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Analog Devices Inc. LT8640IUDC-1#TRPBF
- Part No.:
- LT8640IUDC-1#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 20-WFQFN, 18 Leads, Exposed Pad
- Datasheet:
-
LT8640IUDC-1#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 5A 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:5,256
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Product details
Overview
LT8640IUDC-1#TRPBF from Analog Devices is a 42V, 5A synchronous step-down Silent Switcher regulator with forced continuous mode (FCM), 2.5µA quiescent current in regulation, 30ns minimum on-time, and AEC-Q100 qualification for automotive power supplies delivering stable 3.3V/5V outputs from 12VIN–36VIN sources.
For engineers reviewing the LT8640IUDC-1#TRPBF datasheet, LT8640IUDC-1#TRPBF pinout, LT8640IUDC-1#TRPBF application, or LT8640IUDC-1#TRPBF equivalent, key selection criteria include ultralow EMI performance in automotive ECU designs, FCM-enabled fast load transient response in ADAS camera modules, and compatibility with 3MHz switching using 1µH inductors in space-constrained infotainment systems.
Technical Context
The LT8640IUDC-1#TRPBF implements peak current mode control with internal 0.97V reference and 200kHz–3MHz programmable frequency via RT resistor. Its forced continuous mode eliminates pulse skipping, enabling consistent switching during light-load transients and supporting output soft-start/tracking via TR/SS pin.
Silent Switcher architecture integrates split VIN and GND paths with internal bypass capacitors to suppress common-mode EMI; spread spectrum modulation (±22% frequency dither) further reduces radiated emissions without compromising efficiency-verified per CISPR 25 Class 5 limits in horizontal/vertical polarization tests.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.4V to 42V - supports wide automotive battery range including cold-crank (4.5V) and load-dump (40V) conditions |
| Output Current | 5A continuous, 7A peak - sustains burst loads in radar sensor power rails without dropout |
| Quiescent Current | 2.5µA at full regulation - enables >10-year battery life in always-on telematics modules |
| Min On-Time | 30ns - allows 12VIN→1.0VOUT conversion at 2MHz with high duty-cycle accuracy |
| EMI Performance | CISPR 25 Class 5 compliant - eliminates need for external EMI filters in Tier-1 automotive designs |
| Thermal Rating | –40°C to 125°C junction - qualified for under-hood engine control unit (ECU) mounting |
| Switching Frequency | 200kHz–3MHz (RT-programmable) - enables optimization between inductor size and efficiency in compact layouts |
Pinout & Package
LT8640IUDC-1#TRPBF uses an 18-lead 3mm × 4mm plastic QFN package with exposed SW pads (pins 21, 22) requiring PCB solder connection for thermal management. Pin 5 and pin 12 are omitted per JEDEC outline mismatch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BIAS (1) | Internal regulator bias supply | Connect to VOUT ≥3.3V to reduce VIN current draw and improve light-load efficiency |
| INTVCC (2) | Internal 3.4V LDO output | Bypass with ≥1µF ceramic capacitor; powers gate drivers and control logic |
| BST (3) | Bootstrap voltage node | Requires 0.1µF capacitor to SW for top-FET gate drive above VIN |
| VIN1/VIN2 (4,13) | Main input power inputs | Each requires dedicated 1µF local ceramic bypass; shared bulk cap connects both |
| GND1/GND2 (6,7,10,11) | Power switch return paths | Must be tied together and connected to low-impedance ground plane for EMI suppression |
| SW (8,9,21,22) | Switch node outputs | Pins 8/9 and exposed pads 21/22 must be shorted on PCB; critical for thermal and EMI performance |
| EN/UV (14) | Enable and input UVLO input | Hysteresis of 40mV; threshold 1.00V rising enables operation above 3.4VIN |
| RT (15) | Frequency programming | Resistor to GND sets fSW: 221k = 210kHz, 60.4k = 700kHz, 18.2k = 2.0MHz |
| TR/SS (16) | Soft-start and tracking | 1.9µA internal current source enables capacitor-programmed slew rate; pulled low during fault |
| SYNC/MODE (17) | Operating mode control | Ground = Burst Mode; float = FCM; INTVCC-high = FCM + spread spectrum; driven = sync |
| GND (18) | System ground reference | Connect to system ground plane; separate from power GNDs but tied at single point |
| PG (19) | Power good indicator | Open-drain output active when FB within ±7.5% of 0.97V and VIN >3.4V |
| FB (20) | Feedback reference node | Regulated to 0.970V ±0.006V; connect divider tap and 4.7pF–22pF phase-lead cap to VOUT |
Key Features
| Feature | Design Value |
|---|---|
| Forced Continuous Mode (FCM) | Enables zero-current dead time elimination for <10µs load-step response in ADAS vision processors |
| Silent Switcher Architecture | Reduces peak radiated EMI by >30dB vs conventional buck converters at 100MHz–1GHz |
| Spread Spectrum Modulation | ±22% frequency dither lowers EMI peaks without affecting average efficiency or thermal performance |
| AEC-Q100 Grade I Qualification | Validated for automotive applications including engine control, infotainment, and body electronics |
| 30ns Minimum On-Time | Supports high-frequency, high-step-down ratios (e.g., 24VIN→1.2VOUT @ 2MHz) with minimal duty-cycle error |
Applications
| Automotive Engine Control Unit (ECU) | ADAS Camera Power Supply |
|---|---|
Use Scenario: Regulating 12VIN to 5V/3.3V for microcontroller, CAN transceiver, and sensor interface in under-hood ECU. IC Role / Device Role / Timing Role: Primary DC/DC converter providing isolated, low-noise, high-reliability power with AEC-Q100 compliance. Use Value: 2.5µA IQ extends battery backup runtime during vehicle sleep mode; FCM ensures immediate response to ignition wake-up signals. | Use Scenario: Powering high-speed image sensor and ISP in forward-facing collision avoidance camera. IC Role / Device Role / Timing Role: Main 5V rail generator with tight output ripple (<10mVP-P) and fast transient recovery for pixel clock stability. Use Value: Spread spectrum + Silent Switcher meets OEM EMI requirements without shielding cans, reducing BOM cost and board area. |
| Infotainment System Core Rail | Telematics Control Unit (TCU) |
Use Scenario: Generating 1.0V core supply for application processor in head-unit infotainment system. IC Role / Device Role / Timing Role: High-efficiency, high-frequency buck converter operating at 2MHz to minimize inductor size. Use Value: 30ns min on-time enables 12VIN→1.0VOUT conversion at 2MHz with <±1% output error across temperature. | Use Scenario: Providing always-on 3.3V supply for cellular modem and GNSS receiver in TCU with 10-year battery life target. IC Role / Device Role / Timing Role: Ultra-low-IQ regulator maintaining regulation during vehicle park mode with periodic wake-ups. Use Value: 2.5µA IQ directly enables >10-year coin-cell or supercapacitor backup lifetime in disconnected state. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8640S-1#TRPBF | LQFN package with side-wettable leads; identical electrical specs and FCM capability | Enhanced manufacturability for automated optical inspection (AOI) in high-volume automotive production | Select when IPC-A-610 Class 3 solder joint inspection is required |
| MPQ4420AGL-AEC1-Z | 42V/2A AEC-Q100 buck; no spread spectrum; 17µA IQ; 100ns min on-time | Limited to lower current loads; higher IQ increases battery drain in always-on systems | Select only for cost-sensitive, non-EMI-critical 2A applications where footprint matches |
Compared with LT8640S-1#TRPBF, LT8640IUDC-1#TRPBF offers identical regulation performance in standard QFN but lacks side-wettable leads for AOI; versus MPQ4420AGL-AEC1-Z, it delivers 7× lower IQ, 3.3× shorter min on-time, and integrated EMI suppression-critical for radar and camera subsystems.
Availability
LT8640IUDC-1#TRPBF is available at Aetrix Electronics and suitable for automotive engine control units, ADAS camera modules, and infotainment systems requiring stable component supply with AEC-Q100 qualification and long-term lifecycle support.
Supply support for LT8640IUDC-1#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, industrial automation, and automotive markets.
The LT8640/LT8640-1 product line was designed specifically for automotive and industrial applications demanding ultralow EMI, high efficiency at light loads, and robust operation across extreme temperature ranges.
FAQ
What is the maximum output current capability of the LT8640IUDC-1#TRPBF?
The LT8640IUDC-1#TRPBF delivers 5A continuous output current and supports 7A peak transient current. This rating is validated over the full –40°C to 125°C junction temperature range with proper PCB thermal design-including soldering the exposed SW pads (21, 22) to a thermal plane-and using recommended input/output capacitance per the datasheet layout guidelines.
How does the SYNC/MODE pin configure forced continuous mode on the LT8640IUDC-1#TRPBF?
On the LT8640IUDC-1#TRPBF, forced continuous mode (FCM) is activated by leaving the SYNC/MODE pin (pin 17) floating-no external connection required. Internal leakage remains below 1µA, ensuring stable FCM operation. Grounding the pin enables Burst Mode for ultralow IQ, while applying 3V–4V enables FCM with spread spectrum modulation.
Does the LT8640IUDC-1#TRPBF require external compensation components?
No, the LT8640IUDC-1#TRPBF uses internal compensation and requires no external loop compensation components. Stability is ensured across all operating conditions with only the recommended feedback resistors (R1/R2) and a 4.7pF–22pF phase-lead capacitor from FB to VOUT, as specified in the datasheet's standard application circuit.
What thermal derating applies to the LT8640IUDC-1#TRPBF at 150°C ambient?
The LT8640IUDC-1#TRPBF is rated for –40°C to 125°C junction temperature. At 150°C ambient, junction temperature exceeds specification unless thermal resistance is reduced below 20°C/W (via enhanced copper area, multiple vias, and airflow). Derating curves in the datasheet show >50% output current reduction is required above 125°C case temperature to maintain reliability.
Can the LT8640IUDC-1#TRPBF be synchronized to an external clock source?
Yes, the LT8640IUDC-1#TRPBF supports external clock synchronization: drive the SYNC/MODE pin (pin 17) with a TTL/CMOS-compatible clock signal (200kHz–3MHz). During sync, the device operates in forced continuous mode with switching edges aligned to the external clock, enabling deterministic timing in multi-rail power systems.
LT8640IUDC-1#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- Silent Switcher®1
- Package/Case:
- 20-WFQFN, 18 Leads, Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.4V
- Voltage - Input (Max):
- 42V
- Voltage - Output (Min/Fixed):
- 0.97V
- Voltage - Output (Max):
- 42V
- Current - Output:
- 5A
- Frequency - Switching:
- 210kHz ~ 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QFN (3x4)
LT8640IUDC-1#TRPBF FAQ
1.How can I place an order for LT8640IUDC-1#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8640IUDC-1#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 LT8640IUDC-1#TRPBF reliable?
The price and inventory of LT8640IUDC-1#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8640IUDC-1#TRPBF is usually 5 days.
3.What payment methods are accepted for LT8640IUDC-1#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8640IUDC-1#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8640IUDC-1#TRPBF?
LT8640IUDC-1#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8640IUDC-1#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 LT8640IUDC-1#TRPBF?
For technical support, including LT8640IUDC-1#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8640IUDC-1#TRPBF requirements.
6.How does Aetrix verify that LT8640IUDC-1#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT8640IUDC-1#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 LT8640IUDC-1#TRPBF meets industry standards.
7.What is the process for return or replacement of LT8640IUDC-1#TRPBF?
All LT8640IUDC-1#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8640IUDC-1#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 LT8640IUDC-1#TRPBF part is unused and in its original packaging.
Return procedure for LT8640IUDC-1#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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