LT1933HDCB - 600mA, 36V Buck Regulator | Analog Devices
MPN: LT1933HDCB ✓ نشطLT1933HDCB نظرة عامة
A buck converter (step-down switching regulator) is a type of DC-DC converter that uses an internal power switch, an inductor, and a rectifying element to convert a higher DC input voltage to a lower DC output voltage at high efficiency. Buck regulators sit within the broader hierarchy of switched-mode power supplies (SMPS) and power management ICs, and they are preferred over linear regulators whenever the input-to-output voltage differential or load current would otherwise waste significant power as heat. The LT1933 family targets space-constrained applications that still require wide input range and high efficiency.
Key features of the LT1933HDCB include a 36 V maximum input voltage, 600 mA continuous output current capability, 500 kHz fixed switching frequency, internal 750 mA power switch, internal current sensing, and a low shutdown current of less than 2 uA. The exposed-pad DFN package provides low thermal resistance so the device can deliver full output current across the -40 C to +125 C operating junction temperature range without an external heatsink in typical conditions.
The device uses a constant-frequency current-mode architecture with slope compensation, an internal soft-start to limit inrush current, and an exposed thermal pad that acts as the electrical ground. Efficiency typically reaches 80-90 percent at moderate loads, and the high switching frequency allows the use of small ceramic input and output capacitors. The combination of wide VIN range and high switching frequency makes it well suited to battery-powered, industrial, and automotive-supplied loads.
Typical applications include 12 V and 24 V industrial bus power conversion, distributed 5 V and 3.3 V rails for sensors and microcontrollers, battery-powered portable equipment, automotive infotainment and accessory power, and point-of-load regulation after a front-end switching converter. The wide VIN tolerance lets the same design survive cold-crank and load-dump transients on automotive supplies.
When designing with the LT1933HDCB, follow the datasheet's recommended inductor and capacitor values to ensure stability and acceptable output ripple. Place the input capacitor as close as possible to the VIN and GND pins to minimize switching noise, and use sufficient copper area or thermal vias under the exposed pad to keep the junction temperature within the derating curve.
This page synthesizes distributor pricing, drop-in alternative candidates from the same Analog Devices family, and practical design considerations not found in the manufacturer datasheet alone.
بدائل مباشرة لـ LT1933HDCB — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع LT1933HDCB (نفس عامل الشكل والبصمة) — يختلف في Package, Topology.
LT1933IDCB
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←LT1933HS6
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LT1933ES6
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LT1933IS6
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LT1933HDCB#TRMPBF
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LT1933HDCB#TRPBF
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LT1933HDCB الحدود القصوى والخصائص الكهربائية
| البنية الطوبولوجية | Buck (Step-Down) |
| الوظيفة | Current-Mode PWM Step-Down DC/DC Converter |
| Input Voltage Range (Max) | 3.6 V to 36 V |
| Output Voltage (Min/Adj) | 1.245 V (adjustable) |
| أقصى تيار خرج | 600 mA |
| Internal Power Switch Current | 750 mA |
| تردد التبديل | 500 kHz |
| Control Mode | Current Mode PWM |
| العلبة | 6-pin DFN (2 mm x 3 mm) with Exposed Pad |
| نوع التركيب | Surface Mount |
| حالة RoHS | Compliant |
| Lifecycle Stage | Active |
تكوين أطراف LT1933HDCB
| دبوس 1 | SW — Switch node - connect to inductor |
| دبوس 2 | VIN — Input supply voltage (3.6 V to 36 V) |
| دبوس 3 | GND — Ground (also the exposed thermal pad) |
| دبوس 4 | FB — Feedback - voltage divider tap to set VOUT (1.245 V reference) |
| دبوس 5 | SHDN — Shutdown - active-high; tie to VIN for always-on |
| دبوس 6 | Vc — Compensation node - external RC network for loop stability |
التطبيقات النموذجية
LT1933HDCB مناسب لـ 6 التطبيقs: Industrial 24V Bus to 5V Conversion, Automotive Accessory and Infotainment Power, Battery-Powered Portable Equipment, Distributed Point-of-Load Regulation, LED Driver Supply Rail, Sensor and IoT Edge-Node Power.
Industrial 24V Bus to 5V Conversion
The LT1933HDCB's 3.6 V to 36 V input range directly accepts 24 V industrial bus power without a preregulator, and its 600 mA output comfortably drives sensor clusters, PLC I/O, and downstream logic rails. The 500 kHz switching frequency allows small ceramic input and output capacitors (typically 1 uF to 4.7 uF), keeping the 5 V supply's footprint under 50 mm squared. Internal current-mode control provides fast line-transient response when neighboring loads step on the 24 V backplane.
موصى به
Automotive Accessory and Infotainment Power
The LT1933HDCB tolerates the wide 36 V load-dump transient common on 12 V automotive supplies while still regulating cleanly during cold-crank dips down to 6 V. Its 600 mA output is well matched to USB charging ports, infotainment controller rails, and auxiliary LED driver supplies. The exposed-pad DFN-6 package handles continuous 600 mA at ambient temperatures up to 85 C with proper PCB copper area, eliminating the heatsink required by linear regulators.
موصى به
Battery-Powered Portable Equipment
The LT1933HDCB's high-side PNP-like shutdown draws microamp-level quiescent current, making it suitable for battery-powered instruments that spend most of their life in standby. A single Li-ion cell (3.6 V to 4.2 V) or a 4-cell NiMH stack can be stepped down to a regulated 3.3 V or 2.5 V for microcontrollers and sensors. Efficiency typically exceeds 85 percent at 200 mA load, extending runtime by 30-40 percent compared to a 3.3 V linear regulator.
موصى به
Distributed Point-of-Load Regulation
After a front-end isolated or non-isolated bus converter produces an intermediate 12 V or 15 V rail, the LT1933HDCB efficiently steps it down to the local 5 V, 3.3 V, or 1.8 V required by MCUs, FPGAs, and ASICs. Placing the LT1933HDCB close to each load minimizes distribution losses and reduces EMI by avoiding long high-current PCB traces. The 500 kHz frequency is well above the AM broadcast band, simplifying EMI compliance for consumer and industrial enclosures.
موصى به
LED Driver Supply Rail
The LT1933HDCB provides a clean constant-voltage rail that downstream LED driver ICs or constant-current regulator stages can modulate via PWM or analog dimming. Its 500 kHz switching frequency stays above the audible band, eliminating ceramic-capacitor piezoelectric noise and inductor whine in dimming transitions. The wide input range allows the same design to drive LED strings from 12 V architectural, 24 V commercial, or 36 V industrial supplies.
موصى به
Sensor and IoT Edge-Node Power
IoT edge nodes powered by energy harvesting or battery sources often need a regulated 3.3 V or 1.8 V rail for low-power MCUs, radios, and sensors. The LT1933HDCB's high efficiency at light loads (typically above 80 percent even at 10 mA) extends battery life between recharge cycles. The small DFN-6 footprint fits inside sub-1-inch sensor modules, and the exposed pad enables direct PCB mounting without a separate heatsink even at 85 C ambient.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ LT1933HDCB — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | LT1933IDCB | LT1933HS6 | LT1933ES6 | LT1933IS6 | LT1933HDCB#TRMPBF | LT1933HDCB#TRPBF |
|---|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 6-pin DFN (2 mm x 3 mm) with Exposed Pad (DCB) | 6-pin DFN (DCB) - same | 6-pin DFN (DCB) - same | 6-pin DFN (DCB) - same | 6-pin DFN (DCB) - same | 6-pin DFN (DCB) - same | 6-pin DFN (DCB) - same |
| Input Voltage Range | 3.6 V to 36 V | 3.6 V to 36 V | 3.6 V to 36 V | 3.6 V to 36 V | 3.6 V to 36 V | 3.6 V to 36 V | 3.6 V to 36 V |
| Maximum Output Current | 600 mA | 600 mA | 600 mA | 600 mA | 600 mA | 600 mA | 600 mA |
| Switching Frequency | 500 kHz | 500 kHz | 500 kHz | 500 kHz | 500 kHz | 500 kHz | 500 kHz |
| Temperature Grade | High temperature (H grade) | Industrial (I grade) | High temperature (H grade) | Extended (E grade) | Industrial (I grade) | High temperature (H grade) | High temperature (H grade) |
| Packaging Media | Tape & Reel (standard) | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel (MP media) | Tape & Reel (P media) |
| RoHS Compliance | Compliant | Compliant | Compliant | Compliant | Compliant | Compliant | Compliant |
أبرز الفروقات
- Wide 36 V input range in a tiny DFN-6 footprint (مقابلLinear regulators in similar packages)
- High 500 kHz switching frequency enables compact magnetics (مقابلLower-frequency 200-300 kHz buck regulators)
- Full family of temperature grades in identical DCB footprint (مقابلLT1933HDCB vs LT1933IDCB)
ملاحظات التصميم
Estimated: at VIN = 24 V, VOUT = 5 V, and 600 mA load, the LT1933HDCB dissipates roughly (24-5) V * 0.6 A * (1/efficiency - 1) = approximately 1.5 W of loss at 85 percent efficiency. The DFN-6 (DCB) package has a theta_JA near 40 C/W on a 1 oz 4-layer board, producing a junction rise of about 60 C above ambient - well within the 125 C maximum. Add thermal vias under the exposed pad for designs at sustained 600 mA above 70 C ambient.
Place the input ceramic capacitor within 2 mm of the VIN and GND pins to minimize switching-node parasitic inductance. The SW node trace should be kept short and away from sensitive analog traces to avoid capacitive coupling. A ground plane on layer 2 directly under the SW node provides shielding and helps thermal dissipation through the exposed pad.
Route the feedback (FB) trace as a short, direct connection from the top resistor of the output divider back to pin 4, away from the SW node and inductor. Keep the compensation network (Vc pin) physically small and close to pin 6 to avoid stray capacitance that can degrade phase margin. Refer to the LT1933 datasheet PCB layout guidelines for the recommended copper-pour pattern under the exposed pad.
Do not operate the LT1933HDCB below 3.6 V at VIN - the internal UVLO will shut down the regulator and may cause undefined behavior at the SW pin. Do not float the SHDN pin - it must be tied high (to VIN through a 100 kohm resistor or directly) for normal operation. Finally, ensure the inductor saturation current rating exceeds 1 A to handle transient peaks without saturating the internal 750 mA switch.
معلومات الامتثال
RoHS-compliant per Analog Devices product page. Not AEC-Q100 qualified - for automotive designs requiring certification, choose LMR23630FQDRRRQ1 or similar AEC-Q100 parts.
