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Analog Devices Inc. LT8603EUJ#PBF
- Part No.:
- LT8603EUJ#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 40-WFQFN Exposed Pad
- Datasheet:
-
LT8603EUJ#PBF.pdf
- Description:
- IC REG BUCK ADJ QUAD 40QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,149
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Product details
Overview
LT8603EUJ#PBF from Analog Devices is a quad-output automotive-grade power management IC integrating two 42V synchronous buck regulators (1.5A and 2.5A), one 5.5V low-input buck regulator (1.8A), and a boost controller for cold-crank resilient supply generation. It delivers precise regulation across four outputs in compact 6mm × 6mm QFN, supporting automotive stop-start, infotainment, and ADAS domain controllers.
For engineers reviewing the LT8603EUJ#PBF datasheet, LT8603EUJ#PBF pinout, LT8603EUJ#PBF application, or LT8603EUJ#PBF equivalent, key selection considerations include its –40°C to 125°C operating range, AEC-Q100 qualification, 28µA quiescent current in Burst Mode®, 40-pin QFN package with exposed thermal pad, and configurable four-output topology enabling VBATT << VOUT operation during cold crank.
Technical Context
The LT8603EUJ#PBF implements three independent synchronous buck regulators with cycle-by-cycle current limiting and integrated high-side/low-side MOSFETs (RDS(ON) = 240mΩ/170mΩ for Ch1, 150mΩ/100mΩ for Ch2, 150mΩ/100mΩ for Ch3), plus a dedicated external-MOSFET boost controller with reverse-battery tolerance down to –42V and programmable switching frequency (250kHz–2.2MHz).
Its architecture supports multiple configurations: boost output powers the high-voltage bucks for cold-crank ride-through (e.g., 8V out at 2V input), or boost operates as SEPIC/boost to deliver fourth regulated output; TRKSS1/TRKSS2 pins enable tracking/soft-start; PG1–PG4 provide individual open-drain power-good signals with ±8% hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | Ch1/Ch2: 3.0V–42V; Ch3: 2.6V–5.5V; Boost sense: 2V–42V - enables direct battery connection and cold-crank support below 3V. |
| Output Current Capability | Ch1: 1.5A; Ch2: 2.5A; Ch3: 1.8A; Boost: external MOSFET - supports multi-rail SoC, MCU, and peripheral powering. |
| Quiescent Current | 28µA with high-voltage channels active in Burst Mode® - meets automotive ISO 16750-2 sleep current requirements. |
| Switching Frequency | 250kHz–2.2MHz (RT-programmable) - allows EMI optimization and small external component selection. |
| Operating Temperature | –40°C to +125°C junction - qualified per AEC-Q100 Grade E for under-hood automotive use. |
| Protection Features | Cycle-by-cycle current limit on all bucks; thermal shutdown; –42V reverse-battery tolerant boost controller - ensures robustness in harsh automotive environments. |
| Power Good Outputs | Four independent open-drain PG1–PG4 with 89–95% lower threshold and 104–110% upper threshold - enables precise sequencing and fault detection. |
Pinout & Package
LT8603EUJ#PBF is housed in a 40-lead 6mm × 6mm plastic QFN package with exposed thermal pad (UJ). All ground pins (Pins 2, 8, 13, 35, 38, and exposed pad 41) 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 indicators | Pull low until respective FB voltage reaches 92–110% of target - enables system-level power sequencing and fault reporting. |
| SW1, SW2 (Pins 3, 6–7), SW3 (Pin 36) | Buck switch nodes | Connect to external inductors; SW2 pins are paralleled for current sharing - defines critical high-di/dt routing zones. |
| BST1, BST2 (Pins 4, 5) | Bootstrap supplies for high-side MOSFETs | Require ceramic capacitor to respective SW node - sustains gate drive above input rail for synchronous rectification. |
| GATE4 (Pin 15) | Boost controller gate driver output | Drives external low-side N-channel MOSFET - requires careful layout to minimize shoot-through and EMI. |
| ISP4, ISN4 (Pins 19, 18) | Boost current-sense inputs | Accept sense resistor between input and inductor - sets peak current limit (43–57mV threshold) and enables overcurrent protection. |
| FSEL4A/FSEL4B (Pins 12, 17) | Boost enable and frequency select | Logic-controlled: both low = boost disabled; combinations set 250kHz/1MHz/2MHz - enables dynamic mode control. |
| TRKSS1/TRKSS2 (Pins 21, 20) | Track/soft-start inputs | 2.4µA pull-up; capacitor-to-ground sets soft-start time (~1ms typical) - prevents inrush and enables output tracking. |
| EN/UVLO (Pin 22) | Enable and input undervoltage lockout | 1.2V rising threshold; supports resistor divider from PVIN - provides precise startup control and brown-out protection. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade E qualification | Validated for automotive applications including stop-start and cold-crank (2V–42V input), ensuring reliability in under-hood environments. |
| Quad-output flexible topology | Configurable as triple buck + boost (cold-crank resilient) or quad buck (via SEPIC/boost), eliminating need for discrete backup supplies. |
| 28µA IQ in Burst Mode® | Enables >10-year battery standby life in always-on automotive modules without compromising regulation accuracy. |
| Individual channel power-good signals | Four independent PG outputs with programmable thresholds allow precise power sequencing and failure isolation in multi-rail systems. |
| Reverse-battery tolerant boost controller | Withstands –42V transients on ISP4/ISN4 - protects against jump-start faults and negative load-dump events. |
| Programmable soft-start and POR | TRKSS pins and CPOR capacitor enable adjustable ramp times; 31–39ms POR delay ensures clean system reset before firmware execution. |
Applications
| Automotive Infotainment Power Supply | ADAS Domain Controller Rail Generator |
|---|---|
Use Scenario: Powering head-unit SoC, display interface, and audio codec from 12V battery with cold-crank immunity. IC Role / Device Role / Timing Role: LT8603EUJ#PBF acts as primary quad-rail PMIC, delivering 5V/3.3V/1.2V/8V simultaneously while maintaining regulation during 2V battery dips. Use Value: Eliminates need for separate cold-crank boost stage; reduces BOM count by 3+ discrete regulators and associated sequencing logic. |
Use Scenario: Supplying radar processor, camera ISP, and CAN transceivers in centralized ADAS ECU with strict EMI and thermal constraints. IC Role / Device Role / Timing Role: LT8603EUJ#PBF provides tightly regulated, low-noise rails with synchronized switching (via SYNC pin) to minimize beat frequencies. Use Value: Achieves CISPR 25 Class 5 radiated emission compliance on DC2114A demo board; 2.2MHz max frequency enables ultra-small filter components. |
| Industrial PLC I/O Module Power | Telematics Control Unit (TCU) Hold-Up Supply |
Use Scenario: Generating isolated sensor bias, microcontroller core, and communication interface rails in DIN-rail mounted PLC. IC Role / Device Role / Timing Role: LT8603EUJ#PBF serves as main power hub, using boost channel to maintain 5V/3.3V during 100ms AC line dropout. Use Value: Delivers "last-gasp" hold-up without supercapacitors or backup batteries; leverages internal current limit and thermal shutdown for field reliability. |
Use Scenario: Providing continuous 3.3V to cellular modem and GNSS receiver during vehicle ignition-off state. IC Role / Device Role / Timing Role: LT8603EUJ#PBF operates in ultra-low-IQ Burst Mode® while monitoring EN/UVLO for wake-on-event, with RST signaling safe boot readiness. Use Value: Reduces parasitic drain to <30µA - extends parked vehicle battery life beyond 30 days without recharge. |
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#PBF | Dual 42V buck + dual 5.5V buck (no boost controller); 32-pin QFN; no cold-crank boost capability. | Suitable only when all rails sourced from stable intermediate bus; cannot regulate during sub-3V battery dips. | Select LT8602EUJ#PBF if cold-crank resilience is unnecessary and board space is constrained (32-pin vs 40-pin). |
| MAX20096ATGB/V+T | Triple 42V buck + LDO (not boost); 32-pin TQFN; integrated LDO replaces boost function but lacks –42V reverse tolerance. | Limited to applications where fourth rail is low-current and reverse-battery stress is mitigated externally. | Choose MAX20096ATGB/V+T when fourth output is ≤150mA and system-level reverse-battery protection exists. |
Compared with LT8602EUJ#PBF and MAX20096ATGB/V+T, the LT8603EUJ#PBF uniquely combines cold-crank-capable boost control with quad synchronous buck regulation in a single AEC-Q100 package - making it the only option for true 2V–42V four-rail automotive power without external boost stages.
Availability
LT8603EUJ#PBF is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS domain controllers, and industrial PLC power supplies requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant sourcing.
Supply support for LT8603EUJ#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 with precision power, sensing, and signal chain solutions.
The LT8603EUJ#PBF belongs to Analog Devices' Power by Linear™ automotive PMIC family, engineered specifically for demanding vehicle subsystems requiring cold-crank resilience, ultra-low quiescent current, and AEC-Q100 reliability.
FAQ
What is the maximum input voltage rating for LT8603EUJ#PBF's high-voltage buck channels?
The LT8603EUJ#PBF's Channel 1 and Channel 2 (PVIN1 and PVIN2) support an absolute maximum input voltage of 42V, with operational range from 3.0V to 42V. This enables direct connection to automotive battery rails and robustness during load-dump transients up to ±42V on boost sense inputs (ISP4/ISN4), as specified in the Absolute Maximum Ratings table.
Does LT8603EUJ#PBF support synchronization to an external clock source?
Yes, the LT8603EUJ#PBF supports external clock synchronization via the SYNC pin (Pin 33). When an external clock signal within 0.25MHz–2.2MHz is applied, the device synchronizes its internal oscillator and operates in pulse-skipping mode. This feature minimizes beat frequencies in multi-converter systems and aids CISPR 25 EMI compliance.
How is cold-crank operation achieved with LT8603EUJ#PBF?
The LT8603EUJ#PBF achieves cold-crank operation by configuring its boost controller (Channel 4) to generate a stable intermediate rail (e.g., 8V) from a collapsing battery (as low as 2V). This boosted rail then powers the high-voltage buck regulators (Channels 1 and 2), allowing them to maintain 5V and 3.3V outputs even when VBATT drops below their dropout voltage - demonstrated in Figure TA01b of the datasheet.
What is the purpose of the TRKSS1 and TRKSS2 pins on LT8603EUJ#PBF?
The TRKSS1 (Pin 21) and TRKSS2 (Pin 20) pins on the LT8603EUJ#PBF serve dual functions: soft-start control and output voltage tracking. Each pin features a 2.4µA internal pull-up current; connecting a capacitor to ground sets the soft-start ramp time (~1ms typical). When driven externally below 1V, they force the corresponding buck channel to regulate its FB pin to the TRKSS voltage instead of the internal reference, enabling precise power sequencing.
Is LT8603EUJ#PBF pin-compatible with other members of the LT860x family?
No, the LT8603EUJ#PBF is not pin-compatible with LT8602EUJ#PBF or LT8609EUJ#PBF. While sharing the same 40-lead 6mm × 6mm QFN (UJ) package footprint, pin assignments differ significantly - particularly for boost-related signals (GATE4, ISP4, ISN4, FSEL4A/B), PG outputs, and TRKSS inputs. PCB layout must be designed specifically for LT8603EUJ#PBF per its Pin Configuration diagram.
LT8603EUJ#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 ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 40-QFN (6x6)
LT8603EUJ#PBF FAQ
1.How can I place an order for LT8603EUJ#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8603EUJ#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 LT8603EUJ#PBF reliable?
The price and inventory of LT8603EUJ#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8603EUJ#PBF is usually 5 days.
3.What payment methods are accepted for LT8603EUJ#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8603EUJ#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8603EUJ#PBF?
LT8603EUJ#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8603EUJ#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 LT8603EUJ#PBF?
For technical support, including LT8603EUJ#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8603EUJ#PBF requirements.
6.How does Aetrix verify that LT8603EUJ#PBF is sourced from the original manufacturer or authorized distributors?
All LT8603EUJ#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 LT8603EUJ#PBF meets industry standards.
7.What is the process for return or replacement of LT8603EUJ#PBF?
All LT8603EUJ#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8603EUJ#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 LT8603EUJ#PBF part is unused and in its original packaging.
Return procedure for LT8603EUJ#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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