onsemi NCP1597AMNTWG

Overview

NCP1597AMNTWG from onsemi is a synchronous buck regulator IC integrating high-side P-channel and low-side N-channel MOSFETs, delivering up to 2.0 A output current at fixed 1 MHz switching frequency, with input voltage range 4.0 V–5.5 V and adjustable output down to 0.8 V; it serves as the primary DC-DC power stage in compact, high-efficiency point-of-load applications such as USB power devices and set-top box SoC supplies.

For engineers reviewing the NCP1597AMNTWG datasheet, pinout, applications, or equivalent options, key selection criteria include its integrated 140 mΩ/90 mΩ MOSFET pair, current-mode control architecture for fast transient response, thermal shutdown at 185°C, soft-start ramp time of 1.0 ms, and EN pin logic-level enable/disable functionality with 3 µA shutdown current.

Technical Context

The NCP1597AMNTWG implements current-mode PWM control with a transconductance error amplifier and internal 1 MHz oscillator (±13% tolerance), enabling stable regulation across load and line variations. Its adaptive dead-time gate driver minimizes shoot-through risk while reducing body-diode conduction loss in the integrated MOSFETs.

Protection circuitry includes cycle-by-cycle current limiting (2.7–4.3 A regulation range), hiccup-mode overcurrent response with 2.0 ms timer, undervoltage lockout (3.2–3.8 V threshold with 335 mV hysteresis), and thermal shutdown at 185°C with 30°C hysteresis - all implemented without external components.

Key Specifications

Pinout & Package

Package: DFN6 (3 mm × 3 mm, 0.95 mm pitch, Case 506AH), thermally enhanced with exposed pad soldered to PCB ground plane for junction-to-board thermal resistance of 1.7°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2315GJ-Z and TPS562201DDFR, the NCP1597AMNTWG offers tighter input voltage matching for 5 V systems, superior thermal management via dedicated VCCP and exposed-pad design, and robust hiccup-mode protection - making it preferred for space-constrained, thermally demanding consumer applications.

Availability

NCP1597AMNTWG is available at Aetrix Electronics and suitable for USB power devices, set-top boxes, and networking equipment requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for NCP1597AMNTWG 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, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The NCP1597AMNTWG belongs to onsemi's NCP1597A family of monolithic synchronous buck regulators designed specifically for high-efficiency, low-profile point-of-load conversion in space- and thermal-constrained consumer electronics.

FAQ

What is the absolute maximum input voltage rating for the NCP1597AMNTWG?

The NCP1597AMNTWG has an absolute maximum input voltage rating of 6.5 V on VCCP and VCC pins relative to GND. Exceeding this value may cause permanent damage. The recommended operating input range remains 4.0 V to 5.5 V per datasheet specifications, and operation above 5.5 V voids guaranteed performance parameters including R_DS(on), efficiency, and thermal behavior. Always include input overvoltage protection if upstream rails may exceed 5.5 V transiently.

Does the NCP1597AMNTWG support pre-biased output startup, and how is it implemented?

Yes, the NCP1597AMNTWG supports pre-biased output startup. It achieves this by holding the low-side MOSFET off until the internal soft-start ramp reaches the FB pin voltage, preventing reverse current flow into a pre-charged output capacitor. This behavior is confirmed in the DETAILED DESCRIPTION section of the datasheet and verified in Figure 19–20 waveforms. For reliable operation, ensure the EN pin is asserted only after system sequencing permits safe startup into existing output voltage.

What is the minimum controllable on-time for the NCP1597AMNTWG, and why does it matter?

The NCP1597AMNTWG has a minimum controllable on-time of 50 ns, as specified in the ELECTRICAL CHARACTERISTICS table. This parameter determines the lowest achievable output voltage at maximum input voltage (e.g., 5.5 V → 0.8 V requires ~14.5% duty cycle). At 1 MHz, 50 ns corresponds to 5% duty cycle - enabling stable regulation down to 0.8 V even with input as high as 5.5 V. Designs targeting sub-1 V outputs must respect this limit to avoid pulse-skipping instability or regulation loss.

How does the NCP1597AMNTWG enter and exit power save mode?

The NCP1597AMNTWG automatically enters power save mode during light load conditions (typically below ~200 mA), where it skips switching cycles to reduce quiescent current and maintain high efficiency. Exit occurs seamlessly when load increases - the controller resumes forced PWM operation without interruption or re-initialization. This transition is managed entirely internally; no external signal or configuration is required. Efficiency curves in Figures 10–14 confirm >85% efficiency at 10 mA load due to this feature.

Can the NCP1597AMNTWG be used with ceramic output capacitors, and what ESR considerations apply?

Yes, the NCP1597AMNTWG is fully compatible with ceramic output capacitors, which are explicitly recommended in the APPLICATION INFORMATION section. Because ceramic capacitors have near-zero ESR, the output ripple is dominated by capacitance value rather than ESR. Equation 4 in the datasheet confirms that ESR contribution to ripple is negligible - thus, designers should prioritize low-ESR ceramics (e.g., X5R/X7R 0805 or 1206) with sufficient RMS current rating and capacitance to meet target ripple (e.g., ≥44 µF for 20 mV ripple at 2 A, 1 MHz).