My Inquiry
My Account
Analog Devices Inc. LT1676IS8#PBF
- Part No.:
- LT1676IS8#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LT1676IS8#PBF.pdf
- Description:
- IC REG BUCK ADJ 550MA 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:5,370
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1676IS8#PBF from Analog Devices (formerly Linear Technology) is a wide-input, current-mode synchronous step-down DC/DC switching regulator IC designed for high-efficiency power conversion in industrial and automotive systems. It accepts 7.4V–60V input, delivers up to 700mA peak switch current, operates at fixed 100kHz (synchronizable to 250kHz), and features true current mode control with adaptive switch drive for stable light-load operation without pulse skipping - used in telecom 48V-to-5V converters and IEEE 1394 power supplies.
For engineers reviewing the LT1676IS8#PBF datasheet, LT1676IS8#PBF pinout, LT1676IS8#PBF application, or LT1676IS8#PBF equivalent, key selection criteria include its 700mA peak switch rating, 1.24V internal reference, SO-8 package thermal resistance (θJA = 110°C/W), shutdown current of 30µA, and compatibility with Schottky freewheeling diodes in high-dV/dt Buck topologies.
Technical Context
The LT1676IS8#PBF implements true current-mode control using an internal transconductance error amplifier (400–1000 µmho) and a cycle-by-cycle current comparator referenced to the VC pin voltage. Its dual dV/dt switching architecture dynamically selects between high-slew-rate (boost-enabled) and low-slew-rate (non-boost) modes based on VC threshold crossing at ~1.35V, enabling efficient operation across continuous and discontinuous conduction modes.
It integrates all oscillator, bias, protection, and gate-drive circuitry on a monolithic die. The VCC pin powers internal logic from the output rail (not VIN), reducing quiescent draw from the high-voltage input; shutdown is controlled via SHDN pin with 0.2–0.8V threshold and lockout hysteresis (1.245V/1.260V), while SYNC enables external frequency synchronization from 130–250kHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 7.4V to 60V - supports direct connection to 24V/48V industrial and automotive battery rails without pre-regulation. |
| Peak Switch Current | 700mA - defines maximum sustainable load current before cycle-by-cycle current limiting engages at VC clamp (~2V). |
| Switching Frequency | 100kHz (fixed), synchronizable to 130–250kHz - enables predictable EMI filtering and minimizes external component size (e.g., 220µH inductor). |
| Reference Voltage | 1.240V (±1.2%) - sets output voltage accuracy via FB divider; line regulation <0.01%/V ensures stability across full VIN range. |
| Shutdown Current | 30µA - enables ultra-low-power standby in battery-backed systems such as cellular charger accessories. |
| Thermal Resistance θJA | 110°C/W (SO-8) - determines maximum power dissipation before junction temperature exceeds 125°C under natural convection. |
| Feedback Bias Current | 600–1500nA - limits minimum FB divider impedance to ≤10kΩ for reliable short-circuit protection and reference accuracy. |
Pinout & Package
LT1676IS8#PBF is housed in an 8-pin plastic SOIC (SO-8) package with exposed pad not specified; JEDEC MS-012AC compliant, 110°C/W junction-to-ambient thermal resistance, rated for –40°C to +125°C operating junction temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SHDN (Pin 1) | Shutdown control input | Pulled below 0.2–0.8V to enter 30µA shutdown; hysteresis (1.245V/1.260V) enables user-defined UVLO extension above 6.7V minimum VIN. |
| VCC (Pin 2) | Internal bias supply input | Powered from regulated output (not VIN) after startup - reduces input quiescent current and improves efficiency at high VIN. |
| VSW (Pin 3) | Switch emitter node | High-dI/dt, high-dV/dt node requiring short PCB traces; drives external Schottky diode anode in standard Buck configuration. |
| GND (Pin 4) | Analog and power ground reference | Reference for FB amplifier and internal 1.24V bandgap; must be star-connected away from high-current return paths to avoid noise coupling. |
| VIN (Pin 5) | High-voltage input supply | Supplies output switch and startup bias; requires low-ESR, high-ripple-current input capacitor due to pulsed 700mA draw. |
| SYNC (Pin 6) | External clock synchronization input | Logic-compatible (10–90% duty); disabled automatically during FB-induced oscillator slowdown for short-circuit protection. |
| FB (Pin 7) | Inverting feedback input | Compares output voltage (via resistor divider) against 1.24V reference; low voltage (<0.83V) triggers oscillator slowdown to 25kHz for short-circuit recovery. |
| VC (Pin 8) | Error amplifier output / current comparator input | Loop compensation node (RC-to-ground); controls peak switch current; clamp at ~2V sets hard current limit; boost threshold at ~1.35V selects dV/dt mode. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive dV/dt switching | Automatically switches between high-slew (boost-enabled) and low-slew (non-boost) modes based on VC voltage - maintains controllability at light loads without pulse skipping. |
| VCC-powered bias regulation | Draws control power from VOUT instead of VIN after startup - reduces input quiescent current by >95% vs VIN-powered controllers at 48V input. |
| True current-mode architecture | Uses VC pin voltage directly as current comparator threshold - provides inherent cycle-by-cycle overcurrent protection and excellent line transient rejection. |
| Integrated oscillator slowdown | Reduces switching frequency linearly from 100kHz to 25kHz when FB voltage drops below ~0.83V - sustains control during output short-circuit without loss of current limiting. |
| SO-8 thermal performance | θJA = 110°C/W enables 1.2W max power dissipation at 25°C ambient - supports 500mA continuous output at 48V→5V with proper layout and airflow. |
Applications
| Telecom 48V Step-Down Converters | Automotive DC/DC Converters |
|---|---|
Use Scenario: Converting 48V telecom rack supply to 5V/3.3V for line cards and interface modules. IC Role / Device Role / Timing Role: Primary step-down controller managing 700mA load with fixed 100kHz switching and adaptive dV/dt for burst-mode efficiency. Use Value: Eliminates need for intermediate pre-regulators; 7.4–60V input range accommodates brownout and surge conditions per GR-1089. | Use Scenario: Powering infotainment and ADAS subsystems from 12V/24V vehicle batteries with cold-crank tolerance. IC Role / Device Role / Timing Role: High-input Buck regulator with –40°C to +125°C operation, UVLO lockout hysteresis, and robust short-circuit recovery. Use Value: Maintains regulation down to 7.4V during cranking; oscillator slowdown prevents current runaway during load dump faults. |
| IEEE 1394 Step-Down Converters | Cellular Phone Battery Charger Accessories |
Use Scenario: Generating isolated 1.8V/3.3V rails from 12V FireWire bus power for PHY and link-layer ICs. IC Role / Device Role / Timing Role: Compact, high-efficiency Buck controller in SO-8 package with minimal external components (220µH inductor, MBR160 Schottky). Use Value: Meets IEEE 1394 EMI limits via fixed-frequency operation and low-noise current-mode control; 30µA shutdown extends host system standby time. | Use Scenario: Charging auxiliary circuits (USB ports, LED drivers) from single-cell Li-ion or multi-cell packs in portable accessories. IC Role / Device Role / Timing Role: Wide-input Buck regulator supporting 8–50V input (from wall adapters or car chargers) with precise 1.24V reference for ±1% output accuracy. Use Value: Enables universal input compatibility without input selector switches; adaptive dV/dt ensures stable 10mA–500mA operation across charge states. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3630EMSE#PBF | Higher integration: integrated 700mA MOSFET switch; 3.5–40V input; 1MHz switching; no external diode required. | Eliminates external Schottky diode but requires different compensation and layout; higher quiescent current (120µA) than LT1676IS8#PBF's 30µA shutdown. | Select LTC3630EMSE#PBF when board space is constrained and diode losses must be eliminated; retain LT1676IS8#PBF for legacy designs, lower shutdown IQ, or 48V+ input support. |
| LM5009AMMX/NOPB | 75V max input; 500mA peak switch; 1MHz fixed frequency; external diode required; 75µA shutdown current. | Broader input range but lower peak current and higher shutdown IQ; lacks adaptive dV/dt mode - may exhibit pulse skipping below ~50mA. | Select LM5009AMMX/NOPB for >60V input requirements (e.g., PoE++); choose LT1676IS8#PBF where 700mA capability, 30µA shutdown, and light-load controllability are critical. |
Compared with LTC3630EMSE#PBF and LM5009AMMX/NOPB, the LT1676IS8#PBF uniquely balances 60V input capability, 700mA peak current, 30µA shutdown, and adaptive dV/dt control - making it optimal for 48V telecom and automotive applications demanding both high efficiency and robust light-load behavior without external MOSFETs or diode replacement.
Availability
LT1676IS8#PBF is available at Aetrix Electronics and suitable for telecom 48V step-down converters, automotive DC/DC converters, and IEEE 1394 power supplies requiring stable component supply, extended temperature operation (–40°C to +125°C), and long-term industrial lifecycle support.
Supply support for LT1676IS8#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, Inc. (acquired Linear Technology in 2017) is a global semiconductor leader specializing in high-performance analog, mixed-signal, and power management ICs for precision signal chain and power applications.
The LT1676 product line was developed by Linear Technology as a family of high-input-voltage, current-mode Buck regulators targeting industrial, telecom, and automotive power conversion where reliability across wide input ranges and robust short-circuit protection are essential.
FAQ
What is the maximum input voltage rating for the LT1676IS8#PBF?
The LT1676IS8#PBF has an absolute maximum input voltage rating of 60V on the VIN pin, with a recommended operating minimum of 7.4V. This 7.4V–60V range allows direct use with 24V and 48V industrial and automotive supplies, including transient-tolerant designs where input surges may reach 60V. Exceeding 60V risks permanent damage to the internal bipolar output switch.
Does the LT1676IS8#PBF require an external Schottky diode, and why?
Yes, the LT1676IS8#PBF requires an external Schottky diode (e.g., MBR160) connected from VSW to GND in standard Buck topology. Unlike synchronous rectifier ICs, LT1676IS8#PBF uses a bipolar NPN output switch and relies on the Schottky's low forward voltage and zero reverse recovery to minimize conduction and switching losses. Ultrafast diodes are discouraged due to voltage overshoot and RFI caused by reverse recovery slingshot effects.
How does the LT1676IS8#PBF achieve stable operation at very light loads?
The LT1676IS8#PBF achieves stable light-load operation through adaptive dV/dt switching: when the VC pin voltage falls below ~1.35V, it disables the boost circuitry and reverts to low-slew-rate switching, relaxing minimum on-time constraints and eliminating pulse skipping. This allows continuous conduction down to zero load in many configurations, supported by its modest VCC bias current (~4mA) acting as a natural minimum load.
What thermal derating applies to the LT1676IS8#PBF in SO-8 package?
The LT1676IS8#PBF in SO-8 package has a junction-to-ambient thermal resistance (θJA) of 110°C/W. At 25°C ambient, maximum allowable power dissipation before reaching 125°C junction temperature is 0.91W. For a 48V→5V/500mA application, total dissipation (PDC + PAC + PQ) must remain below this limit - typically requiring 2–3 cm² of 2-oz copper pour and moderate airflow for full-load operation.
Can the LT1676IS8#PBF be synchronized to an external clock, and what is the valid frequency range?
Yes, the LT1676IS8#PBF can be synchronized to an external clock via the SYNC pin, accepting logic-level signals (10–90% duty cycle) from 130kHz to 250kHz. Synchronization is automatically disabled if the FB pin voltage drops below ~0.83V (indicating short-circuit), reverting to internal oscillator slowdown for protection - ensuring robust fault handling even when externally clocked.
LT1676IS8#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 7.4V
- Voltage - Input (Max):
- 60V
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 51V
- Current - Output:
- 550mA (Switch)
- Frequency - Switching:
- 100kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO
LT1676IS8#PBF FAQ
1.How can I place an order for LT1676IS8#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1676IS8#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 LT1676IS8#PBF reliable?
The price and inventory of LT1676IS8#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1676IS8#PBF is usually 5 days.
3.What payment methods are accepted for LT1676IS8#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1676IS8#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1676IS8#PBF?
LT1676IS8#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1676IS8#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 LT1676IS8#PBF?
For technical support, including LT1676IS8#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1676IS8#PBF requirements.
6.How does Aetrix verify that LT1676IS8#PBF is sourced from the original manufacturer or authorized distributors?
All LT1676IS8#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 LT1676IS8#PBF meets industry standards.
7.What is the process for return or replacement of LT1676IS8#PBF?
All LT1676IS8#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1676IS8#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 LT1676IS8#PBF part is unused and in its original packaging.
Return procedure for LT1676IS8#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1676IS8#PBF 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…
