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Analog Devices Inc. LTC1439EG#TRPBF
- Part No.:
- LTC1439EG#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 36-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
LTC1439EG#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 36SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,441
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Product details
Overview
LTC1439EG#TRPBF from Analog Devices (formerly Linear Technology) is a dual synchronous step-down switching regulator controller driving external N-channel MOSFETs in a phase-lockable fixed-frequency architecture. It delivers two independently regulated outputs (e.g., 5V/3.3V), supports Adaptive Power™ mode for ultrahigh efficiency down to ~1% load, and integrates a 0.5A auxiliary linear regulator for low-noise VPP or audio supply - used in notebook computers and portable instrumentation.
For engineers reviewing the LTC1439EG#TRPBF datasheet, LTC1439EG#TRPBF pinout, LTC1439EG#TRPBF application, or LTC1439EG#TRPBF equivalent, key selection criteria include its dual-channel current-mode control, programmable 112–240 kHz oscillator with PLL synchronization, remote voltage sensing on both outputs, and logic-controlled micropower shutdown (IQ < 30 µA).
Technical Context
The LTC1439EG#TRPBF implements a constant-frequency, current-mode control architecture with independent error amplifiers per channel, where ITH1/ITH2 set peak inductor current via external sense resistors. Its Adaptive Power™ stage dynamically switches between TGL/TGS/BG drive paths to maintain fixed frequency operation at light loads while minimizing gate charge losses.
It features dual independent feedback loops with pin-selectable output voltages (1.19V–9V), secondary winding feedback (SFB1) forcing continuous operation on Channel 1, and integrated power-on reset (POR2) with 65536-cycle delay. The auxiliary regulator uses AUXON/AUXFB/AUXDR pins to control an external PNP for 12V or adjustable low-noise output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Topology | Dual synchronous buck controller - requires external N-MOSFETs and inductors; no integrated power switches. |
| Switching Frequency | 112–138 kHz (base), up to 240 kHz with PLL - set by COSC capacitor; enables EMI control and layout optimization. |
| Input Voltage Range | 3.5V to 30V (36V absolute max) - supports wide-range battery and DC distribution inputs. |
| Output Voltage Range | 1.19V to 9V per channel - configured via VPROG1/VPROG2 pins or external dividers with remote sense (VOSENSE1/2). |
| Efficiency Mode | Adaptive Power™ - maintains fixed frequency down to ~1% load using TGS small-MOSFET path; avoids burst-mode noise. |
| Auxiliary Regulator | 0.5A linear regulator - controlled via AUXON; provides low-noise 12V (internal divider) or adjustable output using external PNP. |
| Shutdown Current | <30 µA - achieved by pulling RUN/SS1 and RUN/SS2 below 1.3V; enables long battery life in portable systems. |
Pinout & Package
Package: 36-lead plastic SSOP (GW package), RoHS-compliant, moisture-sensitive level 3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RUN/SS1, RUN/SS2 | Soft-start & enable control | Capacitor-to-ground sets ramp time (~0.5 s/µF); <1.3V forces shutdown of respective channel; both low disables entire IC. |
| SENSE+1/2, SENSE−1/2 | Main current-sense inputs | Differential pair per channel; built-in offset with RSENSE sets current limit threshold (130–180 mV typical). |
| VOSENSE2 | Remote feedback input (Ch2) | Connects to external resistor divider for precise regulation; not present on Ch1 for LTC1439 (only LTC1438-ADJ has VOSENSE1). |
| TGL1/TGL2, BG1/BG2 | High-current gate drivers | TGL drives top N-MOSFET (floating); BG drives bottom N-MOSFET (ground-referenced); 2A peak capability. |
| TGS1/TGS2 | Low-current top-MOSFET driver | Enables Adaptive Power™ mode at light loads; open = Burst Mode fallback. |
| SFB1 | Secondary winding feedback | Forces continuous operation on Ch1 when pulled below 1.19V; ensures regulation under cross-load conditions. |
| POR2 | Power-on reset output | Open-drain signal asserting when VOUT2 drops >7.5%; releases after 65536 oscillator cycles once regulation restored. |
| AUXON, AUXFB, AUXDR | Auxiliary regulator interface | AUXON enables regulator; AUXFB is feedback node (1.19V ref); AUXDR sinks base current of external PNP pass device. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent current-mode controllers | Each channel has dedicated ITH, SENSE+, SENSE−, and RUN/SS - enables asymmetric output configurations (e.g., 5V/3.3V) with separate soft-start and fault handling. |
| Phase-locked loop (PLL) synchronization | PLLIN and PLL LPF pins allow external clock locking or frequency shifting (0–2.4V control range) - critical for noise-sensitive multi-rail systems. |
| Remote output voltage sensing | VOSENSE2 and internal SENSE−1 connections support Kelvin sensing - eliminates IR drop errors in high-current PCB traces. |
| Programmable foldback current limiting | Optional external circuitry enables foldback protection - reduces stress on MOSFETs and inductors during short-circuit events. |
| Logic-controlled auxiliary regulator | AUXON pin enables/disables 0.5A PNP-based linear supply - provides clean bias for ADCs, DACs, or RF sections without switching noise. |
Applications
| Portable Instrumentation | Notebook Computing |
|---|---|
Use Scenario: Handheld multimeter with dual analog front-end rails (±5V, +3.3V) and low-noise reference supply. IC Role / Device Role / Timing Role: LTC1439EG#TRPBF controls two synchronous buck stages for main system rails and powers a low-noise auxiliary rail via external PNP. Use Value: Adaptive Power™ maintains fixed-frequency operation during battery discharge, avoiding audible noise and enabling predictable EMI filtering. | Use Scenario: Dual-output power management in ultra-thin laptop motherboard with tight thermal constraints. IC Role / Device Role / Timing Role: LTC1439EG#TRPBF regulates core logic (5V) and I/O (3.3V) supplies while synchronizing to system clock via PLLIN to reduce beat frequencies. Use Value: Remote sensing on both outputs compensates for PCB voltage drop, ensuring ±0.8% load regulation across full temperature range. |
| Battery-Operated Medical Devices | DC Power Distribution Systems |
Use Scenario: Portable ECG monitor requiring isolated analog supply and clean digital rail with battery fuel gauging. IC Role / Device Role / Timing Role: LTC1439EG#TRPBF generates 3.3V digital rail and 12V analog supply (via AUX regulator), while LBI/LBO pins interface with battery monitor IC. Use Value: Micropower shutdown (<30 µA) extends standby time; low-dropout operation (99% duty cycle) maximizes usable battery voltage range. | Use Scenario: Industrial 24V DC distribution board powering multiple subsystems with coordinated power sequencing. IC Role / Device Role / Timing Role: LTC1439EG#TRPBF serves as primary controller for redundant 5V/3.3V rails, with POR2 providing sequenced enable signals to downstream modules. Use Value: Dual independent RUN/SS pins allow staggered startup; SFB1 input ensures stable regulation even when secondary loads vary dynamically. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1439IGW#TRPBF | Same silicon, industrial-grade (-40°C to +85°C), GW package (36-lead SSOP, θJA = 85°C/W) | Required for extended temperature environments; higher thermal performance than EG grade | Select when operating ambient exceeds 70°C or reliability validation mandates industrial temp grade |
| LTC3727-1EUH#TRPBF | Single-channel, 2-phase controller; higher max fSW (1 MHz); no auxiliary regulator or SFB1 | Used in high-current single-rail designs (e.g., CPU core); lacks dual independent outputs and low-noise linear option | Choose only if dual-channel independence and auxiliary linear supply are not required |
Compared with LTC1439IGW#TRPBF, the LTC1439EG#TRPBF offers identical functionality but is rated only to 70°C ambient and has higher thermal resistance; compared with LTC3727-1EUH#TRPBF, it provides true dual-channel autonomy and integrated auxiliary regulation - making it uniquely suited for space-constrained dual-rail portable systems.
Availability
LTC1439EG#TRPBF is available at Aetrix Electronics and suitable for notebook computing, portable instrumentation, and battery-operated medical devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LTC1439EG#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 full technical and manufacturing continuity for all Linear power products.
The LTC1439EG#TRPBF belongs to Linear's high-efficiency DC/DC controller family, designed specifically for dual-rail portable and instrumentation applications demanding ultralow quiescent current, adaptive light-load efficiency, and precision remote sensing.
FAQ
What is the maximum supported switching frequency for the LTC1439EG#TRPBF?
The LTC1439EG#TRPBF supports up to 400 kHz in standard operation, with base oscillator frequency ranging from 112 kHz to 138 kHz (set by COSC capacitor). When using the PLL feature, the frequency can be shifted up to 240 kHz by applying a control voltage (0–2.4 V) to the PLL LPF pin. Exceeding 400 kHz is not recommended due to increased gate charge losses and reduced efficiency.
Does the LTC1439EG#TRPBF integrate power MOSFETs?
No, the LTC1439EG#TRPBF is a controller-only IC and does not integrate power MOSFETs. It drives external N-channel MOSFETs via dedicated gate driver pins: TGL1/TGL2 (top-side floating), BG1/BG2 (bottom-side grounded), and TGS1/TGS2 (auxiliary top-side for Adaptive Power™ mode). External components must be selected per application requirements.
How does the Adaptive Power™ mode function in the LTC1439EG#TRPBF?
Adaptive Power™ mode in the LTC1439EG#TRPBF automatically switches between high-current (TGL/BG) and low-current (TGS) drive paths based on load. When inductor current reversal is detected and sustained for one cycle, the controller routes top-side drive to TGS pins and disables BG outputs - maintaining fixed-frequency operation down to ~1% of full load and avoiding burst-mode noise.
Can the LTC1439EG#TRPBF regulate both outputs with remote sensing?
Yes - the LTC1439EG#TRPBF supports remote sensing on both channels: Channel 1 uses internal connection from SENSE−1 to its output (no VOSENSE1 pin), while Channel 2 explicitly provides VOSENSE2 for external Kelvin connection. This allows precise regulation of both 5V and 3.3V rails despite PCB trace resistance, meeting ±0.8% load regulation specs across temperature.
What is the purpose of the SFB1 pin on the LTC1439EG#TRPBF?
The SFB1 pin on the LTC1439EG#TRPBF is a secondary winding feedback input that forces continuous synchronous operation on Channel 1 when pulled below 1.19 V. It ensures regulation stability under dynamic cross-loading conditions - for example, when a secondary winding supplies auxiliary circuitry and its voltage droop would otherwise cause Channel 1 to enter discontinuous conduction mode.
LTC1439EG#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 36-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 2
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 3.5V ~ 30V
- Frequency - Switching:
- Up to 400kHz
- Duty Cycle (Max):
- 99%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Enable, Power on Reset, Soft Start
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 36-SSOP
LTC1439EG#TRPBF FAQ
1.How can I place an order for LTC1439EG#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1439EG#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 LTC1439EG#TRPBF reliable?
The price and inventory of LTC1439EG#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1439EG#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC1439EG#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1439EG#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1439EG#TRPBF?
LTC1439EG#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1439EG#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 LTC1439EG#TRPBF?
For technical support, including LTC1439EG#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1439EG#TRPBF requirements.
6.How does Aetrix verify that LTC1439EG#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC1439EG#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 LTC1439EG#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC1439EG#TRPBF?
All LTC1439EG#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1439EG#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 LTC1439EG#TRPBF part is unused and in its original packaging.
Return procedure for LTC1439EG#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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