My Inquiry
My Account
Analog Devices Inc. LTC3728EUH#PBF
- Part No.:
- LTC3728EUH#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 32-WFQFN Exposed Pad
- Datasheet:
-
LTC3728EUH#PBF.pdf
- Description:
- IC REG CTRLR BUCK 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:146
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3728EUH#PBF from Analog Devices (formerly Linear Technology) is a dual-phase, constant-frequency current-mode synchronous step-down controller driving two independent N-channel MOSFET stages. It operates at 250–550 kHz with 180° phase shift, delivers ±1% output voltage accuracy at 0.8 V reference, supports 3.5 V to 36 V input, and integrates a 3.3 V/10 mA linear regulator - optimized for high-efficiency dual-rail power in notebook computers and telecom DC distribution systems.
For engineers reviewing the LTC3728EUH#PBF datasheet, LTC3728EUH#PBF pinout, LTC3728EUH#PBF application, or LTC3728EUH#PBF equivalent, key selection criteria include its dual-phase interleaved architecture, OPTI-LOOP® compensation for wide-output-capacitance stability, FCB-selectable operating modes (Burst Mode®, constant-frequency PWM, forced continuous), and integrated overvoltage/short-circuit protection with latchoff and foldback.
Technical Context
The LTC3728EUH#PBF implements two independent current-mode control loops with 180° phase offset, minimizing input ripple and EMI by interleaving SW1 and SW2 switching nodes. Each channel features a transconductance error amplifier (gm = 1.3 mmho, GBW = 3 MHz), precision 0.8 V feedback reference (±1%), and ITH-controlled peak-current sensing via external RSENSE.
Its PLLIN/PLLFLTR interface enables external synchronization or DC voltage-controlled frequency tuning (250–550 kHz), while the FCB pin selects among Burst Mode® (low-IQ), constant-frequency discontinuous conduction, or forced continuous PWM - with dedicated circuitry for secondary-winding regulation and dropout recovery via periodic top-FET blanking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Topology | Dual-channel, synchronous buck controller with 180° interleaved phase operation - reduces RMS input capacitor current by ~30% vs. single-phase. |
| Switching Frequency | 250 kHz to 550 kHz, adjustable via PLLFLTR voltage or external sync on PLLIN - enables EMI optimization and layout flexibility. |
| Output Voltage Accuracy | ±1% over temperature and line/load - ensures stable core logic rail compliance for microprocessors and FPGAs. |
| Input Voltage Range | 3.5 V to 36 V (absolute max 36 V) - supports 12 V/24 V industrial buses and multi-cell Li-ion battery inputs. |
| Reference Voltage | 0.800 V ±0.8 mV - low-drift reference enabling precise 1.0 V, 1.2 V, 1.8 V, or 3.3 V outputs with standard resistor dividers. |
| Shutdown Quiescent Current | 20 μA - enables ultra-low-power system standby without external enable sequencing. |
| Integrated LDO | 3.3 V / 10 mA linear regulator (±2% load regulation) - powers auxiliary circuitry without external bias supply. |
Pinout & Package
Package: 32-lead (5 mm × 5 mm) plastic QFN with exposed thermal pad (SGND). Requires soldering of exposed pad to PCB ground plane for thermal performance (θJA = 68°C/W on 4-layer board) and electrical integrity.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| VOSENSE1 / VOSENSE2 | Remote feedback sense inputs | Accepts resistive divider output from regulated rails - enables accurate remote voltage regulation despite PCB trace IR drop. |
| SENSE1+/SENSE1− / SENSE2+/SENSE2− | Differential current sense inputs | Measures voltage across external RSENSE to set peak inductor current limit - supports foldback during short-circuit events. |
| TG1/TG2, BG1/BG2 | Top/bottom gate drivers | Drive N-channel MOSFET gates with 3 A peak current, 90 ns transition times - supports fast-switching GaN or low-RDS(on) Si devices. |
| RUN/SS1 / RUN/SS2 | Soft-start and fault timer inputs | Capacitor-based ramp controls startup dI/dt; falling edge triggers shutdown and timed latchoff during sustained overcurrent. |
| FCB | Mode selection and secondary regulation control | Voltage-selectable: <0.8 V → forced continuous; 0.8–3.5 V → Burst Mode®; >4.3 V → constant-frequency - also regulates auxiliary windings. |
| PGOOD | Open-drain power-good indicator | Asserts low when either VOSENSE deviates >±7.5% from setpoint - provides system-level power sequencing and fault signaling. |
Key Features
| Feature | Design Value |
|---|---|
| OPTI-LOOP® compensation | Enables stable loop response across 10× variation in output capacitance and ESR - eliminates need for custom compensation per design. |
| Interleaved 2-phase operation | Reduces input RMS current by up to 30%, cuts required input capacitance, and lowers conducted EMI - simplifies front-end filtering. |
| Three selectable operating modes | Burst Mode® (ultra-low IQ), constant-frequency PWM (low-noise), or forced continuous (bidirectional current) - adaptable to dynamic load profiles. |
| Integrated 3.3 V linear regulator | Supplies 10 mA with ±2% load regulation - powers level shifters, ADC references, or monitoring ICs without extra LDO. |
| Comprehensive protection suite | Includes output overvoltage latching, current foldback, timed short-circuit shutdown, and dropout recovery - enhances system reliability. |
Applications
| Notebook Power Management | Telecom DC Distribution |
|---|---|
Use Scenario: Dual-rail power for CPU core (1.2 V/15 A) and I/O (3.3 V/5 A) in ultraportable notebooks with strict thermal and EMI limits. IC Role / Device Role / Timing Role: Dual-phase synchronous buck controller managing interleaved switching, phase alignment, and coordinated soft-start. Use Value: 180° phase shift cuts input capacitor RMS current by 28%, enabling smaller 22 μF ceramic input caps instead of 100 μF tantalum - reducing BOM cost and board area. |
Use Scenario: Distributed 5 V/3.3 V power for line cards in 48 V telecom chassis with hot-swap and redundancy requirements. IC Role / Device Role / Timing Role: High-vin dual controller regulating isolated secondary rails with remote sense, PGOOD coordination, and robust overvoltage protection. Use Value: ±1% output accuracy and ±7.5% PGOOD window ensure compatibility with JEDEC-compliant digital loads under varying line/load conditions. |
| Portable Instrumentation | Battery-Powered Digital Systems |
Use Scenario: Precision analog + digital power in handheld test equipment requiring low-noise 3.3 V and clean 5 V supplies. IC Role / Device Role / Timing Role: Dual-channel controller operating in constant-frequency mode to suppress switching noise in sensitive analog signal chains. Use Value: Constant-frequency PWM mode (enabled via FCB = INTVCC) maintains fixed 500 kHz switching - avoids beat frequencies with ADC sampling clocks. |
Use Scenario: Power conversion for multi-rail IoT edge node (Wi-Fi SoC + sensor hub + display) powered by 3S Li-ion (9–12.6 V). IC Role / Device Role / Timing Role: Primary buck controller with Burst Mode® operation and 20 μA shutdown IQ to maximize battery runtime in sleep states. Use Value: Burst Mode® extends battery life by reducing no-load power dissipation to <15 mW - critical for >1-year coin-cell-equivalent operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-phase synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2918GL-Z | Single-chip dual-phase controller with integrated MOSFET drivers only (no 3.3 V LDO); 4.5–28 V input; fixed 500 kHz frequency. | Lacks remote sense, PGOOD coordination, and FCB-selectable modes - suitable for cost-sensitive, fixed-frequency designs without auxiliary rail needs. | Select MP2918GL-Z when board space is constrained and auxiliary 3.3 V bias is available externally; avoid if remote sensing or multi-mode operation is required. |
| LTC3855IUFD#PBF | Dual-phase controller with identical 3.5–36 V input, 0.8 V reference, and OPTI-LOOP®; adds digital power system management (PMBus) and telemetry. | Supports real-time voltage/current/temperature reporting and programmable fault responses - targets high-reliability server/industrial systems. | Select LTC3855IUFD#PBF when telemetry, fault logging, or dynamic margining is needed; LTC3728EUH#PBF remains optimal for analog-only, cost-optimized designs. |
Compared with MP2918GL-Z, LTC3728EUH#PBF provides superior flexibility via FCB-selectable modes and integrated 3.3 V LDO, while LTC3855IUFD#PBF adds digital control at higher complexity and cost - making LTC3728EUH#PBF the balanced choice for analog-intensive, dual-rail embedded power.
Availability
LTC3728EUH#PBF is available at Aetrix Electronics and suitable for notebook computing, telecom DC distribution, and portable instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.
Supply support for LTC3728EUH#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 product support, documentation, and manufacturing continuity for all Linear power management ICs.
The LTC3728EUH#PBF belongs to Linear's high-performance synchronous controller family, designed specifically for efficiency-critical, multi-rail DC/DC conversion in space-constrained portable and telecom systems.
FAQ
What is the maximum supported switching frequency for LTC3728EUH#PBF?
The LTC3728EUH#PBF supports a nominal switching frequency range of 250 kHz to 550 kHz. This is achieved either by applying a DC voltage (0 V to 2.4 V) to the PLLFLTR pin or by synchronizing to an external clock via PLLIN. At VPLLFLTR ≥ 2.4 V, the device operates at its highest guaranteed frequency of 550 kHz, enabling compact magnetics and reduced output ripple.
Does LTC3728EUH#PBF support remote voltage sensing?
Yes, LTC3728EUH#PBF supports true remote voltage sensing via dedicated VOSENSE1 and VOSENSE2 pins. These inputs accept feedback signals from external resistor dividers placed directly at the load, compensating for PCB trace resistance and ensuring ±1% output regulation accuracy regardless of board layout or current level.
How does the FCB pin affect LTC3728EUH#PBF operating mode selection?
The FCB pin on LTC3728EUH#PBF selects among three distinct operating modes: below 0.8 V enables forced continuous conduction; between 0.8 V and 4.3 V activates Burst Mode® for ultra-low IQ; above 4.3 V disables Burst Mode® for constant-frequency PWM. This same pin also enables secondary-winding regulation when used with transformer-coupled outputs.
What protection features are integrated into LTC3728EUH#PBF?
LTC3728EUH#PBF integrates output overvoltage latching (with bottom-FET activation), current foldback during short-circuit, timed latchoff via RUN/SS discharge, undervoltage lockout (3.5 V), and dropout recovery with periodic top-FET blanking. All protections operate independently per channel and require no external components beyond standard RSENSE and CSS timing capacitors.
Can LTC3728EUH#PBF drive both high-side and low-side N-channel MOSFETs?
Yes, LTC3728EUH#PBF drives both high-side (TG1/TG2) and low-side (BG1/BG2) N-channel MOSFETs using integrated floating gate drivers. TG outputs swing from SW node to INTVCC – 0.5 V, while BG outputs swing from PGND to INTVCC - supporting efficient synchronous rectification without external driver ICs or P-channel devices.
LTC3728EUH#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 32-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 2
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 3.5V ~ 30V
- Frequency - Switching:
- 260kHz ~ 550kHz
- Duty Cycle (Max):
- 99.4%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Enable, Power Good, Soft Start
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-QFN (5x5)
LTC3728EUH#PBF FAQ
1.How can I place an order for LTC3728EUH#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3728EUH#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 LTC3728EUH#PBF reliable?
The price and inventory of LTC3728EUH#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3728EUH#PBF is usually 5 days.
3.What payment methods are accepted for LTC3728EUH#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3728EUH#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3728EUH#PBF?
LTC3728EUH#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3728EUH#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 LTC3728EUH#PBF?
For technical support, including LTC3728EUH#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3728EUH#PBF requirements.
6.How does Aetrix verify that LTC3728EUH#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3728EUH#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 LTC3728EUH#PBF meets industry standards.
7.What is the process for return or replacement of LTC3728EUH#PBF?
All LTC3728EUH#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3728EUH#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 LTC3728EUH#PBF part is unused and in its original packaging.
Return procedure for LTC3728EUH#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3728EUH#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…
