My Inquiry
My Account
Analog Devices Inc. LT8471EUFD#PBF
- Part No.:
- LT8471EUFD#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 28-WFQFN Exposed Pad
- Datasheet:
-
LT8471EUFD#PBF.pdf
- Description:
- IC REG BUCK BOOST ADJ DL 28QFN
- Quantity:
- Payment:
- Shipping:
Inventory:593
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT8471EUFD#PBF from Analog Devices (formerly Linear Technology) is a dual-channel, multitopology PWM DC/DC controller IC with two integrated 2A/50V NPN power switches and one 500mA Skyhook boost switch. It supports independent buck, boost, SEPIC, ZETA, flyback, and inverting configurations per channel, enabling ±5V dual-rail generation from a single 6–32V input. Designed for local signal-chain power supplies requiring high topology flexibility and anti-phase ripple reduction.
For engineers reviewing the LT8471EUFD#PBF datasheet, LT8471EUFD#PBF pinout, LT8471EUFD#PBF application, or LT8471EUFD#PBF equivalent, key selection considerations include its 2.6–50V input range, programmable 100kHz–2MHz switching frequency via RT pin or external SYNC, dual-channel soft-start control, integrated power-good monitoring (PG1/PG2), and QFN-28 package thermal performance (θJA = 44°C/W).
Technical Context
The LT8471EUFD#PBF implements constant-frequency current-mode control for both primary channels, with anti-phase clocking (≈180° phase shift) to minimize input ripple. Each channel features independent error amplifiers, peak-current limiting, and voltage-mode Skyhook regulation delivering 4.25V (typ) above C2 for high-side switch biasing.
It integrates programmable UVLO/OVLO via the OV/UV pin, frequency foldback during startup, and thermal shutdown at ≈164°C. The Skyhook channel operates as a dedicated voltage-mode boost converter with internal Schottky diode, 500mA current limit, and SHOUT-C2 regulation-enabling reliable high-side operation in buck/ZETA/inverting topologies without external charge pumps.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.6V to 50V - Supports wide industrial and automotive input rails; VIN1 powers all circuitry including Skyhook. |
| Primary Switch Rating | 2A, 50V - Enables ≥1.5A continuous output in buck/boost/SEPIC with margin; VCE(SAT) = 300mV @ 1.5A. |
| Skyhook Switch Rating | 500mA, 50V - Provides regulated ~4.25V boost above C2 to drive high-side NPN bases; VCE(SAT) = 250mV @ 250mA. |
| Switching Frequency Range | 100kHz to 2MHz - Set by RT resistor (e.g., 46.4kΩ → 1.8MHz) or synchronized externally; foldback reduces min duty cycle during startup. |
| Feedback Reference Voltage | +789mV / −788mV - Precision reference for positive/negative output regulation; enables accurate ±1% output tolerance with external dividers. |
| Power Good Threshold | ±7.5% window - PG1/PG2 open-drain outputs assert low when FB voltage falls below 92.5% of target; supports system sequencing and fault detection. |
| Operating Temperature | −40°C to +125°C - Qualified for extended industrial environments; thermal shutdown activates at ≈164°C with hysteresis. |
Pinout & Package
LT8471EUFD#PBF is housed in a 28-lead (4mm × 5mm) plastic QFN package with exposed thermal pad (Pin 29 = GND). The package provides low thermal resistance (θJA = 44°C/W, θJC = 8°C/W) and requires soldering the exposed pad to PCB ground for electrical integrity and thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| C1, C2 (Pins 1, 20) | Primary Channel Collector Outputs | Switch node connections for CH1/CH2 NPN transistors; require minimized trace area for EMI control; C2 ties to Skyhook input when enabled. |
| E1, E2 (Pins 2, 19) | Primary Channel Emitter Outputs | Emitter terminals of CH1/CH2 NPN switches; must be grounded or routed with minimal loop area to reduce noise coupling. |
| FB1, FB2 (Pins 5, 16) | Output Voltage Feedback Inputs | High-impedance inputs sensing resistive divider ratios; set positive output with +789mV ref, negative with −788mV ref. |
| PG1, PG2 (Pins 4, 17) | Open-Drain Power-Good Indicators | Assert low when respective output deviates >7.5% from target; require external pull-up resistors for system monitoring. |
| SHOUT (Pin 14) | Skyhook Boost Output | Cathode of integrated Schottky diode; delivers regulated voltage ~4.25V above C2; must connect to VIN1/VIN2 for high-side biasing. |
| RT (Pin 7) | Oscillator Timing Input | Resistor-to-ground sets free-running frequency (fOSC = 85.5/(RT+1) MHz); floating not allowed. |
| SYNC (Pin 9) | External Clock Input | Accepts 100kHz–2MHz digital clock; high >1.3V enables sync mode; low <0.4V reverts to internal oscillator. |
| SS1, SS2 (Pins 8, 15) | Soft-Start Control Inputs | Capacitor-connected pins controlling ramp rate of duty cycle and current limit; internal 250kΩ pull-up charges to ~2.15V. |
| VIN1, VIN2 (Pins 3, 18) | Channel Power Inputs | VIN1 powers CH1, Skyhook, and core logic; must be ≥2.6V to operate any function. VIN2 powers CH2 only; optional if CH2 unused. |
| OV/UV (Pin 6) | Programmable Enable/UVLO/OVLO | Resistor-divider input enabling device at ≥1.215V; configurable for precise undervoltage lockout and overvoltage protection. |
| GND (Pins 10–12, 21, 29) | Ground Connections | Multiple dedicated GND pins plus exposed thermal pad (Pin 29); all must connect directly to PCB ground plane for stability and thermal management. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 2A/50V NPN switches | Enables flexible multitopology design (buck/boost/SEPIC/flyback/inverting) per channel without external transistors. |
| Integrated 500mA Skyhook boost regulator | Generates stable ~4.25V above C2 to bias high-side NPN switches in buck/ZETA/inverting topologies-eliminates external charge pump. |
| Anti-phase switching between channels | Reduces input capacitor RMS current and input ripple by ≈70% compared to in-phase operation-lowers EMI and bulk cap stress. |
| Programmable UVLO/OVLO via OV/UV pin | Allows user-defined input voltage thresholds using external resistor divider-supports custom brown-in/brown-out behavior and fault isolation. |
| Independent soft-start on SS1/SS2 | External capacitors control ramp rate of current limit and duty cycle per channel-prevents inrush current and enables staggered startup sequencing. |
| Frequency foldback during startup | Automatically reduces switching frequency (by factor of 2/4/8) when FB voltage is low-improves controllability at light loads and eases capacitor charging. |
Applications
| Industrial Signal Chain Power | Automotive Infotainment Rails |
|---|---|
Use Scenario: Generating isolated ±5V rails for precision ADCs, DACs, and op-amps in PLC I/O modules. IC Role / Device Role / Timing Role: Dual-rail DC/DC controller managing independent buck and inverting channels to deliver clean, low-noise analog supply domains. Use Value: Anti-phase switching minimizes input ripple on shared 24V bus; integrated PG1/PG2 enables coordinated power sequencing with FPGA or MCU. |
Use Scenario: Providing regulated +5V and −5V for audio codecs and display timing controllers in head-unit designs. IC Role / Device Role / Timing Role: Multitopology controller supporting buck (for +5V) and inverting (for −5V) from 6–16V battery input with cold-crank tolerance. Use Value: 2.6V minimum input ensures operation during cranking; Skyhook enables reliable high-side buck operation without external bias circuitry. |
| Medical Imaging Sensor Bias | Test Equipment Dual Supply |
Use Scenario: Powering CCD/CMOS sensor bias voltages (+12V, −8V) in portable ultrasound probes. IC Role / Device Role / Timing Role: Configured as boost (CH1) and inverting (CH2) to generate asymmetric rails from single Li-ion battery input (3–4.2V). Use Value: Wide 2.6–50V input accommodates battery pack variations; frequency synchronization eliminates beat frequencies with imaging clocks. |
Use Scenario: Delivering tightly regulated ±15V for op-amp test fixtures and calibration equipment. IC Role / Device Role / Timing Role: Dual-channel controller operating in buck (CH1) and boost (CH2) modes to maintain rail accuracy across load steps. Use Value: Independent soft-start (SS1/SS2) prevents cross-regulation during power-on; PG1/PG2 signals validate rail readiness before DUT connection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-channel DC/DC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3892EUF#PBF | Two synchronous step-down controllers (no inverting/Skyhook); supports up to 60V input; requires external MOSFETs. | Better suited for high-efficiency, high-current buck-only systems; lacks native negative rail or Skyhook support. | Select when efficiency >90% and >5A per rail are required; avoid when inverting topology or compact Skyhook biasing is needed. |
| MAX20406AWE+T | Single 3.5A buck controller with integrated FETs; no second channel or Skyhook; supports 3.5–36V input. | Lower BOM count for single-rail applications; cannot generate dual-polarity outputs without additional ICs. | Choose for cost-sensitive, space-constrained single-rail designs; not viable for dual-rail or inverting topologies without added components. |
Compared with LTC3892EUF#PBF and MAX20406AWE+T, the LT8471EUFD#PBF uniquely combines dual independent multitopology control, integrated NPN switches, and an on-chip Skyhook boost-making it the only solution capable of generating ±5V from 6–32V in a single QFN-28 package without external bias circuitry or discrete transistors.
Availability
LT8471EUFD#PBF is available at Aetrix Electronics and suitable for industrial signal chain power, automotive infotainment rails, and medical imaging sensor bias applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.
Supply support for LT8471EUFD#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, formed through the acquisition of Linear Technology in 2017.
The LT8471EUFD#PBF belongs to ADI's Power by Linear™ portfolio of highly integrated DC/DC controllers, designed specifically for space-constrained, multitopology local power applications where flexibility, reliability, and reduced external component count are critical.
FAQ
What topologies does the LT8471EUFD#PBF support per channel?
The LT8471EUFD#PBF supports buck, boost, SEPIC, ZETA, flyback, and inverting configurations independently on each of its two primary channels. This is enabled by its dual 2A/50V NPN switches and flexible pinout-C1/E1 and C2/E2 allow direct connection to inductor and transformer windings without topology-specific external components. The LT8471EUFD#PBF does not support synchronous rectification or Cuk topologies.
How does the Skyhook channel function in the LT8471EUFD#PBF?
The Skyhook channel in the LT8471EUFD#PBF is a dedicated 500mA voltage-mode boost regulator that delivers a regulated output (SHOUT) approximately 4.25V above the C2 pin voltage. It powers the base of high-side NPN switches in buck, ZETA, or single-inductor inverting configurations-eliminating the need for external charge pumps. When unused, C3 must be tied to GND to disable it and reduce quiescent current in the LT8471EUFD#PBF.
Can the LT8471EUFD#PBF generate both positive and negative outputs simultaneously?
Yes-the LT8471EUFD#PBF can generate simultaneous positive and negative outputs from a single input rail. For example, CH1 can be configured as a buck converter for +5V while CH2 operates as an inverting converter for −5V, as shown in the typical application circuit (6V–32V to ±5V). The LT8471EUFD#PBF achieves this using separate feedback networks (FB1/FB2) with +789mV and −788mV references, and independent power-good indicators (PG1/PG2).
What is the purpose of anti-phase switching in the LT8471EUFD#PBF?
Anti-phase switching in the LT8471EUFD#PBF means the two primary channels operate with ≈180° phase offset, reducing input capacitor RMS current and peak-to-peak ripple by up to 70% compared to in-phase operation. This lowers EMI emissions, extends bulk capacitor lifetime, and allows smaller input filtering-critical in dense layouts like industrial PLCs or automotive ECUs where the LT8471EUFD#PBF is commonly deployed.
How is frequency synchronization implemented on the LT8471EUFD#PBF?
Frequency synchronization on the LT8471EUFD#PBF is achieved by driving the SYNC pin (Pin 9) with a clean digital clock signal between 100kHz and 2MHz. The high-level threshold is 1.3V and low-level is 0.4V; duty cycle must be 35–65%. When SYNC is held low (<0.4V), the LT8471EUFD#PBF reverts to its internal RT-set oscillator. Driving SYNC high for extended periods halts switching-useful for controlled shutdown sequences.
LT8471EUFD#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Down, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Boost, Flyback, SEPIC
- Output Type:
- Adjustable
- Number of Outputs:
- 2
- Voltage - Input (Min):
- 2.6V
- Voltage - Input (Max):
- 50V
- Voltage - Output (Min/Fixed):
- 2.6V
- Voltage - Output (Max):
- 50V (Switch)
- Current - Output:
- 1.35A (Switch), 2.1A (Switch)
- Frequency - Switching:
- 100kHz ~ 2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-QFN (4x5)
LT8471EUFD#PBF FAQ
1.How can I place an order for LT8471EUFD#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8471EUFD#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 LT8471EUFD#PBF reliable?
The price and inventory of LT8471EUFD#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8471EUFD#PBF is usually 5 days.
3.What payment methods are accepted for LT8471EUFD#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8471EUFD#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8471EUFD#PBF?
LT8471EUFD#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8471EUFD#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 LT8471EUFD#PBF?
For technical support, including LT8471EUFD#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8471EUFD#PBF requirements.
6.How does Aetrix verify that LT8471EUFD#PBF is sourced from the original manufacturer or authorized distributors?
All LT8471EUFD#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 LT8471EUFD#PBF meets industry standards.
7.What is the process for return or replacement of LT8471EUFD#PBF?
All LT8471EUFD#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8471EUFD#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 LT8471EUFD#PBF part is unused and in its original packaging.
Return procedure for LT8471EUFD#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT8471EUFD#PBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
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…
