.85 V, 500 mA CMOS low-dropout regulator in TSOT-23-5 package, featuring 300 mV typical dropout at full load, ±1.0% initial output accuracy, and 150 µs turn-on time with external 10 nF bypass capacitor. It delivers stable power to noise-sensitive RF and baseband circuits in portable battery-powered devices.

For engineers reviewing the CAT6219-285TDGT3 datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed 500 mA output under 2.3–5.5 V input, zero shutdown current, thermal/overcurrent protection, and compatibility with small ceramic output capacitors (2.2 µF).

Technical Context

The CAT6219-285TDGT3 employs a CMOS pass transistor architecture enabling ultra-low ground current (55 µA no-load, 85 µA full-load) and fast transient response. Its internal bandgap reference and error amplifier maintain tight regulation across line (±0.1%/V) and load (1.5%) variations.

Under-voltage lockout disables output below 2.15 V typical, while foldback current limiting and thermal shutdown at 160 °C protect against fault conditions. The BYP pin supports optional 10 nF capacitor for PSRR enhancement (64 dB @ 1 kHz) and reduced output noise (45 µV_RMS).

Key Specifications

Pinout & Package

Package: TSOT-23-5 (Case 419AE), 2.9 mm × 1.6 mm × 1.0 mm max height, RoHS-compliant NiPdAu finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP1117ST285T3G and TPS7A20285PDBVR, the CAT6219-285TDGT3 uniquely balances 500 mA delivery, 300 mV dropout, 55 µA quiescent current, and BYP-enabled noise suppression-all in a 2.9 mm × 1.6 mm TSOT-23-5 package-making it the only fit for compact, battery-powered RF systems demanding simultaneous high current and low noise.

Availability

CAT6219-285TDGT3 is available at Aetrix Electronics and suitable for cellular transceivers, wearable sensor hubs, Bluetooth audio SoCs, and IoT edge node MCUs requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for CAT6219-285TDGT3 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 silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The CAT6219 series belongs to onsemi's precision LDO portfolio, engineered specifically for battery-powered portable electronics where low dropout, ultra-low IQ, fast transient response, and noise-sensitive analog power integrity are critical.

FAQ

What is the maximum input voltage rating for CAT6219-285TDGT3?

The CAT6219-285TDGT3 has an absolute maximum input voltage rating of 6.5 V. However, its recommended operating input range is 2.3 V to 5.5 V. Exceeding 5.5 V may cause reliability degradation or immediate failure, and operation above 6.5 V risks permanent damage per the Absolute Maximum Ratings table in the datasheet. Designers must ensure transient spikes remain within this limit using appropriate input filtering.

Does CAT6219-285TDGT3 require an external bypass capacitor to function?

No, the CAT6219-285TDGT3 operates fully functional without an external bypass capacitor on the BYP pin. The 10 nF capacitor is optional and used solely to enhance PSRR (64 dB @ 1 kHz) and reduce output noise (45 µV_RMS). Omitting it does not affect regulation, startup, or basic functionality-only noise performance degrades. The device remains stable and meets all specifications with only the required 1 µF input and 2.2 µF output ceramic capacitors.

Can CAT6219-285TDGT3 be used with ceramic output capacitors smaller than 2.2 µF?

No-onsemi specifies a minimum 2.2 µF ceramic output capacitor (X5R/X7R) for stable operation of the CAT6219-285TDGT3. Using smaller values risks oscillation or poor transient response, as confirmed in the "Stable with Ceramic Output Capacitor" feature and Typical Application Circuit (Figure 1). The 2.2 µF value was validated across temperature and load; reducing it compromises phase margin and may violate the stability guarantee stated in the datasheet.

What is the enable logic polarity and threshold voltage for CAT6219-285TDGT3?

The CAT6219-285TDGT3 uses active-high enable logic: the EN pin must be driven ≥1.6 V (minimum over temperature) to activate regulation. It features an internal 2.5 MΩ pull-down resistor, ensuring automatic disable when left floating. Logic low is defined as ≤0.4 V. This design eliminates external pull-down components and simplifies interface with 1.8 V or 3.3 V GPIOs, provided drive strength exceeds the leakage current into EN.

How does thermal protection behave during sustained 500 mA load in CAT6219-285TDGT3?

Under continuous 500 mA load in the TSOT-23-5 package, the CAT6219-285TDGT3 may trigger thermal shutdown at junction temperatures exceeding 160 °C. With θ_JA = 235 °C/W, even modest ambient temperatures (e.g., 50 °C) can reach trip point without adequate PCB copper area. The device includes 10 °C hysteresis, so it resumes regulation only after cooling to ~150 °C. For sustained 500 mA use, thermal relief via exposed pad grounding and ≥1 in² copper pour is strongly recommended.