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Analog Devices Inc. LTC1775IS#TRPBF
- Part No.:
- LTC1775IS#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC1775IS#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK/BCK-BST 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,680
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Product details
Overview
LTC1775IS#TRPBF from Analog Devices (formerly Linear Technology) is a synchronous step-down switching regulator controller that drives external dual N-channel MOSFETs without a current-sense resistor, using VDS sensing. It operates from 4.3V to 36V input, delivers 1.19V–VIN output, and supports up to 150kHz (±15kHz) fixed-frequency or externally synchronized operation with 1.5:1 lock range - used in high-efficiency notebook DC/DC power supplies.
For engineers reviewing the LTC1775IS#TRPBF datasheet, LTC1775IS#TRPBF pinout, LTC1775IS#TRPBF application, or LTC1775IS#TRPBF equivalent, key selection considerations include its no-RSENSE architecture, ±1% 1.19V reference accuracy, 300mV max current sense threshold, forced continuous mode control (FCB), and industrial-grade –40°C to +85°C operation in 16-lead SO package.
Technical Context
The LTC1775IS#TRPBF implements constant-frequency current-mode control with MOSFET VDS sensing for peak-current regulation, eliminating external sense resistors and reducing conduction loss. Its error amplifier (ITH pin) sets current threshold via a 0–2.4V control voltage, referenced to a ±1% 1.19V internal bandgap.
It integrates dual gate drivers (TG/BG) with 2A peak sink/source capability, a 5.2V internal LDO (INTVCC), and programmable Burst Mode operation enabled/disabled via FCB pin voltage (<1.19V forces continuous mode). Synchronization occurs over 100–225kHz via SYNC pin with 1.2V threshold and 50kΩ input resistance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.3V to 36V - supports automotive battery, industrial 24V rails, and wide-input notebook adapters. |
| Output Voltage Range | 1.19V to VIN - adjustable via external resistor divider or pin-selectable 3.3V/5V outputs. |
| Reference Accuracy | ±1% at 1.19V - ensures tight output regulation across temperature and line/load variations. |
| Max Current Sense Threshold | 300mV - enables high-current designs with low RDS(ON) MOSFETs while avoiding sense-resistor losses. |
| Oscillator Frequency | 135–165kHz (typ. 150kHz), syncable 1.5:1 range - balances efficiency vs. size; reduces EMI via synchronization. |
| Shutdown Quiescent Current | <30µA - extends battery life in portable systems during standby or sleep modes. |
| Operating Temperature | –40°C to +85°C - qualified for industrial and automotive under-hood applications. |
Pinout & Package
Package: 16-lead plastic SO (Small Outline), 150 mil width, RoHS-compliant, moisture sensitivity level 3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| EXTVCC (1) | External INTVCC supply input | Enables high-efficiency biasing from VOUT or auxiliary rail when >4.7V; bypasses internal LDO. |
| SYNC (2) | Oscillator synchronization input | Accepts external clock (100–225kHz); 1.2V threshold enables frequency locking without jitter accumulation. |
| RUN/SS (3) | Enable and soft-start control | Pull <0.8V for shutdown; capacitor to ground sets ramp time (~1s/µF) for controlled inrush limiting. |
| FCB (4) | Forced Continuous Mode control | Tie to GND to disable Burst Mode - critical for secondary-winding regulation in multi-output flyback-derived topologies. |
| ITH (5) | Error amplifier compensation node | 0–2.4V analog control of peak inductor current; directly interfaces with Type II/III compensation networks. |
| SGND (6) | Signal ground reference | Must connect to COUT negative terminal to minimize noise coupling into feedback path. |
| VOSENSE (7) | Output voltage feedback input | High-impedance (10nA max) remote sense point - enables Kelvin connection for precision regulation. |
| VPROG (8) | Output voltage selection | 0V → 3.3V output; INTVCC → 5V output; open → adjustable via external divider (1.19V reference). |
| VIN (16) | Main input supply | 4.3–36V input; requires RC filter (1Ω + 0.1µF) for >3A applications to suppress high-frequency noise. |
| TK (15) | Top MOSFET Kelvin sense | Must route separately from VIN to top MOSFET drain - essential for accurate VDS sensing and stable current limit. |
| SW (14) | Switch node | Connects to inductor and bootstrap capacitor negative terminal; swings from –0.3V to VIN + INTVCC. |
| TG (13) | Top gate driver output | Drives top N-MOSFET gate with swing = INTVCC superimposed on SW node - requires low-ESR bootstrap cap (≥0.33µF). |
| BOOST (12) | Bootstrap capacitor positive terminal | Swings between INTVCC – 0.3V and VIN + INTVCC - powers high-side driver during top-FET conduction. |
| INTVCC (11) | Internal 5.2V regulator output | Supplies gate drivers and logic; requires ≥4.7µF tantalum/low-ESR capacitor to PGND for stability. |
| BG (10) | Bottom gate driver output | Drives bottom N-MOSFET gate from PGND to INTVCC - optimized for fast turn-on/turn-off (50–150ns transitions). |
| PGND (9) | Power ground return | Connects to bottom MOSFET source, CIN(–), and CVCC(–); separates high-current paths from SGND to avoid ground bounce. |
Key Features
| Feature | Design Value |
|---|---|
| No RSENSE current sensing | Uses MOSFET VDS detection to eliminate sense resistor power loss and PCB area - improves full-load efficiency by 1–2%. |
| Programmable Burst Mode | Reduces light-load quiescent current to <30µA and maintains >85% efficiency down to 1mA load - ideal for battery-powered standby. |
| Dual N-MOSFET synchronous drive | Integrated TG/BG drivers support logic-level MOSFETs (VGS(th) ≤ 2.5V) with 2A peak current - eliminates body-diode conduction loss. |
| Output overvoltage protection | 1.24–1.32V OVLO threshold triggers immediate top-FET shutdown and bottom-FET activation - prevents damage to downstream ICs. |
| 99% maximum duty cycle | Enables ultra-low dropout operation (e.g., 5.1V→5.0V conversion) - extends runtime in battery systems near end-of-discharge. |
| Pin-selectable output voltages | VPROG pin configures 3.3V (0V), 5.0V (INTVCC), or adjustable (open) - simplifies BOM management across multiple product variants. |
Applications
| Notebook Computer Power Supply | Automotive Infotainment DC/DC |
|---|---|
Use Scenario: Main 5V/3.3V system rail generation from 12V battery or 19V adapter in thin-and-light notebooks. IC Role / Device Role / Timing Role: Primary synchronous buck controller managing up to 10A output with adaptive light-load efficiency. Use Value: No-RSENSE architecture achieves >94% peak efficiency at 5A/5V, reducing thermal stress on compact PCBs. |
Use Scenario: Stable 3.3V supply for MCU, display, and audio codecs in vehicle head units operating across cold-crank (4.3V) to load-dump (36V) conditions. IC Role / Device Role / Timing Role: Industrial-grade buck controller providing regulated output with OVP and foldback current limiting for fault resilience. Use Value: –40°C to +85°C rating and 4.3–36V input ensure reliable startup and operation in automotive ambient extremes. |
| Battery Charger Auxiliary Rail | Distributed Power System Intermediate Bus |
Use Scenario: Generating isolated 3.3V/5V bias rails for charger ICs, ADCs, and communication interfaces in Li-ion fast-charging systems. IC Role / Device Role / Timing Role: Secondary buck controller synchronized to main converter clock (via SYNC pin) to reduce conducted EMI. Use Value: 1.5:1 sync range allows precise alignment with primary switching frequency - lowers filtering component count and cost. |
Use Scenario: Point-of-load (POL) conversion from 12V intermediate bus to 5V/3.3V for FPGA I/O banks or Ethernet PHYs in telecom equipment. IC Role / Device Role / Timing Role: High-current synchronous controller supporting >8A loads with forced continuous mode for tight cross-regulation. Use Value: FCB pin enables continuous conduction during light-load conditions - maintains regulation on coupled windings in multi-rail systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3850IGN#TRPBF | Higher 250kHz–750kHz frequency range; integrated MOSFET drivers rated for 5A peak; supports phase-shedding. | Targeted at higher-density, higher-frequency POL designs where smaller inductors are prioritized over absolute peak efficiency. | Select LTC3850IGN#TRPBF when board space is constrained and 500kHz+ operation is acceptable; not drop-in due to different pinout and compensation scheme. |
| MP2315DJ-LF-Z | Monolithic 3A buck (integrated MOSFETs); fixed 5V/3.3V outputs only; no SYNC or FCB pins; lower 4.5–28V input range. | Suitable for cost-sensitive, low-current applications where external MOSFET flexibility and industrial temp range are not required. | Choose MP2315DJ-LF-Z for simple, low-BOM-count 3A solutions - but cannot replace LTC1775IS#TRPBF in high-current, no-RSENSE, or sync-critical designs. |
Compared with LTC3850IGN#TRPBF and MP2315DJ-LF-Z, the LTC1775IS#TRPBF uniquely combines no-RSENSE current sensing, industrial temperature grade, and pin-selectable outputs in a 16-pin SO package - making it optimal for high-reliability, medium-power synchronous buck designs requiring design flexibility and thermal robustness.
Availability
LTC1775IS#TRPBF is available at Aetrix Electronics and suitable for notebook computer power supplies, automotive infotainment systems, and distributed power intermediate bus converters requiring stable component supply, long-term lifecycle support, and industrial-grade reliability.
Supply support for LTC1775IS#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 (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.
The LTC1775IS#TRPBF belongs to Linear's legacy high-efficiency DC/DC controller family, designed specifically for synchronous step-down conversion in space-constrained, thermally demanding applications where sense-resistor elimination and wide input range are critical.
FAQ
What is the minimum input voltage specification for LTC1775IS#TRPBF?
The LTC1775IS#TRPBF has a minimum input voltage of 4.3V across its full industrial temperature range (–40°C to +85°C), as specified in Note 5 of the datasheet. This is 0.3V higher than the 4.0V minimum for the commercial-grade LTC1775CGN/C variants - ensuring reliable startup and regulation during cold-crank automotive conditions.
Does LTC1775IS#TRPBF require an external current-sense resistor?
No, the LTC1775IS#TRPBF does not require an external current-sense resistor. It uses MOSFET VDS sensing via the TK and SW pins to measure inductor current, achieving a maximum sense threshold of 300mV. This eliminates sense-resistor power loss and improves full-load efficiency - a core feature confirmed in the device's "No RSENSE" trademarked architecture.
How is output voltage selected on LTC1775IS#TRPBF?
The LTC1775IS#TRPBF supports three output configurations via the VPROG pin: grounding VPROG selects 3.3V output; connecting VPROG to INTVCC selects 5.0V output; leaving VPROG open enables adjustable output using an external resistor divider referenced to the 1.19V internal bandgap - providing design flexibility without changing external feedback components.
What protection features are integrated into LTC1775IS#TRPBF?
The LTC1775IS#TRPBF integrates output overvoltage protection (OVLO at 1.24–1.32V), foldback current limiting (reducing peak current from 300mV to ~80mV during short-circuit), and thermal shutdown (TJ = 125°C). These functions are implemented in hardware with no external components required - ensuring robust fault response in mission-critical power systems.
Can LTC1775IS#TRPBF be synchronized to an external clock?
Yes, the LTC1775IS#TRPBF can be synchronized to an external clock applied to the SYNC pin. It locks over a 1.5:1 frequency range (e.g., 100–225kHz for a nominal 150kHz oscillator), with a 1.2V threshold and 50kΩ input resistance. The rising edge of the external clock aligns the top MOSFET turn-on event - enabling EMI reduction in noise-sensitive systems.
LTC1775IS#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Buck-Boost
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 4.3V ~ 36V
- Frequency - Switching:
- 150kHz
- Duty Cycle (Max):
- 99%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- Yes
- Serial Interfaces:
- -
- Control Features:
- Enable, Soft Start
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SO
LTC1775IS#TRPBF FAQ
1.How can I place an order for LTC1775IS#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1775IS#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 LTC1775IS#TRPBF reliable?
The price and inventory of LTC1775IS#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1775IS#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC1775IS#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1775IS#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1775IS#TRPBF?
LTC1775IS#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1775IS#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 LTC1775IS#TRPBF?
For technical support, including LTC1775IS#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1775IS#TRPBF requirements.
6.How does Aetrix verify that LTC1775IS#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC1775IS#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 LTC1775IS#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC1775IS#TRPBF?
All LTC1775IS#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1775IS#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 LTC1775IS#TRPBF part is unused and in its original packaging.
Return procedure for LTC1775IS#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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