My Inquiry
My Account
Analog Devices Inc. LTC1438CG-ADJ#TRPBF
- Part No.:
- LTC1438CG-ADJ#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 28-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
LTC1438CG-ADJ#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 28SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,035
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1438CG-ADJ#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 adjustable output voltages (1.19V–9V), supports 3.5V–30V input, maintains constant frequency down to ~1% load via Adaptive Power™ mode, and integrates a 0.5A auxiliary linear regulator - used in notebook DC/DC power rails requiring high efficiency and low-noise bias.
For engineers reviewing the LTC1438CG-ADJ#TRPBF datasheet, LTC1438CG-ADJ#TRPBF pinout, LTC1438CG-ADJ#TRPBF application, or LTC1438CG-ADJ#TRPBF equivalent, key selection criteria include dual-channel programmable VOUT, remote sense capability on Channel 1, SFB1-assisted secondary winding regulation, and compatibility with external PNP-based VPP/audio supplies.
Technical Context
The LTC1438CG-ADJ#TRPBF implements current-mode control with two independent error amplifiers (ITH1/ITH2), each regulating its channel via voltage-controlled current-sense threshold (ΔVSENSE up to 180mV). Its Adaptive Power™ architecture dynamically routes gate drive between TGL/TGS pins to sustain 400kHz operation at light loads while minimizing switching losses.
Channel 1 features VOSENSE1 (available only on -ADJ variant) for true remote sensing and adjustable output; Channel 2 uses VPROG2-selectable or externally divided feedback. The SFB1 pin forces continuous conduction when pulled below 1.19V, enabling precise regulation of isolated secondary windings independent of main output loading.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.5V to 30V (absolute max 36V) - supports wide-range battery and industrial DC inputs. |
| Output Voltage Range (Ch1) | 1.19V to 9V, adjustable via external resistive divider on VOSENSE1 - enables custom rail generation without fixed-VOUT constraints. |
| Switching Frequency | Programmable 112–138kHz (COSC-dependent); up to 400kHz with Adaptive Power™ - balances efficiency vs. component size. |
| Current Sense Threshold | 130–180mV (ΔVSENSE) - sets peak inductor current limit with <±1% tolerance over temp. |
| Quiescent Current | 320µA typical (normal mode); <30µA in shutdown - critical for battery runtime in portable systems. |
| Operating Temp Range | 0°C to 70°C (Commercial grade, CG suffix) - validated for notebook and handheld thermal environments. |
| Auxiliary Regulator Output | 0.5A linear regulator controlled by AUXON/AUXFB - provides low-noise, low-dropout supply for audio codecs or flash VPP. |
Pinout & Package
Package: 28-Lead Plastic SSOP (G package), RoHS-compliant, moisture-sensitive level 3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VOSENSE1 | Remote feedback input (Ch1 only) | Enables true remote sensing for adjustable Channel 1 output - not present on non-ADJ variants. |
| VPROG2 | Channel 2 output voltage select | Open = adjustable mode; grounded = 3.3V; tied to INTVCC = 5V - configures second regulator without external resistors. |
| SFB1 | Secondary winding feedback | Pulling below 1.19V forces continuous conduction on Channel 1 - ensures regulation under light/no main-load conditions. |
| RUN/SS1, RUN/SS2 | Soft-start & enable control | Capacitor-to-ground sets ramp time (~0.5s/µF); <1.3V disables respective channel - supports sequenced power-up. |
| ITH1, ITH2 | Error amplifier compensation | Voltage controls current-sense threshold - direct interface for loop compensation networks. |
| TGL1/TGS1, BG1 | Top/bottom gate drives (Ch1) | TGL1 drives large N-MOSFET; TGS1 drives small N-MOSFET+Schottky for Adaptive Power™ - reduces light-load losses. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive Power™ architecture | Maintains fixed 400kHz switching down to ~1% rated load by switching between large and small top-side MOSFET drives - eliminates audible noise and improves light-load efficiency. |
| Dual independent current-mode loops | Each channel has dedicated ITH pin, SENSE+/– inputs, and programmable soft-start - enables asymmetric rail sequencing and independent stability tuning. |
| Remote sensing on Channel 1 | VOSENSE1 pin allows Kelvin connection to load - eliminates IR drop errors in high-current PCB traces or connectors. |
| Integrated 0.5A auxiliary linear regulator | Controlled by AUXON logic input and AUXFB feedback - generates clean, low-noise 12V (or adjustable) supply for analog subsystems without external LDO. |
| Secondary feedback enforcement (SFB1) | Forces continuous operation on Channel 1 when SFB1 <1.19V - guarantees regulation of isolated secondary windings regardless of main output loading. |
Applications
| Portable Computing Power | Battery-Powered Instrumentation |
|---|---|
Use Scenario: Dual-rail DC/DC conversion in ultra-thin notebooks requiring 5V/3.3V or custom-adjustable core/memory supplies. IC Role / Device Role / Timing Role: Primary controller for synchronous buck stages driving external N-MOSFETs; VOSENSE1 enables precision remote sensing at CPU socket. Use Value: Adaptive Power™ sustains 400kHz operation during sleep states, avoiding Burst Mode noise and simplifying EMI filtering. | Use Scenario: Multi-rail power management in handheld test equipment with mixed analog/digital signal chains. IC Role / Device Role / Timing Role: Dual-channel regulator controlling main system rails and auxiliary low-noise supply for ADC reference or op-amp bias. Use Value: Integrated 0.5A auxiliary linear regulator (AUXON-controlled) eliminates need for discrete LDO, reducing BOM count and board area. |
| DC Power Distribution Systems | Industrial Embedded Control |
Use Scenario: Centralized 24V-to-5V/3.3V conversion feeding multiple downstream modules in modular PLC backplanes. IC Role / Device Role / Timing Role: High-efficiency primary controller with remote sense on both outputs; SFB1 ensures stable regulation despite variable module loading. Use Value: Wide 3.5V–30V input range accommodates unregulated industrial bus voltages; foldback current limiting protects against shorted downstream modules. | Use Scenario: Power for fanless embedded controllers in factory automation, requiring silent operation and extended temperature reliability. IC Role / Device Role / Timing Role: Dual synchronous buck controller managing processor core voltage and I/O rail, with programmable soft-start for inrush control. Use Value: Logic-controlled micropower shutdown (<30µA) enables rapid system-level power gating without compromising startup timing. |
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 |
|---|---|---|---|
| LTC1439CG | Fixed 3.3V/5V outputs on Channel 1; no VOSENSE1 pin; includes PLLIN/PLL LPF for synchronization. | Used where dual fixed outputs suffice and clock synchronization across multiple converters is required. | Select LTC1439CG if fixed-VOUT and PLL locking are needed; LTC1438CG-ADJ#TRPBF is required for adjustable Channel 1 with remote sensing. |
| MP2491DS-LF-Z | Single-channel, integrated MOSFETs, 2.5–18V input, 0.8–15V adjustable output; no auxiliary LDO or SFB1 functionality. | Targeted at cost-sensitive, space-constrained single-rail applications without secondary winding support. | Choose MP2491DS-LF-Z for simplified single-output designs; LTC1438CG-ADJ#TRPBF remains necessary for dual-channel, remote-sense, and auxiliary-regulator requirements. |
Compared with LTC1439CG and MP2491DS-LF-Z, the LTC1438CG-ADJ#TRPBF uniquely combines adjustable Channel 1 with VOSENSE1 remote sensing, SFB1-enforced continuous conduction, and an integrated 0.5A auxiliary linear regulator - making it irreplaceable for precision multi-rail systems requiring low-noise bias and secondary-winding regulation.
Availability
LTC1438CG-ADJ#TRPBF is available at Aetrix Electronics and suitable for portable computing power, battery-powered instrumentation, DC power distribution systems, and industrial embedded control requiring stable component supply across long production lifecycles.
Supply support for LTC1438CG-ADJ#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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving industrial, automotive, communications, and healthcare markets.
The LTC1438 series belongs to ADI's legacy Linear Technology high-efficiency power management portfolio, designed specifically for dual-rail, low-noise, battery-conscious DC/DC conversion in portable and embedded systems.
FAQ
What is the function of the VOSENSE1 pin on the LTC1438CG-ADJ#TRPBF?
The VOSENSE1 pin on the LTC1438CG-ADJ#TRPBF is a dedicated remote feedback input for Channel 1, enabling Kelvin sensing directly at the load to eliminate PCB trace IR drop errors. It is exclusive to the -ADJ variant and required when configuring Channel 1 as an adjustable output using an external resistive divider - a capability absent in non-ADJ versions like LTC1438CG.
Does the LTC1438CG-ADJ#TRPBF support phase-lock synchronization?
No, the LTC1438CG-ADJ#TRPBF does not support phase-lock synchronization. PLLIN and PLL LPF pins are not implemented on this variant. For synchronization capability, the LTC1439CG (same package) must be selected - it includes full PLL circuitry and is pin-compatible except for the absence of VOSENSE1 and different VPROG1 behavior.
How does the SFB1 pin affect regulation behavior in the LTC1438CG-ADJ#TRPBF?
The SFB1 pin on the LTC1438CG-ADJ#TRPBF forces continuous conduction mode on Channel 1 when pulled below 1.19V. This guarantees regulation of isolated secondary windings even when the main output is lightly loaded or unloaded - a critical feature for flyback-derived auxiliary rails in notebook adapters and industrial power supplies using the LTC1438CG-ADJ#TRPBF.
What is the maximum output current supported by the auxiliary linear regulator in the LTC1438CG-ADJ#TRPBF?
The auxiliary linear regulator in the LTC1438CG-ADJ#TRPBF supports up to 0.5A output current when driving an external PNP pass transistor. Its operation is controlled by the AUXON pin (logic-enable) and regulated via the AUXFB pin, supporting either fixed 12V output (when AUXDR >9.5V) or adjustable voltages using an external feedback divider - all managed internally without additional op-amps or references.
Can the LTC1438CG-ADJ#TRPBF operate with input voltage below 3.5V?
No, the LTC1438CG-ADJ#TRPBF has a minimum specified input voltage of 3.5V per Absolute Maximum Ratings and Electrical Characteristics tables. Operation below this violates the device's guaranteed performance envelope; attempting sub-3.5V operation may result in failure to regulate, erratic soft-start behavior, or undefined shutdown recovery - the LTC1438CG-ADJ#TRPBF must be powered within its 3.5V–30V operational range.
LTC1438CG-ADJ#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SSOP
LTC1438CG-ADJ#TRPBF FAQ
1.How can I place an order for LTC1438CG-ADJ#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1438CG-ADJ#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 LTC1438CG-ADJ#TRPBF reliable?
The price and inventory of LTC1438CG-ADJ#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1438CG-ADJ#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC1438CG-ADJ#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1438CG-ADJ#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1438CG-ADJ#TRPBF?
LTC1438CG-ADJ#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1438CG-ADJ#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 LTC1438CG-ADJ#TRPBF?
For technical support, including LTC1438CG-ADJ#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1438CG-ADJ#TRPBF requirements.
6.How does Aetrix verify that LTC1438CG-ADJ#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC1438CG-ADJ#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 LTC1438CG-ADJ#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC1438CG-ADJ#TRPBF?
All LTC1438CG-ADJ#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1438CG-ADJ#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 LTC1438CG-ADJ#TRPBF part is unused and in its original packaging.
Return procedure for LTC1438CG-ADJ#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1438CG-ADJ#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…
