My Inquiry
My Account
Analog Devices Inc. LT3975HMSE#TRPBF
- Part No.:
- LT3975HMSE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LT3975HMSE#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 2.5A 16MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,491
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3975HMSE#TRPBF from Analog Devices (formerly Linear Technology) is a 42V, 2.5A monolithic step-down switching regulator with current-mode control, 2.7µA no-load quiescent current, and adjustable 200kHz–2MHz switching frequency. It features low-ripple Burst Mode® operation (<15mVP-P), 500mV dropout voltage, and integrated 75mΩ NPN switch for automotive cold-crank and industrial power supply applications.
For engineers reviewing the LT3975HMSE#TRPBF datasheet, LT3975HMSE#TRPBF pinout, LT3975HMSE#TRPBF application, or LT3975HMSE#TRPBF equivalent, key selection considerations include ultralow IQ performance at light loads, thermal-grade H-temperature range (–40°C to 150°C), programmable UVLO via EN pin, soft-start control via SS pin, and power-good flag signaling at 91.6% of regulated output.
Technical Context
The LT3975HMSE#TRPBF uses an internally compensated current-mode topology with fixed-frequency PWM and automatic transition to low-ripple Burst Mode® under light loads. Its bipolar NPN power switch is driven by a boost capacitor network enabling full saturation down to 500mV dropout.
It integrates a 1.197V reference error amplifier, active VC clamp for current limiting, frequency foldback during startup/overload, and thermal shutdown protection. The exposed-pad 16-lead MSOP package provides θJA = 40°C/W and supports continuous operation up to 150°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.3V to 42V - supports automotive battery transients including cold-crank (down to ~4.3V) and load-dump immunity. |
| Max Output Current | 2.5A - sustained DC load capability with foldback current limiting during short-circuit conditions. |
| No-Load Quiescent Current | 2.7µA at 12VIN/3.3VOUT - enables >10-year battery life in always-on IoT and telematics systems. |
| Switching Frequency Range | 200kHz to 2MHz - adjustable via RT resistor; enables optimization of inductor size vs. efficiency vs. EMI. |
| Feedback Reference Voltage | 1.197V ±1.2% - high-accuracy regulation with <0.01%/V line regulation for stable output across input range. |
| Dropout Voltage | 500mV - enforced minimum (VIN – VOUT) ensures boost capacitor remains charged and switch stays saturated during dropout. |
| Power Good Threshold | 91.6% of VOUT - open-drain PG flag signals valid regulation; valid when VIN > 2V. |
| Junction Temperature Range | –40°C to +150°C - H-grade qualification enables use in under-hood automotive and high-ambient industrial environments. |
Pinout & Package
LT3975HMSE#TRPBF is housed in a thermally enhanced 16-lead plastic MSOP package with exposed pad (Pin 17 = GND), θJA = 40°C/W. The exposed pad must be soldered to PCB for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FB (1) | Feedback input | Regulates output by sensing divider voltage; internal 1.197V reference sets accuracy and line/load regulation. |
| SS (2) | Soft-start control | Internal 1.8µA current source ramps peak switch current limit; capacitor here controls inrush and prevents overshoot. |
| OUT (3) | Output sense / bias source | Connects to output node; supplies internal bias when VOUT > 3.2V; enables dropout comparator (500mV threshold). |
| BOOST (4) | Boost capacitor drive | Provides >VIN voltage to saturate internal NPN switch; requires external capacitor between BOOST and SW. |
| SW (5,6,7) | Switch node | Drives external inductor and catch diode; ties to BOOST capacitor; carries full switching current and high dv/dt. |
| NC (8,9) | No connect | Not bonded internally; must remain unconnected per datasheet to avoid parasitic coupling or latch-up. |
| VIN (10,11,12) | Main power input | Supplies internal circuitry and switch driver; requires local ceramic bypassing (≥1µF) near pins. |
| EN (13) | Enable / UVLO input | Hysteretic threshold (1.02V fall / 1.08V rise); enables programmable undervoltage lockout and shutdown (IQ = 700nA). |
| RT (14) | Frequency programming | Resistor to GND sets switching frequency from 200kHz to 2MHz; tolerance directly impacts fSW accuracy. |
| PG (15) | Power good flag | Open-drain output asserts high when FB reaches 91.6% of target; sinks ≥125µA at 0.4V; valid above VIN = 2V. |
| SYNC (16) | External clock sync | Accepts 250kHz–2MHz external clock; grounding enables Burst Mode®, floating prohibited. |
| GND (17) | Ground / thermal pad | Exposed pad is internal GND; must be soldered to large PCB copper area for thermal dissipation and noise reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Ultralow quiescent current | 2.7µA at no load enables multi-year operation on coin-cell or supercapacitor backup in safety-critical monitoring systems. |
| Low-ripple Burst Mode® | Maintains <15mVP-P output ripple while delivering single current pulses and sleeping between them - critical for noise-sensitive analog/RF circuits. |
| Thermal-grade H-package | Rated for –40°C to +150°C junction operation with derated current above 125°C - qualified for engine-control, ADAS, and industrial motor drives. |
| Integrated boost diode & switch | On-die Schottky boost diode and 75mΩ NPN switch eliminate external components and reduce board space versus discrete solutions. |
| Programmable UVLO and soft-start | EN pin threshold (1.02V/1.08V) and SS pin ramp allow precise system-level power sequencing and inrush control without extra ICs. |
| Current limit foldback | Reduces switch current limit during overload to limit power dissipation - protects device and PCB during sustained short-circuit events. |
Applications
| Automotive Battery Regulation | Industrial Process Sensors |
|---|---|
Use Scenario: Powering CAN/LIN transceivers and microcontrollers in vehicle body control modules where input drops to 4.3V during cold-crank. IC Role / Device Role / Timing Role: Primary buck regulator maintaining 3.3V/5V rail despite wide VIN swing; delivers 2.5A peak during actuator activation. Use Value: 500mV dropout and 2.7µA IQ ensure uninterrupted operation and extended battery standby time during ignition-off states. |
Use Scenario: Supplying 24V-to-5V conversion for loop-powered 4–20mA field transmitters in hazardous-area process plants. IC Role / Device Role / Timing Role: Isolated secondary-side regulator providing stable 5V for ADC, sensor interface, and HART modem. Use Value: H-grade temperature rating (–40°C to 150°C) and robust 42V input withstand capability enable reliable deployment in high-ambient enclosures. |
| Portable Medical Monitors | Smart Building Controllers |
Use Scenario: Powering ECG front-end amplifiers and Bluetooth LE radios in handheld patient monitors powered by Li-ion batteries. IC Role / Device Role / Timing Role: Main system regulator operating in Burst Mode® during sleep cycles to minimize battery drain. Use Value: 2.7µA no-load IQ extends battery runtime beyond 7 days on single 2000mAh cell; <15mV ripple avoids signal corruption in analog acquisition paths. |
Use Scenario: Converting 24VAC/DC building automation bus to 3.3V for ARM-based controllers managing HVAC, lighting, and security subsystems. IC Role / Device Role / Timing Role: High-efficiency primary DC-DC stage supporting 2.5A peak loads from multiple peripheral interfaces. Use Value: Adjustable 200kHz–2MHz fSW allows EMI filtering compliance in shared wiring ducts; PG flag enables firmware-controlled power health monitoring. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8614EMSE#TRPBF | 42V input, 4A output, 2.5µA IQ, Silent Switcher® architecture; requires external compensation. | Better EMI performance and higher current; lacks integrated boost diode and has different pinout. | Select when ultra-low EMI is mandatory and layout space allows larger inductor/capacitor footprint. |
| TPS54240DGQR | 40V input, 2.5A output, 116µA IQ, current-mode control; no Burst Mode®, no PG flag, SOIC-10 package. | Lower cost but significantly higher quiescent current; unsuitable for battery-backed or always-on systems. | Select only for cost-sensitive, line-powered industrial applications where IQ >100µA is acceptable. |
Compared with LT3975HMSE#TRPBF, LT8614EMSE#TRPBF offers superior EMI suppression and higher output current but demands more complex layout and lacks integrated boost diode; TPS54240DGQR provides basic functionality at lower cost but cannot meet ultralow-IQ requirements essential for energy harvesting or long-life battery systems.
Availability
LT3975HMSE#TRPBF is available at Aetrix Electronics and suitable for automotive battery regulation, industrial process sensors, portable medical monitors, and smart building controllers requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LT3975HMSE#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 semiconductors, formed through the acquisition of Linear Technology in 2017.
The LT3975 belongs to ADI's high-voltage monolithic buck regulator product line, designed specifically for demanding automotive, industrial, and instrumentation applications requiring ultralow quiescent current, wide input range, and robust thermal performance.
FAQ
What is the maximum junction temperature rating for LT3975HMSE#TRPBF?
The LT3975HMSE#TRPBF is specified for continuous operation from –40°C to +150°C junction temperature. This H-grade qualification exceeds standard E- and I-grade versions (125°C max), making LT3975HMSE#TRPBF suitable for under-hood automotive, motor drive, and high-ambient industrial applications where thermal derating must be minimized.
How does LT3975HMSE#TRPBF achieve 2.7µA quiescent current?
The LT3975HMSE#TRPBF achieves 2.7µA no-load IQ through low-ripple Burst Mode® operation: it delivers discrete current pulses to the output capacitor and then enters deep sleep, powering down all non-essential circuitry. During sleep, only the bandgap reference and wake-up comparators remain active - a design confirmed in the datasheet's Typical Performance Characteristics (Figure G05).
Can LT3975HMSE#TRPBF operate below 4.3V input?
No - the LT3975HMSE#TRPBF has a minimum input voltage of 4.3V under normal regulation. Below this, the internal UVLO circuit disables switching. However, during automotive cold-crank events where VIN dips transiently below 4.3V, the part maintains regulation down to ~4.3V via its 500mV dropout mode, provided the OUT pin is connected to the output and sufficient boost voltage is maintained.
What is the purpose of the OUT pin on LT3975HMSE#TRPBF?
The OUT pin on LT3975HMSE#TRPBF serves three functions: (1) it connects to the output node to enable the dropout comparator (500mV threshold), (2) it supplies bias current to the internal regulator when VOUT > 3.2V - improving efficiency, and (3) it connects to the anode of the internal boost Schottky diode. Leaving OUT unconnected disables dropout protection and degrades light-load efficiency.
Is LT3975HMSE#TRPBF pin-compatible with other LT3975 variants?
Yes - LT3975HMSE#TRPBF shares identical pinout, footprint, and electrical characteristics with LT3975EMSE#TRPBF and LT3975IMSE#TRPBF. The only difference is the guaranteed junction temperature range: H-grade (–40°C to 150°C) versus E/I-grade (–40°C to 125°C). No PCB or schematic changes are required when upgrading to LT3975HMSE#TRPBF for higher thermal reliability.
LT3975HMSE#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.3V
- Voltage - Input (Max):
- 42V
- Voltage - Output (Min/Fixed):
- 1.197V
- Voltage - Output (Max):
- 40.74V
- Current - Output:
- 2.5A
- Frequency - Switching:
- 200kHz ~ 2.25MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-MSOP-EP
LT3975HMSE#TRPBF FAQ
1.How can I place an order for LT3975HMSE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3975HMSE#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 LT3975HMSE#TRPBF reliable?
The price and inventory of LT3975HMSE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3975HMSE#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3975HMSE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3975HMSE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3975HMSE#TRPBF?
LT3975HMSE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3975HMSE#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 LT3975HMSE#TRPBF?
For technical support, including LT3975HMSE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3975HMSE#TRPBF requirements.
6.How does Aetrix verify that LT3975HMSE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3975HMSE#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 LT3975HMSE#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3975HMSE#TRPBF?
All LT3975HMSE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3975HMSE#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 LT3975HMSE#TRPBF part is unused and in its original packaging.
Return procedure for LT3975HMSE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3975HMSE#TRPBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
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…
