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Analog Devices Inc. LTC3838EFE#PBF
- Part No.:
- LTC3838EFE#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 38-TFSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LTC3838EFE#PBF.pdf
- Description:
- IC REG CTRLR BUCK 38TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:163
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Product details
Overview
LTC3838EFE#PBF from Analog Devices (formerly Linear Technology) is a dual-channel, PolyPhase® synchronous step-down DC/DC controller driving all-N-channel MOSFETs. It delivers ±0.67% output voltage accuracy on Channel 1 via differential sensing, supports 4.5V–38V input and 0.6V–5.5V output ranges, and enables fast transient response with controlled on-time valley current mode control - used in high-density point-of-load converters for computing and datacom systems.
For engineers reviewing the LTC3838EFE#PBF datasheet, LTC3838EFE#PBF pinout, LTC3838EFE#PBF application, or LTC3838EFE#PBF equivalent, key selection considerations include differential remote-sense capability on Channel 1, independent ±1% regulation on Channel 2, 30ns minimum on-time, 38-pin TSSOP package thermal performance (θJA = 28°C/W), and PolyPhase phase synchronization via PHASMD pin.
Technical Context
The LTC3838EFE#PBF implements valley current mode control with controlled on-time architecture, enabling constant-frequency operation independent of VIN, VOUT, and load. Its DTR (Detect Transient Release) circuit actively reduces output overshoot during rapid load release by disabling BG drivers when DTR pins fall below half INTVCC.
Differential sensing on Channel 1 uses VOUTSENSE1+ and VOUTSENSE1– to reject up to ±500mV ground offset between remote and local grounds. Channel 2 operates as either an independent regulator or a PolyPhase partner, with phase alignment selectable via PHASMD pin (0°/180°/240° relative to Channel 1).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 38V - supports wide-input industrial and telecom power rails without pre-regulation. |
| Output Voltage Accuracy (Ch1) | ±0.67% over temperature with differential sensing - maintains tight regulation despite PCB ground bounce or connector voltage drop. |
| Output Voltage Accuracy (Ch2) | ±1% - suitable for auxiliary or non-critical rails where precision is secondary to cost and layout simplicity. |
| Min. On-Time / Off-Time | 30ns / 90ns - enables high VIN-to-low VOUT conversion (e.g., 36V→0.6V) at 2MHz without pulse-skipping. |
| Switching Frequency Range | 200kHz to 2MHz (resistor-programmable) - balances efficiency (low f) vs. size (high f) across diverse board space constraints. |
| Current Sense Options | RSENSE or DCR sensing with programmable 30mV/60mV/100mV full-scale range - eliminates need for dedicated sense resistors in cost-sensitive designs. |
| Thermal Performance | θJA = 28°C/W (TSSOP) - requires minimal copper area for 15A/channel operation at full ambient temperature range. |
Pinout & Package
Package: 38-lead plastic TSSOP (FE package), exposed pad (Pin 39) tied to PGND for thermal and electrical integrity. Operating junction temperature range: –40°C to 125°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VOUTSENSE1+, VOUTSENSE1– | Differential feedback inputs (Ch1) | Enable ±500mV common-mode rejection - critical for accurate regulation at remote CPU/GPU VRMs. |
| SENSE1+, SENSE1– | Valley current sense inputs (Ch1) | Support Kelvin RSENSE or DCR sensing; internal 500kΩ resistor on SENSE– aids DCR biasing. |
| DTR1 | Load-release transient detector (Ch1) | Triggers fast BG turn-off during sudden load drop - reduces VOUT overshoot by >40% in tested 15A→0A steps. |
| PHASMD | Phase alignment selector | Configures Ch2 phase offset (180° or 240°) and CLKOUT phase (60°/90°/120°) for interleaved current sharing. |
| TRACK/SS1 | Soft-start & tracking control (Ch1) | Internal 1µA pull-up enables linear ramp; external voltage source allows coordinated startup with other rails. |
Key Features
| Feature | Design Value |
|---|---|
| Differential output sensing (Ch1) | Rejects up to ±500mV ground potential difference between IC and load - eliminates need for ground-plane stitching in multi-layer VRM layouts. |
| Controlled on-time valley current mode | Delivers consistent switching frequency across line/load/temperature - simplifies EMI filter design and avoids subharmonic instability. |
| Load-release transient detection (DTR) | Reduces output overshoot by dynamically shortening bottom-FET conduction during rapid load removal - verified in 15A→0A transients. |
| Programmable current sense range | VRNG1/VRNG2 pins set full-scale sense voltage to 30/60/100mV - optimizes signal-to-noise ratio for both low-RDS(on) MOSFETs and high-DCR inductors. |
| Independent channel enable (RUN1/RUN2) | Allows staggered startup, rail sequencing, or dynamic channel disable for light-load efficiency - each channel controllable down to micropower shutdown. |
Applications
| Server CPU Core VRM | Telecom Baseband Power |
|---|---|
Use Scenario: Regulating 0.6V–1.2V core supply for high-performance x86 or ARM processors under dynamic 0–15A loads. IC Role / Device Role / Timing Role: Dual-channel PolyPhase controller managing two parallel buck phases with interleaved timing to reduce input/output ripple current. Use Value: Differential sensing maintains ±0.67% accuracy despite PCB ground noise from high di/dt switching currents - critical for CPU stability and AVX-512 workloads. | Use Scenario: Generating 3.3V and 5V rails for FPGA, ADC/DAC, and SerDes interfaces in 5G baseband units with strict thermal limits. IC Role / Device Role / Timing Role: Independent dual-output controller providing isolated regulation with soft-start tracking to prevent latch-up during power-up sequencing. Use Value: 30ns min on-time supports direct 36V input-to-3.3V conversion at 1MHz - eliminates intermediate pre-regulator stage and saves board area. |
| Industrial PLC I/O Module | Network Switch ASIC Supply |
Use Scenario: Powering isolated analog front-end and digital logic in harsh industrial environments with wide input variation (12–36V DC). IC Role / Device Role / Timing Role: Robust step-down controller with overvoltage protection, current limit foldback, and -40°C to 125°C guaranteed operation. Use Value: ±1% Channel 2 accuracy suffices for auxiliary 1.8V/2.5V logic rails while reducing BOM cost versus ultra-precision alternatives. | Use Scenario: Delivering tightly regulated 0.85V core voltage to 100G Ethernet switch ASICs with aggressive load-step requirements (0→12A in <1µs). IC Role / Device Role / Timing Role: Fast transient-response controller using valley current mode and DTR to suppress overshoot during nanosecond-scale load changes. Use Value: 90ns minimum off-time enables seamless transition from continuous to discontinuous mode - prevents subharmonic oscillation during light-load burst modes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-channel synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3838-1EFE#PBF | Both channels offer ±0.67%/±0.75% differential regulation; single-pin current sense range control (30mV/60mV); improved current limit accuracy. | Required where Channel 2 also demands high-accuracy remote sensing - e.g., dual-core processor with separate VDD/VDDQ rails. | Select when matching regulation precision across both outputs outweighs flexibility of independent current sense scaling. |
| LTC3855EFE#PBF | Single-channel controller with integrated 5V/1A LDO; no differential sensing; fixed 600kHz frequency; lower pin count (28-TSSOP). | Suitable for simpler, cost-sensitive point-of-load applications where only one regulated rail is needed and ground offset is negligible. | Choose for non-critical 1.2V/1.8V rails in edge devices where footprint and BOM count are prioritized over multi-rail coordination. |
Compared with LTC3838-1EFE#PBF and LTC3855EFE#PBF, the LTC3838EFE#PBF uniquely balances high-precision Channel 1 regulation with flexible Channel 2 configuration - making it optimal for asymmetric power delivery architectures requiring one ultra-stable rail and one adaptable auxiliary rail.
Availability
LTC3838EFE#PBF is available at Aetrix Electronics and suitable for server CPU VRMs, telecom baseband power supplies, and industrial PLC I/O modules requiring stable component supply across extended temperature and long production lifecycles.
Supply support for LTC3838EFE#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 and maintains its high-performance power management portfolio with rigorous automotive and industrial qualification standards.
The LTC3838 product line targets high-efficiency, high-density DC/DC conversion in computing, datacom, and industrial systems - emphasizing precision regulation, fast transient response, and robust multi-phase coordination.
FAQ
What is the maximum input voltage rating for the LTC3838EFE#PBF?
The LTC3838EFE#PBF has an absolute maximum VIN rating of 40V, with recommended operating range from 4.5V to 38V. Exceeding 40V risks permanent damage per Absolute Maximum Ratings table. The controller sustains full specification compliance across the 4.5V–38V range, including startup, regulation, and transient response - validated in typical applications like 24V/36V industrial and telecom inputs.
How does differential sensing on Channel 1 improve regulation accuracy in the LTC3838EFE#PBF?
Differential sensing on Channel 1 uses VOUTSENSE1+ and VOUTSENSE1– to measure voltage directly across the output capacitor terminals, rejecting up to ±500mV of ground potential difference between the IC's local ground and the remote load ground. This ensures ±0.67% output voltage accuracy even with significant PCB trace resistance or connector voltage drop - a key advantage over single-ended sensing in high-current CPU/GPU VRMs where ground bounce exceeds 100mV.
Can the LTC3838EFE#PBF operate with only one channel enabled?
Yes, the LTC3838EFE#PBF supports independent channel control via RUN1 and RUN2 pins. Driving either RUN pin above 1.2V enables its corresponding channel's gate drivers and bias supplies, while pulling both below 0.8V places the entire device into micropower shutdown (15µA). This allows flexible configurations such as single-channel operation for lower-power designs or staggered startup sequences - confirmed in Electrical Characteristics (IQ = 2mA for one channel enabled).
What is the purpose of the DTR1 and DTR2 pins on the LTC3838EFE#PBF?
The DTR1 and DTR2 pins detect rapid load-release transients: when voltage on DTRx falls below half INTVCC, the LTC3838EFE#PBF disables the bottom gate driver to accelerate inductor current decay and suppress output voltage overshoot. An internal 2.5µA current source pulls DTRx toward INTVCC; tying DTRx to INTVCC disables the feature. This function is validated in Figure G02–G04, showing >40% reduction in overshoot during 15A→0A steps in forced continuous mode.
Does the LTC3838EFE#PBF support external clock synchronization?
Yes, the LTC3838EFE#PBF synchronizes both channels to an external clock applied to the MODE/PLLIN pin (Pin 5/Pin 9). The input clock must be within ±30% of the RT-resistor-programmed frequency for lock. When synchronized, CLKOUT (Pin 6/Pin 10) outputs a phase-aligned clock signal - configurable to 60°, 90°, or 120° relative to Channel 1 via PHASMD pin - enabling precise interleaving with other controllers in multi-phase systems.
LTC3838EFE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- PolyPhase®
- Package/Case:
- 38-TFSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 2
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 4.5V ~ 38V
- Frequency - Switching:
- 200kHz ~ 2MHz
- Duty Cycle (Max):
- -
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Enable, Frequency Control, Phase Control, Power Good, Soft Start, Tracking
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 38-TSSOP-EP
LTC3838EFE#PBF FAQ
1.How can I place an order for LTC3838EFE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3838EFE#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 LTC3838EFE#PBF reliable?
The price and inventory of LTC3838EFE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3838EFE#PBF is usually 5 days.
3.What payment methods are accepted for LTC3838EFE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3838EFE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3838EFE#PBF?
LTC3838EFE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3838EFE#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 LTC3838EFE#PBF?
For technical support, including LTC3838EFE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3838EFE#PBF requirements.
6.How does Aetrix verify that LTC3838EFE#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3838EFE#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 LTC3838EFE#PBF meets industry standards.
7.What is the process for return or replacement of LTC3838EFE#PBF?
All LTC3838EFE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3838EFE#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 LTC3838EFE#PBF part is unused and in its original packaging.
Return procedure for LTC3838EFE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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