My Inquiry
My Account
Analog Devices Inc. LTC3873EDDB#TRPBF
- Part No.:
- LTC3873EDDB#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 8-WFDFN Exposed Pad
- Datasheet:
-
LTC3873EDDB#TRPBF.pdf
- Description:
- IC REG CTRLR MULT TOPOLOGY 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,059
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3873EDDB#TRPBF from Analog Devices (formerly Linear Technology) is a constant-frequency current-mode DC/DC controller for boost, flyback, and SEPIC topologies, driving external N-channel MOSFETs in high-input-voltage telecom and automotive power supplies. It delivers ±1.5% output voltage accuracy, 200kHz fixed switching frequency, 300μA quiescent current, and supports RDS(ON) current sensing up to 60V on the SW node.
For engineers reviewing the LTC3873EDDB#TRPBF datasheet, LTC3873EDDB#TRPBF pinout, LTC3873EDDB#TRPBF application, or LTC3873EDDB#TRPBF equivalent, this page provides verified package mapping (8-lead 2mm × 3mm DFN), validated pin functions, confirmed current-sense threshold options (95–325mV), real-world soft-start behavior (3.3ms internal, capacitor-programmable), and direct alternative part comparisons for high-voltage DC/DC design.
Technical Context
The LTC3873EDDB#TRPBF implements No RSENSE™ current sensing by monitoring the voltage drop across the external N-MOSFET's RDS(ON), eliminating the need for a discrete sense resistor and reducing conduction losses. Its internal 9.3V shunt regulator enables direct biasing from input voltages up to 72V via a series resistor.
It features a 200kHz oscillator with ±10% temperature stability, programmable peak current limit via IPRG pin (GND/floating/VIN), and internal slope compensation that eliminates subharmonic oscillation up to 50% duty cycle-external ramp injection is optional for higher duty cycles.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Oscillator Frequency | 200kHz fixed; ensures predictable EMI profile and simplifies filter design for telecom 48V systems. |
| Output Voltage Accuracy | ±1.5% over –40°C to 85°C; guarantees tight regulation without post-production trimming in industrial power rails. |
| Quiescent Current | 300μA normal / 55μA micropower start-up; enables low-power standby modes in battery-backed telecom equipment. |
| SW Node Max Voltage | 60V absolute max; supports RDS(ON) sensing in 42V automotive and 36–72V telecom inputs without external sense resistor. |
| Current Sense Threshold | 95mV (IPRG=GND) to 325mV (IPRG=VIN); allows optimization of MOSFET selection and efficiency vs. noise immunity trade-offs. |
| Soft-Start Time | 3.3ms internal (capacitor-programmable); prevents inrush current in hot-plug 48V backplane applications. |
| VCC Shunt Regulator | 9.3V ±0.3V at 1–25mA; permits direct high-voltage biasing with minimal external components in isolated flyback designs. |
Pinout & Package
Package: 8-lead 2mm × 3mm plastic DFN (DDB) with exposed pad (Pin 9 = GND), 0.75mm height, θJA = 76°C/W - optimized for high-power density telecom modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IPRG (Pin 1) | Current limit select | Configures peak current threshold: GND = 95mV, floating = 185mV, VIN = 295mV - sets MOSFET conduction window. |
| ITH (Pin 2) | Error amplifier output | Drives current comparator threshold; voltage range 0.7–1.9V determines inductor peak current during regulation. |
| VFB (Pin 3) | Feedback input | Compares divided output voltage to 1.2V reference; 25nA input bias enables high-resistor-divider networks for low quiescent loss. |
| GND (Pin 4) | Power and signal ground | Common return for VCC, NGATE, RUN/SS, and feedback; exposed pad must be soldered for thermal and electrical integrity. |
| NGATE (Pin 5) | N-MOSFET gate driver | High-current (±1.5A) push-pull output swinging 0V to VIN; drives logic-level MOSFETs directly without level shifters. |
| VCC (Pin 6) | Supply input | Accepts 4.0–9.0V; internal 9.3V shunt regulator enables resistor-fed bias from 36–72V inputs in telecom applications. |
| RUN/SS (Pin 7) | Shutdown & soft-start control | Logic-compatible enable (0.7V threshold); open-circuit = 3.3ms internal soft-start; capacitor-to-GND extends ramp time linearly. |
| SW (Pin 8) | Switch node interface | Connects to MOSFET drain and inductor; senses RDS(ON) voltage or external resistor; rated for 60V transient swing. |
Key Features
| Feature | Design Value |
|---|---|
| No RSENSE™ current sensing | Eliminates discrete sense resistor, reducing BOM count, board space, and conduction losses in high-current boost/flyback converters. |
| 9.3V internal shunt regulator | Enables single-resistor biasing from 36–72V telecom inputs without external LDO or zener, simplifying auxiliary supply design. |
| Programmable current limit | Three threshold options (95/185/295mV) via IPRG pin allow MOSFET selection based on RDS(ON) and thermal constraints. |
| Internal soft-start (3.3ms) | Prevents output overshoot and inrush current during cold start in 48V distributed power architectures. |
| Low 300μA quiescent current | Maintains high light-load efficiency in always-on telecom line cards and remote radio units without compromising regulation. |
Applications
| Telecom Power Supply | Automotive 42V System |
|---|---|
|
Use Scenario: Non-isolated 5V/2A converter powered from 36–72V telecom rectified bus. IC Role / Device Role / Timing Role: Primary controller managing MOSFET switching, current-mode loop compensation, and soft-start sequencing. Use Value: ±1.5% output accuracy and 200kHz fixed frequency ensure stable operation across wide input range without external clock sync. |
Use Scenario: 12V auxiliary rail generation from 24–42V vehicle battery in ADAS ECUs. IC Role / Device Role / Timing Role: Flyback controller regulating isolated 12V output while tolerating load dump transients up to 60V on SW node. Use Value: 60V SW rating and RDS(ON) sensing eliminate sense resistor, improving efficiency and reliability under harsh automotive conditions. |
| Portable Test Equipment | Industrial IoT Gateway |
|
Use Scenario: SEPIC converter generating 12V from 9–15V Li-ion battery pack with seamless transition across battery discharge curve. IC Role / Device Role / Timing Role: Dual-mode controller supporting both boost and buck-boost operation via single IC footprint. Use Value: Adjustable current limit and internal soft-start prevent brownout during battery sag, ensuring uninterrupted operation of measurement circuitry. |
Use Scenario: Isolated 3.3V/3A power for wireless modem in edge gateway operating from 24V industrial bus. IC Role / Device Role / Timing Role: Flyback controller interfacing with optocoupler feedback for primary-side regulation and safety isolation. Use Value: 55μA micropower start-up enables reliable cold start from backup capacitors during main power interruption. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar boost/flyback/SEPIC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3757EMSE#TRPBF | Higher 100V SW rating, 1MHz max frequency, integrated bootstrap diode; requires external compensation network. | Better suited for high-frequency, high-input-voltage flyback in compact AC/DC adapters; lacks No RSENSE™ capability. | Select when >60V input or >500kHz operation required; avoid if RDS(ON) sensing and minimal BOM are priorities. |
| UCC28C43DR | Fixed 200kHz frequency, 30V VCC max, no internal shunt regulator; requires external bias supply and sense resistor. | Lower-cost solution for 12–24V input boost converters where input voltage stays within VCC limits. | Choose for cost-sensitive 24V industrial applications; not viable for 48V telecom or automotive without added bias circuitry. |
Compared with LT3757EMSE#TRPBF and UCC28C43DR, the LTC3873EDDB#TRPBF uniquely combines 60V SW tolerance, No RSENSE™ sensing, and 9.3V internal shunt regulation - enabling simpler, more efficient high-input-voltage designs without external bias or sense components.
Availability
LTC3873EDDB#TRPBF is available at Aetrix Electronics and suitable for telecom power supplies, 42V automotive systems, and portable electronic equipment requiring stable component supply and long-term industrial lifecycle support.
Supply support for LTC3873EDDB#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 acquired Linear Technology in 2017 and maintains its high-performance analog and power management product lines with rigorous qualification and long-term support.
The LTC3873EDDB#TRPBF belongs to Linear's legacy high-voltage DC/DC controller family, designed specifically for robust, efficient boost/flyback/SEPIC conversion in telecom infrastructure and automotive electronics.
FAQ
What is the maximum input voltage the LTC3873EDDB#TRPBF can handle in a boost configuration?
The LTC3873EDDB#TRPBF itself does not impose a hard input voltage limit-the VIN range is determined by external components. Its SW pin is rated for 60V absolute maximum, enabling use with 36–72V telecom inputs when RDS(ON) sensing is applied. For higher voltages, an external sense resistor must be used, and the external MOSFET's BVDSS rating becomes the limiting factor-not the LTC3873EDDB#TRPBF.
Does the LTC3873EDDB#TRPBF support synchronous rectification?
No, the LTC3873EDDB#TRPBF does not include a second gate driver for synchronous rectification. It provides only one high-side N-channel gate driver (NGATE) for the primary switch. In flyback or SEPIC topologies, a separate controller or diode-based secondary-side rectification is required. The datasheet explicitly references Schottky diodes (e.g., UPS840, BAT760) in all typical applications.
How is the output voltage set on the LTC3873EDDB#TRPBF?
The LTC3873EDDB#TRPBF uses a precision 1.2V internal reference. Output voltage is set by an external resistor divider connected between VOUT, VFB, and GND per the formula VOUT = 1.2V × (1 + R2/R1). The VFB pin draws only 25nA, allowing high-value resistors (e.g., 121kΩ/12.1kΩ for 12V) to minimize quiescent current loss while maintaining <1% error.
Can the LTC3873EDDB#TRPBF operate without an external soft-start capacitor?
Yes-the LTC3873EDDB#TRPBF includes a built-in 3.3ms soft-start function activated when the RUN/SS pin is left open. During this period, the ITH voltage ramps linearly from 0.85V to 1.9V, controlling inductor peak current rise and preventing output overshoot. An external capacitor is optional and only needed to extend soft-start beyond 3.3ms for specific inrush control requirements.
What is the purpose of the IPRG pin on the LTC3873EDDB#TRPBF?
The IPRG pin on the LTC3873EDDB#TRPBF selects the peak current limit threshold: tying it to GND sets 95mV, leaving it floating sets 185mV, and connecting it to VIN sets 295mV. This allows designers to match the current limit to the chosen MOSFET's RDS(ON) and thermal margin-lower thresholds suit low-RDS(ON) devices in high-efficiency designs, while higher thresholds accommodate higher-RDS(ON) MOSFETs in cost-sensitive layouts.
LTC3873EDDB#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive, Isolation Capable
- Topology:
- Boost, Flyback, SEPIC
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 8.4V ~ 60V
- Frequency - Switching:
- -
- Duty Cycle (Max):
- 78%
- Synchronous Rectifier:
- No
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Soft Start
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (3x2)
LTC3873EDDB#TRPBF FAQ
1.How can I place an order for LTC3873EDDB#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3873EDDB#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 LTC3873EDDB#TRPBF reliable?
The price and inventory of LTC3873EDDB#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3873EDDB#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3873EDDB#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3873EDDB#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3873EDDB#TRPBF?
LTC3873EDDB#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3873EDDB#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 LTC3873EDDB#TRPBF?
For technical support, including LTC3873EDDB#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3873EDDB#TRPBF requirements.
6.How does Aetrix verify that LTC3873EDDB#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3873EDDB#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 LTC3873EDDB#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3873EDDB#TRPBF?
All LTC3873EDDB#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3873EDDB#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 LTC3873EDDB#TRPBF part is unused and in its original packaging.
Return procedure for LTC3873EDDB#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3873EDDB#TRPBF Tags
-
UCC28C45DR
Texas Instruments
-
UCC28C40DR
Texas Instruments
-
UCC28C43DR
Texas Instruments
-
ZXSC410E6TA
Diodes Incorporated
-
LM3524DMX/NOPB
Texas Instruments
-
LM3489MMX/NOPB
Texas Instruments
-
MIC2102YML-TR
Microchip Technology
-
LM5148RGYR
Texas Instruments
-
TL598CDR
Texas Instruments
-
LM5155DSSR
Texas Instruments
-
LM25085MYX/NOPB
Texas Instruments
-
UCC2813DTR-0
Texas Instruments
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…
