MC33063ADG4 - 1.5A Buck/Boost/Inverting Switching Regulator | TI
MPN: MC33063ADG4 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.85 | $0.85 |
| 10 | $0.72 | $7.20 |
| 100 | $0.55 | $55.00 |
| 500 | $0.42 | $210.00 |
| 1,000 | $0.35 | $350.00 |
| 3,000 | $0.31 | $930.00 |
MC33063ADG4 Overview
A switching regulator is a power-conversion IC that uses an energy-storage element (inductor or transformer) and a switching transistor to transfer energy from input to output at high efficiency, unlike a linear regulator which dissipates the VIN-VOUT differential as heat. The MC33063 family belongs to the SMPS (Switched-Mode Power Supply) controller hierarchy: switching regulator -> DC-DC converter -> power management IC. Within that hierarchy, the MC33063 occupies the 'all-in-one controller + internal switch' tier that lets engineers build a complete converter with a handful of external passive components and one Schottky rectifier.
Key features include a 2% internal reference, 100 kHz maximum oscillator frequency, short-circuit protection via the current-sense comparator, and a guaranteed 1.5 A output switch. The exposed thermal pad (DAP) on the SOIC-8 package lowers thermal resistance versus a standard SOIC-8, allowing continuous operation near the 1.5 A switch limit at moderate ambient temperatures. The same silicon die is offered across the MC33063 (industrial -40C to +85C), MC34063 (commercial 0C to +70C), and MC33063A (extended voltage tolerance) families, giving designers direct drop-in migration paths.
The architecture is built around a current-mode control loop: the internal comparator monitors the output voltage via a resistor divider, the oscillator sets the switching period, and the on-time is modulated to keep VOUT in regulation. The integrated Darlington output switch drops about 1.5 V at full load, so for 5 V outputs from a 12 V rail, efficiency reaches roughly 80 percent. Compared with newer TI WEBENCH-targeted controllers, the MC33063 is a low-cost, well-documented legacy part that remains in service due to its simplicity, broad input range, and second-source availability.
Typical applications include non-isolated point-of-load converters in industrial controls, 24 V to 5 V auxiliary rails in factory automation, negative bias supplies for op-amps and LCDs, battery chargers with current limiting, and distributed 12 V buss regulators in telecom and automotive subsystems. Its 40 V input tolerance also suits automotive load-dump-protected rails.
When designing with this part, select the timing capacitor CT to set the oscillator near 30-50 kHz for typical buck or boost designs; lower frequencies improve efficiency but require larger inductors. Place the catch diode and inductor close to the switch pin to minimize parasitic inductance, and use a low-ESR output capacitor to limit ripple. The current-sense resistor RS determines peak switch current and therefore the converter's load capability.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in a single manufacturer document.
Drop-in alternatives for MC33063ADG4 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MC33063ADG4 (same form factor and footprint) — differing in Internal Reference, Output Voltage Range, Package, Synchronous Rectifier, Topology.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC33063ADR
✅ Drop-In✓ In Stock
$0.17 / Unit
View Datasheet →MC33063ADE4
✅ Drop-In📋 Reference alternative (not in catalog)
MC34063ADG
✅ Drop-In📋 Reference alternative (not in catalog)
MC33063ADR2G
✅ Drop-In📋 Reference alternative (not in catalog)
MC33063ADG
✅ Drop-In📋 Reference alternative (not in catalog)
MC33063AVDR2G
✅ Drop-In📋 Reference alternative (not in catalog)
MC33063ADG4 Maximum Ratings & Electrical Characteristics
| Topology | Buck, Boost, Inverting (Step-Down/Step-Up) |
| Output Type | Adjustable |
| Number of Outputs | 1 |
| Input Voltage Range | 3 V to 40 V |
| Output Voltage Range | 1.25 V to 40 V |
| Output Current (Switch) | 1.5 A peak |
| Switching Frequency (max) | 100 kHz |
| Internal Reference | 1.25 V (2% tolerance) |
| Synchronous Rectifier | No (external diode required) |
| Operating Temperature | -40 C to +85 C |
| Package | 8-SOIC (0.154", 3.90 mm width) |
| Mounting Type | Surface Mount |
| Current Limit | Yes (programmable via sense resistor) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
MC33063ADG4 Pin Configuration
| Pin 1 | Switch Collector — Darlington switch collector; connects to VIN (buck) or inductor (boost/inverting) |
| Pin 2 | Switch Emitter — Darlington switch emitter; source of switching current |
| Pin 3 | Timing Capacitor (CT) — Sets oscillator frequency; CT to VCC via internal current source |
| Pin 4 | GND — Ground reference |
| Pin 5 | Comparator Inverting Input (Cmp) — Feedback input; connect to VOUT resistor divider |
| Pin 6 | VCC — Supply voltage (3 V to 40 V) |
| Pin 7 | IPK (Current Sense) — Current-limit sense input; Rsense to Switch Emitter |
| Pin 8 | Driver Collector — Driver stage collector; typically tied to VCC |
Typical Applications
MC33063ADG4 is suitable for 6 applications: 24V to 5V Industrial Buck Converter, Negative Voltage Bias Supply (Inverting Topology), Step-Up (Boost) Converter for Battery-Powered Devices, Automotive 12V Auxiliary Power Rail, Battery Charger with Current Limiting, Distributed 12V/24V Bus Point-of-Load Regulator.
24V to 5V Industrial Buck Converter
The MC33063ADG4 is widely used as a 24 V to 5 V buck converter in industrial control and PLC systems. Its 40 V absolute-maximum input comfortably covers 24 V industrial bus rails with surge margin, and the 1.5 A peak switch supports continuous load currents of 500-800 mA depending on thermal design. The exposed-pad SOIC-8 package dissipates the VIN-VOUT x Iout losses efficiently when soldered to a copper pour. In this topology, the switch is in series with the inductor, the catch diode returns to GND, and the output capacitor filters the switching ripple - typically 100 uF low-ESR aluminum or ceramic. Designers select the timing capacitor CT to set fOSC near 40 kHz, balancing efficiency and inductor size. According to the TI MC33063 datasheet, this configuration achieves roughly 80 percent efficiency at 500 mA load.
Recommended
Negative Voltage Bias Supply (Inverting Topology)
The MC33063ADG4's voltage-inverting topology produces a negative output from a positive input, commonly used to generate -5 V, -12 V, or -15 V rails for op-amp dual supplies, LCD contrast bias, and analog sensor interfaces. In this configuration, the inductor and diode are oriented so the output sits below ground, and the internal switch charges the inductor during on-time then discharges through the diode to the load. A 12 V to -12 V implementation delivers up to 200 mA continuously per TI's datasheet example. The -40 C to +85 C industrial temperature range supports outdoor and factory-ambient installations. Compared with a charge-pump inverter, the MC33063ADG4 offers higher current capability at the cost of one extra inductor and Schottky diode.
Recommended
Step-Up (Boost) Converter for Battery-Powered Devices
The MC33063ADG4 supports boost topology for stepping up battery or 5 V rails to higher voltages such as 12 V or 15 V needed by op-amps, RS-232 transceivers, or gate drivers. With VIN as low as 3 V the IC still operates, enabling single-cell Li-ion to 5 V or 12 V conversion. Peak switch current of 1.5 A allows 100-200 mA continuous at 12 V output. The internal 1.25 V reference and comparator form a closed feedback loop through a resistor divider; duty cycle is automatically adjusted to maintain regulation. According to TI's MC33063 datasheet boost-converter section, fOSC near 30 kHz with a 100 uH inductor is a common starting point. The exposed-pad SOIC-8 must be soldered to at least 1 sq cm copper pour to keep junction temperature in spec at full load.
Recommended
Automotive 12V Auxiliary Power Rail
The MC33063ADG4 is specified for -40 C to +85 C operation, which covers automotive cabin and under-hood ambient extremes (with derating). Its 40 V input rating tolerates 12 V load-dump transients up to the abs-max limit, making it suitable for non-safety body-electronics rails - infotainment auxiliary, sensor excitation, lighting drivers, and accessory 5 V conversion. The 8-SOIC footprint and 1.5 A peak switch support distributed point-of-load conversion directly from the vehicle battery bus. For AEC-Q100 qualified automotive designs, the onsemi MC33063AVDR2G (extended voltage tolerance variant in the same SOIC-8 package) provides the same pinout with automotive-grade qualification per the manufacturer's datasheet.
Recommended
Battery Charger with Current Limiting
The MC33063ADG4's programmable current-limit comparator (IPK pin, pin 7) makes it well suited to constant-current battery charger designs. By sizing the sense resistor Rsense to set IPK threshold at the desired charge current, the converter operates in constant-current mode until battery voltage reaches the regulation setpoint, then naturally transitions to constant-voltage mode. This topology is documented in TI's MC33063 datasheet and supports NiCd, NiMH, and small Li-ion packs. The 40 V input accommodates rectified 24 VAC or 36 V industrial supplies. The 8-SOIC package, 1.5 A switch, and 100 kHz oscillator cover most sub-2 A charger designs without adding a separate controller IC.
Recommended
Distributed 12V/24V Bus Point-of-Load Regulator
In telecom, building automation, and industrial-control systems, distributed DC-DC converters step a 24 V or 48 V bus down to local 5 V or 3.3 V loads. The MC33063ADG4's wide 3-40 V input range covers 24 V telecom rails directly, and its 1.5 A switch supports sub-rail power for sensor arrays, fan controllers, and indicator LEDs. Designers benefit from the well-documented reference design library: the TI MC33063 datasheet includes buck, boost, and inverting application circuits with component-selection tables for CT, CT, L, COUT, and Rsense. Second-source availability from onsemi (MC33063ADG/MC33063ADR2G) reduces single-source risk in long-life industrial products. The exposed-pad SOIC-8 enables compact PCB layouts without external heatsinks at outputs under 500 mA.
Recommended
Recommended Products Summary
Engineering reference data for MC33063ADG4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC33063ADR | MC33063ADE4 | MC34063ADG | MC33063ADR2G | MC33063ADG | MC33063AVDR2G |
|---|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | onsemi | onsemi | onsemi |
| Package | 8-SOIC | 8-SOIC (same) | 8-SOIC (same) | 8-SOIC (same) | 8-SOIC (same) | 8-SOIC (same) | 8-SOIC (same) |
| Input Voltage Range | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V |
| Peak Switch Current | 1.5 A | 1.5 A | 1.5 A | 1.5 A | 1.5 A | 1.5 A | 1.5 A |
| Max Oscillator Frequency | 100 kHz | 100 kHz | 100 kHz | 100 kHz | 100 kHz | 100 kHz | 100 kHz |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | 0 C to +70 C | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C (automotive) |
| Automotive Grade | No | No | No | No | No | No | Yes (extended voltage tolerance) |
| Unit Price (qty 1000) | $0.35 | $0.35 (est., same die) | $0.35 (est., same die) | $0.40 (est., lower volume) | $0.42 (est., onsemi) | $0.42 (est., onsemi) | $0.65 (est., automotive) |
Key Differentiators
- Industry-standard 8-SOIC buck/boost/inverting controller with 40 V input (vs MC34063ADG)
- Wide second-source availability from onsemi in same footprint (vs MC33063ADR2G)
- Automotive-grade variant available in same SOIC-8 (vs MC33063AVDR2G)
Design Notes
Estimated: the MC33063ADG4 in 8-SOIC dissipates up to ~1.5 W at full 1.5 A load (VIN=12V, VOUT=5V, VDIODE=0.5V, fOSC=40 kHz, eff~80%). Solder the exposed thermal pad to a copper pour of at least 1 sq cm (preferably 2-3 sq cm connected to GND) to keep theta_JA near 50 C/W. Without the DAP soldered, theta_JA exceeds 100 C/W and the IC will thermal-shutdown above 600 mA continuous load. Place input bypass (1 uF ceramic), output capacitor, catch diode, and inductor within 5 mm of the package to reduce parasitic inductance and EMI.
The MC33063ADG4's internal Darlington switch drops ~1.5 V VCE(sat) at full load. In buck topology with VIN=5V to VOUT=3.3V, the headroom is only 1.7V, leaving virtually no margin - choose a non-saturated switching controller for low-dropout 5V-to-3.3V conversion. For buck VIN>=8V, the ~1.5V drop is acceptable. The IPK current-sense resistor sets peak switch current: IPK = 330 mV / Rsense per the datasheet, so Rsense = 0.33V / I_desired_switch. Select a 1% or better resistor for predictable current limit.
Common MC33063ADG4 design pitfalls: (1) Forgetting the Timing Capacitor CT on pin 3 - without it the oscillator does not run and VOUT collapses. (2) Choosing an inductor with insufficient saturation current - peak switch current reaches 1.5A in burst mode and saturates an underspec'd core, causing efficiency loss and audible noise. (3) Using a slow-recovery rectifier instead of a Schottky diode - efficiency drops 5-10% and switch-node ringing increases EMI. (4) Driving the IPK pin directly to ground or VIN - the comparator expects a low-impedance Rsense; floating IPK disables current limit.
Compliance Information
Per TI product page, the MC33063ADG4 is RoHS-compliant and lead-free. Standard part is NOT AEC-Q100 qualified - choose onsemi MC33063AVDR2G for AEC-grade automotive applications.
