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Analog Devices Inc. LTC7815HUHF#TRPBF
- Part No.:
- LTC7815HUHF#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 38-WFQFN Exposed Pad
- Datasheet:
-
LTC7815HUHF#TRPBF.pdf
- Description:
- LOW IQ, 2.25MHZ, TRIPLE OUTPUT,
- Quantity:
- Payment:
- Shipping:
Inventory:1,274
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Product details
Overview
LTC7815HUHF#TRPBF from Analog Devices is a triple-output synchronous DC/DC controller implementing buck/buck/boost topology with all-N-channel MOSFET drive capability, 2.25MHz max switching frequency, 0.8V/1.2V precision references for buck and boost outputs respectively, and 28μA no-load quiescent current - enabling high-efficiency operation in automotive start-stop and battery-powered digital systems.
For engineers reviewing the LTC7815HUHF#TRPBF datasheet, LTC7815HUHF#TRPBF pinout, LTC7815HUHF#TRPBF application, or LTC7815HUHF#TRPBF equivalent, key selection considerations include its triple-output phase relationship (buck1/buck2 180° out-of-phase, boost in-phase with buck1), cold-crank input support down to 2.5V after startup, OPTI-LOOP compensation, and programmable light-load modes (Burst Mode®, pulse-skipping, forced continuous).
Technical Context
The LTC7815HUHF#TRPBF integrates three independent current-mode controllers: two synchronous buck channels with 180° interleaving to reduce input ripple and improve thermal distribution, and one synchronous boost channel operating in-phase with buck1. Each channel features dedicated ITH error amplifier output, SENSE± differential current sensing, and TRACK/SS control for soft-start and voltage tracking.
Its constant-frequency architecture supports phase-locking across all three channels via PLLIN/MODE, with frequency programmability from 320kHz to 2.25MHz using the FREQ pin. The controller maintains regulation during cold-crank events by sustaining operation down to 2.5V VBIAS when biased from boost output or auxiliary supply, while delivering 98% duty cycle in buck dropout and 100% duty cycle for boost top-side MOSFET even in Burst Mode®.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Topology | Buck/Buck/Boost triple-output synchronous controller - enables compact multi-rail power with shared gate drivers and coordinated timing. |
| Max Switching Frequency | 2.25MHz - supports ultra-small magnetics and high-density PCB layout; phase-lockable across all channels. |
| Input Voltage Range | 4.5V to 38V main bias; extends to 2.5V post-startup when biased from boost output - critical for automotive cold-crank survival. |
| Quiescent Current | 28μA (one buck channel active) - extends battery runtime in always-on systems without compromising transient response. |
| Feedback References | 0.8V ±1.2mV (buck), 1.2V ±18mV (boost) - enables precise, low-voltage rail generation with tight load regulation (±0.1%). |
| Duty Cycle Range | 98% (buck dropout), 100% (boost top-FET) - ensures regulation under extreme VIN–VOUT differentials and high-side conduction. |
| Package | 38-lead 5mm × 7mm QFN with exposed PGND pad - provides low thermal resistance (θJC = 2°C/W) for high-power density designs. |
Pinout & Package
Package: 38-lead plastic QFN (5mm × 7mm), exposed PGND pad (Pin 39) requiring solder connection to PCB for thermal and electrical performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FREQ (1) | Oscillator frequency programming | Resistor-to-GND sets 320kHz–2.25MHz; GND = 0.94MHz, INTVCC = 1.44MHz - enables precise EMI control and layout optimization. |
| PLLIN/MODE (2) | Phase-lock input / light-load mode select | External clock syncs all channels; floating or GND = Burst Mode®, INTVCC = forced CCM, mid-voltage = pulse-skipping - direct control of efficiency vs. noise trade-off. |
| SS3 (3) | Boost soft-start control | 5µA internal pull-up charges external capacitor - sets controlled ramp time for VOUT3, preventing inrush into downstream loads. |
| SENSE3+ (4) | Boost current sense positive input | Supplies current to comparator; used with SENSE3– to set peak current limit - supports RSENSE or DCR sensing with 50mV typical threshold. |
| SENSE3– (5) | Boost current sense negative input | Common-mode range 2.5V–40V - enables accurate sensing across full VIN range including cold-crank conditions. |
| VFB3 (6) | Boost feedback input | Compares against 1.2V reference; regulates VOUT3 to smaller of 1.2V or SS3 voltage - enables tracking or programmable overvoltage protection. |
| ITH3 (7) | Boost error amplifier output | Controls peak inductor current via current comparator; voltage range 0.7V–2V - defines current limit and loop stability margin. |
| SGND (8) | Small-signal ground reference | Separate return for analog circuitry (VFB, ITH, TRACK/SS) - prevents noise coupling from high-current PGND paths. |
| RUN1 (9) | Buck1 enable control | Threshold 1.21V rising; hysteresis 70mV - allows independent sequencing and fault isolation per channel. |
| RUN2 (10) | Buck2 enable control | Same threshold/hysteresis as RUN1 - enables staggered startup or dynamic channel disable for partial-load efficiency. |
| RUN3 (11) | Boost enable control | Same threshold/hysteresis as RUN1 - permits boost-only operation during low-VIN conditions. |
| SENSE2– (12) | Buck2 current sense negative input | Supplies current when VSENSE2– > INTVCC + 0.5V - supports high-side sensing and accurate current limiting at light loads. |
| SENSE2+ (13) | Buck2 current sense positive input | Differential input with ±1µA bias - minimizes offset errors in RSENSE-based current measurement. |
| VFB2 (14) | Buck2 feedback input | Compares against 0.8V reference; regulates VOUT2 to smaller of 0.8V or TRACK/SS2 voltage - enables output tracking or margining. |
| ITH2 (15) | Buck2 error amplifier output | Same function and range as ITH1/ITH3 - enables independent loop compensation per buck channel. |
| TRACK/SS2 (16) | Buck2 tracking/soft-start | 5µA internal pull-up; accepts external voltage divider - allows VOUT2 to track another supply during startup or hold soft-start profile. |
| OV3 (17) | Boost overvoltage indicator | Open-drain output asserting low when VFB3 exceeds 110% of setpoint - provides fail-safe monitoring without external comparator. |
| TG2 (18) | Buck2 top-gate driver output | Drives N-MOSFET gate with 2.4Ω pull-down, 2.5Ω pull-up - delivers fast transitions (25ns rise, 16ns fall) for high-frequency efficiency. |
| SW2 (19) | Buck2 switch node | Connects to inductor and BOOST2 capacitor - high dv/dt node requiring careful layout and snubber design. |
| BOOST2 (20) | Buck2 bootstrap supply | Charged via Schottky diode from INTVCC; supplies TG2 floating driver - enables high-side N-MOSFET drive above VIN. |
| BG2 (21) | Buck2 bottom-gate driver output | Drives N-MOSFET source to PGND; 1.1Ω pull-down, 2.4Ω pull-up - optimized for low-conduction loss in synchronous rectification. |
| INTVCC (22) | Internal LDO output (5.4V nominal) | Power source for logic and gate drivers; regulated from VBIAS or EXTVCC - requires ≥4.7µF ceramic decoupling to PGND. |
| EXTVCC (23) | External bias input for INTVCC LDO | Switchover at 4.7V; bypasses VBIAS LDO when active - reduces power loss and heat in high-input-voltage applications. |
| VBIAS (24) | Main bias supply input | 4.5V–38V range; powers internal LDO and startup circuitry - must be bypassed to SGND with ceramic capacitor. |
| BOOST3 (26) | Boost bootstrap supply | Charged from INTVCC; supports TG3 floating driver up to 71V - enables high-voltage boost operation with N-MOSFETs. |
| BG3 (25) | Boost bottom-gate driver output | Drives N-MOSFET source to PGND; 1.0Ω pull-down, 1.2Ω pull-up - optimized for high-side switching in boost configuration. |
| SW3 (28) | Boost switch node | Connects to inductor and output capacitor; withstands –5V to 65V - requires robust layout for high-voltage transients. |
| TG3 (27) | Boost top-gate driver output | 1.0Ω pull-down, 1.2Ω pull-up; 25ns rise/fall - ensures minimal dead-time loss and efficient 100% duty-cycle operation. |
| SENSE1– (38) | Buck1 current sense negative input | Same behavior and specs as SENSE2– - enables matched current sensing across interleaved buck stages. |
| PGND (39) | Power ground (exposed pad) | Must be soldered to PCB plane - provides primary thermal path (θJC = 2°C/W) and low-impedance return for all high-current paths. |
Key Features
| Feature | Design Value |
|---|---|
| Triple-output synchronization | Buck1/buck2 180° interleaving reduces input ripple by ~70% and improves thermal balance; boost in-phase with buck1 simplifies timing coordination. |
| OPTI-LOOP compensation | Adapts loop response to wide range of output capacitance (10µF–1000µF) and ESR (0.5mΩ–100mΩ) - eliminates manual compensation tuning across designs. |
| Cold-crank operation | Maintains regulation with VBIAS as low as 2.5V after startup - meets ISO 16750-2 automotive cranking requirements without auxiliary bias. |
| Multi-mode light-load control | Burst Mode® (28μA IQ), pulse-skipping, or forced CCM selectable per application - balances efficiency, noise, and transient response. |
| Robust protection suite | Integrated PGOOD1 (buck1), OV3 (boost), undervoltage lockout (4.15V rising), and foldback current limiting - reduces need for external supervision ICs. |
| Flexible current sensing | Supports RSENSE or DCR sensing on all channels with programmable gain; SENSE pins tolerate common-mode voltages up to 40V - simplifies high-side sensing. |
Applications
| Automotive Start-Stop Systems | Battery-Powered Digital Devices |
|---|---|
|
Use Scenario: Powering infotainment, ADAS, and telematics ECUs during engine cranking where battery voltage dips to 3.5V–6V for 15ms. IC Role / Device Role / Timing Role: Triple-output controller generating 5V (buck1), 3.3V (buck2), and 10V (boost) rails from 6V–16V battery, with cold-crank hold-up via 2.5V VBIAS operation. Use Value: Eliminates need for separate boost converter and enables single-chip solution for multi-rail automotive subsystems with <100µs recovery from load transients. |
Use Scenario: Supplying FPGA core (0.85V), I/O (1.8V), and DDR memory (1.2V) from a single Li-ion cell (2.7V–4.2V). IC Role / Device Role / Timing Role: Buck/buck/boost controller generating regulated rails with 28μA quiescent current in sleep mode and fast wake-up via RUN pin control. Use Value: Extends standby runtime by >3× versus standard controllers while maintaining <50µs transient response for processor wake events. |
| Distributed DC Power Systems | Multioutput Buck-Boost Applications |
|
Use Scenario: Converting 24V industrial bus to isolated 12V, 5V, and 3.3V rails for PLC I/O modules with strict EMI limits. IC Role / Device Role / Timing Role: Phase-locked triple-output controller operating at 2.1MHz with spread-spectrum capability (via FREQ pin) to meet CISPR-22 Class B conducted emissions. Use Value: Reduces filter size by 60% versus 500kHz solutions and enables single-layer PCB layout for cost-sensitive industrial controls. |
Use Scenario: Powering USB-C PD sink devices requiring 5V/9V/15V/20V outputs from variable input (5V–24V) such as portable power banks. IC Role / Device Role / Timing Role: Configurable buck/buck/boost controller with independent TRACK/SS pins enabling programmable output sequencing and voltage ramp rates. Use Value: Supports dynamic output reconfiguration without firmware changes, reducing BOM count and enabling universal adapter designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar triple-output synchronous controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC7813IUHF#TRPBF | Double-buck + single-boost; lower max frequency (1.5MHz); 40-pin QFN; rated for –40°C to 125°C only. | Lacks third independent buck channel; unsuitable for dual-core processor rails requiring strict 180° interleaving. | Select when triple-buck is unnecessary and cost sensitivity outweighs thermal grade requirement. |
| MP2918GL-Z | Dual-buck + single-boost; fixed 600kHz frequency; no PLL sync; 32-pin QFN; 2.5V–28V input; 100μA IQ. | No Burst Mode®; limited cold-crank support (min 3.0V); no OPTI-LOOP; lower integration (no PGOOD/OV outputs). | Select for non-automotive, cost-driven applications where 2.25MHz switching and cold-crank are not required. |
Compared with LTC7815HUHF#TRPBF, LTC7813IUHF#TRPBF offers lower cost but sacrifices 150°C operation and 2.25MHz flexibility, while MP2918GL-Z provides simpler implementation at the expense of efficiency, thermal robustness, and advanced protection features essential for automotive and industrial use.
Availability
LTC7815HUHF#TRPBF is available at Aetrix Electronics and suitable for automotive start-stop systems, battery-powered digital devices, and distributed DC power systems requiring stable component supply, extended temperature operation, and high-reliability packaging.
Supply support for LTC7815HUHF#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 (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving industrial, automotive, communications, and healthcare markets.
The LTC7815HUHF#TRPBF belongs to ADI's Power by Linear™ controller family, designed specifically for high-efficiency, multi-rail DC/DC conversion in thermally constrained and electrically noisy environments such as automotive and industrial edge systems.
FAQ
What is the maximum operating junction temperature for the LTC7815HUHF#TRPBF?
The LTC7815HUHF#TRPBF is rated for an operating junction temperature range of –40°C to 150°C, as indicated by the "H" grade suffix. This high-temperature rating enables reliable operation in under-hood automotive applications and high-power-density industrial converters where ambient temperatures exceed 105°C. Thermal derating begins above 125°C to ensure long-term reliability.
How does the LTC7815HUHF#TRPBF support cold-crank conditions in automotive systems?
The LTC7815HUHF#TRPBF supports cold-crank by maintaining regulation with VBIAS as low as 2.5V after initial startup - achieved when biased from the boost output or an auxiliary supply. Its undervoltage lockout threshold is 4.15V (rising), but internal circuitry remains functional below that level if powered externally, enabling uninterrupted operation during ISO 16750-2 cranking pulses.
Can the LTC7815HUHF#TRPBF synchronize all three channels to a single external clock?
Yes, the LTC7815HUHF#TRPBF can synchronize all three channels to a single external clock applied to the PLLIN/MODE pin. When an external clock is present, the internal phase-locked loop forces the rising edge of TG1 to align with the external clock's rising edge, and all regulators operate in forced continuous conduction mode - ensuring deterministic timing across buck1, buck2, and boost outputs.
What is the purpose of the EXTVCC pin on the LTC7815HUHF#TRPBF?
The EXTVCC pin on the LTC7815HUHF#TRPBF provides an alternative power path for the INTVCC LDO. When EXTVCC exceeds 4.7V, it bypasses the internal VBIAS-powered LDO, reducing power dissipation and heat generation - especially beneficial in high-input-voltage applications (e.g., 24V industrial buses) where VBIAS-to-INTVCC dropout would otherwise cause significant loss.
Does the LTC7815HUHF#TRPBF support both RSENSE and DCR current sensing?
Yes, the LTC7815HUHF#TRPBF supports both RSENSE and DCR current sensing on all three channels via its differential SENSE± inputs. The controller accommodates wide common-mode voltage ranges (up to 40V on SENSE3±) and provides programmable current thresholds through the ITH voltage, enabling accurate peak-current-mode control regardless of sensing method - critical for efficiency and stability across load conditions.
LTC7815HUHF#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 38-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck, Buck, Boost
- Number of Outputs:
- 3
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 4.5V ~ 38V
- Frequency - Switching:
- 320kHz ~ 2.25MHz
- Duty Cycle (Max):
- 100%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Power Good, Soft Start, Tracking
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 38-QFN (5x7)
LTC7815HUHF#TRPBF FAQ
1.How can I place an order for LTC7815HUHF#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC7815HUHF#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 LTC7815HUHF#TRPBF reliable?
The price and inventory of LTC7815HUHF#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC7815HUHF#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC7815HUHF#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC7815HUHF#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC7815HUHF#TRPBF?
LTC7815HUHF#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC7815HUHF#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 LTC7815HUHF#TRPBF?
For technical support, including LTC7815HUHF#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC7815HUHF#TRPBF requirements.
6.How does Aetrix verify that LTC7815HUHF#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC7815HUHF#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 LTC7815HUHF#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC7815HUHF#TRPBF?
All LTC7815HUHF#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC7815HUHF#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 LTC7815HUHF#TRPBF part is unused and in its original packaging.
Return procedure for LTC7815HUHF#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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