My Inquiry
My Account
Analog Devices Inc. LTC7851IUHH-1#TRPBF
- Part No.:
- LTC7851IUHH-1#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 58-WFQFN Exposed Pad
- Datasheet:
-
LTC7851IUHH-1#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 58QFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,391
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC7851IUHH-1#TRPBF from Analog Devices is a quad-output, multiphase synchronous step-down voltage mode DC/DC controller optimized for DrMOS power stages. It delivers precise current sharing across up to four phases, supports 250kHz–2.25MHz switching frequency, operates with VCC 3V–5.5V and VIN 3V–27V, and regulates outputs from 0.6V to VCC – 0.5V - enabling high-current FPGA/DSP supplies such as 1V/90A and 1.5V/30A dual-rail systems.
For engineers reviewing the LTC7851IUHH-1#TRPBF datasheet, LTC7851IUHH-1#TRPBF pinout, LTC7851IUHH-1#TRPBF application, or LTC7851IUHH-1#TRPBF equivalent, key selection criteria include its lower-current-sense-amplifier-gain architecture (4V/V), compatibility with integrated current-sense DrMOS devices, 58-lead QFN package thermal performance, and phase-lockable synchronization for multi-controller scaling.
Technical Context
The LTC7851IUHH-1#TRPBF implements voltage-mode control with a high-bandwidth error amplifier (40MHz unity-gain bandwidth, 75dB open-loop gain) and remote differential output sensing via VSNSP/VSNSN inputs per channel. Its internal current sharing loop uses IAVG bus averaging and polyphase master-slave coordination to maintain ±1% current balance across paralleled phases.
It features lossless DCR or precision resistor-based current sensing, with a dedicated 150mV maximum differential sense voltage and ±3mV input-referred offset (–40°C to 125°C). The device supports external clock synchronization (250kHz–2.25MHz), programmable frequency via FREQ pin (250kHz–2.25MHz), and preset 600kHz/1MHz modes when CLKIN is low.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 3V to 5.5V - powers internal circuitry; requires local 0.1–1µF ceramic bypass at Pin 11. |
| Switching Frequency | 250kHz to 2.25MHz - selectable via FREQ resistor or external CLKIN; enables optimization of size, efficiency, and transient response. |
| Current Sense Gain | 4V/V - lower gain than LTC7851 (20V/V), matched to DrMOS internal sense signal amplitude for accurate overcurrent protection. |
| Output Voltage Range | 0.6V to VCC – 0.5V - supports core rails for modern processors and ASICs; regulated by ±0.75% 0.6V reference. |
| Operating Temp | –40°C to 125°C - industrial-grade junction temperature range; validated for continuous operation under full load. |
| Package | 58-lead 5mm × 9mm QFN with exposed thermal pad (Pin 59 = SGND) - θJC = 15.5°C/W, requires PCB soldering for thermal compliance. |
| Phase Support | Quad-phase per IC; scalable to 8+ phases via daisy-chained CLKOUT/CLKIN - enables >100A total output with interleaved ripple cancellation. |
Pinout & Package
Package: 58-lead plastic QFN (5mm × 9mm, 0.4mm pitch), exposed thermal pad (Pin 59) tied to SGND and required to be soldered to PCB ground plane for thermal performance (θJA = 49°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| COMP1–COMP4 (Pins 1,9,13,20) | Error amplifier output | Drives PWM duty cycle; low-impedance op-amp output; must not be directly paralleled unless FB disabled on slave channels. |
| VSNSP1–VSNSP4 (Pins 2,8,14,19) | Differential sense non-inverting input | Connects to feedback divider midpoint at output capacitor; enables remote sensing to reject PCB ground bounce. |
| VSNSN1–VSNSN4 (Pins 3,7,15,18) | Differential sense inverting input | Connects to load ground; establishes common-mode reference for accurate output regulation under dynamic load. |
| IAVG1–IAVG4 (Pins 47,42,35,30) | Average current monitor | Master channel sources 20µA to set shared current reference; slaves integrate difference to equalize phase currents. |
| ILIM1–ILIM4 (Pins 48,41,36,29) | Overcurrent threshold set | Resistor-to-SGND sets trip point; only master ILIM sources 20µA - ensures consistent OCP across all phases. |
| RUN1–RUN4 (Pins 53,51,27,23) | Channel enable input | Logic-high (>2.25V) enables channel; internal 1.5µA pull-up allows simple resistor-enable or microcontroller control. |
| PWM1–PWM4 (Pins 52,50,26,24) | Top gate drive output | Three-state compatible; drives DrMOS or external gate driver; minimum on/off times prevent shoot-through. |
| PGOOD1–PGOOD4 (Pins 49,38,28,25) | Open-drain power-good flag | Asserts low after 30µs delay when output is within ±10% of target - used for sequencing and system fault detection. |
Key Features
| Feature | Design Value |
|---|---|
| DrMOS-optimized current sense | 4V/V gain and 150mV max differential input - matches typical DrMOS current monitor output, eliminating external scaling. |
| Quad-channel independent control | Each channel has dedicated COMP, FB, TRACK/SS, RUN, and PGOOD - supports four distinct output rails or phased parallel operation. |
| Accurate current sharing | ±1% inter-phase current matching achieved via IAVG bus and internal integrator - critical for thermal derating and reliability in high-current designs. |
| Phase-lockable synchronization | CLKIN accepts 250kHz–2.25MHz external clock; CLKOUT provides aligned output for daisy-chaining multiple controllers without jitter accumulation. |
| Robust overcurrent protection | 128-cycle consecutive fault detection with automatic soft-start reset and 32768-cycle retry delay - prevents latch-up during short-circuit events. |
Applications
| FPGA Core Supply | DSP/ASIC Multi-Rail System |
|---|---|
Use Scenario: Powering Xilinx Versal or Intel Stratix 10 FPGA cores requiring tightly regulated 0.8V–1.2V at up to 100A with fast load-step response. IC Role / Device Role / Timing Role: Quad-phase controller managing four parallel DrMOS power stages; synchronizes switching to minimize input ripple and EMI. Use Value: Achieves <50mV output deviation during 0→50A/µs transients while maintaining <±1% current balance - extends FPGA lifetime and avoids timing violations. | Use Scenario: Delivering coordinated 1.0V/90A and 1.5V/30A rails to TI C66x DSPs or custom ASICs in telecom line cards. IC Role / Device Role / Timing Role: Dual-output configuration with TRACK/SS pin coupling enables coincident startup and voltage tracking within ±5mV. Use Value: Eliminates sequencing ICs; reduces BOM count and board area while guaranteeing safe power-up order between core and I/O supplies. |
| High-Density Server VR13/VR14 | AI Accelerator Module |
Use Scenario: Implementing VR13.0/VR14.0-compliant voltage regulator for AMD EPYC or Intel Xeon Scalable CPUs in 1U servers. IC Role / Device Role / Timing Role: Master-slave multiphase controller using daisy-chained CLKOUT/CLKIN across two LTC7851IUHH-1#TRPBF ICs for 8-phase operation. Use Value: Meets VR14 transient specification (ΔV ≤ ±15mV @ 100A/µs) with 400kHz switching and 0.22µH inductors - enables compact, high-efficiency CPU power delivery. | Use Scenario: Supplying NVIDIA A100 GPU memory (1.35V) and logic (0.8V) rails in edge AI inference modules with strict thermal envelope. IC Role / Device Role / Timing Role: Independent 4-phase control per rail; uses VINSNS feedforward and remote sensing to reject board-level noise and IR drop. Use Value: Maintains <±5mV regulation accuracy across 0–85°C ambient with airflow-limited cooling - prevents GPU throttling and inference latency spikes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multiphase step-down controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC7851EUHH-1#TRPBF | Same functionality and pinout; rated for 0°C to 85°C junction temperature instead of –40°C to 125°C. | Suitable for commercial-temperature environments only; not qualified for extended industrial or automotive use. | Select LTC7851IUHH-1#TRPBF when operating ambient exceeds 85°C or when long-term reliability under thermal cycling is required. |
| MP2960A from Monolithic Power Systems | Triple-output controller with integrated MOSFET drivers; lacks quad-phase capability and DrMOS-specific 4V/V gain calibration. | Targeted at mid-power applications (<60A); does not support daisy-chain synchronization or IAVG-based current sharing. | Choose MP2960A only for cost-sensitive, lower-current designs where external DrMOS integration and phase scalability are unnecessary. |
Compared with LTC7851EUHH-1#TRPBF and MP2960A, the LTC7851IUHH-1#TRPBF uniquely combines industrial temperature rating, DrMOS-optimized current sensing, and scalable quad-phase architecture - making it the only option for high-reliability, high-current, thermally demanding server and AI power systems.
Availability
LTC7851IUHH-1#TRPBF is available at Aetrix Electronics and suitable for high-current distributed power systems, FPGA/DSP core supplies, and datacom/telecom computing platforms requiring stable component supply, long lifecycle support, and guaranteed industrial-temperature performance.
Supply support for LTC7851IUHH-1#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 industrial, automotive, communications, and aerospace markets.
The LTC7851IUHH-1#TRPBF belongs to Analog Devices' Power by Linear™ multiphase controller family, engineered specifically for high-efficiency, high-current DC/DC conversion in advanced computing and AI infrastructure where precision current sharing and thermal robustness are critical.
FAQ
What is the key functional difference between LTC7851IUHH-1#TRPBF and LTC7851IUHH#TRPBF?
The LTC7851IUHH-1#TRPBF features a lower current sense amplifier gain of 4V/V (vs. 20V/V in LTC7851IUHH#TRPBF), optimized specifically for DrMOS devices with integrated current sense outputs. This eliminates need for external gain scaling and improves overcurrent detection accuracy when paired with FDMF5820DC or similar DrMOS stages. Both share identical pinout, package, and temperature rating.
Can LTC7851IUHH-1#TRPBF operate with discrete MOSFETs and external gate drivers?
Yes, LTC7851IUHH-1#TRPBF supports discrete N-channel MOSFETs with external gate drivers via its three-state PWM outputs (Pins 52/50/26/24). While optimized for DrMOS, it also accommodates lossless DCR or precision RSENSE current sensing. Ensure gate driver logic levels match the 3V–5.5V VCC range and that PWM timing constraints (min 20ns on-time) are met.
How is current sharing implemented across multiple LTC7851IUHH-1#TRPBF ICs?
Current sharing across multiple LTC7851IUHH-1#TRPBF ICs is achieved by daisy-chaining CLKOUT to CLKIN for synchronization, tying all IAVG pins together, and connecting ILIM pins to a common resistor. Only one IC operates as master (its ILIM pin sources 20µA); others act as slaves. The master's IAVG voltage becomes the shared current reference, and each slave integrates its current error to adjust duty cycle.
What is the purpose of the VINSNS pin on LTC7851IUHH-1#TRPBF?
The VINSNS pin (Pin 39) provides line feedforward compensation by sensing input voltage directly. A change in VIN modulates the PWM comparator input inversely and immediately - bypassing the feedback loop to significantly improve line transient response. An external RC filter may be added to suppress noise without degrading regulation speed.
Does LTC7851IUHH-1#TRPBF support output voltage tracking during startup?
Yes, LTC7851IUHH-1#TRPBF supports precise coincident tracking via its TRACK/SS pins (Pins 57/40/37/22). By connecting a resistor divider from a primary output to a secondary TRACK/SS pin - matching the divider ratio on that rail's VSNSP network - the secondary output ramps in lockstep with the primary, achieving <±5mV tracking error during startup without external circuitry.
LTC7851IUHH-1#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 58-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- PWM Signal
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 4
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 3V ~ 5.5V
- Frequency - Switching:
- 250kHz ~ 3MHz
- Duty Cycle (Max):
- 91.5%
- 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:
- 58-QFN (5x9)
LTC7851IUHH-1#TRPBF FAQ
1.How can I place an order for LTC7851IUHH-1#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC7851IUHH-1#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 LTC7851IUHH-1#TRPBF reliable?
The price and inventory of LTC7851IUHH-1#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC7851IUHH-1#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC7851IUHH-1#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC7851IUHH-1#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC7851IUHH-1#TRPBF?
LTC7851IUHH-1#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC7851IUHH-1#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 LTC7851IUHH-1#TRPBF?
For technical support, including LTC7851IUHH-1#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC7851IUHH-1#TRPBF requirements.
6.How does Aetrix verify that LTC7851IUHH-1#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC7851IUHH-1#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 LTC7851IUHH-1#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC7851IUHH-1#TRPBF?
All LTC7851IUHH-1#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC7851IUHH-1#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 LTC7851IUHH-1#TRPBF part is unused and in its original packaging.
Return procedure for LTC7851IUHH-1#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC7851IUHH-1#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…
