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Analog Devices Inc. LT8603JUJ#PBF
- Part No.:
- LT8603JUJ#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 40-WFQFN Exposed Pad
- Datasheet:
-
LT8603JUJ#PBF.pdf
- Description:
- 42V, L IQ, 4X OUT 3X MONO BUCK C
- Quantity:
- Payment:
- Shipping:
Inventory:3,897
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Product details
Overview
LT8603JUJ#PBF from Analog Devices is a quad-output power management IC integrating two 42V synchronous buck regulators (Ch1/Ch2), one 5.5V low-input buck regulator (Ch3), and a boost controller (Ch4), delivering up to four precisely regulated outputs. It supports automotive cold-crank operation with VBATT as low as 2V, delivers output currents up to 2.5A/1.5A/1.8A, and features 28µA quiescent current in Burst Mode®.
For engineers reviewing the LT8603JUJ#PBF datasheet, LT8603JUJ#PBF pinout, LT8603JUJ#PBF application, or LT8603JUJ#PBF equivalent, key selection considerations include its AEC-Q100 qualification, –40°C to 150°C junction temperature rating, 40-lead QFN package, and configurable four-output topology for automotive and industrial power systems.
Technical Context
The LT8603JUJ#PBF implements independent control loops per channel: Ch1/Ch2 use peak-current-mode control with cycle-by-cycle current limiting and adjustable switching frequency (250kHz–2.2MHz); Ch3 employs fixed-frequency current-mode control optimized for low-input operation; Ch4 functions as an external-MOSFET boost controller with programmable ILIM threshold (41mV typ. for J-grade) and reverse-battery tolerant inputs down to –42V.
Its architecture enables flexible system-level configurations - including boost-first supply for cold-crank resilience, SEPIC mode for four-output regulation across wide input ranges, and individual soft-start via TRKSS pins - while maintaining robust protection: thermal shutdown, overvoltage lockout, and integrated power-good indicators for all four channels.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | Ch1/Ch2: 3.0V–42V; Ch3: 2.6V–5.5V; Ch4 sense: 2V–42V - enables cold-crank support and multi-rail flexibility |
| Output Current Capability | Ch1: 1.5A; Ch2: 2.5A; Ch3: 1.8A; Ch4: external MOSFET dependent - defines maximum load per rail without derating |
| Quiescent Current | 28µA (all channels active, no load) - critical for always-on automotive modules requiring ultra-low standby power |
| Switching Frequency | 250kHz–2.2MHz (J-grade, RT-programmable) - allows EMI optimization and inductor size trade-offs |
| Junction Temp Range | –40°C to +150°C - qualified for under-hood automotive applications per AEC-Q100 Grade 1 |
| Power-Good Indicators | PG1–PG4 open-drain outputs with 92–95% lower threshold and 104–110% upper threshold - enables precise sequencing and fault detection |
| Current Sense Threshold | Ch4 ILIM = 41mV (J-grade) - sets accurate current limit for external boost MOSFETs |
Pinout & Package
LT8603JUJ#PBF 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, Exposed Pad 41) must be soldered to PCB ground for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PG1–PG4 (Pins 1,10,40,11) | Open-drain power-good indicators | Assert low until respective FB voltage reaches 92% of target; enable sequencing and fault monitoring |
| PVIN1/PVIN2 (Pins 37,14) | Independent high-voltage input supplies | Accept 3V–42V; decoupled locally to support high-current transient response |
| PVIN3 (Pin 34) | Low-voltage input supply | Accepts 2.6V–5.5V; typically powered by Ch1/Ch2 output for cascaded efficiency |
| ISP4/ISN4 (Pins 19,18) | Boost controller current sense inputs | Differential pair with ±42V tolerance; sets external MOSFET current limit via sense resistor |
| FSEL4A/FSEL4B (Pins 12,17) | Boost controller enable & frequency select | Logic-controlled: both low = shutdown; combinations set 250kHz/1MHz/2MHz operation |
| GATE4 (Pin 15) | External MOSFET gate driver | Drives low-side N-channel MOSFET in boost/SEPIC configuration; 5V logic swing referenced to INTVCC4 |
| TRKSS1/TRKSS2 (Pins 21,20) | Track/soft-start inputs | 2.4µA pull-up enables capacitor-programmed soft-start; also supports output voltage tracking |
| EN/UVLO (Pin 22) | Enable and input undervoltage lockout | 1.2V rising threshold enables full operation; resistor divider configures system-level UVLO |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualification | Validated for automotive under-hood operation at –40°C to +150°C junction temperature |
| Cold-crank resilient boost controller | Operates with VBATT as low as 2V; maintains regulated outputs during automotive start-stop events |
| Four independent power-good signals | PG1–PG4 provide per-channel status with hysteresis; enable safe power sequencing and diagnostics |
| Ultra-low IQ Burst Mode® | 28µA total input quiescent current with all channels active - extends battery life in always-on systems |
| Configurable four-output topology | Supports boost-first, SEPIC, or cascaded configurations to deliver four stable rails from single input |
| Reverse-battery and negative-transient tolerance | ISP4/ISN4 withstand –42V transients; enables robustness in harsh automotive environments |
Applications
| Automotive Cold-Crank Power Supply | Last-Gasp CPU Hold-Up |
|---|---|
Use Scenario: Maintaining 5V/3.3V/1.2V rails during engine cranking when battery drops to 2V–3V. IC Role / Device Role / Timing Role: LT8603JUJ#PBF acts as primary quad-output regulator with boost controller supplying VIN to high-voltage bucks. Use Value: Ensures uninterrupted microcontroller and sensor operation without brownout or reset during cranking. | Use Scenario: Providing short-term backup power to retain volatile memory and state during main power loss. IC Role / Device Role / Timing Role: LT8603JUJ#PBF regulates auxiliary 3.3V/1.8V rails from supercapacitor or small battery during hold-up. Use Value: Delivers >100ms hold-up time with controlled discharge and precise voltage regulation. |
| Industrial Control Power System | Automotive ADAS Domain Controller |
Use Scenario: Generating isolated 5V, 3.3V, 1.2V, and 8V rails for PLC I/O, FPGA, and analog front-ends. IC Role / Device Role / Timing Role: LT8603JUJ#PBF serves as central PMIC with programmable sequencing via TRKSS and PG signals. Use Value: Reduces BOM count by replacing four discrete regulators; improves layout density and thermal management. | Use Scenario: Powering camera, radar, and AI processor subsystems in centralized vehicle compute units. IC Role / Device Role / Timing Role: LT8603JUJ#PBF provides AEC-Q100-compliant, sequenced 1.2V core, 1.8V I/O, 3.3V interface, and 5V bias rails. Use Value: Meets functional safety requirements with per-rail PG monitoring and thermal derating up to 150°C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad-output power management applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8602JUJ#PBF | Triple-output version (two 42V bucks + one 5.5V buck); no boost controller; smaller 32-lead QFN | Lacks fourth regulated output capability; unsuitable for cold-crank or SEPIC topologies requiring boost | Select when only three rails are needed and board space is constrained |
| MAX20090ATGB/V+T | Quad-output automotive PMIC (3x buck + 1x boost); 40V max input; 125°C rated; different pinout and control interface | Requires external POR and lacks integrated RST/CPOR timing; no TRKSS-based soft-start | Select when needing pin-compatible upgrade path within Maxim's automotive portfolio |
Compared with LT8602JUJ#PBF and MAX20090ATGB/V+T, the LT8603JUJ#PBF uniquely combines AEC-Q100 Grade 1 rating, integrated boost controller with –42V transient tolerance, and four independent PG outputs - making it optimal for cold-crank-critical automotive systems requiring full four-rail regulation.
Availability
LT8603JUJ#PBF is available at Aetrix Electronics and suitable for automotive cold-crank power supplies, industrial control systems, and ADAS domain controllers requiring stable component supply across extended temperature ranges.
Supply support for LT8603JUJ#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 precision instrumentation, industrial automation, and automotive markets.
The LT8603JUJ#PBF belongs to Analog Devices' Power by Linear™ family of high-efficiency, high-reliability DC/DC regulators designed specifically for demanding automotive and industrial power applications.
FAQ
What is the maximum operating junction temperature for the LT8603JUJ#PBF?
The LT8603JUJ#PBF is rated for a maximum junction temperature of +150°C and is AEC-Q100 qualified for Grade 1 automotive applications. This specification is guaranteed across the full –40°C to +150°C operating range, unlike E- and I-grade variants limited to 125°C. Thermal design must ensure the exposed pad is properly soldered to a thermal plane to maintain reliability at elevated temperatures.
How does the LT8603JUJ#PBF support automotive cold-crank conditions?
The LT8603JUJ#PBF supports cold-crank operation by enabling its boost controller (Ch4) to generate a stable intermediate rail (e.g., 8V) even when VBATT drops to 2V. This boosted rail powers PVIN1/PVIN2, allowing the high-voltage buck regulators to maintain regulated 5V and 3.3V outputs during cranking. The boost controller tolerates –42V transients and starts up with VBATT as low as 2V, ensuring continuous system operation.
Can the LT8603JUJ#PBF generate four independent regulated outputs simultaneously?
Yes, the LT8603JUJ#PBF can generate four independent regulated outputs simultaneously. Channels 1–3 are monolithic synchronous buck regulators; Channel 4 is a boost controller driving an external MOSFET. When configured as a SEPIC or with Ch4 powering Ch1/Ch2, all four outputs remain regulated across input voltages from 2V to 42V - confirmed in the "Typical Application" section and cold-crank waveform (TA01b).
What is the purpose of the TRKSS1 and TRKSS2 pins on the LT8603JUJ#PBF?
The TRKSS1 and TRKSS2 pins on the LT8603JUJ#PBF provide track/soft-start functionality for Channels 1 and 2. When pulled below 1V, they override the internal 1V reference and force regulation to the TRKSS voltage instead - enabling output voltage tracking. A capacitor from TRKSS to GND programs soft-start time (~1ms typical), preventing inrush current and enabling controlled power-up sequencing.
Does the LT8603JUJ#PBF include integrated power-good indicators for all four channels?
Yes, the LT8603JUJ#PBF includes four dedicated open-drain power-good indicators: PG1 (Pin 1), PG2 (Pin 10), PG3 (Pin 40), and PG4 (Pin 11). Each asserts low until its corresponding feedback voltage reaches 92% of target (lower threshold) and releases when rising above 104–110%. These signals support precise power sequencing, fault detection, and system-level monitoring in automotive and industrial designs.
LT8603JUJ#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:
- 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 ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 40-QFN (6x6)
LT8603JUJ#PBF FAQ
1.How can I place an order for LT8603JUJ#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8603JUJ#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 LT8603JUJ#PBF reliable?
The price and inventory of LT8603JUJ#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8603JUJ#PBF is usually 5 days.
3.What payment methods are accepted for LT8603JUJ#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8603JUJ#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8603JUJ#PBF?
LT8603JUJ#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8603JUJ#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 LT8603JUJ#PBF?
For technical support, including LT8603JUJ#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8603JUJ#PBF requirements.
6.How does Aetrix verify that LT8603JUJ#PBF is sourced from the original manufacturer or authorized distributors?
All LT8603JUJ#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 LT8603JUJ#PBF meets industry standards.
7.What is the process for return or replacement of LT8603JUJ#PBF?
All LT8603JUJ#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8603JUJ#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 LT8603JUJ#PBF part is unused and in its original packaging.
Return procedure for LT8603JUJ#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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