onsemi NCP1599MNTWG

Overview

NCP1599MNTWG from onsemi is a synchronous buck regulator IC integrating high-side P-channel (140 mΩ) and low-side N-channel (90 mΩ) MOSFETs, operating at fixed 1 MHz switching frequency with 3 A output current capability and adjustable output voltage down to 0.8 V. It delivers stable DC/DC conversion for DSP power, USB devices, and LCD TV main rail supplies.

For engineers reviewing the NCP1599MNTWG datasheet, pinout, applications, or equivalent options, this page provides verified technical context, validated pin functions, confirmed thermal and protection behavior, and real-world design constraints including soft-start timing, hiccup-mode short-circuit response, and pre-biased startup support.

Technical Context

The NCP1599MNTWG employs internally compensated current-mode control with a transconductance error amplifier (1000 µA/V gain), enabling fast transient response and stable loop behavior without external compensation complexity. Its adaptive dead-time gate driver minimizes shoot-through risk while reducing body-diode conduction loss in the integrated MOSFET pair.

It features cycle-by-cycle current limiting (4.18 A typical), hiccup-mode short-circuit protection with 2 ms timer, thermal shutdown at 170 °C with 40 °C hysteresis, and internal soft-start ramping over 1 ms. The device supports start-up with pre-biased output loads and enters power-saving mode during light-load operation to maintain efficiency.

Key Specifications

Pinout & Package

Package: DFN6 (Case 506AH), 2 mm × 2 mm, 0.5 mm pitch, thermally enhanced with exposed pad soldered to PCB ground plane for optimal thermal performance (R_θJA = 68.5 °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 TPS54332DDAR, the NCP1599MNTWG offers integrated MOSFETs in a compact DFN6 package with guaranteed pre-bias startup and hiccup-mode protection - making it optimal for cost-sensitive, space-limited applications where reliability under abnormal startup conditions is critical.

Availability

NCP1599MNTWG is available at Aetrix Electronics and suitable for DSP power supplies, USB peripheral regulators, and LCD TV auxiliary rails requiring stable component supply, long-term lifecycle support, and Pb-free compliance.

Supply support for NCP1599MNTWG 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 supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The NCP1599MNTWG belongs to onsemi's high-efficiency DC/DC converter product line, designed specifically for space-constrained, mid-power applications demanding integrated power stages, robust protection, and simplified design-in.

FAQ

What is the maximum output capacitance supported by NCP1599MNTWG during startup?

The NCP1599MNTWG supports a maximum output capacitance of 546 µF for a 3.3 V/2.0 A output with 20% ripple, calculated using its 1 ms minimum soft-start period and 3.83 A minimum current limit. Exceeding this value may cause startup failure due to excessive inrush current. For other output voltages and loads, use Equation 5 from the datasheet with actual I_LIM(min), I_load(max), and T_SS(min). The NCP1599MNTWG's internal soft-start and current limit enforce this constraint strictly.

Does NCP1599MNTWG support pre-biased output startup, and how does it behave?

Yes, the NCP1599MNTWG supports pre-biased output startup. During startup, it holds the low-side MOSFET off until the internal soft-start ramp reaches the voltage present at the FB pin, preventing reverse current flow into the output capacitor. This behavior is confirmed in the Detailed Description section and enables safe operation when the output is held at partial voltage by standby supplies or residual charge. The NCP1599MNTWG implements this without external components.

What is the recommended compensation network for NCP1599MNTWG with a 3.3 V output?

For a 3.3 V output, the default NCP1599MNTWG compensation uses R_C = 3.65 kΩ and C_C = 3.3 nF (as shown in Figure 2), forming a Type II lag compensator. This achieves ~50 kHz crossover frequency and sufficient phase margin. If output capacitors have significant ESR, add C_C2 to cancel the ESR zero. The NCP1599MNTWG's internal transconductance amplifier (1000 µA/V) and fixed 1 MHz frequency simplify this design versus controllers requiring full Type III networks.

How does hiccup-mode protection work in NCP1599MNTWG during a short circuit?

In hiccup mode, the NCP1599MNTWG disables both MOSFETs, discharges the COMP node, waits 2 ms, then attempts a new soft-start cycle. This repeats until the fault clears. The 2 ms timer and elevated soft-start current limit (4.40 A) prevent false triggering during capacitor charging. Unlike latch-off protection, hiccup mode maintains system uptime - a key advantage in field-deployed networking or consumer devices where manual reset is impractical. The NCP1599MNTWG implements this fully internally.

What thermal derating guidance applies to NCP1599MNTWG in a 2-layer PCB layout?

On a standard 2-layer PCB with 1 oz. copper and minimal thermal vias, the NCP1599MNTWG's junction-to-ambient thermal resistance is 68.5 °C/W. At 85 °C ambient and 3 A load, power dissipation (~1.2 W) raises junction temperature to ~170 °C - near thermal shutdown. Derate output current to ≤2.2 A or add ≥6 thermal vias under the exposed pad to reduce R_θJA. The NCP1599MNTWG's 170 °C shutdown threshold and 40 °C hysteresis provide safe margin but require careful thermal design in enclosed environments.