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Analog Devices Inc. LTC1439IG#TRPBF
- Part No.:
- LTC1439IG#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 36-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
LTC1439IG#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 36SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,351
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Product details
Overview
LTC1439IG#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 regulated outputs (e.g., 5V/3.3V), supports 3.5V–30V input, maintains constant frequency down to ~1% load via Adaptive Power™ mode, and integrates a 0.5A low-noise linear regulator for VPP or audio supply - used in notebook computers and portable instrumentation.
For engineers reviewing the LTC1439IG#TRPBF datasheet, LTC1439IG#TRPBF pinout, LTC1439IG#TRPBF application, or LTC1439IG#TRPBF equivalent, key selection criteria include programmable output voltage (1.19V–9V), PLL-synchronizable oscillator (112–240 kHz), remote sense capability on VOSENSE2, foldback current limiting option, and logic-controlled micropower shutdown (IQ < 30 µA).
Technical Context
The LTC1439IG#TRPBF implements a current-mode, dual-phase synchronous buck controller with independent error amplifiers, ITH1/ITH2 compensation nodes, and adaptive gate drive routing between TGL/TGS (high-current) and BG (bottom-FET) outputs. Its Adaptive Power™ architecture dynamically selects between large- and small-MOSFET drive paths based on inductor current reversal detection and RSENSE voltage hysteresis (~20 mV), enabling constant-frequency operation at light loads.
It features dual independent control loops with SFB1-assisted secondary winding regulation for the first channel, POR2 power-on reset timed to 65536 oscillator cycles (~300 ms), and an auxiliary linear regulator block with AUXON logic enable, AUXFB feedback, and AUXDR open-drain output capable of 12 V (with internal divider) or adjustable outputs (via external divider when VAUXDR < 8.5 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.5 V to 30 V (absolute max 36 V) - supports wide-range battery and DC distribution inputs. |
| Switching Frequency | 112–138 kHz (free-running); up to 240 kHz (PLL-locked) - enables optimization of efficiency vs. size via COSC capacitor. |
| Output Voltage Range | 1.19 V to 9 V (pin-selectable: 3.3 V / 5 V / adjustable) - configured via VPROG1/VPROG2 pins and VOSENSE2 remote sense. |
| Quiescent Current | 320 µA (normal mode); <30 µA (shutdown) - enables long battery life in portable systems. |
| Current Sense Threshold | 130–180 mV (ΔVSENSE(MAX)) - sets overcurrent trip point with external RSENSE resistors (e.g., 0.03 Ω for 3.5 A). |
| Auxiliary Regulator Output | 12.0 V ±0.5 V (internal divider) or adjustable (external divider) - provides low-noise, low-dropout supply for VPP or analog circuits. |
| Operating Temperature | –40°C to +85°C (Industrial grade) - qualified for harsh-environment embedded applications. |
Pinout & Package
Package: 36-lead plastic SSOP (GW package), RoHS-compliant, moisture sensitivity level 3. Thermal resistance θJA = 85°C/W.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| RUN/SS1, RUN/SS2 | Soft-start & enable control | Capacitor-to-ground sets ramp time (~0.5 s/µF); <1.3 V forces shutdown of respective channel. |
| SENSE+1/2, SENSE−1/2 | Current-sense differential inputs | Measure voltage across external RSENSE to regulate peak inductor current; built-in offset sets trip threshold. |
| VOSENSE2 | Remote output voltage feedback | Connects to external resistive divider for precise regulation of second output; enables remote sensing topology. |
| VPROG1, VPROG2 | Output voltage programming | DC voltage levels select 3.3 V / 5 V / adjustable mode; open-circuit enables external divider configuration for VOSENSE2. |
| TGL1/TGL2, BG1/BG2 | High-current gate drivers | TGL drives top N-MOSFET (floating); BG drives bottom N-MOSFET (ground-referenced); support synchronous rectification. |
| TGS1/TGS2 | Low-current top-MOSFET driver | Enables Adaptive Power™ mode at light loads; open = Burst Mode operation. |
| SFB1 | Secondary winding feedback | Forces continuous operation on Channel 1 when pulled <1.19 V; ensures regulation under secondary-load transients. |
| POR2 | Power-on reset output | Open-drain signal asserted when VOUT2 drops >7.5%; releases after 65536 oscillator cycles (~300 ms) once regulation restored. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive Power™ architecture | Automatically switches between TGL/BG (high-current) and TGS (low-current) drive paths to maintain fixed frequency down to ~1% load - avoids audible noise and EMI spikes from Burst Mode. |
| Phase-locked loop (PLL) | Allows synchronization of switching frequency to external clock via PLLIN; PLL LPF pin accepts 0–2.4 V control voltage for ±30% frequency tuning - critical for EMI reduction in multi-rail systems. |
| Dual independent control loops | Each channel has dedicated ITH compensation, VPROG programming, and remote sense (VOSENSE2), enabling asymmetric outputs (e.g., 5 V/3.3 V) with independent stability tuning. |
| Integrated auxiliary linear regulator | 0.5 A PNP-based LDO with AUXON logic enable, AUXFB feedback, and AUXDR open-drain output - delivers low-noise 12 V (or adjustable) without external op-amp or reference. |
| Programmable soft start & shutdown | Independent RUN/SS pins per channel allow staggered startup, fault isolation, and micropower state (<30 µA) - simplifies system power sequencing. |
Applications
| Notebook Computer Power Management | Portable Instrumentation Supply |
|---|---|
|
Use Scenario: Dual-rail CPU core (3.3 V) and I/O (5 V) supply in space-constrained clamshell design with battery backup. IC Role / Device Role / Timing Role: Primary dual-output synchronous buck controller managing high-efficiency DC/DC conversion and adaptive light-load behavior. Use Value: Adaptive Power™ maintains fixed 125 kHz switching at light loads, eliminating Burst Mode noise and ensuring clean ADC reference rails. |
Use Scenario: Handheld multimeter requiring ultra-low-noise analog supply and stable digital rail during battery discharge. IC Role / Device Role / Timing Role: Dual buck controller with auxiliary LDO generating 12 V VPP for LCD bias and low-noise 3.3 V for microcontroller. Use Value: Integrated AUX regulator eliminates discrete LDO, while SFB1 ensures main output remains regulated even when secondary winding load varies. |
| Battery-Operated Medical Sensor | DC Power Distribution System |
|
Use Scenario: Wearable ECG monitor powered by single-cell Li-ion (3.0–4.2 V), needing regulated 1.8 V and 3.3 V with minimal quiescent current. IC Role / Device Role / Timing Role: High-efficiency dual buck controller operating across full battery range with programmable shutdown and remote sense. Use Value: <30 µA shutdown IQ extends battery life; VIN min = 3.5 V allows operation down to near-end-of-discharge cell voltage. |
Use Scenario: Industrial IoT gateway with multiple sub-systems requiring isolated, synchronized 5 V and 3.3 V rails from 12–24 V bus. IC Role / Device Role / Timing Role: PLL-synchronized dual controller enabling deterministic EMI filtering and inter-rail timing coordination. Use Value: PLLIN input allows master-slave synchronization across multiple LTC1439IG#TRPBF units - reduces conducted EMI peaks by aligning switching edges. |
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 |
|---|---|---|---|
| LTC3728CUH#TRPBF | Single-channel, higher current (up to 25 A), no integrated auxiliary LDO, supports MOSFET RDS(on) current sensing. | Lacks dual-output capability and auxiliary regulator - requires external circuitry for second rail or VPP generation. | Choose when higher per-channel current or RDS(on) sensing is required, and dual outputs can be implemented with two ICs. |
| MP2918GL-Z | Dual-channel, 5 V/3.3 V fixed outputs only, no PLL sync, no SFB1 or auxiliary LDO, lower IQ (120 µA normal). | Fixed-output-only architecture limits flexibility; no remote sense or secondary feedback - unsuitable for adjustable or precision-regulated designs. | Choose for cost-sensitive, fixed-rail applications where Adaptive Power™, PLL, or auxiliary regulation are unnecessary. |
Compared with LTC3728CUH#TRPBF and MP2918GL-Z, the LTC1439IG#TRPBF uniquely combines dual independent programmable outputs, Adaptive Power™ light-load operation, PLL synchronization, and an integrated auxiliary LDO - making it optimal for compact, multi-rail, battery-powered systems demanding low noise and flexible regulation.
Availability
LTC1439IG#TRPBF is available at Aetrix Electronics and suitable for notebook computers, portable instrumentation, and battery-operated medical sensors requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.
Supply support for LTC1439IG#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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.
The LTC1439IG#TRPBF belongs to Linear's legacy high-efficiency power controller family, designed specifically for dual-output, battery-powered, and noise-sensitive applications where adaptive light-load operation and precise regulation are critical.
FAQ
What is the maximum supported switching frequency for the LTC1439IG#TRPBF?
The LTC1439IG#TRPBF supports up to 240 kHz when PLL-locked (VPLLLPF = 2.4 V), and 138 kHz in free-running mode (COSC = 100 pF). The datasheet specifies 400 kHz as the absolute maximum recommended frequency to maintain ultrahigh efficiency - exceeding this increases gate charge losses and reduces light-load performance. Always verify thermal derating at elevated frequencies.
How does the Adaptive Power™ mode function in the LTC1439IG#TRPBF?
The LTC1439IG#TRPBF activates Adaptive Power™ mode when inductor current reversal is detected (via I2 comparator) and the RSENSE voltage stays below ~20 mV for one full cycle. It then routes top-MOSFET drive from TGL to TGS and disables BG, reducing gate charge loss. Operation reverts to TGL/BG when ITH exceeds 0.6 V or RSENSE voltage exceeds 20 mV - ensuring seamless transition across load ranges.
Can the LTC1439IG#TRPBF generate both 5 V and 3.3 V outputs simultaneously?
Yes - the LTC1439IG#TRPBF natively supports simultaneous 5 V and 3.3 V outputs. Configure VPROG1 = INTVCC (5 V) and VPROG2 = 0 V (3.3 V), with SENSE−1/2 tied to respective output dividers. VOSENSE2 enables remote sensing on the 3.3 V rail. The datasheet Figure 1 shows a validated 5 V/3.3 V, 3.5 A each design using Si4412ADY and IRLML2803 MOSFETs.
What is the purpose of the SFB1 pin on the LTC1439IG#TRPBF?
The SFB1 pin on the LTC1439IG#TRPBF provides secondary winding feedback for Channel 1. When pulled below 1.19 V, it forces continuous synchronous operation regardless of load - ensuring regulation stability when the main output is affected by secondary-side loading (e.g., flyback-derived auxiliary rails). It must be tied to ground, INTVCC, or a resistive divider depending on transformer configuration.
Does the LTC1439IG#TRPBF include a power-on reset function?
Yes - the LTC1439IG#TRPBF includes a dedicated POR2 open-drain output that asserts low when VOUT2 deviates >7.5% from regulation. After VOUT2 recovers to within –5%, a 65536-cycle timer (≈300 ms at 125 kHz) starts; POR2 releases only after this delay. This ensures downstream logic resets reliably after power stabilization - a feature absent in the pin-compatible LTC1438X variant.
LTC1439IG#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
LTC1439IG#TRPBF FAQ
1.How can I place an order for LTC1439IG#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1439IG#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 LTC1439IG#TRPBF reliable?
The price and inventory of LTC1439IG#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1439IG#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC1439IG#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1439IG#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1439IG#TRPBF?
LTC1439IG#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1439IG#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 LTC1439IG#TRPBF?
For technical support, including LTC1439IG#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1439IG#TRPBF requirements.
6.How does Aetrix verify that LTC1439IG#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC1439IG#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 LTC1439IG#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC1439IG#TRPBF?
All LTC1439IG#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1439IG#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 LTC1439IG#TRPBF part is unused and in its original packaging.
Return procedure for LTC1439IG#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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