onsemi MC33163DWR2G

Overview

MC33163DWR2G from onsemi is a monolithic switching regulator IC designed for step-up, step-down, and voltage-inverting DC-DC converter applications. It integrates a 3.4 A output switch, temperature-compensated 2% reference, controlled-duty-cycle oscillator, bootstrap-capable driver, cycle-by-cycle current limiting, and thermal shutdown. It operates from 2.5 V to 40 V input and delivers stable power in automotive and industrial power supplies.

For engineers reviewing the MC33163DWR2G datasheet, pinout, applications, or equivalent options, key selection criteria include its 3.4 A switch current rating, SOIC-16W package with heat-tab thermal design, dual feedback comparators (1.25 V and 1.125 V thresholds), LVI output for microprocessor reset, and bootstrap capability enabling >81% efficiency in step-down configurations.

Technical Context

The MC33163DWR2G implements a fixed on-time, variable off-time voltage-mode ripple control architecture-eliminating need for dominant-pole loop compensation. Its oscillator generates a sawtooth waveform (1.25 V peak / 0.55 V valley) via 225 µA charge / 25 µA discharge currents, yielding 45–55 kHz frequency with ±2% variation over line and temperature.

Two independent high-impedance feedback comparators enable dual-loop control: FB1 (5.05 V nominal reference) supports output regulation, while FB2 (1.25 V internal threshold) and LVI (1.125 V threshold with 15 mV hysteresis) provide low-voltage detection for system reset. Current limiting triggers at 250 mV across R_SC, enforcing cycle-by-cycle protection with <200 ns propagation delay.

Key Specifications

Pinout & Package

The MC33163DWR2G is housed in a thermally enhanced SOIC-16W (Case 751G) surface-mount package with exposed heat-tab pins (Pins 4, 5, 12, 13) soldered to PCB copper for junction-to-air thermal resistance of 94°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC34163DWR2G and LM2577-ADJ, the MC33163DWR2G uniquely supports all three topologies (buck, boost, inverter) with integrated LVI and dual feedback-making it optimal for multi-rail embedded systems requiring thermal robustness and system-level fault management.

Availability

MC33163DWR2G is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor power supplies, consumer set-top box PSUs, and medical portable device chargers requiring stable component supply and long-term manufacturability.

Supply support for MC33163DWR2G 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, and sensing solutions for automotive, industrial, and cloud infrastructure markets.

The MC33163 series belongs to onsemi's legacy monolithic switching regulator product line, engineered for cost-sensitive, thermally demanding DC-DC conversion in automotive and industrial equipment where reliability across extended temperature ranges is critical.

FAQ

What is the maximum output current achievable with the MC33163DWR2G in a step-down configuration?

The MC33163DWR2G integrates a 3.4 A peak switch, enabling up to 3.0 A continuous output in well-heatsinked step-down designs (e.g., Figure 21). Actual current depends on PCB copper area, ambient temperature, and use of bootstrap-efficiency reaches 81.2% at 3.0 A with bootstrap, reducing thermal load. Derating is required above 70°C ambient per the −40°C to +85°C operating range specification.

Does the MC33163DWR2G support voltage-inverting topology, and what external components are required?

Yes, the MC33163DWR2G natively supports voltage-inverting (buck-boost) topology, as demonstrated in Figure 25. Required external components include an inductor (e.g., Coilcraft LO451-A), Schottky diode (e.g., 1N5822), timing capacitor (470 pF), current-sense resistor (0.075 Ω), and feedback resistors (R1 = 953 Ω, R2 = 8.2 kΩ for −12 V output). No additional ICs are needed.

How does the Low Voltage Indicator (LVI) function in the MC33163DWR2G, and can it drive a microprocessor reset directly?

The LVI in the MC33163DWR2G is an open-collector comparator with 1.125 V threshold and 15 mV hysteresis, sinking ≥6 mA. It drives microprocessor reset inputs directly-no external transistor or pull-up is required. When V_FB2 falls below 1.125 V, LVI pulls low; rising above 1.14 V releases reset. This enables reliable brownout protection in automotive and portable systems.

What is the purpose of the Bootstrap Input (Pin 9) on the MC33163DWR2G, and how is it implemented?

The Bootstrap Input (Pin 9) on the MC33163DWR2G sources 2 mA to raise the internal driver bias above V_CC, reducing switch saturation voltage (V_CE(sat)) by up to 40%. It is implemented with a series resistor and capacitor tied between Pin 9 and the switch emitter. An internal zener clamps voltage to V_CC+7.0 V, and the capacitor must limit zener current to <100 mA-critical for achieving >81% efficiency in step-down converters.

Is the MC33163DWR2G pin-compatible with the MC34163DWR2G, and what are the key operational differences?

Yes, the MC33163DWR2G is pin-compatible and functionally identical to the MC34163DWR2G, sharing the same SOIC-16W package and electrical architecture. The sole difference is temperature rating: MC33163DWR2G operates from −40°C to +85°C, while MC34163DWR2G is rated for 0°C to +70°C. Both are Pb-free and share identical datasheet specifications except for ambient temperature limits.