My Inquiry
My Account
Analog Devices Inc. LT3958EUHE#PBF
- Part No.:
- LT3958EUHE#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 36-WFQFN, 28 Leads, Exposed Pad
- Datasheet:
-
LT3958EUHE#PBF.pdf
- Description:
- IC REG BOOST CUK ADJ 3.3A 36QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,064
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3958EUHE#PBF from Analog Devices is a wide-input, current-mode DC/DC controller IC with an integrated 3.3A/84V N-channel power MOSFET, supporting boost, flyback, SEPIC, and inverting topologies. It delivers ± output voltage regulation via a single FBX pin, operates from 5V to 80V input, and features programmable 100kHz–1MHz switching frequency - ideal for high-voltage industrial power supplies and automotive battery systems.
For engineers reviewing the LT3958EUHE#PBF datasheet, LT3958EUHE#PBF pinout, LT3958EUHE#PBF application, or LT3958EUHE#PBF equivalent, key selection considerations include its dual-polarity feedback capability (±1.6V/±0.8V reference), internal LDO-regulated 7.2V INTVCC supply, <1µA shutdown IQ, thermally enhanced 36-lead QFN package, and frequency foldback protection during low-VOUT startup.
Technical Context
The LT3958EUHE#PBF implements fixed-frequency current-mode control with slope compensation, using SENSE1/SENSE2 for Kelvin current sensing and VC as error amplifier output for loop compensation. Its dual-comparator feedback architecture (A1/A2) enables seamless positive or negative output configuration without external reconfiguration.
It integrates a 7.2V LDO for gate drive, with UVLO (3.75V) and OVLO (12.8V) on INTVCC, programmable EN/UVLO threshold (1.22V nominal falling), and synchronous operation via SYNC pin - requiring RT biasing 20% below sync frequency when enabled.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 5V to 80V - supports direct connection to 24V/48V industrial buses and 12V–72V automotive batteries without pre-regulation. |
| Internal Power Switch | 3.3A/84V N-MOSFET - eliminates need for external high-voltage switch in boost/flyback designs up to ~100W. |
| Feedback Reference | +1.6V or –0.8V at FBX - enables single-pin polarity selection for positive or negative output without topology change. |
| Switching Frequency | 100kHz to 1MHz (RT-programmable) - balances efficiency (lower fSW) vs. size (higher fSW); supports synchronization to external clock. |
| Shutdown Quiescent Current | <1µA - extends battery life in always-on monitoring or backup power systems. |
| INTVCC Regulator | 7.2V LDO with 3.75V UVLO and 12.8V OVLO - ensures robust gate drive while protecting internal circuitry from supply faults. |
| Operating Temperature | –40°C to +125°C - qualified for under-hood automotive and industrial ambient environments. |
Pinout & Package
LT3958EUHE#PBF is housed in a thermally enhanced 36-lead (5mm × 6mm) plastic QFN package with two exposed pads: Pin 37 (SGND) and Pin 38 (SW), both requiring soldering to dedicated PCB planes for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SENSE2 (Pin 3) | Current sense input | Receives filtered sense voltage from SENSE1; sets peak current limit threshold (48mV typical) for overcurrent protection. |
| SGND (Pins 4,23,24,37) | Signal ground | Kelvin return for current sensing; must be isolated from power GND to maintain accuracy and avoid noise coupling. |
| SENSE1 (Pin 6) | Current sense output | Drives SENSE2 via RC filter; connects directly to source of external sense resistor or internal MOSFET sense node. |
| SW (Pins 8,9,20,21,38) | Power switch drain | High-side switching node for boost/flyback/SEPIC; exposed pad (38) must be connected to SW copper area for thermal relief. |
| GND (Pins 12–17) | Power ground | Source terminal return for internal MOSFET; internally tied to SGND but must remain externally separate to preserve sensing accuracy. |
| EN/UVLO (Pin 25) | Enable & input UVLO | 1.22V falling threshold with programmable hysteresis; resets soft-start during undervoltage events. |
| VIN (Pin 27) | Main input supply | Accepts 5V–80V; powers internal LDO and logic; requires local ceramic bypass to GND (not SGND). |
| INTVCC (Pin 28) | Internal LDO output | 7.2V regulated supply for gate driver; must be bypassed with ≥4.7µF ceramic capacitor to SGND. |
| VC (Pin 30) | Error amplifier output | Compensation node for voltage loop; connects to SGND via series RC network for stability tuning. |
| FBX (Pin 31) | Feedback input | Single pin accepts either positive (1.6V ref) or negative (–0.8V ref) divider; modulates frequency during fault conditions. |
| SS (Pin 32) | Soft-start control | 10µA pull-up current charges external capacitor; clamps VC to limit inrush current during startup or fault recovery. |
| RT (Pin 33) | Frequency programming | Resistor to SGND sets switching frequency (e.g., 41.2kΩ = 300kHz); open-circuit disables operation. |
| SYNC (Pin 34) | External clock input | Accepts digital clock signal; overrides RT setting; ignored when FBX near SGND (e.g., during short-circuit). |
Key Features
| Feature | Design Value |
|---|---|
| Single FBX pin for ± output polarity | Eliminates topology-specific IC variants - same part supports boost (positive VOUT) and inverting (negative VOUT) with no hardware change. |
| Programmable frequency foldback | Reduces switching frequency automatically when FBX voltage drops near SGND (e.g., during startup or output short), preventing current runaway. |
| Integrated 7.2V LDO with UV/OV lockout | Ensures stable gate drive across wide VIN range; disables switching if INTVCC falls below 3.75V or exceeds 12.8V - prevents MOSFET misfire. |
| Thermally enhanced QFN with dual exposed pads | Exposes SGND (Pin 37) and SW (Pin 38) separately - enables independent thermal management of signal and power paths. |
| Low shutdown IQ & accurate EN/UVLO | Sub-1µA shutdown current plus 1.22V ±20mV EN threshold allows precise brown-out detection and battery-aware enable sequencing. |
Applications
| Automotive LED Headlamp Driver | Industrial 48V-to-±15V Dual-Rail Supply |
|---|---|
|
Use Scenario: Driving high-brightness LEDs from 12V–48V vehicle battery with tight current regulation and EMI control. IC Role / Device Role / Timing Role: Controller in boost topology with constant-current regulation via SENSE1/SENSE2; FBX used for voltage margining and fault reporting. Use Value: 80V input rating withstands load-dump transients; programmable frequency avoids AM band; <1µA shutdown preserves battery during parking mode. |
Use Scenario: Generating isolated ±15V rails for op-amp signal conditioning in factory automation I/O modules. IC Role / Device Role / Timing Role: Flyback controller with optocoupler feedback; FBX configured for negative output; SYNC pin synchronized to system clock for deterministic EMI. Use Value: Dual-reference FBX simplifies dual-rail design; 3.3A switch supports >20W output; –40°C to +125°C rating ensures reliability in uncooled enclosures. |
| Telecom 48V Backup Power Converter | Medical Portable Infusion Pump Power Stage |
|
Use Scenario: Converting 48V telecom battery to 5V/3.3V logic rails during AC failure, with fast transient response. IC Role / Device Role / Timing Role: SEPIC controller enabling buck-boost behavior; current-mode control provides <10µs load-step response. Use Value: Wide 5V–80V input accommodates aging battery discharge; frequency foldback prevents inductor saturation during cold-start. |
Use Scenario: Generating isolated negative bias for precision analog front-end in battery-powered infusion pumps. IC Role / Device Role / Timing Role: Inverting converter with FBX referenced to –0.8V; SS pin used for controlled ramp-up to avoid motor surge current. Use Value: Single-part solution reduces BOM count and board space; <1µA shutdown extends single-charge runtime; medical-grade temperature range certified. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar DC/DC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3789EUF#PBF | Requires external MOSFETs; supports 4V–38V input; no integrated 84V switch. | Better suited for lower-voltage, higher-efficiency synchronous buck-boost where layout control is critical. | Select LTC3789EUF#PBF only when input stays ≤38V and discrete FET optimization is required. |
| LM5122MH/NOPB | 5V–65V input; 3A external switch drive; no negative-output capability; no FBX polarity auto-detect. | Designed for high-efficiency boost-only applications with simpler feedback networks. | Choose LM5122MH/NOPB for cost-sensitive 12V–48V boost converters where negative output is unnecessary. |
Compared with LTC3789EUF#PBF and LM5122MH/NOPB, the LT3958EUHE#PBF uniquely integrates an 84V/3.3A switch and dual-polarity FBX reference - reducing component count and enabling single-IC solutions for high-input-voltage boost, flyback, SEPIC, and inverting converters across automotive and industrial domains.
Availability
LT3958EUHE#PBF is available at Aetrix Electronics and suitable for automotive lighting systems, industrial 48V power distribution, telecom backup supplies, and medical portable equipment requiring stable component supply and long-term lifecycle support.
Supply support for LT3958EUHE#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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision instrumentation, industrial, automotive, and communications markets.
The LT3958EUHE#PBF belongs to Linear's high-voltage DC/DC controller product line, engineered specifically for rugged, wide-input industrial and automotive power conversion where integration, reliability, and topology flexibility are critical.
FAQ
What is the maximum input voltage rating for the LT3958EUHE#PBF?
The LT3958EUHE#PBF has an absolute maximum input voltage rating of 80V on the VIN pin, with guaranteed operation across 5V to 80V. This makes it suitable for direct connection to 48V industrial buses and automotive systems experiencing load-dump transients up to 80V, provided proper input filtering and clamping are implemented per the datasheet guidelines.
Can the LT3958EUHE#PBF generate both positive and negative output voltages?
Yes, the LT3958EUHE#PBF supports both polarities using a single FBX pin: it regulates to +1.6V for positive outputs (e.g., boost, flyback, SEPIC) and to –0.8V for negative outputs (e.g., inverting topology). The internal dual-comparator architecture (A1/A2) automatically selects the appropriate reference based on FBX voltage level - no external component changes are needed.
How does the LT3958EUHE#PBF handle overcurrent conditions during startup?
The LT3958EUHE#PBF employs frequency foldback triggered by low FBX voltage (e.g., during output short or cold-start), reducing switching frequency to maintain peak current within the 3.3A limit. Combined with soft-start (via SS pin) and current-limit comparator A6 (48mV threshold), this prevents inductor saturation and MOSFET overstress without requiring external current-limit circuitry.
What is the purpose of the dual exposed pads (Pins 37 and 38) on the LT3958EUHE#PBF QFN package?
Pin 37 is SGND (signal ground) and Pin 38 is SW (switch drain) - both are exposed pads requiring separate PCB copper connections. SGND must connect to the signal ground plane for accurate current sensing, while SW must connect to the high-current switch node copper area for thermal dissipation. Separating these pads prevents noise coupling and improves thermal performance versus single-pad QFNs.
Is the LT3958EUHE#PBF pin-compatible with other members of the LT3958 family?
Yes, all LT3958 variants (e.g., LT3958EUHE#PBF, LT3958IUHE#PBF) share identical pinout, package, and electrical characteristics - differing only in temperature grade (E = –40°C to +125°C, I = same range with extended testing). No PCB redesign is required when upgrading between grades, and schematic symbols/layouts are fully interchangeable.
LT3958EUHE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 36-WFQFN, 28 Leads, Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Boost, Cuk, Flyback, SEPIC
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 5V
- Voltage - Input (Max):
- 80V
- Voltage - Output (Min/Fixed):
- 1.6V
- Voltage - Output (Max):
- 84V (Switch)
- Current - Output:
- 3.3A (Switch)
- Frequency - Switching:
- 100kHz ~ 1MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 36-QFN (5x6)
LT3958EUHE#PBF FAQ
1.How can I place an order for LT3958EUHE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3958EUHE#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 LT3958EUHE#PBF reliable?
The price and inventory of LT3958EUHE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3958EUHE#PBF is usually 5 days.
3.What payment methods are accepted for LT3958EUHE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3958EUHE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3958EUHE#PBF?
LT3958EUHE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3958EUHE#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 LT3958EUHE#PBF?
For technical support, including LT3958EUHE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3958EUHE#PBF requirements.
6.How does Aetrix verify that LT3958EUHE#PBF is sourced from the original manufacturer or authorized distributors?
All LT3958EUHE#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 LT3958EUHE#PBF meets industry standards.
7.What is the process for return or replacement of LT3958EUHE#PBF?
All LT3958EUHE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3958EUHE#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 LT3958EUHE#PBF part is unused and in its original packaging.
Return procedure for LT3958EUHE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3958EUHE#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…
