My Inquiry
My Account
Analog Devices Inc. LTC7811IUJ#PBF
- Part No.:
- LTC7811IUJ#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 40-WFQFN Exposed Pad
- Datasheet:
-
LTC7811IUJ#PBF.pdf
- Description:
- LOW IQ TRIPLE BUCK-BOOST CTL
- Quantity:
- Payment:
- Shipping:
Inventory:109
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC7811IUJ#PBF from Analog Devices is a high-performance triple-output synchronous buck/buck/boost DC/DC controller driving all-N-channel MOSFET stages. It delivers 3.3V/6A, 5V/4A, and regulated 9.5V boost outputs from 1V–40V input, with 14μA no-load IQ, 3MHz max switching frequency, and AEC-Q100 qualification for automotive cold-crank operation.
For engineers reviewing the LTC7811IUJ#PBF datasheet, LTC7811IUJ#PBF pinout, LTC7811IUJ#PBF application, or LTC7811IUJ#PBF equivalent, key selection criteria include its triple-output topology, spread-spectrum EMI reduction, OPTI-LOOP® compensation, low-IQ sleep mode (1.5μA), and precise 0.8V/1.2V feedback references across buck and boost channels.
Technical Context
The LTC7811IUJ#PBF implements constant-frequency current-mode control with independent ITH error amplifier outputs per channel, enabling precise current sensing via RSENSE or DCR. Its phase-lockable oscillator supports 100kHz–3MHz operation, with programmable spread spectrum reducing peak conducted/radiated noise.
It integrates three independent gate drivers (TG/BG pairs), dual buck controllers with 0.8V reference and 40V output capability, and a boost controller with 1.2V reference (or fixed 8V/9.5V via VPRG3). The device features cold-crank support down to 1V VIN, low-battery detection (BATTSNS), and power-good signaling (PGOOD1, BATTGOOD).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V–40V bias supply; operates down to 1V after startup when biased from boost output or auxiliary rail. |
| Switching Frequency | Programmable 100kHz–3MHz; phase-lockable up to 3MHz for synchronized multi-rail systems. |
| No-Load Quiescent Current | 14μA (14V→3.3V, Channel 1 active); enables >1-year battery runtime in always-on automotive modules. |
| Feedback Reference Voltages | 0.8V ±12mV for buck channels; 1.2V ±18mV for boost (or fixed 8V/9.5V via VPRG3 pin). |
| Output Capability | Dual synchronous buck (up to 40V each) + single boost (voltage limited only by external components). |
| EMI Reduction | Integrated spread-spectrum modulation reduces peak radiated/conducted emissions to ease CISPR 25 Class 5 compliance. |
| Temperature Grade | AEC-Q100 qualified; specified for –40°C to +125°C junction temperature (LTC7811I grade). |
Pinout & Package
Package: 40-lead 6mm × 6mm QFN (UJ) with exposed thermal pad (Pin 41 = GND). RoHS-compliant, lead-free finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| MODE (1) | Light-load operation mode select | Configures Burst Mode (GND/floating), continuous conduction (INTVCC), or pulse-skipping (INTVCC via 100kΩ). |
| RUN1, RUN2, RUN3 (8–10) | Per-channel enable inputs | Disable individual buck/boost stages below 1.1V; full shutdown at <0.7V (IQ = 1.5μA). |
| VFB1, VFB2 (37, 13), VFB3 (5) | Buck/boost feedback inputs | Set output voltage via resistor divider; buck refs = 0.8V, boost ref = 1.2V (or fixed 8V/9.5V via VPRG3). |
| ITH1, ITH2, ITH3 (36, 14, 6) | Error amplifier outputs | Compensation points for OPTI-LOOP®; adjust transient response across wide output capacitance/ESR range. |
| TG1, TG2, BG1, BG2 (32, 18, 33, 19), BG3 (21) | N-MOSFET gate drivers | Drive top/bottom switches with 2Ω pull-up/pull-down; min on-times of 40ns (buck) / 80ns (boost). |
| SENSE1+/–, SENSE2+/–, SENSE3+/– (38/39, 12/11, 3/4) | Differential current sense inputs | Support RSENSE or DCR sensing; SENSE1– ≥3.2V enables sleep-mode current sourcing from buck input. |
| IMON3 (7) | Boost inductor current monitor | Analog voltage output (0.4V–1.4V) proportional to boost current; usable for telemetry or overcurrent protection. |
| BATTGOOD (17) | Low-battery status indicator | Open-drain output asserting low when BATTSNS <9.5V; hysteresis ensures clean transition at 9.75V. |
Key Features
| Feature | Design Value |
|---|---|
| Triple-output architecture | Independent buck/buck/boost control enables single-chip 3-rail power for ADAS ECUs, infotainment, and telematics. |
| Ultra-low quiescent current | 14μA operating IQ and 1.5μA shutdown IQ extend battery life in always-on automotive modules during sleep cycles. |
| Spread-spectrum modulation | Reduces EMI peak amplitudes by up to 15%, simplifying front-end filter design and easing CISPR 25 compliance. |
| OPTI-LOOP® compensation | Allows stable loop response across 10μF–1000μF output capacitors and 1mΩ–100mΩ ESR, eliminating custom tuning per design. |
| Cold-crank operation | Maintains regulation down to 1V input-critical for engine start-stop systems where battery dips below 6V. |
| AEC-Q100 qualification | Validated for automotive use (Grade I: –40°C to +125°C), including HTOL, temperature cycling, and ESD testing. |
Applications
| Automotive ADAS Camera Module | Industrial Programmable Logic Controller |
|---|---|
Use Scenario: Powering image sensor (3.3V), SoC core (5V), and interface transceiver (9.5V) in a compact rear-view camera ECU. IC Role / Device Role / Timing Role: Triple-output controller managing all rails with synchronized switching to minimize beat frequencies and EMI coupling. Use Value: Eliminates need for three discrete controllers; spread spectrum and low IQ meet OEM requirements for EMC and parking-mode battery drain. | Use Scenario: Generating 3.3V logic, 5V I/O, and 9.5V isolated RS-485 bus power in a DIN-rail mounted PLC with wide-input industrial supply. IC Role / Device Role / Timing Role: Primary power controller delivering tightly regulated, ripple-free outputs across 12V–36V input range with cold-start capability. Use Value: Single-chip solution reduces BOM count and PCB area; AEC-Q100 qualification ensures reliability in harsh factory environments. |
| Avionics Display Unit | Medical Portable Diagnostic Device |
Use Scenario: Supplying 3.3V FPGA, 5V LCD backlight driver, and 9.5V analog front-end in a certified cockpit display with strict EMI limits. IC Role / Device Role / Timing Role: High-reliability controller with phase-lockable frequency enabling synchronization to system clock to avoid interference in sensitive RF bands. Use Value: Spread spectrum + 3MHz switching minimizes conducted emissions into avionics data buses; 125°C rating supports convection-cooled enclosures. | Use Scenario: Powering low-noise analog sensors (3.3V), microcontroller (5V), and ultrasound transducer bias (9.5V) in a battery-operated handheld ultrasound probe. IC Role / Device Role / Timing Role: Ultra-low-IQ controller extending single-charge battery life while maintaining tight output regulation during variable load pulses. Use Value: 14μA no-load IQ enables >18-month shelf life; OPTI-LOOP® ensures stable response during rapid transducer firing events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar triple-output buck/buck/boost controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC7813IUJ#PBF | Same pinout, identical architecture, but supports higher 4.5V–60V input range and includes integrated LDO for VBIAS generation. | Better suited for 48V automotive or industrial systems requiring >40V input tolerance. | Select LTC7813IUJ#PBF when input exceeds 40V or when internal VBIAS LDO simplifies biasing. |
| MP2918GL-Z | Triple-output controller with lower 2.5V–36V input range, no spread spectrum, and 30μA typical IQ (vs 14μA). | Targeted at cost-sensitive consumer/industrial applications without automotive EMI or cold-crank requirements. | Choose MP2918GL-Z only for non-automotive designs where 40V+ input and sub-20μA IQ are not required. |
Compared with LTC7813IUJ#PBF and MP2918GL-Z, the LTC7811IUJ#PBF uniquely balances ultra-low IQ (14μA), 1V cold-crank operation, and integrated spread spectrum-making it the optimal choice for AEC-Q100-compliant automotive modules where battery longevity and EMC robustness are critical.
Availability
LTC7811IUJ#PBF is available at Aetrix Electronics and suitable for automotive ADAS systems, industrial programmable logic controllers, and avionics display units requiring stable component supply with long-term lifecycle assurance.
Supply support for LTC7811IUJ#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving automotive, industrial, communications, and healthcare markets.
The LTC7811IUJ#PBF belongs to Analog Devices' Power by Linear™ controller family, engineered specifically for high-efficiency, low-EMI, multi-rail power conversion in safety-critical automotive and industrial applications.
FAQ
What is the minimum input voltage required for LTC7811IUJ#PBF to operate after startup?
The LTC7811IUJ#PBF can operate from an input supply as low as 1V after startup when biased from the boost converter output or another auxiliary supply. This capability is essential for automotive cold-crank scenarios where battery voltage drops below 6V during engine cranking. The 4.5V–40V nominal VBIAS range applies only when powered directly from the main input rail.
How does the MODE pin configure light-load behavior in LTC7811IUJ#PBF?
The MODE pin on the LTC7811IUJ#PBF selects light-load operation mode for all three channels: grounded or floating enables Burst Mode® (lowest IQ), tied to INTVCC forces continuous conduction, and pulled to INTVCC via a 100kΩ resistor enables pulse-skipping. This single-pin control simplifies system-level efficiency optimization without requiring separate configuration per channel.
Can LTC7811IUJ#PBF generate a fixed 9.5V boost output without external resistors?
Yes. By connecting the VPRG3 pin (Pin 16) to INTVCC, the LTC7811IUJ#PBF configures the boost channel for a fixed 9.5V output, with VFB3 tied directly to the boost output. This eliminates the need for external resistor dividers and improves accuracy by removing resistor tolerance and thermal drift effects-ideal for stable reference rail generation.
What is the purpose of the SENSE1– pin in LTC7811IUJ#PBF beyond current sensing?
In addition to its role in differential current sensing, the SENSE1– pin on the LTC7811IUJ#PBF serves as a dynamic current source in sleep mode: when SENSE1– ≥ 3.2V, it supplies the majority of the controller's quiescent current instead of VBIAS, reducing input-referred IQ and extending battery life. This feature is unique to the buck1 channel and requires proper connection to a ≥3.2V output rail.
Does LTC7811IUJ#PBF support synchronization to an external clock source?
Yes. The PLLIN/SPREAD pin (Pin 26) accepts an external clock signal to synchronize the LTC7811IUJ#PBF's switching frequency from 100kHz to 3MHz. This enables noise spectral spreading across multiple converters in a system, preventing beat frequencies and simplifying EMI filtering-particularly valuable in multi-rail automotive ECUs where timing alignment is critical.
LTC7811IUJ#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 40-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck-Boost
- Number of Outputs:
- 3
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 1V ~ 40V
- Frequency - Switching:
- 100kHz ~ 3MHz
- Duty Cycle (Max):
- 100%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Frequency Control, Power Good, Soft Start
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 40-QFN (6x6)
LTC7811IUJ#PBF FAQ
1.How can I place an order for LTC7811IUJ#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC7811IUJ#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 LTC7811IUJ#PBF reliable?
The price and inventory of LTC7811IUJ#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC7811IUJ#PBF is usually 5 days.
3.What payment methods are accepted for LTC7811IUJ#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC7811IUJ#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC7811IUJ#PBF?
LTC7811IUJ#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC7811IUJ#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 LTC7811IUJ#PBF?
For technical support, including LTC7811IUJ#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC7811IUJ#PBF requirements.
6.How does Aetrix verify that LTC7811IUJ#PBF is sourced from the original manufacturer or authorized distributors?
All LTC7811IUJ#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 LTC7811IUJ#PBF meets industry standards.
7.What is the process for return or replacement of LTC7811IUJ#PBF?
All LTC7811IUJ#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC7811IUJ#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 LTC7811IUJ#PBF part is unused and in its original packaging.
Return procedure for LTC7811IUJ#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC7811IUJ#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…
