My Inquiry
My Account
Analog Devices Inc. LT3435IFE#PBF
- Part No.:
- LT3435IFE#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LT3435IFE#PBF.pdf
- Description:
- IC REG BUCK ADJ 3A 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,643
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3435IFE#PBF from Analog Devices (formerly Linear Technology) is a high-voltage, current-mode monolithic buck switching regulator with integrated 3A NPN power switch, 500kHz fixed-frequency operation, 100µA quiescent current in Burst Mode, and 3.3V to 60V input range. It delivers regulated DC-DC conversion for automotive load-dump-tolerant systems, industrial power supplies, and battery-powered equipment requiring low-noise, high-efficiency step-down.
For engineers reviewing the LT3435IFE#PBF datasheet, LT3435IFE#PBF pinout, LT3435IFE#PBF application, or LT3435IFE#PBF equivalent, key selection criteria include its 60V absolute maximum input rating, programmable Power Good flag with CT-based delay, soft-start via CSS pin, BIAS pin efficiency optimization, and thermal performance enabled by exposed-pad 16-pin TSSOP packaging.
Technical Context
The LT3435IFE#PBF employs constant-frequency current-mode control with internal oscillator, error amplifier, and peak-current comparator - enabling fast transient response and stable loop compensation across wide duty cycles. Its patented circuitry maintains 3A peak switch current over full duty cycle range, independent of input-output differential.
Burst Mode® operation reduces supply current to 100µA at no load by cycling the control circuitry on/off while retaining regulation; shutdown draws <1µA. The BOOST pin enables saturation of the internal NPN switch via external capacitor-diode network, achieving 0.1Ω effective on-resistance and minimizing conduction loss at high VIN.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.3V to 60V - supports 12V/24V/42V automotive systems and industrial rails without external pre-regulation. |
| Switch Current Limit | 3A typical peak - sustains full output current capability across input voltage and duty cycle variations. |
| Quiescent Current | 100µA in Burst Mode - enables multi-year battery life in always-on IoT sensors and telematics modules. |
| Switch On Resistance | 0.1Ω - minimizes I²R losses during high-current operation, reducing thermal stress on die and PCB. |
| Feedback Reference | 1.25V ±2.5% - enables precise output voltage setting with standard resistor dividers; FB pin bias current ≤200nA preserves accuracy. |
| Power Good Threshold | Programmable via PGFB divider - allows custom output voltage monitoring with adjustable delay using external CT capacitor. |
| Thermal Performance | θJC(PAD) = 10°C/W - exposed pad (Pin 17) must be soldered to PCB ground plane for reliable 125°C junction operation. |
Pinout & Package
LT3435IFE#PBF is housed in a thermally enhanced 16-pin TSSOP package with exposed GND pad (Pin 17), optimized for high-power density and low thermal resistance. Pin 1 is NC; Pins 2 and 5 are SW (switch emitter); Pins 3 and 4 are VIN (switch collector); Pin 17 is GND and must be soldered to PCB ground plane per datasheet requirement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW (2,5) | Emitter of internal NPN switch | Drives inductor; clamped externally to –0.8V max; requires catch diode and low-inductance return path to VIN. |
| VIN (3,4) | Collector of internal NPN switch & primary supply | Supplies control circuitry when BIAS is unconnected; high di/dt node - demands short, low-inductance input bypassing. |
| BOOST (6) | Switch driver boost voltage input | Accepts voltage ≥VIN + 3.3V via external capacitor-diode; enables full saturation of NPN switch for 0.1Ω RCE(SAT). |
| GND (8,17) | Reference and thermal ground | Pins 8 and 17 both connect to die substrate; exposed pad (17) is mandatory thermal path - must be soldered to solid copper ground plane. |
| FB (12) | Feedback input for output voltage regulation | Senses 1.25V reference; input bias ≤200nA; enables frequency foldback and soft-start activation below 0.9V. |
| PGFB (13) | Power Good comparator input | Compares against 90% of VREF; initiates programmable PG delay via CT capacitor when threshold exceeded. |
| SHDN (15) | Shutdown control input | Active-high; threshold 1.3V typical; reduces total supply current to <1µA when pulled low. |
| PG (16) | Open-drain Power Good output | Active-low sink (200µA) when PGFB < threshold; high-impedance when CT clamp active - indicates valid output regulation. |
Key Features
| Feature | Design Value |
|---|---|
| Load Dump Protection | Withstands 60V transients on VIN - eliminates need for external TVS in 12V/24V automotive applications per ISO 7637-2 Pulse 5a. |
| Burst Mode® Operation | Reduces no-load input current to 100µA while maintaining regulation - critical for battery-backed systems with long sleep intervals. |
| Saturating Switch Design | 0.1Ω effective on-resistance achieved via BOOST-driven NPN - delivers higher efficiency than comparable MOSFET-based regulators at VIN > 24V. |
| Programmable Power Good | PGFB threshold and CT-based delay allow system-level sequencing and fault detection without external comparators or timers. |
| Soft-Start Control | CSS pin accepts capacitor to output to set dV/dt ramp rate - prevents inrush current into large output capacitors during cold start. |
Applications
| Automotive Infotainment Power Supply | Industrial 24V-to-5V Conversion |
|---|---|
Use Scenario: Powering DSP, display controller, and USB hub in head-unit with 12V/24V battery input subject to load dump and cold-crank conditions. IC Role / Device Role / Timing Role: Primary buck regulator delivering 5V@2A with programmable PG signaling MCU readiness after startup and fault detection. Use Value: 60V input rating and load dump tolerance eliminate external protection components; Burst Mode extends runtime during vehicle sleep mode. | Use Scenario: Converting 24V factory bus to 5V for PLC I/O modules operating in ambient temperatures up to 85°C. IC Role / Device Role / Timing Role: High-reliability DC-DC converter with thermal shutdown and robust feedback loop for continuous industrial operation. Use Value: Exposed-pad TSSOP ensures θJC = 10°C/W - maintains safe junction temperature under full load at elevated ambient; BIAS pin improves efficiency at high VIN/light load. |
| Portable Medical Instrument DC-DC Stage | USB-Powered Test Equipment |
Use Scenario: Battery-powered ECG monitor requiring ultra-low quiescent current and clean 3.3V rail for analog front-end and BLE radio. IC Role / Device Role / Timing Role: Main power stage regulating Li-ion (3.0–4.2V) or 2-cell alkaline (2.4–3.2V) to stable 3.3V with soft-start and PG confirmation. Use Value: 100µA Burst Mode current enables multi-week standby; 1.25V reference and low FB bias current ensure precision output voltage over battery discharge. | Use Scenario: Benchtop oscilloscope accessory powered from USB 5V port, needing isolated 3.3V and –5V rails with tight noise control. IC Role / Device Role / Timing Role: Primary 5V-to-3.3V buck converter feeding LDOs and isolated DC-DC; synchronized to system clock via SYNC pin. Use Value: 500kHz fixed frequency enables predictable EMI filtering; SYNC pin accepts logic-level inputs up to 700kHz - simplifies system-level clock domain alignment. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3639EMSE#PBF | 40V max input, 2A output, integrated MOSFETs, 3mm × 4mm MSOP; no BOOST pin or load dump rating. | Lower voltage, lower current; lacks 60V tolerance and automotive transient immunity. | Select when board space is constrained and input never exceeds 40V; not suitable for 42V automotive or industrial 60V rails. |
| LM5164QPWPRQ1 | 65V max input, 1A output, integrated MOSFETs, 1.5MHz switching; no programmable PG or Burst Mode - uses pulse-skipping. | Higher frequency, lower current; PG function requires external circuitry; quiescent current 95µA (similar but not identical architecture). | Choose for compact designs needing >1MHz operation and AEC-Q100 qualification; verify PG implementation matches system sequencing needs. |
Compared with LTC3639EMSE#PBF and LM5164QPWPRQ1, the LT3435IFE#PBF uniquely combines 60V input tolerance, 3A output, programmable Power Good, and true 100µA Burst Mode - making it optimal for ruggedized 12–42V systems where reliability under transients and ultra-low standby power are non-negotiable.
Availability
LT3435IFE#PBF is available at Aetrix Electronics and suitable for automotive infotainment, industrial PLC power supplies, portable medical instrumentation, and USB-powered test equipment requiring stable component supply across extended temperature and high-reliability environments.
Supply support for LT3435IFE#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 acquired Linear Technology in 2017 and maintains full technical and manufacturing continuity for the LT® product line, including rigorous AEC-Q100 stress testing for automotive-grade variants.
The LT3435IFE#PBF belongs to Linear's high-voltage monolithic buck regulator family, engineered specifically for harsh-environment DC-DC conversion where input transients, wide VIN range, and ultra-low quiescent current are simultaneously required.
FAQ
What is the absolute maximum input voltage rating for the LT3435IFE#PBF?
The LT3435IFE#PBF has an absolute maximum input voltage rating of 60V on the VIN pin, and it is explicitly rated for load dump protection up to 60V per datasheet specifications. This makes the LT3435IFE#PBF suitable for 12V and 24V automotive systems compliant with ISO 7637-2 Pulse 5a. Exceeding 60V risks permanent damage, even momentarily.
How does the BOOST pin function in the LT3435IFE#PBF, and what external components are required?
The BOOST pin on the LT3435IFE#PBF supplies a boosted gate drive voltage to fully saturate the internal NPN switch, achieving 0.1Ω on-resistance. It requires an external flying capacitor (typically 10nF–100nF ceramic) and Schottky diode (e.g., DFLS160) connected between VIN and BOOST. The LT3435IFE#PBF datasheet specifies minimum BOOST voltage as 1.8V above SW during turn-on.
Can the LT3435IFE#PBF be synchronized to an external clock, and what are the timing constraints?
Yes, the LT3435IFE#PBF supports external synchronization via the SYNC pin, which accepts logic-level inputs (1.5V–2.0V min amplitude) with 5%–75% duty cycle across a 575kHz–700kHz range. Synchronization is disabled when FB voltage falls below 0.9V (e.g., during soft-start or fault). The LT3435IFE#PBF's internal oscillator operates at 425–575kHz, and SYNC overrides it only when within spec.
What is the purpose of the CSS pin on the LT3435IFE#PBF, and how is it configured?
The CSS pin on the LT3435IFE#PBF controls soft-start by sourcing current into an external capacitor connected to the output rail. When CSS current exceeds the threshold (7–20µA, proportional to FB voltage), the LT3435IFE#PBF limits output dV/dt to prevent inrush. Soft-start is automatically disabled when FB reaches 0.9V. A typical CSS capacitor is 10nF–100nF, selected based on desired ramp time and output capacitance.
Does the LT3435IFE#PBF require the exposed pad (Pin 17) to be soldered, and why?
Yes, the exposed pad (Pin 17) of the LT3435IFE#PBF must be soldered to a PCB ground plane. It serves as both electrical ground and primary thermal path, with θJC(PAD) = 10°C/W specified only when properly soldered. Failure to solder the pad results in excessive junction temperature rise, potential thermal shutdown, and violation of guaranteed –40°C to 125°C operation per the LT3435IFE#PBF datasheet.
LT3435IFE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width) 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):
- 3V
- Voltage - Input (Max):
- 60V
- Voltage - Output (Min/Fixed):
- 1.25V
- Voltage - Output (Max):
- 55.2V
- Current - Output:
- 3A (Switch)
- Frequency - Switching:
- 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP-EP
LT3435IFE#PBF FAQ
1.How can I place an order for LT3435IFE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3435IFE#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 LT3435IFE#PBF reliable?
The price and inventory of LT3435IFE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3435IFE#PBF is usually 5 days.
3.What payment methods are accepted for LT3435IFE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3435IFE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3435IFE#PBF?
LT3435IFE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3435IFE#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 LT3435IFE#PBF?
For technical support, including LT3435IFE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3435IFE#PBF requirements.
6.How does Aetrix verify that LT3435IFE#PBF is sourced from the original manufacturer or authorized distributors?
All LT3435IFE#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 LT3435IFE#PBF meets industry standards.
7.What is the process for return or replacement of LT3435IFE#PBF?
All LT3435IFE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3435IFE#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 LT3435IFE#PBF part is unused and in its original packaging.
Return procedure for LT3435IFE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3435IFE#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…
