onsemi CAT6217-250TDGT3

Overview

CAT6217-250TDGT3 from onsemi is a 150 mA CMOS low dropout (LDO) regulator with 2.5 V fixed output voltage, 90 mV typical dropout at full load, ±1.0% initial accuracy, and stable operation using only a 1 µF ceramic output capacitor. It features quick-start capability with external 10 nF bypass capacitor for noise reduction, zero shutdown current, and thermal/short-circuit protection - deployed in battery-powered consumer electronics requiring compact, low-noise power regulation.

For engineers reviewing the CAT6217-250TDGT3 datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed 150 mA output under 2.3–5.5 V input, 150 µs turn-on time, 45 µV_RMS output noise, and TSOT-23-5 package compatibility with space-constrained PCB layouts.

Technical Context

The CAT6217-250TDGT3 implements a CMOS-based LDO architecture with internal reference, error amplifier, and pass transistor - optimized for fast transient response during load steps up to 150 mA and line changes across its 2.3–5.5 V input range. Its enable pin includes a built-in 2.5 MΩ pull-down resistor, ensuring default-off behavior when left floating.

Stability is achieved with minimal external components: a single 1 µF ceramic capacitor on VOUT and optional 10 nF on BYP for PSRR enhancement above 1 kHz. The device integrates under-voltage lockout (2.1 V typical), thermal shutdown (160 °C), and 250 Ω output discharge switch in shutdown mode.

Key Specifications

Pinout & Package

The CAT6217-250TDGT3 is housed in a 5-lead TSOT-23 package (Case 419AE), 1 mm maximum height, RoHS-compliant and halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-2502E/TO and XC6206P252MR-G, the CAT6217-250TDGT3 uniquely combines low-noise operation (via BYP), fast 150 µs startup, and integrated enable with pull-down - making it optimal for battery-powered mixed-signal systems demanding both precision and responsiveness.

Availability

CAT6217-250TDGT3 is available at Aetrix Electronics and suitable for wearable health sensors, IoT edge nodes, and portable audio DACs requiring stable component supply, consistent parametric performance, and long-term manufacturability in TSOT-23-5 packaging.

Supply support for CAT6217-250TDGT3 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 CAT6217-250TDGT3 belongs to onsemi's precision LDO regulator product line, engineered specifically for space-constrained, battery-operated devices needing low noise, fast transient response, and ultra-low quiescent current.

FAQ

What is the output voltage tolerance of the CAT6217-250TDGT3 over temperature?

The CAT6217-250TDGT3 provides ±2.0% output voltage accuracy across the full −40 °C to +125 °C junction temperature range. This specification applies because its fixed 2.5 V output is ≥2.0 V, satisfying the datasheet's accuracy condition. The ±1.0% initial accuracy is measured at 25 °C before temperature cycling.

Does the CAT6217-250TDGT3 require an external capacitor on the BYP pin to operate?

No, the CAT6217-250TDGT3 operates fully functional without any capacitor on the BYP pin. The 10 nF bypass capacitor is optional and used solely to reduce output noise and improve PSRR above 1 kHz. Omitting it results in higher broadband noise but maintains regulation, stability, and all other core functions of the CAT6217-250TDGT3.

What is the minimum input voltage required for the CAT6217-250TDGT3 to regulate 2.5 V output at 150 mA?

The CAT6217-250TDGT3 requires a minimum input voltage of 2.59 V to sustain 2.5 V output at 150 mA load, based on its 90 mV typical dropout voltage (2.5 V + 0.09 V). At worst-case 125 mV dropout (per datasheet), VIN must be ≥2.625 V. Input below 2.3 V disables regulation via internal UVLO.

Can the CAT6217-250TDGT3 be used with ceramic capacitors having ESR outside the 5–500 mΩ range?

No - the CAT6217-250TDGT3 is specified and tested for stable operation only with ceramic output capacitors exhibiting 5–500 mΩ equivalent series resistance (ESR). Capacitors outside this range may cause oscillation or degraded transient response. The 1 µF ceramic capacitor must meet this ESR requirement and be placed adjacent to the VOUT and GND pins.

How does the CAT6217-250TDGT3 behave when the EN pin is left unconnected?

When the EN pin is left unconnected, the internal 2.5 MΩ pull-down resistor pulls it to GND, placing the CAT6217-250TDGT3 into shutdown mode with <1 µA ground current. This fail-safe behavior prevents unintended power-up and ensures zero output voltage until a valid high logic level (>1.6 V) is applied to EN - a key safety feature for battery-critical systems using the CAT6217-250TDGT3.