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Analog Devices Inc. LTC4381IDKE-4#PBF
- Part No.:
- LTC4381IDKE-4#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Surge Suppression Ics
- Package:
- 32-WFDFN Exposed Pad
- Datasheet:
-
LTC4381IDKE-4#PBF.pdf
- Description:
- LOW ICC, 1A SURGE STOPPER
- Quantity:
- Payment:
- Shipping:
Inventory:9,504
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Product details
Overview
LTC4381IDKE-4#PBF from Analog Devices is a low-quiescent-current eFuse IC with integrated 9mΩ N-channel MOSFET, fixed 6µA operating current, 4V–72V input range, and adjustable overvoltage clamp for automotive load dump protection in 12V/24V/48V systems.
For engineers reviewing the LTC4381IDKE-4#PBF datasheet, LTC4381IDKE-4#PBF pinout, LTC4381IDKE-4#PBF application, or LTC4381IDKE-4#PBF equivalent, key selection considerations include its auto-retry fault behavior, VCC-referenced output clamping (no internal GND-referenced clamp), MOSFET SOA guarantee (20ms @ 70V/1A), reverse input protection to –60V, and compatibility with high-surge environments up to 100V.
Technical Context
The LTC4381IDKE-4#PBF implements an adaptive fault timer using TMR pin current proportional to MOSFET power dissipation (VDS × ID), where VDS is sensed via DRN pin current through RDRN and ID is derived from ΔVSNS. It features a regulated 20µA gate charge pump delivering ∆VGATE = 11.1V (min) above OUT.
This variant (LTC4381-4) provides externally adjustable output clamp voltage via VCC pin Zener clamping, latches off only on undervoltage or ON pin reset, and supports auto-retry after cool-down - unlike latch-off variants LTC4381-1/LTC4381-3. Its SRC pin is clamped only to VCC + 10.5V, not to GND.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4V to 72V - enables operation through automotive cold crank (down to 4V) while supporting 48V industrial systems. |
| Quiescent Current | 6µA typical - allows use in always-on battery-powered applications without significant standby drain. |
| MOSFET On-Resistance | 9mΩ (typ), 13mΩ (max) - minimizes conduction loss and thermal stress at rated load currents. |
| Safe Operating Area | Guaranteed 20ms at 70V/1A - ensures robustness during sustained load dump transients per ISO 7637-2. |
| Fault Timer Threshold | TMR pin trips at 1.215V - triggers MOSFET turn-off and FLT assertion when integrated fault energy exceeds SOA limits. |
| Reverse Input Protection | –60V - eliminates need for external reverse-polarity diode in harsh automotive/industrial inputs. |
| Output Clamp Reference | VCC-referenced only (no internal GND clamp) - requires external Zener on VCC to set precise clamp voltage (e.g., 36V, 42V, 56V). |
Pinout & Package
32-lead (7mm × 5mm) plastic DFN package with exposed pad (pin 33) for thermal management. Pin count and layout match industry-standard DFN-32 footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN | MOSFET drain input | Connects to unregulated supply rail; withstands 100V surge transients. |
| SRC | MOSFET source output | Drives load through external sense resistor; clamped to VCC + 10.5V only. |
| SNS | Current sense input | Monitors voltage drop across sense resistor; sets 50mV/62mV current limit threshold. |
| OUT | Output voltage sense | Reference point for SNS, GATE, and DRN; bypassed with ≥22µF capacitor. |
| GATE | Internal MOSFET gate driver | Regulated 20µA charge pump delivers 11.1V–14V above OUT; requires 47nF + 33Ω compensation. |
| GFET | Internal MOSFET gate terminal | Connected to GATE via 10Ω resistor; internal node not user-accessible. |
| DRN | VDS sense monitor | Current proportional to VDS; used with RDRN to scale TMR fault timing. |
| TMR | Fault timer integrator | Capacitor-based timing node; charges to 1.215V to trigger shutdown and enter auto-retry cool-down. |
| FLT | Open-drain fault indicator | Pulls low during fault; high-Z otherwise; sinks up to 3mA for system-level fault signaling. |
| ON | Enable/disable control | 1.05V threshold; internal 1MΩ pull-up enables default-on operation; supports undervoltage lockout. |
| SEL | Clamp voltage select | No effect on LTC4381-4 - internally disconnected; may be tied to GND or VCC. |
| VCC | Bias supply input | 4V–72V operating range; Zener-clamped to set adjustable output clamp voltage (e.g., 68V Zener → ~78.5V clamp). |
| GND | Device ground reference | Common return for all analog and power paths; connects to exposed thermal pad. |
Key Features
| Feature | Design Value |
|---|---|
| Auto-retry fault recovery | Enables automatic restart after cool-down period - reduces manual intervention in remote or inaccessible systems. |
| VCC-referenced output clamp | Eliminates fixed GND-referenced clamp; allows precise, application-specific overvoltage protection via external Zener. |
| Reverse input protection to –60V | Replaces Schottky diode solution, removing 0.3–0.5V forward drop and associated power loss. |
| Guaranteed MOSFET SOA | Production-tested 20ms @ 70V/1A ensures reliability under worst-case automotive load dump conditions. |
| Low 6µA quiescent current | Extends battery life in always-on telematics, ADAS sensors, and infotainment modules. |
| Integrated 9mΩ MOSFET | Reduces BOM count and PCB area vs discrete eFuse solutions; eliminates gate drive design complexity. |
Applications
| Automotive Load Dump Protection | Industrial 48V DC Power Distribution |
|---|---|
Use Scenario: Protecting infotainment head units and ADAS ECUs from 100V/400ms load dump transients in 12V vehicle electrical systems. IC Role / Device Role / Timing Role: High-side eFuse providing overvoltage clamping, overcurrent limiting, and adaptive fault timing based on MOSFET power dissipation. Use Value: Eliminates need for external TVS diodes and reduces system cost by 30% versus discrete protection schemes while meeting ISO 7637-2 Pulse 5a requirements. |
Use Scenario: Safeguarding programmable logic controllers (PLCs) and motor drives connected to 48V industrial bus with ±10% tolerance and transient surges. IC Role / Device Role / Timing Role: Adjustable-voltage eFuse enabling precise clamp setting (e.g., 56V) via VCC Zener to avoid nuisance tripping during normal 48V regulation ripple. Use Value: Prevents damage from 80V+ surges while maintaining >98% efficiency due to 9mΩ RON, extending equipment uptime in factory automation. |
| Avionics Power Conditioning | Battery-Powered Telematics Module |
Use Scenario: Securing flight-critical avionics subsystems against 100V lightning-induced transients on 28V aircraft buses. IC Role / Device Role / Timing Role: Surge-hardened eFuse with guaranteed SOA and reverse polarity protection to –60V for dual-bus redundancy designs. Use Value: Meets DO-160 Section 22 Level 3 surge immunity without derating or parallel devices, simplifying certification. |
Use Scenario: Enabling ultra-low-power GPS tracking modules that remain active for >5 years on a single Li-SOCl₂ cell. IC Role / Device Role / Timing Role: Always-on eFuse with 6µA IQ and cold-crank operation down to 4V for vehicle ignition-off monitoring. Use Value: Reduces average system current by 85% vs legacy eFuses, directly extending battery service life in asset-tracking applications. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar eFuse applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS26631PWPR | Fixed 36V output clamp; no VCC-referenced adjustment; 1.2A max continuous current. | Designed for USB PD and PoE++ applications; lacks reverse input protection and SOA guarantee. | Select when fixed clamp voltage suffices and lower cost is prioritized over automotive-grade surge resilience. |
| LTC4381IDKE-2#PBF | Same package and pinout; includes internal 28.5V/47V GND-referenced clamp; identical auto-retry behavior. | Optimized for standard 12V/24V systems where adjustable clamp is unnecessary; eliminates external Zener. | Choose for simplified design in conventional automotive platforms where 28.5V or 47V clamping meets OEM specs. |
Compared with TPS26631PWPR, LTC4381IDKE-4#PBF offers superior surge resilience (100V), reverse polarity protection, and production-guaranteed SOA - critical for automotive and avionics. Versus LTC4381IDKE-2#PBF, it trades fixed clamp simplicity for precise, application-tailored overvoltage protection via VCC Zener.
Availability
LTC4381IDKE-4#PBF is available at Aetrix Electronics and suitable for automotive load dump protection, industrial 48V power distribution, avionics surge conditioning, and battery-powered telematics requiring stable component supply across extended temperature ranges.
Supply support for LTC4381IDKE-4#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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LTC4381 family is designed as a highly integrated, low-IQ eFuse platform for harsh-environment power path protection - specifically targeting automotive, avionics, and industrial systems demanding guaranteed SOA, reverse polarity immunity, and flexible overvoltage response.
FAQ
What is the output clamp voltage of LTC4381IDKE-4#PBF?
The LTC4381IDKE-4#PBF has no internal GND-referenced output clamp. Its output clamp voltage is set externally by clamping the VCC pin with a Zener diode - for example, a 68V Zener yields ~78.5V clamp (VCC + 10.5V). This enables precise, application-specific overvoltage protection without fixed-voltage limitations.
Does LTC4381IDKE-4#PBF support reverse input voltage protection?
Yes, LTC4381IDKE-4#PBF supports reverse input voltage protection down to –60V on the IN pin. This eliminates the need for an external Schottky diode, reducing forward voltage drop, power loss, and board space - especially valuable in battery-powered and automotive applications.
How does the fault timer in LTC4381IDKE-4#PBF respond to overvoltage events?
The LTC4381IDKE-4#PBF fault timer uses TMR pin current proportional to MOSFET power dissipation (VDS × ID). During overvoltage, DRN pin current scales with VDS, accelerating TMR charging. When TMR reaches 1.215V, the MOSFET turns off and FLT asserts - then enters auto-retry cool-down, discharging TMR before automatic restart.
What is the guaranteed safe operating area (SOA) for LTC4381IDKE-4#PBF?
LTC4381IDKE-4#PBF guarantees MOSFET SOA of 20ms at 70V and 1A - verified across production lots. This ensures reliable operation during sustained automotive load dump transients (ISO 7637-2 Pulse 5a), preventing thermal runaway even under worst-case VDS/ID stress.
Can LTC4381IDKE-4#PBF operate during automotive cold crank?
Yes, LTC4381IDKE-4#PBF operates continuously down to 4V input, making it fully compatible with automotive cold crank conditions. Its 6µA quiescent current and wide 4V–72V input range ensure uninterrupted protection for always-on modules like telematics and alarm systems during engine start.
LTC4381IDKE-4#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Package/Case:
- 32-WFDFN Exposed Pad
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Obsolete
- Voltage - Clamping:
- 100V
- Technology:
- External Switch
- Number of Circuits:
- 1
- Applications:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-DFN (7x5)
LTC4381IDKE-4#PBF FAQ
1.How can I place an order for LTC4381IDKE-4#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC4381IDKE-4#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 LTC4381IDKE-4#PBF reliable?
The price and inventory of LTC4381IDKE-4#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC4381IDKE-4#PBF is usually 5 days.
3.What payment methods are accepted for LTC4381IDKE-4#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC4381IDKE-4#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC4381IDKE-4#PBF?
LTC4381IDKE-4#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC4381IDKE-4#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 LTC4381IDKE-4#PBF?
For technical support, including LTC4381IDKE-4#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC4381IDKE-4#PBF requirements.
6.How does Aetrix verify that LTC4381IDKE-4#PBF is sourced from the original manufacturer or authorized distributors?
All LTC4381IDKE-4#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 LTC4381IDKE-4#PBF meets industry standards.
7.What is the process for return or replacement of LTC4381IDKE-4#PBF?
All LTC4381IDKE-4#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC4381IDKE-4#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 LTC4381IDKE-4#PBF part is unused and in its original packaging.
Return procedure for LTC4381IDKE-4#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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