My Inquiry
My Account
Analog Devices Inc. LT1676CS8#PBF
- Part No.:
- LT1676CS8#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LT1676CS8#PBF.pdf
- Description:
- IC REG BUCK ADJ 550MA 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:6,985
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1676CS8#PBF from Analog Devices (formerly Linear Technology) is a wide-input, current-mode synchronous step-down DC/DC switching regulator IC with fixed 100kHz operation, 7.4V–60V input range, 700mA peak switch current rating, and true current mode control for high line rejection and short-circuit protection. It delivers stable 5V/400mA output in telecom 48V step-down converters.
For engineers reviewing the LT1676CS8#PBF datasheet, LT1676CS8#PBF pinout, LT1676CS8#PBF application, or LT1676CS8#PBF equivalent, key selection criteria include its adaptive dV/dt switch drive, VCC-biased internal control circuitry, shutdown current of 30µA, and SO-8 package compatibility with minimal PCB area requirements.
Technical Context
The LT1676CS8#PBF implements true current mode control using a transconductance feedback amplifier (400–1000 µmho) referenced to a 1.24V internal bandgap, with VC pin serving as both error amplifier output and current comparator input. Its dual-dV/dt output switch architecture-employing boost-driven lateral PNPs for fast turn-on above 1.35V VC threshold and DC-only drive below-enables continuous efficiency optimization across load ranges without pulse skipping.
Internal oscillator synchronization (130–250kHz), programmable undervoltage lockout via SHDN pin, and FB-pin-triggered oscillator slowdown (down to 25kHz during short-circuit) provide robust system-level protection. The VCC pin powers control circuitry from the output rail post-startup, reducing VIN supply current draw and improving overall efficiency at high input voltages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 7.4V to 60V - supports direct 48V telecom, automotive battery, and industrial bus inputs without pre-regulation. |
| Switch Current Limit | 0.55A to 0.70A - DC-trimmed peak current limit ensures cycle-by-cycle overcurrent protection with minimal derating. |
| Reference Voltage | 1.240V ±15mV - precise internal bandgap reference enables accurate output voltage setting via external resistor divider. |
| Shutdown Current | 30µA typical - enables ultra-low-power standby in battery-backed systems without external disconnect switches. |
| Switching Frequency | 100kHz fixed, synchronizable to 130–250kHz - balances EMI, inductor size, and efficiency; avoids audible noise in sensitive applications. |
| Thermal Resistance θJA | 110°C/W - SO-8 package allows 1.2W dissipation at 25°C ambient before reaching 125°C junction limit. |
| Feedback Bias Current | 600–1500nA - low input bias enables high-impedance FB dividers for reduced light-load power loss. |
Pinout & Package
LT1676CS8#PBF is housed in an 8-lead plastic SOIC (SO-8) package with standard JEDEC MS-012AC footprint, 1.27mm lead pitch, and exposed pad not present. Thermal performance is rated at θJA = 110°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SHDN (Pin 1) | Shutdown control input | Pulled below 0.3V to enter 30µA shutdown; between 0.3V–1.245V enables lockout mode; externally biased for adjustable UVLO above 6.7V. |
| VCC (Pin 2) | Internal bias supply input | Powered from output rail post-startup to reduce VIN current draw; requires local 0.1µF bypass if >1 inch from output capacitor. |
| VSW (Pin 3) | Switch emitter node | High-dV/dt node carrying full inductor current; must be routed with minimal trace length to suppress EMI and voltage overshoot. |
| GND (Pin 4) | Analog and power ground reference | Reference for FB amplifier and internal bandgap; must be star-connected near FB divider to avoid ground bounce errors. |
| VIN (Pin 5) | Main high-voltage input | Supplies output switch and startup bias; requires high-ripple-current input capacitor rated for ≥60V and full-switching-frequency RMS current. |
| SYNC (Pin 6) | Oscillator synchronization input | Logic-compatible sync input (10–90% duty); automatically disabled during FB-triggered oscillator slowdown for short-circuit safety. |
| FB (Pin 7) | Inverting feedback input | Compares output voltage against 1.24V reference; low voltage (<0.83V) triggers oscillator slowdown to 25kHz for short-circuit protection. |
| VC (Pin 8) | Error amplifier output / current comparator input | Loop compensation node; connects to RC network for stability; clamp voltage limits switch current to ~0.7A. |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive dV/dt switch drive | Boost mode active above 1.35V VC for fast rise time at heavy loads; disabled below threshold for improved light-load controllability without pulse skipping. |
| VCC-powered control circuitry | Reduces VIN supply current by >95% after startup, enabling >90% efficiency at 48V→5V conversion with minimal self-heating. |
| FB-triggered oscillator slowdown | Automatically reduces switching frequency from 100kHz to 25kHz when FB voltage drops below 0.83V, maintaining control under short-circuit conditions. |
| True current mode architecture | Provides inherent cycle-by-cycle current limiting, excellent line transient response, and simplified loop compensation via single-pole dominant pole. |
| Programmable UVLO via SHDN | External resistor divider on SHDN pin raises effective minimum input voltage above internal 6.7V UVLO, enabling custom brown-out thresholds. |
Applications
| Automotive DC/DC Converters | Telecom 48V Step-Down Converters |
|---|---|
Use Scenario: Converting unregulated 9–16V vehicle battery to stable 5V for infotainment microcontrollers and CAN transceivers. IC Role / Device Role / Timing Role: Primary step-down regulator with integrated switch, providing regulated output while rejecting engine cranking transients up to 60V. Use Value: 7.4V–60V input range accommodates cold-crank dips and load-dump spikes without external protection; 30µA shutdown current preserves battery life during vehicle sleep mode. | Use Scenario: Deriving 5V/400mA from -48V telecom central office power for line card peripherals and FPGA configuration supplies. IC Role / Device Role / Timing Role: High-efficiency buck controller managing constant-power load steps in distributed power architecture. Use Value: 100kHz fixed frequency simplifies EMI filter design; VCC-biasing eliminates need for auxiliary 5V rail, reducing BOM count and board space. |
| Cellular Phone Battery Charger Accessories | IEEE 1394 Step-Down Converters |
Use Scenario: Powering USB-C PD adapters and multi-port charging hubs requiring 5V/3A from variable AC-DC adapter outputs (12–24V). IC Role / Device Role / Timing Role: Secondary-side buck regulator delivering tightly regulated 5V with fast transient response to dynamic USB load changes. Use Value: True current mode control provides <10µs recovery from 0–100% load steps; adaptive dV/dt prevents audible noise during light-load trickle charging. | Use Scenario: Supplying 3.3V/1A to IEEE 1394 (FireWire) PHY and link layer ICs from 12V or 24V host power rails. IC Role / Device Role / Timing Role: Isolated secondary-side regulator meeting FireWire's strict 3.3V ±5% tolerance and <100mV ripple requirements. Use Value: 1.24V reference accuracy and low FB bias current enable ±0.5% output regulation; SO-8 package fits compact 1394 add-in card layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3631EMSE#PBF | 42V max input, 1.2A switch, 3mm × 4mm MSOP-10, 1MHz switching, integrated soft-start | Better suited for space-constrained designs needing higher current and faster transient response | Select when board area is critical and input voltage ≤42V; not drop-in due to different pinout and higher frequency. |
| LM5164QPWPRQ1 | 100V max input, 0.6A switch, 1.5MHz, automotive AEC-Q100 Grade 1, integrated bootstrap diode | Required for automotive under-hood applications with 65V load dump immunity | Choose for automotive qualification and extended input range; requires layout revision due to different thermal pad and SYNC functionality. |
Compared with LT1676CS8#PBF, LTC3631EMSE#PBF offers higher integration and frequency but sacrifices 60V input capability, while LM5164QPWPRQ1 adds automotive robustness and wider input range at the cost of increased complexity and non-pin-compatibility.
Availability
LT1676CS8#PBF is available at Aetrix Electronics and suitable for automotive DC/DC converters, telecom 48V step-down converters, and IEEE 1394 power supplies requiring stable component supply across extended temperature and voltage ranges.
Supply support for LT1676CS8#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 legacy high-performance analog and power management portfolio with rigorous reliability testing and long-term product support.
The LT1676CS8#PBF belongs to Linear's high-voltage monolithic buck regulator family, designed specifically for efficient, robust DC/DC conversion in harsh environments where wide input range and fault resilience are critical.
FAQ
What is the maximum input voltage rating for the LT1676CS8#PBF?
The LT1676CS8#PBF has an absolute maximum input voltage rating of 60V on the VIN pin, with recommended operating range from 7.4V to 60V. Exceeding 60V risks permanent damage to the internal bipolar output switch and control circuitry. The device includes internal protection against transient overvoltage events within this limit, but sustained operation above 60V is not supported.
Does the LT1676CS8#PBF require an external freewheeling diode?
Yes, the LT1676CS8#PBF requires an external Schottky freewheeling diode connected between VSW and GND. It does not integrate a synchronous rectifier. A Schottky diode such as MBR160 (60V, 1A) is recommended to minimize forward voltage drop and eliminate reverse recovery losses that would degrade efficiency and cause EMI.
Can the LT1676CS8#PBF operate with zero load current?
Yes, the LT1676CS8#PBF can operate down to zero external load without pulse skipping, thanks to its adaptive dV/dt switch drive that relaxes minimum on-time requirements in low-load conditions. The internal VCC bias current (~4mA) provides sufficient minimum load to maintain regulation, eliminating need for dummy loads in standby modes.
What is the purpose of the VC pin on the LT1676CS8#PBF?
On the LT1676CS8#PBF, the VC pin serves as the output of the transconductance feedback amplifier and the input to the current comparator. It sets the peak switch current via its voltage level and is the primary node for loop compensation-requiring an external RC network to ground for stability. Its internal clamp at ~2V limits maximum switch current to ~0.7A.
How does the LT1676CS8#PBF handle short-circuit conditions?
The LT1676CS8#PBF handles short-circuits via two coordinated mechanisms: first, the FB pin voltage collapse triggers automatic oscillator slowdown from 100kHz to 25kHz, increasing minimum on-time margin; second, the VC pin clamps at ~2V, limiting peak switch current to ~0.7A. These features maintain control and prevent thermal runaway without external circuitry.
LT1676CS8#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:
- 0°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO
LT1676CS8#PBF FAQ
1.How can I place an order for LT1676CS8#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1676CS8#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 LT1676CS8#PBF reliable?
The price and inventory of LT1676CS8#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1676CS8#PBF is usually 5 days.
3.What payment methods are accepted for LT1676CS8#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1676CS8#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1676CS8#PBF?
LT1676CS8#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1676CS8#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 LT1676CS8#PBF?
For technical support, including LT1676CS8#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1676CS8#PBF requirements.
6.How does Aetrix verify that LT1676CS8#PBF is sourced from the original manufacturer or authorized distributors?
All LT1676CS8#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 LT1676CS8#PBF meets industry standards.
7.What is the process for return or replacement of LT1676CS8#PBF?
All LT1676CS8#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1676CS8#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 LT1676CS8#PBF part is unused and in its original packaging.
Return procedure for LT1676CS8#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1676CS8#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…
