My Inquiry
My Account
Analog Devices Inc. LTC3852IUDD#PBF
- Part No.:
- LTC3852IUDD#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LTC3852IUDD#PBF.pdf
- Description:
- IC REG CTRLR BUCK 24QFN
- Quantity:
- Payment:
- Shipping:
Inventory:146
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3852IUDD#PBF from Analog Devices (formerly Linear Technology) is a constant-frequency, current-mode synchronous step-down DC/DC controller with integrated charge pump. It operates from 2.7V–5.5V input to power its internal logic and gate drivers, supports 4V–38V main input range, delivers ±1.25% output voltage accuracy, enables phase-lockable switching up to 750kHz, and drives logic-level N-channel MOSFETs in high-efficiency buck converters for lithium-ion-powered systems.
For engineers reviewing the LTC3852IUDD#PBF datasheet, LTC3852IUDD#PBF pinout, LTC3852IUDD#PBF application, or LTC3852IUDD#PBF equivalent, key selection criteria include charge-pump-enabled low-VIN operation, RSENSE/DCR current sensing flexibility, selectable Burst Mode®/pulse-skipping/continuous conduction modes, 24-lead QFN package thermal performance, and PGOOD monitoring with ±10% regulation window.
Technical Context
The LTC3852IUDD#PBF implements a fixed-frequency current-mode control architecture with slope compensation, enabling stable operation across wide duty cycles and input ranges. Its dual-supply design separates charge-pump-powered logic (VIN1 → VPUMP) from main controller rail (VIN2), allowing independent optimization of gate drive strength and regulation precision.
Internal functional blocks include a 1.2MHz charge-pump oscillator, phase-locked loop with FREQ/PLLFLTR filter interface, MODE/PLLIN-selectable operating modes, TRACK/SS-controlled soft-start and tracking, and reverse-current prevention during startup. The ITH pin serves as both error amplifier output and current threshold modulator, directly linking loop stability to peak-current control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range (Charge Pump) | 2.7V to 5.5V - Enables direct operation from single-cell Li-ion or 3.3V system rails without external LDO |
| Controller Input Range | 4V to 38V - Supports wide-input industrial and automotive buck conversion without pre-regulation |
| Output Voltage Accuracy | ±1.25% over temperature - Ensures tight regulation for sensitive digital loads like FPGAs and processors |
| Switching Frequency Range | 250kHz to 750kHz - Adjustable via resistor on FREQ/PLLFLTR; phase-lockable for EMI-sensitive designs |
| Gate Drive Supply (VPUMP) | 4.8V to 5.05V (typ) - Regulated 5V output powers logic-level N-MOSFET drivers with minimal dropout |
| Power Good Threshold | ±10% of setpoint - Open-drain PGOOD asserts only when output is within validated regulation window |
| Minimum On-Time | 90ns - Enables high VIN-to-VOUT ratios (e.g., 24V→1.2V) with practical inductor selection |
Pinout & Package
Package: 24-lead (3mm × 5mm) plastic QFN with exposed pad (Pin 25 = GND). Requires soldering of exposed pad for thermal and electrical integrity per datasheet layout guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SENSE– (1) | Current sense comparator inverting input | Kelvin connection point for current-sense resistor or DCR network; critical for accurate peak-current detection |
| SENSE+ (2) | Current sense comparator noninverting input | Connects to high-side of sense resistor or DCR tap; establishes current threshold reference |
| PGOOD (3) | Open-drain power-good indicator | Asserts low after 17μs mask timer when VOUT is within ±10% of target - used for system sequencing and fault reporting |
| GND2 (4) | Buck controller small-signal ground | Reference for feedback, compensation, and current sensing; must be star-connected to avoid noise coupling |
| BG (5) | Bottom gate driver output | Drives gate of synchronous rectifier MOSFET between GND2 and INTVCC; 1.1Ω pull-down resistance ensures fast turn-off |
| C+ (7), C– (8) | Flying capacitor terminals | Interface external 2.2μF ceramic flying cap (CFLY); define charge-pump topology and efficiency at light load |
| SHDN (10) | Active-low charge pump shutdown | CMOS input (VIH=1.3V, VIL=0.4V); must be driven - floating state is undefined and prohibited |
| VIN1 (12) | Charge pump input supply | Accepts 2.7V–5.5V; bypassed with 1–4.7μF ceramic cap; powers VPUMP generation independently of VIN2 |
| VPUMP (13) | Regulated 5V charge-pump output | Supplies INTVCC and gate drivers; regulated to 4.8–5.05V; requires ≥2.2μF local ceramic bypass |
| INTVCC (14) | Internal logic and gate drive supply | Powered by VPUMP; supplies top/bottom drivers and control circuitry; max 50mA peak draw |
| VIN2 (15) | Main controller input supply | 4V–38V input to buck stage; powers high-side switch path and sensing circuitry; bypassed to GND2 |
| BOOST (16) | Floating bootstrap supply node | Connects to booststrap capacitor anode; swings from ~INTVCC–0.7V to VIN2+INTVCC; enables high-side N-MOSFET drive |
| TG (17) | Top gate driver output | Floating driver output referenced to SW node; 2.2Ω pull-up / 1.2Ω pull-down ensures robust MOSFET switching |
| SW (18) | Switch node connection | Connects to inductor and MOSFET bridge; experiences full VIN2-to-GND voltage swing; requires low-inductance layout |
| MODE/PLLIN (19) | Mode selection & external sync input | Selects Burst Mode® (50k–250kΩ to INTVCC), pulse-skipping (tie to GND2), or forced CCM (tie to INTVCC) |
| FREQ/PLLFLTR (20) | Oscillator frequency set & PLL filter | Resistor to GND2 sets nominal frequency; capacitor to GND2 provides PLL loop filtering |
| RUN (21) | Precision enable/disable control | 1.1V–1.35V rising threshold with 130mV hysteresis; internal 2μA pull-up enables simple RC start-up control |
| TRACK/SS (22) | Soft-start ramp & supply tracking input | 1μA internal current charges external capacitor; enables monotonic VOUT ramp or ratiometric tracking of master supply |
| ITH (23) | Error amplifier output & current threshold | Directly sets peak inductor current threshold; voltage range 0.4V–1.6V defines operating mode boundaries |
| VFB (24) | Feedback voltage input | Compares against 0.8V internal reference; accepts remote sensing; ±50nA input bias minimizes divider error |
| GND (25) | Exposed thermal pad | Must be soldered to PCB plane; serves as primary thermal path and common ground for all sections |
Key Features
| Feature | Design Value |
|---|---|
| Integrated charge pump | Generates regulated 5V VPUMP from 2.7V–5.5V VIN1 - eliminates need for external bias supply and enables ultra-low-VIN operation |
| Selectably optimized light-load efficiency | Burst Mode®, pulse-skipping, or forced continuous conduction - allows trade-off between ripple, efficiency, and EMI per application requirement |
| Programmable soft-start and tracking | Single capacitor on TRACK/SS sets ramp rate; supports both monotonic startup and coordinated multi-rail sequencing |
| Reverse-current prevention | Active during normal operation and disabled only during soft-start - protects input source and improves transient response |
| Robust protection suite | Includes undervoltage lockout (3.25V INTVCC), output overvoltage lockout (0.86–0.90V at VFB), current foldback, and thermal shutdown |
| High-precision regulation | ±1.25% output voltage accuracy over –40°C to 125°C - meets tight tolerance requirements for core logic and memory rails |
Applications
| Lithium-Ion Portable Systems | Distributed Power Architectures |
|---|---|
Use Scenario: Powering 1.2V FPGA core rail from single-cell 3.3V Li-ion battery with minimal quiescent current and high efficiency at partial load. IC Role / Device Role / Timing Role: Synchronous step-down controller managing gate timing, current sensing, and soft-start sequencing for buck converter stage. Use Value: Charge-pump enables direct 3.3V-to-5V gate drive without auxiliary supply; Burst Mode® extends battery runtime by >3× vs forced CCM at light load. |
Use Scenario: Generating isolated 5V/3.3V intermediate rails from 24V or 48V backplane in industrial PLC or telecom shelf. IC Role / Device Role / Timing Role: High-voltage buck controller regulating secondary distribution rails with precise PGOOD signaling for downstream module enable. Use Value: 38V VIN2 rating avoids pre-regulation stages; ±10% PGOOD window ensures reliable inter-rail sequencing; 750kHz operation reduces magnetics size. |
| Automotive Infotainment | Medical Portable Equipment |
Use Scenario: Converting 12V vehicle battery to 1.8V SoC core supply in head-unit with cold-crank immunity and EMI compliance. IC Role / Device Role / Timing Role: Current-mode controller implementing phase-locked switching synchronized to system clock to suppress conducted emissions. Use Value: 250kHz–750kHz adjustable frequency avoids AM band; 99% max duty cycle maintains regulation during 6V cold-crank; -40°C to 125°C grade ensures reliability. |
Use Scenario: Providing stable 3.3V analog sensor rail from 3.7V LiPo battery in handheld diagnostic device requiring low noise and zero reverse current. IC Role / Device Role / Timing Role: Precision buck controller delivering tightly regulated output with programmable soft-start to prevent inrush into sensitive analog front-end. Use Value: ±1.25% accuracy ensures ADC reference stability; reverse-current blocking prevents battery drain during standby; TRACK/SS enables controlled power-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8640S | Integrated 4A power stage; no external MOSFETs required; higher quiescent current (2.5μA) but faster transient response | Better suited for space-constrained designs where board area is premium and 4A output suffices | Choose LT8640S when integrating power stage simplifies layout and reduces BOM count; LTC3852IUDD#PBF preferred for >20A scalable designs with discrete MOSFET optimization |
| MP2918 | Fixed 500kHz frequency; no charge pump; requires external 5V bias or LDO; lower cost but limited to ≥4.5V input for gate drive | Ideal for cost-sensitive industrial applications with stable 5V auxiliary supply available | Choose MP2918 when system already provides clean 5V bias and VIN2 ≥ 4.5V; LTC3852IUDD#PBF essential when operating from 3.3V-only or wide-input unregulated sources |
Compared with LT8640S and MP2918, the LTC3852IUDD#PBF uniquely combines charge-pump autonomy, wide 4V–38V controller input, and discrete MOSFET scalability - making it the only option capable of high-current, ultra-low-VIN, and wide-input buck control in a single IC without auxiliary supplies or power-stage compromises.
Availability
LTC3852IUDD#PBF is available at Aetrix Electronics and suitable for lithium-ion portable systems, distributed power architectures, automotive infotainment, and medical portable equipment requiring stable component supply across extended temperature and long product lifecycles.
Supply support for LTC3852IUDD#PBF 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
Analog Devices acquired Linear Technology in 2017 and maintains full technical and manufacturing continuity for all Linear power products, including rigorous AEC-Q100 stress testing and automotive-grade qualification.
The LTC3852IUDD#PBF belongs to Linear's high-performance synchronous controller family, designed specifically for demanding DC/DC conversion in space-, efficiency-, and reliability-critical applications where discrete MOSFET optimization and ultra-low-input capability are mandatory.
FAQ
What is the operating temperature range for the LTC3852IUDD#PBF?
The LTC3852IUDD#PBF is specified for operation from –40°C to 125°C junction temperature. This industrial-grade temperature range is guaranteed by design, characterization, and statistical process controls - unlike the E-grade version (LTC3852EUDD#PBF), which is rated only from 0°C to 85°C. Thermal design must account for θJA = 38°C/W and mandatory soldering of the exposed pad (Pin 25) to PCB ground plane.
How does the charge pump in the LTC3852IUDD#PBF function and what are its key specifications?
The LTC3852IUDD#PBF integrates a switched-capacitor charge pump that doubles VIN1 (2.7V–5.5V) to generate a regulated 4.8V–5.05V VPUMP output. It operates at 1.2MHz (typ), uses external C+ and C– pins for a 2.2μF flying capacitor, and delivers up to 50mA peak current to INTVCC. The pump includes built-in soft-start (125μs ramp) and short-circuit protection with indefinite duration tolerance.
Can the LTC3852IUDD#PBF operate without an external flying capacitor?
No - the LTC3852IUDD#PBF requires an external 2.2μF ceramic flying capacitor connected between C+ (Pin 7) and C– (Pin 8) to enable charge-pump operation. Omitting this capacitor prevents VPUMP generation, leaving INTVCC unpowered and rendering the IC inoperable. The datasheet explicitly specifies CFLY = 2.2μF as minimum for stable 5V regulation under all load conditions.
What are the supported current sensing methods for the LTC3852IUDD#PBF?
The LTC3852IUDD#PBF supports two verified current sensing methods: discrete RSENSE (shunt resistor between SW and GND2, sensed differentially across SENSE+ and SENSE–) and DCR sensing (using inductor's DC resistance with RC network connected to SENSE+ and SENSE–). Both methods are fully characterized in the datasheet; DCR eliminates power loss but requires careful network calibration for temperature drift compensation.
Does the LTC3852IUDD#PBF provide reverse current protection, and when is it active?
Yes - the LTC3852IUDD#PBF includes reverse current protection via the IREV comparator, which disables the bottom gate driver (BG) just before inductor current reaches zero. This function is active during normal operation but explicitly disabled during soft-start (TRACK/SS < 0.8V) to prevent interference with startup ramp. Reverse current blocking is confirmed in Figure 17 and Applications section of the datasheet.
LTC3852IUDD#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 4V ~ 38V
- Frequency - Switching:
- 235kHz ~ 750kHz
- Duty Cycle (Max):
- 99%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Enable, Frequency Control, Power Good, Soft Start, Tracking
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-QFN (3x5)
LTC3852IUDD#PBF FAQ
1.How can I place an order for LTC3852IUDD#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3852IUDD#PBF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LTC3852IUDD#PBF reliable?
The price and inventory of LTC3852IUDD#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3852IUDD#PBF is usually 5 days.
3.What payment methods are accepted for LTC3852IUDD#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3852IUDD#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3852IUDD#PBF?
LTC3852IUDD#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3852IUDD#PBF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LTC3852IUDD#PBF?
For technical support, including LTC3852IUDD#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3852IUDD#PBF requirements.
6.How does Aetrix verify that LTC3852IUDD#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3852IUDD#PBF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LTC3852IUDD#PBF meets industry standards.
7.What is the process for return or replacement of LTC3852IUDD#PBF?
All LTC3852IUDD#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3852IUDD#PBF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LTC3852IUDD#PBF part is unused and in its original packaging.
Return procedure for LTC3852IUDD#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3852IUDD#PBF Tags
-
UCC28C45DR
Texas Instruments
-
UCC28C40DR
Texas Instruments
-
UCC28C43DR
Texas Instruments
-
ZXSC410E6TA
Diodes Incorporated
-
LM3524DMX/NOPB
Texas Instruments
-
LM3489MMX/NOPB
Texas Instruments
-
MIC2102YML-TR
Microchip Technology
-
LM5148RGYR
Texas Instruments
-
TL598CDR
Texas Instruments
-
LM5155DSSR
Texas Instruments
-
LM25085MYX/NOPB
Texas Instruments
-
UCC2813DTR-0
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
