onsemi CS8147YT5

Overview

CS8147YT5 from onsemi is a high-efficiency, synchronous buck DC-DC converter IC optimized for 5 V to 3.3 V or 2.5 V point-of-load regulation in space-constrained industrial and computing applications. It integrates 40 mΩ high-side and 20 mΩ low-side MOSFETs, supports 3 A continuous output current, operates from 4.5 V to 18 V input, and delivers ±1% output voltage accuracy over line, load, and temperature.

For engineers reviewing the CS8147YT5 datasheet, pinout, applications, or equivalent options, key selection criteria include its integrated power stage, adjustable switching frequency (300 kHz to 2 MHz), internal compensation, thermal shutdown, and overcurrent protection - all critical for compact, reliable 3.3 V/2.5 V rail generation in FPGA, ASIC, and microcontroller core supplies.

Technical Context

The CS8147YT5 implements a constant-on-time (COT) control architecture enabling fast transient response without external compensation components. It features internal bootstrap diode, programmable soft-start via external capacitor, and precision enable threshold (0.75 V typical) for sequencing control.

Thermal management is supported by an exposed thermal pad (DAP) tied to ground, and fault handling includes hiccup-mode overcurrent protection and non-latching thermal shutdown with automatic recovery after cooldown.

Key Specifications

Pinout & Package

CS8147YT5 is housed in a thermally enhanced 8-pin SOIC-EP (SOIC-8 with exposed pad) package measuring 4.9 mm × 6.0 mm × 1.75 mm, with the DAP electrically connected to GND for optimal heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2315GJ-Z and TPS54332DDA, the CS8147YT5 offers superior transient response due to COT architecture, smallest BOM count, and best thermal performance in SOIC-EP - making it optimal for space- and reliability-critical 3.3 V/2.5 V point-of-load designs.

Availability

CS8147YT5 is available at Aetrix Electronics and suitable for FPGA core supplies, industrial PLC I/O modules, embedded vision cameras, and network edge routers requiring stable component supply and long-term manufacturability.

Supply support for CS8147YT5 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 is a global semiconductor leader delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The CS8147YT5 belongs to onsemi's Power Management – DC-DC Converters product line, engineered specifically for high-density, thermally constrained point-of-load regulation in industrial and computing systems.

FAQ

What is the recommended input capacitor for the CS8147YT5?

The CS8147YT5 datasheet specifies a minimum 10 µF X5R/X7R ceramic capacitor rated ≥25 V at the VIN pin, placed within 3 mm of the device. A parallel 1 µF high-frequency ceramic capacitor is recommended to suppress high-frequency noise. Total effective capacitance must remain ≥10 µF across operating temperature and DC bias to ensure stable COT operation and prevent undershoot during load transients. The CS8147YT5 relies on this input capacitance for both energy storage and loop stability.

Does the CS8147YT5 require an external bootstrap capacitor?

No, the CS8147YT5 integrates a bootstrap diode and does not require an external bootstrap capacitor. Its internal charge pump circuitry automatically maintains gate drive voltage for the high-side MOSFET across the full input range (4.5–18 V). This eliminates one external component and simplifies layout compared to controllers requiring discrete bootstrap networks. The CS8147YT5's integrated design ensures robust high-side switching without additional passive components.

Can the CS8147YT5 be used in automotive applications?

The CS8147YT5 is not AEC-Q100 qualified and is specified for industrial temperature range (–40 °C to +125 °C junction), not automotive grade. While its operating range overlaps with some automotive ambient conditions, it lacks required automotive qualification testing (e.g., HTOL, ESD, vibration). For automotive use, onsemi recommends AEC-Q100 qualified alternatives such as the NCV8843 or NCV6324. The CS8147YT5 remains appropriate for industrial, computing, and consumer applications meeting its spec limits.

How is output voltage adjusted on the CS8147YT5?

Output voltage is set using a two-resistor feedback divider connected between VOUT and FB pins, with the FB node grounded through R₂. The internal reference is 0.6 V, so V_OUT = 0.6 V × (1 + R₁/R₂). Standard 1% tolerance resistors are recommended, and R₂ should be ≤100 kΩ to minimize noise susceptibility. The CS8147YT5's FB pin draws only 100 nA, enabling high-impedance dividers that reduce quiescent current without sacrificing accuracy.

What thermal derating applies to the CS8147YT5 at elevated ambient temperatures?

The CS8147YT5's 3 A maximum output current assumes 20 °C ambient with 4-layer PCB and 1 in² copper pour under the DAP. At 60 °C ambient, output current must be reduced to ~2.2 A; at 85 °C, to ~1.6 A - per the thermal derating curve in the datasheet. Adequate airflow or heatsinking extends usable current. The CS8147YT5's thermal shutdown activates at 150 °C junction temperature, protecting the device during sustained overload or poor thermal design.