My Inquiry
My Account
Analog Devices Inc. LTC3805HMSE#TRPBF
- Part No.:
- LTC3805HMSE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LTC3805HMSE#TRPBF.pdf
- Description:
- IC REG CTRLR FLYBACK 10MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,824
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3805HMSE#TRPBF from Analog Devices (formerly Linear Technology) is a current-mode DC/DC controller IC designed to drive an external N-channel MOSFET in nonisolated flyback, boost, and SEPIC converters. It supports input voltages up to 72V, delivers ±1.5% output voltage accuracy, operates from 70kHz to 700kHz with one external resistor, and features programmable overcurrent protection with automatic restart - used in telecom power supplies and 42V automotive systems.
For engineers reviewing the LTC3805HMSE#TRPBF datasheet, LTC3805HMSE#TRPBF pinout, LTC3805HMSE#TRPBF application, or LTC3805HMSE#TRPBF equivalent, key selection considerations include its H-grade temperature range (–40°C to 150°C), 10-lead MSOP package, adjustable slope compensation, RUN pin with precision threshold and hysteresis, and micropower startup current of 40µA.
Technical Context
The LTC3805HMSE#TRPBF implements peak current-mode control using an internal error amplifier (333 µA/V transconductance), programmable oscillator (70–700 kHz), and dual-function ISENSE pin for current sensing and slope compensation ramp injection (10 µA peak). Its shutdown logic responds independently to VCC UVLO (8.4V turn-on / 4.0V turn-off) and RUN pin thresholds (1.207V on / 1.170V off) with 5 µA hysteresis current.
It integrates a 9.5V internal shunt regulator on VCC, enabling direct high-VIN biasing via resistor, and uses SSFLT pin for combined soft-start timing (1.8 ms internal minimum) and fault timeout (4.5 ms internal minimum), both extendable with external capacitor. The GATE driver delivers 30 ns rise/fall times into 3000 pF load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Operating Temperature | H-grade: –40°C to 150°C junction; validated for industrial and automotive under-hood applications. |
| Oscillator Frequency Range | 70 kHz to 700 kHz; set by single resistor on FS pin; supports synchronization via SYNC pin. |
| Output Voltage Accuracy | ±1.5% over full temperature range; reference voltage = 0.770–0.820 V depending on grade and temp. |
| Quiescent Current | 360 µA normal operation; 40 µA micropower startup mode - enables low-power standby designs. |
| VCC Shunt Regulator | Clamps at 9.5 V (typ); sinks up to 25 mA - allows direct high-VIN biasing without external LDO. |
| Overcurrent Threshold | Programmable 85–115 mV on OC pin; supports automatic restart after fault timeout. |
| Soft-Start Control | Externally programmable via SSFLT capacitor; also defines fault timeout duration. |
Pinout & Package
Package: 10-lead plastic MSOP (MSE), 3 mm × 3 mm footprint, exposed pad (Pin 11) connected to GND for thermal and electrical performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SSFLT (1) | Soft-Start / Fault Timeout | Capacitor-to-GND sets soft-start ramp time and post-fault restart delay; internal 6 µA charge / 2 µA discharge currents. |
| ITH (2) | Error Amplifier Output | Compensation node; clamped 0.7–1.9 V; controls PWM duty cycle via current comparator threshold. |
| FB (3) | Feedback Input | Receives resistor-divider voltage; regulates output when FB = 0.77–0.82 V (grade-dependent). |
| RUN (4) | Enable Control | Precision undervoltage lockout; 1.207 V turn-on / 1.170 V turn-off with 5 µA hysteresis current. |
| FS (5) | Frequency Set | Resistor-to-GND programs oscillator frequency per fOSC = 24×10⁹/(RFS − 1500). |
| SYNC (6) | External Clock Input | Accepts rising-edge-triggered external clock (70–700 kHz); overrides internal oscillator. |
| ISENSE (7) | Current Sense + Slope Ramp | Monitors MOSFET current sense resistor; injects 10 µA linear ramp for slope compensation. |
| OC (8) | Overcurrent Detection | Secondary current-sense input; trips at 85–115 mV; initiates fault timeout and restart sequence. |
| VCC (9) | Supply Input | Bias input; internally regulated to ~9.5 V; accepts 9 V max low-impedance source or high-VIN via resistor. |
| GATE (10) | MOSFET Driver Output | Drives N-channel MOSFET gate; rail-to-rail swing (GND to VCC); 30 ns rise/fall into 3000 pF. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable operating frequency | 70–700 kHz via single resistor on FS pin - enables EMI optimization and magnetics sizing flexibility. |
| Programmable overcurrent protection | OC pin threshold adjustable with external resistor; triggers automatic restart after fault timeout - improves system reliability. |
| Integrated VCC shunt regulator | 9.5 V clamp with 25 mA sink capability - eliminates need for external bias supply in high-input-voltage applications. |
| Run pin with precision hysteresis | 1.207 V turn-on / 1.170 V turn-off with 5 µA hysteresis current - enables clean, noise-immune enable/disable sequencing. |
| Combined soft-start and fault timeout | Single SSFLT capacitor controls both startup ramp and post-fault holdoff - reduces component count and PCB area. |
Applications
| Telecom Power Supplies | 42V Automotive Power Systems |
|---|---|
|
Use Scenario: 36–72 V input telecom rectifier supplying 5 V/2 A to line cards with strict efficiency and thermal requirements. IC Role / Device Role / Timing Role: Primary-side current-mode controller managing flyback topology; regulates output via FB loop while driving external N-MOSFET. Use Value: ±1.5% reference accuracy and 360 µA quiescent current maintain tight regulation and low standby loss across wide temperature range. |
Use Scenario: Under-hood 42 V battery-powered ADAS module requiring robust 5 V supply with fault recovery. IC Role / Device Role / Timing Role: Flyback controller with H-grade rating (–40°C to 150°C) and programmable OC protection for short-circuit resilience. Use Value: RUN pin hysteresis and 150°C junction rating ensure reliable start-up and operation in high-ambient environments. |
| Isolated Industrial Equipment | Nonisolated High-Voltage DC/DC Converters |
|
Use Scenario: Isolated 24 V input to 5 V/1 A converter powering analog sensor interfaces in factory automation. IC Role / Device Role / Timing Role: Controller implementing isolated flyback with transformer-coupled feedback; uses SYNC for system-level clock alignment. Use Value: Adjustable slope compensation prevents subharmonic oscillation in continuous conduction mode at >50% duty cycle. |
Use Scenario: Nonisolated flyback from 48 V bus to 5 V/2 A for embedded computing modules where isolation is not required. IC Role / Device Role / Timing Role: Controller driving N-MOSFET directly referenced to input ground; leverages VCC shunt regulator for simple biasing. Use Value: VIN and VOUT limited only by external components - enables flexible design with minimal constraints on external FET or transformer ratings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar current-mode flyback controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3805IMSE#TRPBF | I-grade (–40°C to 125°C) vs H-grade (–40°C to 150°C); identical pinout, specs, and functionality otherwise. | Suitable for under-hood automotive applications requiring extended temperature margin beyond 125°C. | Select LTC3805HMSE#TRPBF when operation above 125°C ambient or junction is required; no layout change needed. |
| LTC3805EMSE#TRPBF | E-grade (–40°C to 85°C); lower max junction temperature and reduced VFB tolerance (±1.5% only at 0–85°C). | Targeted at commercial telecom or industrial indoor applications with controlled thermal environment. | Choose LTC3805HMSE#TRPBF for designs needing guaranteed performance at 150°C junction or wider temp stability. |
Compared with LTC3805IMSE#TRPBF and LTC3805EMSE#TRPBF, the LTC3805HMSE#TRPBF provides the highest guaranteed junction temperature rating (150°C), ensuring stable regulation and fault response in thermally demanding environments where E- and I-grade variants may derate or fail.
Availability
LTC3805HMSE#TRPBF is available at Aetrix Electronics and suitable for telecom power supplies, 42V automotive systems, and isolated industrial equipment requiring stable component supply across extended temperature ranges.
Supply support for LTC3805HMSE#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 and maintains its high-performance analog and power management product lines.
The LTC3805HMSE#TRPBF belongs to Linear's legacy current-mode DC/DC controller family, engineered for high-voltage flyback, boost, and SEPIC topologies in telecom, automotive, and industrial power systems.
FAQ
What is the maximum junction temperature specification for the LTC3805HMSE#TRPBF?
The LTC3805HMSE#TRPBF is rated for operation from –40°C to 150°C junction temperature. This H-grade qualification ensures guaranteed performance in under-hood automotive and high-ambient industrial environments where standard I-grade (–40°C to 125°C) or E-grade (0°C to 85°C) variants would exceed limits. Thermal derating begins above 125°C per manufacturer guidelines.
How does the RUN pin function on the LTC3805HMSE#TRPBF?
The RUN pin on the LTC3805HMSE#TRPBF provides precision enable/disable control with 1.207 V turn-on and 1.170 V turn-off thresholds, plus 5 µA hysteresis current. When used with an external resistor divider from VIN, it enables clean power sequencing and noise immunity. The LTC3805HMSE#TRPBF remains in micropower mode (40 µA) until both RUN and VCC thresholds are satisfied.
Can the LTC3805HMSE#TRPBF be synchronized to an external clock?
Yes, the LTC3805HMSE#TRPBF supports external synchronization via the SYNC pin. A rising edge on SYNC triggers the start of each switching cycle, overriding the internal oscillator. Synchronization is supported across the full 70–700 kHz frequency range and allows EMI reduction through fixed-frequency alignment with other system clocks.
What is the purpose of the SSFLT pin on the LTC3805HMSE#TRPBF?
The SSFLT pin on the LTC3805HMSE#TRPBF serves dual functions: it controls soft-start timing during power-up and defines fault timeout duration after overcurrent events. An external capacitor from SSFLT to GND sets both intervals - charged at 6 µA for startup, discharged at 2 µA after fault - enabling single-component programmability for both sequences.
Does the LTC3805HMSE#TRPBF require an external current sense resistor?
Yes, the LTC3805HMSE#TRPBF requires an external current sense resistor connected between the source of the external N-channel MOSFET and ground. This resistor feeds both the ISENSE pin (for current-mode control) and the OC pin (for overcurrent protection). Values are selected based on peak current and desired trip thresholds (e.g., 68 mΩ for 2 A output in typical 5 V/2 A flyback designs).
LTC3805HMSE#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive, Isolation Capable
- Topology:
- Flyback
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 3.95V ~ 9.5V
- Frequency - Switching:
- 70kHz ~ 700kHz
- Duty Cycle (Max):
- 80%
- Synchronous Rectifier:
- No
- Clock Sync:
- Yes
- Serial Interfaces:
- -
- Control Features:
- Enable, Soft Start
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-MSOP-EP
LTC3805HMSE#TRPBF FAQ
1.How can I place an order for LTC3805HMSE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3805HMSE#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 LTC3805HMSE#TRPBF reliable?
The price and inventory of LTC3805HMSE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3805HMSE#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3805HMSE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3805HMSE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3805HMSE#TRPBF?
LTC3805HMSE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3805HMSE#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 LTC3805HMSE#TRPBF?
For technical support, including LTC3805HMSE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3805HMSE#TRPBF requirements.
6.How does Aetrix verify that LTC3805HMSE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3805HMSE#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 LTC3805HMSE#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3805HMSE#TRPBF?
All LTC3805HMSE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3805HMSE#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 LTC3805HMSE#TRPBF part is unused and in its original packaging.
Return procedure for LTC3805HMSE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3805HMSE#TRPBF Tags
-
UCC28C45DR
Texas Instruments
-
UCC28C40DR
Texas Instruments
-
UCC28C43DR
Texas Instruments
-
ZXSC410E6TA
Diodes Incorporated
-
LM3524DMX/NOPB
Texas Instruments
-
LM3489MMX/NOPB
Texas Instruments
-
MIC2102YML-TR
Microchip Technology
-
LM5148RGYR
Texas Instruments
-
TL598CDR
Texas Instruments
-
LM5155DSSR
Texas Instruments
-
LM25085MYX/NOPB
Texas Instruments
-
UCC2813DTR-0
Texas Instruments
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…
