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Analog Devices Inc. LT8603EUJ#TRPBF
- Part No.:
- LT8603EUJ#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 40-WFQFN Exposed Pad
- Datasheet:
-
LT8603EUJ#TRPBF.pdf
- Description:
- IC REG BUCK ADJ QUAD 40QFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,947
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Product details
Overview
LT8603EUJ#TRPBF from Analog Devices is a 42V, low-IQ, quad-output power management IC integrating two high-voltage synchronous buck regulators (up to 2.5A and 1.5A), one low-voltage synchronous buck regulator (up to 1.8A), and a boost controller - all in a single 40-lead QFN package. It delivers precise regulation during automotive cold-crank (VBATT down to 2V) and supports four regulated outputs via flexible configuration including SEPIC or boost-fed architecture.
For engineers reviewing the LT8603EUJ#TRPBF datasheet, LT8603EUJ#TRPBF pinout, LT8603EUJ#TRPBF application, or LT8603EUJ#TRPBF equivalent, key selection criteria include cold-crank tolerance (2V–42V input), channel-specific quiescent current (28µA total with Burst Mode®), AEC-Q100 qualification (E-grade, –40°C to +125°C), and independent power-good indicators per output.
Technical Context
The LT8603EUJ#TRPBF implements three independent synchronous buck regulators with cycle-by-cycle current limiting and thermal shutdown, plus a dedicated external-MOSFET boost controller supporting reverse-battery tolerance (–42V) and negative transients. Its architecture enables simultaneous operation of all four channels with programmable soft-start, trackable voltage sequencing via TRKSS1/TRKSS2, and configurable switching frequency (250kHz–2.2MHz) using RT resistor or SYNC input.
Each buck channel features separate PVIN inputs, internal error amplifiers referencing 1.0V (Ch1/Ch2) or 0.8V (Ch3), and open-drain PG outputs with ±8% hysteresis. The boost controller uses ISP4/ISN4 for current sensing, GATE4 for NMOS gate drive, and FB4 for 0.8V regulation - enabling seamless integration into automotive supply systems requiring last-gasp hold-up and stop-start compatibility.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | Ch1/Ch2: 3.0V–42V; Ch3: 2.6V–5.5V; Boost (ISP4/ISN4): 2V–42V - supports cold-crank down to 2V without dropout. |
| Output Current Capability | Ch1: 1.5A; Ch2: 2.5A; Ch3: 1.8A; Boost: external MOSFET-dependent - enables multi-rail CPU/SOC core, I/O, and interface power. |
| Quiescent Current | 28µA total with high-voltage channels active in Burst Mode® - meets automotive always-on system requirements. |
| Switching Frequency | 250kHz–2.2MHz (RT-programmable or SYNC-synchronized) - allows EMI optimization and small external component selection. |
| Operating Temperature | –40°C to +125°C (E-grade) - qualified per AEC-Q100 Grade 1 for under-hood automotive use. |
| Power Good Indicators | Four independent open-drain PG1–PG4 outputs with 8% hysteresis - enables reliable system-level power sequencing and fault detection. |
| Protection Features | Cycle-by-cycle current limit (all bucks), thermal shutdown, –42V reverse-battery tolerance (boost controller), UVLO on EN/UVLO, RUN3, POREN - ensures robust operation in harsh environments. |
Pinout & Package
LT8603EUJ#TRPBF is housed in a thermally enhanced 40-lead (6mm × 6mm) plastic QFN package with exposed pad (UJ). All ground pins (Pins 2, 8, 13, 35, 38) and the exposed pad must be soldered to PCB ground for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PG1, PG2, PG3 (Pins 1, 10, 40) | Open-drain Power Good outputs | Assert low until respective FB voltage reaches 92% of target; enable safe system boot and rail monitoring. |
| SW1, SW2 (Pins 3, 6–7), SW3 (Pin 36) | Buck switch nodes | Connect to external inductors; SW2 pins are paralleled for current sharing in dual-phase Ch2 implementation. |
| BST1, BST2 (Pins 4, 5) | Bootstrap supplies | Drive high-side MOSFET gates; require ceramic capacitor from BSTx to corresponding SWx. |
| GATE4 (Pin 15) | Boost low-side gate driver | Drives external NMOS; swing from GND to INTVCC4 (4.6V–5V) - requires gate resistor for dV/dt control. |
| ISP4, ISN4 (Pins 19, 18) | Boost current sense inputs | Differential pair measuring sense-resistor voltage; threshold is 43–57mV (E-grade) for overcurrent protection. |
| FSEL4A/FSEL4B (Pins 12, 17) | Boost enable & frequency select | Logic inputs controlling boost activation and switching frequency (off / 1MHz / 2MHz); support shutdown and dynamic reconfiguration. |
| TRKSS1/TRKSS2 (Pins 21, 20) | Track/soft-start inputs | Enable voltage tracking or soft-start via external capacitor; 2.4µA internal pull-up sets ramp rate. |
| EN/UVLO (Pin 22) | Global enable & input UVLO | 1.2V precision rising threshold; used for system-level undervoltage lockout or sequenced startup. |
Key Features
| Feature | Design Value |
|---|---|
| Cold-crank tolerant triple output | Maintains regulation on Ch1–Ch3 even when VBATT drops to 2V - critical for automotive start-stop and cranking scenarios. |
| Quad-output flexibility | Configurable as three regulated bucks + boost (for VIN supply) or four independent regulated outputs (e.g., boost as SEPIC or fed from buck output). |
| Ultra-low quiescent current | 28µA total IQ with Ch1/Ch2 active - extends battery life in always-on telematics and infotainment modules. |
| Independent power sequencing | TRKSS1/TRKSS2 and RUN3 enable precise voltage ramp timing and inter-rail dependency control for complex SoC power-up. |
| AEC-Q100 qualified | E-grade (–40°C to +125°C) with full characterization - certified for automotive safety-critical power rails. |
| Robust fault protection | –42V reverse-battery tolerance on ISP4/ISN4, thermal shutdown, and cycle-by-cycle current limiting on all bucks - eliminates need for external protection circuitry. |
Applications
| Automotive Infotainment Power Supply | ADAS Domain Controller Rail Generator |
|---|---|
Use Scenario: Powering CPU cores, DDR memory, and display interfaces in head-unit systems subject to cold-crank and load-dump events. IC Role / Device Role / Timing Role: Quad-output PMIC delivering 5V (USB), 3.3V (I/O), 1.2V (core), and 8V (LCD bias) with synchronized soft-start and independent PG signaling. Use Value: Eliminates need for four discrete regulators; maintains 1.2V core rail at 2V VBATT via boost-fed architecture. | Use Scenario: Supplying multiple voltage domains (e.g., radar SoC, camera ISP, CAN transceivers) in autonomous driving ECUs. IC Role / Device Role / Timing Role: Centralized power manager providing sequenced 1.8V (SoC), 3.3V (peripherals), 5V (sensors), and 12V (actuators) with fault reporting via PG1–PG4. Use Value: Reduces BOM count by 70% vs discrete solution; AEC-Q100 qualification ensures reliability in ASIL-B systems. |
| Industrial PLC I/O Module | Medical Portable Diagnostic Device |
Use Scenario: Generating isolated sensor bias, microcontroller VDD, communication interface rails, and analog front-end supplies in harsh factory environments. IC Role / Device Role / Timing Role: High-reliability quad regulator with wide input range (9–36V DC), thermal protection, and reverse-polarity immunity. Use Value: Withstands 42V transients and –42V reverse connections - avoids field failures due to wiring errors or surge events. | Use Scenario: Battery-powered ultrasound or patient monitor requiring ultra-low sleep current and fast wake-up response. IC Role / Device Role / Timing Role: Low-IQ power manager delivering 3.3V (MCU), 1.8V (ADC/DAC), 5V (USB charging), and 12V (transducer bias) with programmable POR delay. Use Value: 28µA no-load IQ extends battery runtime; CPOR capacitor sets precise 35.2ms reset timeout for deterministic boot. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad-output automotive power management applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8602EUJ#TRPBF | Triple-output (no boost controller); lacks Channel 4 and ISP4/ISN4/GATE4 pins - cannot generate fourth regulated rail or support cold-crank hold-up. | Suitable only for three-rail systems; cannot replace LT8603EUJ#TRPBF in boost-dependent architectures. | Select only if fourth output is unnecessary and board space allows separate boost IC. |
| MAX20404ATPA/VY+ | Quad buck-only (no boost); integrates all four controllers but limited to 5.5V max input - no cold-crank capability below 5.5V. | Applicable in non-automotive industrial or consumer systems with stable >5.5V input; fails during automotive cranking. | Use where input stays above 6V; avoid in vehicle battery-supplied designs. |
Compared with LT8602EUJ#TRPBF and MAX20404ATPA/VY+, the LT8603EUJ#TRPBF uniquely combines cold-crank-tolerant quad regulation with integrated boost control - enabling single-chip solutions for automotive systems requiring last-gasp operation and four independent rails.
Availability
LT8603EUJ#TRPBF is available at Aetrix Electronics and suitable for automotive infotainment, ADAS domain controllers, and industrial PLC I/O modules requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LT8603EUJ#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 healthcare markets.
The LT8603EUJ#TRPBF belongs to Analog Devices' Power by Linear™ family of high-efficiency, high-reliability DC/DC regulators designed specifically for demanding automotive and industrial power systems requiring cold-crank resilience and AEC-Q100 compliance.
FAQ
What is the minimum input voltage required for LT8603EUJ#TRPBF to start regulating all four channels?
The LT8603EUJ#TRPBF requires ≥3.1V on PVIN1/PVIN2 to start Channels 1 and 2, ≥2.6V on PVIN3 for Channel 3, and ≥4.15V on the boost input (e.g., VBATT) to initiate Channel 4 operation. However, once started, Channel 4 can sustain regulation down to 2V input - enabling cold-crank operation. The LT8603EUJ#TRPBF's ability to maintain output regulation below its startup threshold is a key differentiator for automotive applications.
How does LT8603EUJ#TRPBF achieve 28µA quiescent current while powering multiple outputs?
The LT8603EUJ#TRPBF achieves 28µA total IQ through Burst Mode® operation on its high-voltage buck channels, combined with optimized internal biasing and low-leakage design. When light loads are present, the LT8603EUJ#TRPBF skips switching cycles while maintaining regulation - reducing average input current. This is measured with Channels 1 and 2 active and no load, per datasheet conditions.
Can LT8603EUJ#TRPBF generate four independent regulated outputs without external components beyond inductors and capacitors?
Yes - the LT8603EUJ#TRPBF can generate four regulated outputs using its integrated boost controller (Channel 4) driven from one of the buck outputs (e.g., Ch1 5V → boost → 12V), or configured as a SEPIC. No additional controller IC is needed; only external MOSFET, inductor, sense resistor, and feedback divider are required for Channel 4. The LT8603EUJ#TRPBF datasheet provides complete reference designs for both configurations.
What is the purpose of the TRKSS1 and TRKSS2 pins on LT8603EUJ#TRPBF?
The TRKSS1 and TRKSS2 pins on LT8603EUJ#TRPBF provide track/soft-start functionality for Channels 1 and 2. When pulled below 1V, they override the internal 1.0V reference and force regulation to the TRKSS voltage - enabling voltage tracking between rails. Adding a capacitor to ground programs soft-start time (~1ms ramp per 1nF). Each pin has a 2.4µA internal pull-up, simplifying sequencing design. This feature is integral to the LT8603EUJ#TRPBF's role in complex SoC power-up sequences.
Is LT8603EUJ#TRPBF pin-compatible with other members of the LT860x family?
No - the LT8603EUJ#TRPBF is not pin-compatible with LT8602 or LT8609 variants. Its 40-pin QFN layout includes dedicated pins for boost control (GATE4, ISP4, ISN4, FSEL4A/B, FB4) and dual-track inputs (TRKSS1/TRKSS2) absent in other family members. Pin mapping, thermal pad configuration, and functional pin assignments are unique to the LT8603EUJ#TRPBF. Migration requires PCB redesign.
LT8603EUJ#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 40-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck-Boost
- Number of Outputs:
- 4
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 3V ~ 42V
- Frequency - Switching:
- 250kHz ~ 2.2MHz
- Duty Cycle (Max):
- -
- Synchronous Rectifier:
- Yes
- Clock Sync:
- Yes
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Power Good, Soft Start
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 40-QFN (6x6)
LT8603EUJ#TRPBF FAQ
1.How can I place an order for LT8603EUJ#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8603EUJ#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 LT8603EUJ#TRPBF reliable?
The price and inventory of LT8603EUJ#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8603EUJ#TRPBF is usually 5 days.
3.What payment methods are accepted for LT8603EUJ#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8603EUJ#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8603EUJ#TRPBF?
LT8603EUJ#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8603EUJ#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 LT8603EUJ#TRPBF?
For technical support, including LT8603EUJ#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8603EUJ#TRPBF requirements.
6.How does Aetrix verify that LT8603EUJ#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT8603EUJ#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 LT8603EUJ#TRPBF meets industry standards.
7.What is the process for return or replacement of LT8603EUJ#TRPBF?
All LT8603EUJ#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8603EUJ#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 LT8603EUJ#TRPBF part is unused and in its original packaging.
Return procedure for LT8603EUJ#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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