LMR33630BDDAR - 3A, 36V Sync Step-Down Converter | Texas Instruments
Teilenummer: LMR33630BDDAR ✓ Aktiv| Menge | Stückpreis | Gesamt |
|---|---|---|
| 1 | $0.98 | $0,98 |
| 10 | $0.85 | $8,50 |
| 100 | $0.68 | $68,00 |
| 500 | $0.58 | $290,00 |
| 1.000 | $0.52 | $520,00 |
| 3.000 | $0.45 | $1.350,00 |
LMR33630BDDAR Übersicht
A buck (step-down) switching regulator is a type of DC-DC converter that uses an internal MOSFET switch, an external inductor, and a capacitor network to efficiently reduce a higher DC input voltage to a lower regulated output voltage. The buck regulator sits in the broader hierarchy of DC-DC converters -> switching regulators -> power management ICs -> semiconductors, and is the dominant topology for point-of-load conversion on industrial, automotive, and consumer boards because it offers 90%+ efficiency across a wide load range.
Key features of the LMR33630BDDAR include 3 A continuous output current from a 36 V maximum input, a 1.4 MHz fixed switching frequency that supports small passive components, integrated synchronous MOSFETs (eliminating the external Schottky diode), a power-good output flag for rail sequencing, and internal compensation that removes the need for an external compensation network. The device also offers internal soft-start, cycle-by-cycle current limit, and thermal shutdown.
Architecturally, the LMR33630 uses TI's peak current-mode control with an internal 1.4 MHz oscillator, internal high-side and low-side MOSFETs (synchronous rectification), and a precision reference for ±1% output accuracy. The high switching frequency keeps the output LC filter small, enabling a complete 3 A solution under 50 mm², while the wide 36 V input tolerance accommodates 12 V and 24 V industrial buses with transient margin.
Typical applications include industrial PLC I/O and sensor rails, factory automation 24 V bus conversion, building automation, battery-powered portable equipment, and automotive infotainment/cold-crank tolerant rails. The wide VIN range makes it ideal for systems that must survive load-dump and jump-start transients on 12 V automotive rails.
When designing with this part, ensure the PowerPAD thermal land is soldered to a sufficient copper pour (at least 100 mm²) to keep junction temperature within limits at 3 A continuous load, and follow the datasheet layout for input capacitor placement to minimize switching-node ringing.
Drop-in-Alternativen für LMR33630BDDAR – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Schnellvergleichstool – Wählen Sie Alternativbauteile für den Direktvergleich:
LMR33630CDDA
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LMR33630ADDAR
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
LMR33630BDDAR
✅ Drop-In✓ Auf Lager
$0.45 / Stück
Datenblatt ansehen →LMR33630BDDAR Grenzwerte & elektrische Eigenschaften
| Topologie | Synchronous Buck (Step-Down) |
| Eingangsspannungsbereich | 3.8 V to 36 V |
| Ausgangsspannungsbereich | 1 V to 28 V (Adjustable) |
| Maximaler Ausgangsstrom | 3 A |
| Schaltfrequenz | 1.4 MHz (typ) |
| Feedback Voltage Reference | 1 V (typical, ±1% accuracy) |
| Betriebstemperaturbereich | -40 °C to +125 °C (junction) |
| Gehäuse | 8-PowerSOIC (DDA), 3.90 mm body width, with PowerPAD |
| Montageart | Surface Mount |
| Control Mode | Current-mode PWM (peak) |
| Power-Good-Ausgang | Yes (open-drain) |
| Internal MOSFETs | Yes (high-side + low-side, synchronous) |
| Sanftanlauf | Internal |
| Thermisches Abschalten | Yes |
| MSL-Level | 2 (per JEDEC J-STD-020, as listed on distributor pages) |
| RoHS-Status | Compliant |
| Lead-Free | Yes |
LMR33630BDDAR Pin-Konfiguration
| Pin 1 | SW — Switch node - connect to output inductor |
| Pin 2 | SW — Switch node (parallel to pin 1 to reduce parasitic inductance) |
| Pin 3 | GND — Analog/signal ground |
| Pin 4 | FB — Feedback - connect to output voltage divider (Vref = 1 V) |
| Pin 5 | EN — Enable input (logic-high to enable, logic-low to shutdown) |
| Pin 6 | PGND — Power ground for internal low-side FET |
| Pin 7 | VIN — Input supply voltage (3.8 V to 36 V) |
| Pin 8 | PGND — Power ground (parallel to pin 6) |
Typische Anwendungen
LMR33630BDDAR ist geeignet für 6 Anwendungs: 24V Industrial PLC I/O Rail, 12V Automotive Infotainment Rail, Building Automation Sensor Power, Battery-Powered Portable Equipment, USB-PD and Type-C Charging Sinks, Factory Automation Motor Control Rails.
24V Industrial PLC I/O Rail
The LMR33630BDDAR is purpose-built for 24V industrial PLC I/O and sensor rails where the input bus must tolerate ±20% tolerance plus transient spikes. With its 3.8V to 36V input range and 3A continuous output, it converts 24V nominal down to 5V or 3.3V logic rails while maintaining >90% efficiency at full load. The integrated synchronous MOSFETs eliminate the external Schottky diode that older asynchronous designs require, simplifying BOM and reducing PCB area. The 1.4 MHz switching frequency keeps the LC filter small - typically 1 µH inductor and 22 µF ceramic output cap - enabling a complete solution under 50 mm². The -40°C to +125°C junction range meets industrial ambient requirements on the factory floor.
Empfohlen
12V Automotive Infotainment Rail
The LMR33630BDDAR's 36V maximum input rating provides critical margin for 12V automotive rails that must survive 40V load-dump transients and cold-crank dips down to 3.8V. It delivers a clean 5V or 3.3V rail to infotainment processors, USB charging ports, and instrument cluster ASICs from the vehicle's 12V battery bus. The internal soft-start, cycle-by-cycle current limit, and thermal shutdown meet AEC-Q100 reliability expectations when paired with the Q1-qualified LMR33630 variant. The open-drain power-good output enables MCU rail-sequencing logic for multi-rail SoC power-up. Wide VIN tolerance reduces the need for upstream TVS protection, lowering BOM cost.
Empfohlen
Building Automation Sensor Power
Building automation systems (HVAC, lighting control, security sensors) often run on 24V AC-DC rails with significant line transient noise. The LMR33630BDDAR's wide 3.8V-36V input window handles rectified 24VAC variations plus peak surge events without sag. It delivers a quiet 3.3V or 5V rail to wireless sensor MCUs and Zigbee radios, with 72 dB+ ripple rejection across the input range. The internal compensation network eliminates external RC components, reducing the BOM to just one inductor, input cap, and output cap - ideal for compact wall-mounted sensor modules. The exposed PowerPAD thermal land provides sufficient cooling at the typical <1A continuous load of sensor nodes.
Empfohlen
Battery-Powered Portable Equipment
The LMR33630BDDAR supports battery-powered portable equipment that uses 2S to 4S Li-ion packs (8.4V-16.8V nominal). Its wide VIN range accommodates the full discharge curve plus fresh-battery peaks, while the 1 µA shutdown current (when EN is pulled low) preserves battery life in storage. The 1.4 MHz switching frequency enables a tiny inductor that fits handheld enclosures. Peak current-mode control provides excellent line and load transient response, which is critical when the radio TX burst suddenly loads the rail. The internal soft-start prevents inrush current from tripping the battery's protection circuit during power-up.
Empfohlen
USB-PD and Type-C Charging Sinks
USB-PD sink applications use the LMR33630BDDAR to step down the 5V/9V/15V/20V PD negotiation voltage to the system's logic rail (3.3V or 5V). Its 36V input margin easily handles 20V PD plus transient overshoot from cable inductance. The 3A output capability supports higher-power downstream subsystems while the 1.4 MHz switching frequency keeps EMI below USB 2.0/3.0 radiated limits when proper layout is observed. The PG (power-good) output can drive a discrete signal back to the PD controller to indicate downstream voltage stability. Synchronous rectification eliminates diode conduction loss, improving efficiency versus legacy diode-rectified designs.
Empfohlen
Factory Automation Motor Control Rails
Stepper motor drivers, BLDC motor controllers, and small servo amplifiers in factory automation systems need isolated, low-noise DC rails for their logic and analog sections. The LMR33630BDDAR provides the secondary-side post-regulation in an isolated bias supply, stepping down 12V or 24V from a flyback or push-pull converter to the 3.3V/5V needed by the DSP/MCU. Its high PSRR rejects the ripple from the upstream isolated converter, delivering clean power to ADCs and gate drivers. The wide operating temperature range matches the harsh factory environment, and the exposed PowerPAD provides the thermal margin needed for continuous duty.
Empfohlen
Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für LMR33630BDDAR – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | LMR33630CDDA | LMR33630ADDAR |
|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-PowerSOIC (DDA) | 8-PowerSOIC (DDA) - same | 8-PowerSOIC (DDA) - same |
| Input Voltage Range | 3.8 V to 36 V | 3.8 V to 36 V | 3.8 V to 36 V |
| Output Current | 3 A | 3 A | 3 A |
| Switching Frequency | 1.4 MHz (BDD) | 2.1 MHz (CDD) | 400 kHz (ADD) |
| Output Voltage Range | 1 V to 28 V | 1 V to 28 V | 1 V to 28 V |
| Power-Good Output | Yes (open-drain) | Yes (open-drain) | Yes (open-drain) |
| Synchronous Rectification | Yes (integrated low-side FET) | Yes | Yes |
Wichtigste Unterscheidungsmerkmale
- Wide 36V maximum input voltage for 24V industrial and 12V automotive rails (vs. TPS62130RGTR)
- 1.4 MHz switching frequency with integrated synchronous FETs (vs. TPS54302DDC)
- Pin-compatible family members at three switching frequencies (vs. TPS54302DDC)
Designhinweise
Estimated: at VIN=24V, VOUT=5V, and 3A continuous load, the LMR33630BDDAR dissipates approximately 4-5W (accounting for ~90% efficiency). Per the TI datasheet layout guidelines, the PowerPAD must be soldered to a copper land of at least 100 mm² (preferably 200 mm²) to achieve the rated θJA of ~40 °C/W. Without this copper area, junction temperature will exceed 125 °C at full load, triggering thermal shutdown. For higher ambient temperatures (>85 °C), consider reducing output current or using the wider LMR33630 family members with different thermal options.
Place the input ceramic bypass capacitor (typically 4.7 µF X7R 50V) as close as possible to the VIN and PGND pins, with the ground return loop minimized to reduce switching-node ringing. The SW node trace should be short and wide, avoiding any adjacent sensitive analog traces (FB, EN) to prevent capacitive coupling. The output inductor should be placed between the SW pin and the output capacitor, with the output capacitor's ground return tied directly to the PGND pin rather than to the analog GND plane.
Do not exceed the absolute maximum VIN of 38V (36V operating). For automotive applications where load-dump can spike above this, add a TVS diode (e.g., SMAJ36A) at the input. The feedback resistor divider should use 1% tolerance resistors with the high-side resistor at most 100 kΩ to minimize FB pin bias current error. When using the EN pin, do not leave it floating - tie it to VIN through a 100 kΩ resistor or drive it directly from a logic output. Finally, do not use an inductor with insufficient saturation current rating - at 3 A continuous load, choose an inductor rated at least 4 A saturation.
The LMR33630BDDAR's input capacitor must handle the RMS ripple current, which is approximately IOUT × √(D × (1-D)) where D = VOUT/VIN. At worst-case (D=0.5), this is about 1.5 A RMS. A single 4.7 µF X7R 50V ceramic typically handles this, but at higher VIN or higher load currents, consider two parallel capacitors. The output capacitor (typically 22 µF X7R 25V) determines the output voltage ripple - calculate as ΔV = ΔI_L / (8 × f_sw × C_out) and ensure it stays below your system's ripple budget.
Compliance-Informationen
RoHS and REACH compliant per DigiKey/Mouser product pages. LMR33630BDDAR is NOT AEC-Q100 qualified - choose the LMR33630AQRNXTQ1 (Q1 suffix) for automotive applications requiring AEC-Q100. Halogen-free status not explicitly stated in provided data.
