My Inquiry
My Account
Analog Devices Inc. LTC7821EUH#TRPBF
- Part No.:
- LTC7821EUH#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 32-WFQFN Exposed Pad
- Datasheet:
-
LTC7821EUH#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK HYBRID 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,415
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC7821EUH#TRPBF from Analog Devices is a hybrid synchronous step-down controller IC that integrates soft-switching charge pump topology with buck regulation for high-efficiency intermediate bus conversion. It operates from 10V to 72V input, delivers ±1% output voltage accuracy at 12V, supports 200kHz–1.5MHz programmable switching frequency, and achieves >97% efficiency in 48V-to-12V/20A applications. It is used in telecom power systems requiring low EMI and fast transient response.
For engineers reviewing the LTC7821EUH#TRPBF datasheet, LTC7821EUH#TRPBF pinout, LTC7821EUH#TRPBF application, or LTC7821EUH#TRPBF equivalent, key selection considerations include its hybrid architecture enabling high-frequency operation without sacrificing efficiency, RSENSE/DCR current sensing flexibility, monotonic start-up, and precise capacitor balancing control for stable 4-switch topology operation.
Technical Context
The LTC7821EUH#TRPBF implements a proprietary hybrid architecture combining a soft-switching charge pump (for VIN/2 generation) with a synchronous buck stage, eliminating hard-switching losses in high-side and flying-capacitor switches. Its internal PLL enables phase-lockable operation across 200kHz–1.5MHz, and it features dedicated MID_SENSE and HYS_PRGM pins for real-time monitoring and correction of mid-rail voltage deviation.
It supports three operating modes-CCM, DCM, and Burst Mode®-selected via MODE/PLLIN pin logic or external sync signal, and includes integrated gate drivers with <4ns transition times, 1Ω pull-down resistance, and precise timing delays (e.g., T1D = 45ns) to prevent shoot-through in the 4-MOSFET half-bridge + flying-capacitor configuration.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 10V to 72V (80V absolute max); enables direct use in 48V and 60V industrial/telecom intermediate bus rails. |
| VOUT Accuracy | ±1% over line/load/temperature; ensures stable 12V output without post-regulation in distributed power systems. |
| fSW Range | 200kHz to 1.5MHz (programmable via FREQ pin); allows optimization of inductor size vs. efficiency trade-off. |
| Current Sensing | RSENSE or DCR options; supports accurate peak-current-mode control with ±50mV sense threshold tolerance. |
| Capacitor Balancing | Automatic CFLY/CMID voltage regulation to VIN/2 with TIMER-controlled retry; prevents voltage imbalance failure in hybrid topology. |
| Thermal Protection | Internal TEMP pin with 1.25V trip point and 100ms timeout; provides localized hot-spot monitoring via external PTC resistor. |
| Package | 32-pin 5mm × 5mm QFN with exposed pad (UH); supports high-power density layout with low θJC = 7.3°C/W. |
Pinout & Package
Package: 32-lead (5mm × 5mm) plastic QFN (UH), exposed pad (Pin 33) soldered to PCB as SGND. Thermal resistance θJA = 44°C/W, θJC = 7.3°C/W. Operating junction temperature range: –40°C to 125°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW1, SW3 | Switch node terminals | SW1 swings from VIN/2 to VIN; SW3 swings from 0V to VIN/2 - defines flying-capacitor and output inductor connection points. |
| MID, MID_SENSE | Mid-rail voltage monitor | MID provides Kelvin-sensed VIN/2 reference; MID_SENSE feeds window comparator for fault detection if deviation exceeds HYS_PRGM-set threshold. |
| TG1, TG2, BG1, BG2 | Floating gate drivers | TG1/TG2 drive upper MOSFETs referenced to SW1/SW3; BG1/BG2 drive lower MOSFETs referenced to PGND - enable full 4-switch control with anti-shoot-through timing. |
| BOOST1–BOOST3 | Bootstrap supplies | Provide floating bias for TG1 (VIN/2+INTVCC), TG2/BOOST2 (VIN/2+INTVCC), and BG2/BOOST3 (INTVCC to VIN/2+INTVCC). |
| ITH, VFB, TRACK/SS | Control loop interfaces | ITH sets current limit threshold; VFB closes feedback loop at 0.8V reference; TRACK/SS enables soft-start ramp or output voltage tracking. |
Key Features
| Feature | Design Value |
|---|---|
| Hybrid soft-switching architecture | Eliminates turn-on loss in high-side switches, enabling >97% efficiency at 500kHz in 48V→12V conversion - 3× higher frequency than conventional controllers achieving same efficiency. |
| Programmable operating mode | Select CCM, DCM, or Burst Mode® via MODE/PLLIN pin state or external clock - optimizes light-load efficiency without compromising transient response. |
| Accurate capacitor balancing | Dedicated TIMER pin with dual-rate slew and auto-retry logic ensures reliable CFLY/CMID precharge to VIN/2 before startup and recovery during fault events. |
| Integrated thermal and fault protection | TEMP pin with 1.25V trip and 100ms timeout, plus FAULT pin asserting on mid-rail deviation, capacitor imbalance, or overtemperature - enables robust system-level fault management. |
| EXTVCC switchover | Automatically powers INTVCC from external 7V–40V supply when present, reducing power loss and improving efficiency in high-VIN applications. |
Applications
| Telecom Intermediate Bus Converter | High-Density Datacom Power Supply |
|---|---|
Use Scenario: 48V backplane powering 12V ASIC/FPGA rails in 1RU server chassis with strict EMI limits. IC Role / Device Role / Timing Role: Hybrid controller managing 4-MOSFET + flying-capacitor topology to generate stable 12V/20A with soft-switched transitions. Use Value: >97% efficiency at 500kHz reduces heatsink size by 40% vs. traditional buck; low EMI eliminates need for additional filtering components. |
Use Scenario: Distributed 12V power delivery across multi-board switch fabric with tight board space constraints. IC Role / Device Role / Timing Role: Synchronous step-down controller with CLKOUT synchronization for multiphase parallel operation across multiple boards. Use Value: Phase-lockable 200kHz–1.5MHz operation enables interleaved current sharing; monotonic start-up prevents rail collapse during hot-plug events. |
| Automotive ADAS Domain Controller | Industrial Storage System PSU |
Use Scenario: 48V battery-powered vision processing unit requiring clean, efficient 12V intermediate rail with extended temperature operation. IC Role / Device Role / Timing Role: High-voltage controller supporting 10V–72V input range and –40°C to 125°C junction temp, with TEMP pin monitoring critical hot spots. Use Value: Integrated thermal protection and UVLO hysteresis (0.28V) ensure reliable cold-cranking and load-dump immunity per automotive requirements. |
Use Scenario: Redundant 12V power module in enterprise SSD array with strict availability and long-term BOM stability needs. IC Role / Device Role / Timing Role: Controller with EXTVCC input and traceable sourcing path, supporting volume procurement and lifecycle continuity management. Use Value: RSENSE/DCR sensing flexibility allows optimal trade-off between accuracy and conduction loss; PGOOD/FAULT signaling enables system-level health monitoring. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar hybrid/hard-switching step-down controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3891EFE#PBF | Single-phase synchronous buck controller (no charge pump); 4–60V VIN, fixed 500kHz fSW, no MID_SENSE or capacitor balancing. | Suitable for standard buck topologies only; lacks hybrid efficiency advantage and mid-rail monitoring for 4-switch designs. | Choose when cost-sensitive, lower-current (<15A), or non-hybrid topology suffices - avoids complexity of flying capacitor layout. |
| MPQ8633BGLE-Z | Monolithic 4-switch buck-boost controller (not hybrid); 3.1–40V VIN, integrated MOSFETs, no external flying capacitor support. | Targets bidirectional or wide-input-range applications; not pin-compatible and lacks soft-switching benefits for high-efficiency unidirectional conversion. | Prefer for compact, low-component-count solutions where 48V→12V efficiency >95% is acceptable and layout area is constrained. |
Compared with LTC3891EFE#PBF and MPQ8633BGLE-Z, the LTC7821EUH#TRPBF uniquely delivers >97% efficiency at high frequency through hybrid soft-switching, supports true 4-switch topology with active capacitor balancing, and offers superior EMI performance - making it the only option for high-density, high-efficiency intermediate bus conversion where VIN/2 stability is critical.
Availability
LTC7821EUH#TRPBF is available at Aetrix Electronics and suitable for telecom intermediate bus converters, high-current distributed power systems, and automotive ADAS domain controllers requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.
Supply support for LTC7821EUH#TRPBF 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, communications, and power management markets.
The LTC7821EUH#TRPBF belongs to Analog Devices' Power by Linear™ controller family, designed specifically for high-efficiency, low-EMI intermediate bus conversion using hybrid soft-switching architectures in telecom, datacom, and industrial systems.
FAQ
What is the primary topology enabled by the LTC7821EUH#TRPBF?
The LTC7821EUH#TRPBF implements a proprietary hybrid topology combining a soft-switching charge pump (to generate VIN/2) with a synchronous buck stage. This enables high-efficiency 4-switch operation without hard-switching losses in the high-side and flying-capacitor paths - distinct from standard buck, boost, or buck-boost controllers. The LTC7821EUH#TRPBF requires external MOSFETs M1–M4 and flying capacitors CFLY/CMID to realize this architecture.
How does the LTC7821EUH#TRPBF achieve >97% efficiency at 500kHz?
The LTC7821EUH#TRPBF achieves >97% efficiency at 500kHz by eliminating turn-on switching losses via soft-switching in the charge pump stage and optimizing gate drive timing (e.g., T1D = 45ns, T2D = 20ns) to prevent shoot-through. In a 48V-to-12V/20A application, this allows high-frequency operation with small inductors while maintaining efficiency levels typically seen only at one-third the frequency in conventional controllers. The LTC7821EUH#TRPBF also supports EXTVCC switchover to reduce INTVCC regulator loss.
What is the function of the MID_SENSE and HYS_PRGM pins on the LTC7821EUH#TRPBF?
MID_SENSE provides Kelvin sensing of the mid-rail voltage (VIN/2) for real-time comparison against a window set by HYS_PRGM. A resistor from HYS_PRGM to ground generates a voltage that defines equal ± thresholds around VIN/2; if MID_SENSE deviates beyond this window, the LTC7821EUH#TRPBF asserts FAULT and halts switching until capacitor balancing restores VIN/2. This ensures safe, reliable operation of the hybrid topology under load transients or component mismatch.
Can the LTC7821EUH#TRPBF be synchronized to an external clock?
Yes - the MODE/PLLIN pin on the LTC7821EUH#TRPBF accepts an external clock signal to synchronize the internal oscillator via its integrated PLL. When driven with a clean square wave within 200kHz–1500kHz, the LTC7821EUH#TRPBF locks phase and frequency, enabling multiphase interleaving with other controllers. The CLKOUT pin outputs a 180° phase-shifted clock for cascaded synchronization. Forced CCM mode is automatically enabled during sync operation.
What are the key differences between the LTC7821EUH#TRPBF and LTC7821IUH#TRPBF?
The LTC7821EUH#TRPBF is specified for 0°C to 85°C ambient operation (E-grade), while the LTC7821IUH#TRPBF is fully tested and guaranteed over –40°C to 125°C (I-grade). Both share identical pinout, electrical characteristics, and functionality. The I-grade version undergoes extended temperature screening and is preferred for automotive, industrial, and outdoor telecom applications where full junction temperature range assurance is required. The LTC7821EUH#TRPBF remains suitable for commercial and controlled-environment datacom systems.
LTC7821EUH#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 32-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 1
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 10V ~ 72V
- Frequency - Switching:
- 200kHz ~ 1.5MHz
- Duty Cycle (Max):
- 40%
- Synchronous Rectifier:
- No
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Frequency Control, Power Good, Soft Start, Tracking
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-QFN (5x5)
LTC7821EUH#TRPBF FAQ
1.How can I place an order for LTC7821EUH#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC7821EUH#TRPBF 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 LTC7821EUH#TRPBF reliable?
The price and inventory of LTC7821EUH#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC7821EUH#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC7821EUH#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC7821EUH#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC7821EUH#TRPBF?
LTC7821EUH#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC7821EUH#TRPBF 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 LTC7821EUH#TRPBF?
For technical support, including LTC7821EUH#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC7821EUH#TRPBF requirements.
6.How does Aetrix verify that LTC7821EUH#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC7821EUH#TRPBF 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 LTC7821EUH#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC7821EUH#TRPBF?
All LTC7821EUH#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC7821EUH#TRPBF, 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 LTC7821EUH#TRPBF part is unused and in its original packaging.
Return procedure for LTC7821EUH#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC7821EUH#TRPBF 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…
