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Analog Devices Inc. LT8640EUDCF-1#TRPBF
- Part No.:
- LT8640EUDCF-1#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 20-WFQFN, 18 Leads, Exposed Pad
- Datasheet:
-
LT8640EUDCF-1#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 5A 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,829
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Product details
Overview
LT8640EUDCF-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 side-wettable 18-lead QFN (3mm × 4mm) package. It delivers up to 96% efficiency at 1MHz (12VIN→5VOUT) and supports automotive-grade operation from –40°C to 125°C.
For engineers reviewing the LT8640EUDCF-1#TRPBF datasheet, LT8640EUDCF-1#TRPBF pinout, LT8640EUDCF-1#TRPBF application, or LT8640EUDCF-1#TRPBF equivalent, key selection criteria include ultralow EMI performance, FCM for fast transient response, spread spectrum capability, input voltage range (3.4V–42V), and AEC-Q100-compliant thermal robustness.
Technical Context
The LT8640EUDCF-1#TRPBF implements peak current mode control with an internal 0.970V reference and programmable switching frequency (200kHz–3MHz via RT resistor). Its Silent Switcher architecture uses integrated bypass capacitors and symmetrical layout to suppress radiated EMI without external filters.
Unlike the LT8640, the LT8640-1 variant (including LT8640EUDCF-1#TRPBF) defaults to forced continuous mode when SYNC/MODE is floating, enabling negative inductor current and improved load-step response. It disables FCM only above 35V VIN or when FB rises >9.5% above reference.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.4V to 42V - supports wide industrial and automotive battery inputs including cold-crank and load-dump conditions. |
| Output Current | 5A continuous, 7A peak - sustains high transient loads without dropout or thermal shutdown. |
| Quiescent Current | 2.5µA at full regulation - enables always-on systems (e.g., telematics, ADAS sensors) with multi-year battery life. |
| Min. On-Time | 30ns - enables high-frequency, high-VIN-to-low-VOUT conversion (e.g., 42V→3.3V at 2MHz). |
| EMI Performance | CISPR 25 Class 5 compliant - meets stringent automotive radiated/conducted EMI limits without ferrite beads or shielding. |
| Thermal Rating | –40°C to 125°C junction - qualified per AEC-Q100 Grade E, suitable for under-hood and infotainment applications. |
| Switching Frequency | 200kHz to 3MHz (RT-programmable) - allows optimization of size (high-freq) vs. efficiency (low-freq) and avoids AM band interference. |
Pinout & Package
LT8640EUDCF-1#TRPBF uses an 18-lead, 3mm × 4mm plastic side-wettable QFN package (LHGX marking) with exposed SW pads (pins 21, 22) for enhanced thermal dissipation and solder-joint inspection.
| 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 power rail | Bypass with ≥1µF ceramic capacitor; powers control logic and gate drivers - not for external loading. |
| BST (3) | Bootstrap capacitor node | Requires 0.1µF ceramic cap between BST and SW to drive high-side NMOS gate above VIN. |
| VIN1 (4), VIN2 (13) | Main input power inputs | Each requires dedicated 1µF local ceramic bypass; shared bulk input cap connects to both. |
| GND1 (6,7), GND2 (10,11), GND (18) | Power and signal ground returns | Must be tied together and connected to low-impedance PCB ground plane; critical for EMI and thermal performance. |
| SW (8,9,21,22) | Switch node outputs | High-current path connecting internal MOSFETs to inductor and BST cap; exposed pads (21,22) must be soldered to SW copper for thermal integrity. |
| EN/UV (14) | Enable and input undervoltage lockout | Hysteretic threshold (0.96V/1.00V) enables programmable VIN start-up and brownout protection. |
| RT (15) | Frequency programming | Resistor to GND sets switching frequency (e.g., 60.4kΩ = ~2MHz); determines inductor size and efficiency trade-off. |
| TR/SS (16) | Soft-start and output tracking | Capacitor here controls VOUT ramp rate; also accepts external voltage for power sequencing with other rails. |
| SYNC/MODE (17) | Operating mode selection | Floating = FCM; grounded = Burst Mode; 3–4V = spread spectrum + FCM; driven clock = external sync - no pulse-skipping (LT8640-only feature). |
| PG (19) | Power good indicator | Open-drain output asserts high when VOUT is within ±8% of regulation and no fault exists - used for system power sequencing. |
| FB (20) | Feedback reference node | Regulated to 0.970V; resistor divider from VOUT sets output voltage; 4.7pF–22pF phase-lead cap improves stability. |
Key Features
| Feature | Design Value |
|---|---|
| Silent Switcher® Architecture | Integrated input capacitors and symmetrical layout reduce radiated EMI by >30dB vs. conventional buck regulators - eliminates need for metal shielding. |
| Forced Continuous Mode (FCM) | Enables negative inductor current and fast load-step response (<50µs recovery for 1A step) - critical for CPU/GPU core supplies and radar modules. |
| Spread Spectrum Modulation | ±20% triangular frequency dithering reduces peak EMI amplitude - helps pass CISPR 25 Class 5 without compromising switching frequency or efficiency. |
| Ultralow Quiescent Current | 2.5µA IQ at full regulation enables >10-year battery life in always-on automotive modules (e.g., CAN gateway, occupancy sensors). |
| Side-Wettable QFN Package | LHGX package enables automated optical inspection (AOI) of solder joints - improves manufacturing yield and field reliability in automotive production. |
Applications
| Automotive ADAS Camera Power | Industrial PLC I/O Module |
|---|---|
Use Scenario: Powering 3.3V image sensor and ISP in forward-facing camera with strict EMI limits and cold-crank survival. IC Role / Device Role / Timing Role: Primary 42V-input buck converter delivering regulated 3.3V/2A with <10mVP-P ripple and <50µs transient response. Use Value: Silent Switcher architecture meets CISPR 25 Class 5 without added filter components; FCM ensures stable imaging during rapid acceleration/deceleration events. | Use Scenario: Generating isolated 5V/3A rail for digital I/O circuitry in DIN-rail mounted programmable logic controller. IC Role / Device Role / Timing Role: High-efficiency, wide-input DC/DC stage converting 24VDC field bus to clean 5V system rail. Use Value: 3.4V–42V input range accommodates 24V nominal with ±25% tolerance; 95% efficiency at 2MHz reduces heatsink requirements in confined enclosures. |
| Telematics Control Unit (TCU) | GSM Base Station RF Power Amplifier Bias |
Use Scenario: Always-on 5V/1.5A supply for LTE modem, GNSS receiver, and CAN transceiver in vehicle connectivity module. IC Role / Device Role / Timing Role: Primary power rail with ultra-low IQ and AEC-Q100 qualification for 15-year automotive service life. Use Value: 2.5µA quiescent current extends backup battery life beyond ISO 16750-2 requirements; side-wettable QFN ensures solder joint reliability over thermal cycling. | Use Scenario: Providing low-noise, fast-response 5V bias for GaN RF power amplifier stages in small-cell base stations. IC Role / Device Role / Timing Role: High-frequency (2MHz) buck regulator minimizing output inductance while maintaining <10mVP-P ripple. Use Value: 30ns min on-time enables direct 28V→5V conversion at 2MHz; spread spectrum mode suppresses switching harmonics near cellular bands (700–2700MHz). |
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 |
|---|---|---|---|
| LT8640EUDC-1#TRPBF | Same electrical specs but standard QFN (not side-wettable); θJA = 40°C/W vs. 35°C/W for UDCF. | Lacks AOI-capable leads; less suitable for high-reliability automotive SMT lines requiring solder-joint verification. | Select when cost sensitivity outweighs manufacturability requirements and thermal margin is sufficient. |
| MPQ4433AGL-AEC1-Z | 40V, 3.5A, 17µA IQ; no spread spectrum; smaller 3x4mm QFN but no side-wettable option. | Higher IQ limits always-on runtime; lacks Silent Switcher EMI suppression - requires external filtering for automotive EMI compliance. | Select for non-AEC-Q100 industrial applications where size and cost are prioritized over EMI and ultra-low IQ. |
Compared with LT8640EUDC-1#TRPBF, the LT8640EUDCF-1#TRPBF offers superior manufacturability and thermal performance via side-wettable leads and lower θJA; versus MPQ4433AGL-AEC1-Z, it delivers 7x lower quiescent current, integrated EMI reduction, and AEC-Q100 qualification for safety-critical automotive use.
Availability
LT8640EUDCF-1#TRPBF is available at Aetrix Electronics and suitable for automotive ADAS, industrial PLCs, telematics control units, and GSM RF power amplifier biasing requiring stable component supply, AEC-Q100 compliance, and long-term lifecycle support.
Supply support for LT8640EUDCF-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 industrial, automotive, communications, and healthcare markets.
The LT8640/LT8640-1 product line was designed specifically for noise-sensitive automotive and industrial applications demanding ultra-low EMI, high efficiency across wide load ranges, and robust operation in harsh environments.
FAQ
What is the maximum input voltage rating for the LT8640EUDCF-1#TRPBF?
The LT8640EUDCF-1#TRPBF has an absolute maximum input voltage rating of 42V across VIN1 and VIN2 pins. Its operational input range is specified from 3.4V to 42V, making it suitable for 24V and 36V automotive and industrial bus systems, including cold-crank and load-dump transients. Exceeding 42V may cause permanent damage.
Does the LT8640EUDCF-1#TRPBF support spread spectrum modulation, and how is it enabled?
Yes, the LT8640EUDCF-1#TRPBF supports spread spectrum modulation to reduce peak EMI emissions. It is enabled by applying a DC voltage of 3V to 4V to the SYNC/MODE pin (pin 17), which activates ±20% triangular frequency dithering around the RT-set switching frequency. This feature operates concurrently with forced continuous mode.
How does the LT8640EUDCF-1#TRPBF differ from the LT8640EUDCF#TRPBF in terms of operating mode?
The LT8640EUDCF-1#TRPBF defaults to forced continuous mode (FCM) when SYNC/MODE is floating, enabling negative inductor current and fast transient response. In contrast, the LT8640EUDCF#TRPBF (non-"-1") defaults to pulse-skipping mode under the same condition, which improves light-load efficiency but sacrifices transient performance.
What is the purpose of the side-wettable leads on the LT8640EUDCF-1#TRPBF package?
The side-wettable leads on the LT8640EUDCF-1#TRPBF's QFN package enable automated optical inspection (AOI) of solder fillets during SMT assembly. This improves process control and field reliability in automotive manufacturing, where zero-defect solder joints are required per IATF 16949, without increasing PCB footprint or thermal resistance.
Can the LT8640EUDCF-1#TRPBF be synchronized to an external clock, and what are the voltage requirements?
Yes, the LT8640EUDCF-1#TRPBF can be synchronized to an external clock applied to the SYNC/MODE pin. The clock must meet TTL/CMOS logic thresholds: low level ≤0.9V, high level ≥2.3V, with 50% duty cycle and frequency matching the RT-programmed range (200kHz–3MHz). During sync, the device operates in forced continuous mode.
LT8640EUDCF-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, Wettable Flank
- Supplier Device Package:
- 20-QFN (3x4)
LT8640EUDCF-1#TRPBF FAQ
1.How can I place an order for LT8640EUDCF-1#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8640EUDCF-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 LT8640EUDCF-1#TRPBF reliable?
The price and inventory of LT8640EUDCF-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 LT8640EUDCF-1#TRPBF is usually 5 days.
3.What payment methods are accepted for LT8640EUDCF-1#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8640EUDCF-1#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8640EUDCF-1#TRPBF?
LT8640EUDCF-1#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8640EUDCF-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 LT8640EUDCF-1#TRPBF?
For technical support, including LT8640EUDCF-1#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8640EUDCF-1#TRPBF requirements.
6.How does Aetrix verify that LT8640EUDCF-1#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT8640EUDCF-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 LT8640EUDCF-1#TRPBF meets industry standards.
7.What is the process for return or replacement of LT8640EUDCF-1#TRPBF?
All LT8640EUDCF-1#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8640EUDCF-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 LT8640EUDCF-1#TRPBF part is unused and in its original packaging.
Return procedure for LT8640EUDCF-1#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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