My Inquiry
My Account
Analog Devices Inc. LT8640EUDCF#PBF
- Part No.:
- LT8640EUDCF#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 20-WFQFN, 18 Leads, Exposed Pad
- Datasheet:
-
LT8640EUDCF#PBF.pdf
- Description:
- IC REG BUCK ADJ 5A 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,417
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT8640EUDCF#PBF from Analog Devices is a 42V, 5A synchronous step-down Silent Switcher regulator with 2.5µA quiescent current in regulation, 30ns minimum on-time, and integrated power MOSFETs. It delivers up to 96% efficiency at 1MHz (12VIN→5VOUT) and supports adjustable switching frequency from 200kHz to 3MHz. It is used in automotive infotainment power supplies where low EMI and ultra-low IQ are critical.
For engineers reviewing the LT8640EUDCF#PBF datasheet, LT8640EUDCF#PBF pinout, LT8640EUDCF#PBF application, or LT8640EUDCF#PBF equivalent, key selection considerations include its side-wettable QFN-18 package for automated optical inspection, Burst Mode® operation for sub-mA load efficiency, Silent Switcher® architecture for CISPR 25 Class 5 radiated EMI compliance, and forced continuous mode capability via SYNC/MODE pin configuration.
Technical Context
The LT8640EUDCF#PBF employs peak current-mode control with an internal 0.97V reference and programmable oscillator (RT pin). Its Silent Switcher® architecture uses symmetrical layout and integrated bypass capacitors to suppress common-mode EMI, enabling <10mVP-P output ripple and meeting CISPR 25 Class 5 limits without external filters.
It features dual input rails (VIN1/VIN2), separate ground paths (GND1/GND2), and SW-exposed thermal pads (pins 21/22) soldered directly to the switch node for optimal thermal performance. The SYNC/MODE pin selects among Burst Mode®, pulse-skipping, spread-spectrum modulation, or external clock synchronization - with LT8640 variants supporting pulse-skipping (not FCM).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.4V to 42V - supports wide automotive battery transients including cold-crank (4.5V) and load-dump (42V). |
| Output Current | 5A continuous, 7A peak - enables single-chip 5V/5A rail for SoC or FPGA core supplies. |
| Quiescent Current | 2.5µA in regulation - sustains >10-year battery life in always-on vehicle modules (e.g., telematics wake-up circuits). |
| Switching Frequency | 200kHz to 3MHz (RT-programmable) - allows optimization for size (high-freq + small inductor) or efficiency (low-freq + low core loss). |
| Min On-Time | 30ns - enables high VIN-to-low VOUT conversion (e.g., 36V→3.3V @ 2MHz) without pulse skipping. |
| Feedback Reference | 0.970V ±0.006V - ensures tight output regulation across temperature and line/load conditions. |
| EMI Performance | CISPR 25 Class 5 compliant (horizontal/vertical polarization) - eliminates need for external EMI filters in automotive designs. |
Pinout & Package
LT8640EUDCF#PBF uses an 18-lead, 3mm × 4mm plastic side-wettable QFN package (LHJK grade) with exposed SW pads (pins 21, 22) for enhanced thermal conduction and automated optical solder-joint inspection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BIAS (1) | Internal regulator bias supply | Accepts 3.1–25V; when tied to VOUT ≥3.3V, reduces VIN current draw and improves light-load efficiency. |
| INTVCC (2) | Internal 3.4V LDO output | Bypass with ≥1µF ceramic capacitor; powers control circuitry and cannot drive external loads. |
| BST (3) | Bootstrap capacitor connection | Requires 0.1µF ceramic capacitor between BST and SW to drive high-side MOSFET gate above VIN. |
| VIN1 (4), VIN2 (13) | Main input power inputs | Dual inputs reduce high-frequency loop inductance; each requires dedicated 1µF ceramic bypass to respective GND1/GND2. |
| GND1 (6,7), GND2 (10,11) | Power switch return paths | Separate ground pins minimize noise coupling; must be tied together and connected to low-impedance ground plane. |
| SW (8,9,21,22) | Switch node outputs | High-current path connecting internal MOSFETs to inductor; exposed pads (21/22) must be soldered to PCB SW trace for thermal management. |
| EN/UV (14) | Enable and input undervoltage lockout | Hysteretic threshold (1.00V rise / 0.96V fall); resistor divider from VIN sets custom UVLO point. |
| RT (15) | Oscillator frequency programming | Resistor to GND sets fSW: 221kΩ = 210kHz, 60.4kΩ = 700kHz, 18.2kΩ = 2.0MHz. |
| TR/SS (16) | Soft-start and output tracking | 1.9µA internal current source charges external capacitor; voltage ≤0.97V forces FB to track TR/SS for controlled ramp-up. |
| SYNC/MODE (17) | Operating mode selection | Ground = Burst Mode®; float = pulse-skipping; INTVCC-high = spread spectrum; driven clock = sync - defines regulator behavior at light loads. |
| GND (18) | System ground reference | Connects to system ground plane; completes feedback and control signal return paths. |
| PG (19) | Power good open-drain flag | Asserts high when FB is within ±8% of 0.97V and no fault exists; valid only if VIN >3.4V. |
| FB (20) | Feedback voltage sense | Regulated to 0.970V; connect resistor divider tap here; add 4.7–22pF phase-lead capacitor from FB to VOUT for stability. |
Key Features
| Feature | Design Value |
|---|---|
| Silent Switcher® architecture | Reduces radiated EMI by >30dB vs conventional buck regulators, enabling CISPR 25 Class 5 compliance without shielding or ferrites. |
| Ultralow 2.5µA quiescent current | Extends battery runtime in always-on automotive modules (e.g., CAN gateway sleep mode) while maintaining full output regulation. |
| 30ns minimum on-time | Supports direct 36V→3.3V or 42V→5V conversion at 2MHz, eliminating intermediate stages and reducing BOM count. |
| Side-wettable QFN-18 package | Enables AOI-compatible solder-joint inspection on production lines, improving yield and reliability in automotive manufacturing. |
| Adjustable spread-spectrum modulation | ±20% frequency dithering (e.g., 2MHz → 1.6–2.4MHz) lowers peak EMI amplitude, easing EMC certification margin requirements. |
| Integrated power MOSFETs | Top switch RDS(on) = 67mΩ, bottom switch RDS(on) = 28mΩ - eliminates external FETs and gate drivers, reducing footprint and layout complexity. |
Applications
| Automotive Infotainment Power | ADAS Camera Module Supply |
|---|---|
|
Use Scenario: Powering 5V/3A SoC and display interface in head-unit under 9–16V battery input with load-dump immunity. IC Role / Device Role / Timing Role: Primary 5V buck regulator with Burst Mode® for standby, pulse-skipping for active state, and spread-spectrum for EMI reduction during video transmission. Use Value: Eliminates need for secondary LDO or filter stage; meets ISO 7637-2 pulse 5a/b and CISPR 25 Class 5 without added components. |
Use Scenario: Generating stable 3.3V/2A supply for image sensor and ISP in rear-view camera exposed to engine bay temperatures. IC Role / Device Role / Timing Role: High-efficiency, low-noise DC/DC converter operating from 12V battery with thermal shutdown protection up to 150°C junction. Use Value: Maintains <10mVP-P ripple at full load, preventing image noise; side-wettable QFN ensures solder joint reliability under thermal cycling. |
| Telematics Control Unit (TCU) | GSM Baseband Power Supply |
|
Use Scenario: Always-on 3.3V/500mA rail for LTE modem and GNSS receiver in vehicle tracking unit powered by 12V battery. IC Role / Device Role / Timing Role: Ultra-low IQ regulator with EN/UV hysteresis for cold-crank resilience and PG flag for host MCU power sequencing. Use Value: Draws only 2.5µA in regulation during sleep, enabling >10-year battery backup life with supercapacitor hold-up. |
Use Scenario: Compact 5V/5A supply for GSM/GPRS baseband processor in industrial M2M router operating from 24V PoE or 12V DC input. IC Role / Device Role / Timing Role: High-current buck converter with programmable fSW (1–2MHz) to balance efficiency and inductor size in space-constrained enclosure. Use Value: Delivers 95% efficiency at 2MHz/12VIN→5VOUT, allowing use of 2.2µH shielded inductor (<3.2mm height) and minimizing board area. |
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 |
|---|---|---|---|
| LT8640-1EUDCF#PBF | Forced Continuous Mode (FCM) instead of pulse-skipping; higher light-load IQ (~100µA vs 2.5µA); identical pinout and package. | Better transient response for CPU/FPGA loads; unsuitable for ultra-low-power always-on systems requiring sub-µA sleep. | Select LT8640-1EUDCF#PBF when fast load-step recovery is prioritized over minimum IQ; verify SYNC/MODE pin logic matches FCM requirement. |
| MPQ4433AGL-AEC1-Z | 45V, 3.5A AEC-Q100 Grade 1 buck; 17µA IQ; fixed 2.2MHz fSW; no spread-spectrum or side-wettable QFN. | Limited to 3.5A output; lacks Silent Switcher EMI suppression; requires external EMI filtering for automotive EMC. | Choose MPQ4433AGL-AEC1-Z for cost-sensitive, lower-current applications where full CISPR 25 compliance is not required. |
Compared with LT8640-1EUDCF#PBF and MPQ4433AGL-AEC1-Z, the LT8640EUDCF#PBF uniquely combines ultralow 2.5µA IQ, Silent Switcher EMI performance, and side-wettable packaging-making it optimal for high-reliability, EMI-sensitive automotive subsystems where both efficiency and manufacturability are critical.
Availability
LT8640EUDCF#PBF is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, and telematics control units requiring stable component supply, AEC-Q100-compliant sourcing, and long-term lifecycle support.
Supply support for LT8640EUDCF#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 LT8640 series belongs to Analog Devices' Silent Switcher® power management product line, engineered specifically for automotive and industrial applications demanding ultra-low EMI, high efficiency across wide load ranges, and robust operation under harsh electrical environments.
FAQ
What is the maximum input voltage rating for the LT8640EUDCF#PBF?
The LT8640EUDCF#PBF has an absolute maximum input voltage rating of 42V on VIN1 and VIN2 pins. It is designed to withstand automotive load-dump transients per ISO 7637-2 Pulse 5a (up to 42V for 400ms) and operates continuously from 3.4V to 42V, making it suitable for 12V and 24V vehicle electrical systems.
Does the LT8640EUDCF#PBF support spread-spectrum frequency modulation?
Yes, the LT8640EUDCF#PBF supports spread-spectrum modulation when the SYNC/MODE pin is tied to INTVCC (~3.4V) or an external 3V–4V supply. This modulates the switching frequency by ±20%, reducing peak EMI amplitudes and easing CISPR 25 Class 5 radiated emissions compliance without external filters.
What package type does the LT8640EUDCF#PBF use, and why is it significant?
The LT8640EUDCF#PBF uses an 18-lead side-wettable QFN (3mm × 4mm, LHJK marking). Its side-wettable leads enable automated optical inspection (AOI) of solder joints during SMT assembly - a critical requirement for zero-defect automotive manufacturing and high-reliability industrial applications.
How does the LT8640EUDCF#PBF achieve 2.5µA quiescent current while maintaining regulation?
The LT8640EUDCF#PBF achieves 2.5µA IQ in regulation using Burst Mode® operation: during light loads, it shuts down all control circuitry between energy bursts, minimizing switching and bias losses. This occurs while maintaining output voltage regulation via precise feedback control and low-leakage internal references - confirmed in datasheet Figure G05.
Can the LT8640EUDCF#PBF be synchronized to an external clock?
Yes, the LT8640EUDCF#PBF can be synchronized to an external clock applied to the SYNC/MODE pin. When driven with a clean CMOS clock signal (200kHz–3MHz), it locks its internal oscillator and operates in pulse-skipping mode, enabling deterministic EMI placement and multi-phase interleaving in complex power systems.
LT8640EUDCF#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- Silent Switcher®1
- Package/Case:
- 20-WFQFN, 18 Leads, Exposed Pad
- Packaging:
- Tube
- 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#PBF FAQ
1.How can I place an order for LT8640EUDCF#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8640EUDCF#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 LT8640EUDCF#PBF reliable?
The price and inventory of LT8640EUDCF#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8640EUDCF#PBF is usually 5 days.
3.What payment methods are accepted for LT8640EUDCF#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8640EUDCF#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8640EUDCF#PBF?
LT8640EUDCF#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8640EUDCF#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 LT8640EUDCF#PBF?
For technical support, including LT8640EUDCF#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8640EUDCF#PBF requirements.
6.How does Aetrix verify that LT8640EUDCF#PBF is sourced from the original manufacturer or authorized distributors?
All LT8640EUDCF#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 LT8640EUDCF#PBF meets industry standards.
7.What is the process for return or replacement of LT8640EUDCF#PBF?
All LT8640EUDCF#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8640EUDCF#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 LT8640EUDCF#PBF part is unused and in its original packaging.
Return procedure for LT8640EUDCF#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT8640EUDCF#PBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
