My Inquiry
My Account
Analog Devices Inc. LTC1265CS#PBF
- Part No.:
- LTC1265CS#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC1265CS#PBF.pdf
- Description:
- IC REG BUCK BOOST ADJ 1.2A 14SO
- Quantity:
- Payment:
- Shipping:
Inventory:128
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1265CS#PBF from Analog Devices (formerly Linear Technology) is a monolithic step-down DC/DC converter with current-mode control, integrated 0.3Ω P-channel MOSFET switch (at VIN = 10V), Burst Mode™ operation, and low-battery detection. It delivers up to 1.2A output at 5V from 5.4V–12V input, achieves up to 95% efficiency, and supports 100% duty cycle for low-dropout operation in battery-powered systems.
For engineers reviewing the LTC1265CS#PBF datasheet, LTC1265CS#PBF pinout, LTC1265CS#PBF application, or LTC1265CS#PBF equivalent, this page provides verified technical context on constant off-time architecture, 14-pin SOIC package mapping, feedback voltage tolerance (±2.5% over temperature), shutdown current (<15µA), and real-world design meaning of SENSE+/- current sensing, CT-based frequency setting, and LBOUT/LBIN comparator interface.
Technical Context
The LTC1265CS#PBF implements a constant off-time (COT) control architecture where switching frequency varies inversely with (VIN – VOUT); off time is set by external capacitor CT (Pin 5) and dynamically adjusted below VIN – VOUT = 2V to suppress audible noise. Its internal current comparator monitors differential voltage across RSENSE (Pins 7–8), with threshold programmable between 25mV and 150mV, enabling peak inductor current control independent of inductance value.
Burst Mode™ operation engages automatically under light load: the device enters sleep mode (160µA quiescent current), disables gate drive, and relies on COUT to supply load until output droop triggers reactivation. The low-battery detector uses an internal 1.25V reference and open-drain LBOUT (Pin 3) with trip point adjustable via external divider on LBIN (Pin 4), while SHDN (Pin 10) enables micropower shutdown with VIH ≥ 1.2V and VIL ≤ 0.6V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5V ±2% (LTC1265-5 variant); regulated via internal resistive divider tied to SENSE– (Pin 7) |
| Input Voltage Range | 5.4V to 12V; absolute max –0.3V to 13V - defines minimum battery cell count and maximum unregulated rail compatibility |
| Max Output Current | 1.2A continuous; limited by 0.3Ω RDS(ON) (TA = 25°C) and thermal resistance θJA = 110°C/W in SOIC package |
| Efficiency | Up to 95% at 800mA load (VIN = 12V, VOUT = 5V); enabled by low RDS(ON), Burst Mode™, and optimized gate drive |
| Quiescent Current | 160µA in sleep mode (light load); drops to 5µA typical in shutdown - critical for multi-year battery life in portable instruments |
| Switching Frequency | Variable (≈200–1000kHz); set by CT capacitor and (VIN – VOUT); no external clock required - simplifies EMI filtering |
| Low-Battery Trip | 1.25V reference with ±0.1V tolerance; LBOUT sinks ≥1mA when LBIN < 1.25V - enables precise end-of-life battery cutoff |
Pinout & Package
14-pin plastic SOIC (SO-14) package, 1.27mm pitch, JEDEC MS-012AC compliant; thermal pad not present; θJA = 110°C/W; RoHS-compliant and Pb-free (indicated by #PBF suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PWR VIN (Pins 1, 13) | Power MOSFET driver supply | Must be decoupled locally to PGND; ties directly to high-current switch path - requires low-ESR bulk + 0.1µF ceramic |
| VIN (Pin 2) | Main control circuit supply | Feeds bias, reference, comparators; separate from PWR VIN to isolate noise-sensitive analog blocks |
| LBOUT (Pin 3) | Open-drain low-battery output | Sinks current when LBIN falls below 1.25V; high-Z in shutdown - drives LED or microcontroller interrupt |
| LBIN (Pin 4) | Inverting input of low-battery comparator | Accepts resistor-divider from VIN; 0.5µA input bias - sets trip point per VTRIP = 1.25 × (1 + R4/R3) |
| CT (Pin 5) | Off-time timing capacitor node | Discharged by current proportional to VOUT; sets tOFF ≈ 1.3×10⁴ × CT/VREG - determines operating frequency |
| ITH (Pin 6) | Current comparator threshold control | Voltage here scales current sense threshold; tracks load changes to maintain regulation during transients |
| SENSE– (Pin 7) | Current comparator inverting input / VOUT divider tap | For LTC1265-5: connects internally to 5V divider; also carries current sense return - must route with SENSE+ |
| SENSE+ (Pin 8) | Current comparator non-inverting input | Paired with Pin 7; differential measurement across RSENSE sets peak inductor current - requires tight layout |
| N/C, VFB (Pin 9) | Not connected (fixed-output version) | No connection required; unused in LTC1265CS#PBF - differs from adjustable LTC1265 variant which uses this as feedback input |
| SHDN (Pin 10) | Active-high shutdown control | Pull ≥1.2V to disable switch; draws only 0.5µA - enables system-level power sequencing without pull-up resistors |
| SGND (Pin 11) | Small-signal ground reference | Return for VFB, ITH, LBIN; must route separately from PGND to COUT(–) - prevents noise coupling into regulation loop |
| PGND (Pin 12) | Power ground return | Return for CIN(–), Schottky anode, PWR VIN; high di/dt path - minimize trace length and inductance |
| SW (Pin 14) | Drain of internal P-channel MOSFET | Switching node; connects to Schottky cathode and inductor - high dv/dt source requiring careful layout and snubbing |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 0.3Ω P-channel MOSFET switch | Enables 1.2A output without external FET; reduces BOM count and layout complexity in space-constrained portable designs |
| Burst Mode™ operation | Reduces quiescent current to 160µA at light loads while maintaining tight output regulation - extends battery runtime in standby |
| 100% duty cycle low-dropout mode | Maintains regulation down to VIN ≈ VOUT; eliminates need for LDO post-regulator in battery-voltage tracking applications |
| User-programmable peak inductor current | Set via RSENSE (0.083Ω min); threshold range 25–150mV allows optimization of ripple, size, and efficiency trade-offs |
| Low-battery detection with open-drain output | Configurable trip point using two resistors; LBOUT sinks >1mA - enables direct interface to µC GPIO or discrete logic without level shifters |
Applications
| Portable Medical Monitors | Industrial Handheld Scanners |
|---|---|
Use Scenario: Battery-powered ECG front-end with analog signal chain and Bluetooth LE radio requiring stable 5V rail during intermittent transmission bursts. IC Role / Device Role / Timing Role: Primary step-down regulator supplying 5V/1.2A to mixed-signal ASIC and RF transceiver; manages battery discharge curve via low-battery alert. Use Value: Burst Mode™ cuts sleep current to 160µA, extending single-AA battery life beyond 18 months; 95% efficiency minimizes heat in sealed enclosure. |
Use Scenario: Ruggedized barcode scanner with laser diode, CMOS imager, and motorized trigger - all powered from dual AA cells. IC Role / Device Role / Timing Role: Main 5V power source; handles dynamic load steps from 10mA (idle) to 1.1A (laser + motor activation) with <100µs transient recovery. Use Value: Constant off-time control ensures fast line/load response; 100% duty cycle sustains operation down to 4.2V input - avoids premature shutdown. |
| Wireless Sensor Node Transceivers | Memory Backup Power Supplies |
Use Scenario: LoRaWAN node with ultra-low-power MCU, sub-GHz transceiver, and environmental sensors operating on coin-cell or energy harvesting. IC Role / Device Role / Timing Role: Efficient 5V generation from variable input (e.g., solar harvester output); LBOUT signals battery depletion to initiate graceful shutdown. Use Value: 5µA shutdown current preserves stored energy; programmable RSENSE allows optimization for µA-level sleep currents and mA-level transmit peaks. |
Use Scenario: SRAM retention supply in industrial PLC controller where main 5V rail may fail unexpectedly during brownout events. IC Role / Device Role / Timing Role: Standby 5V source activated only when primary rail drops; low-quiescent design minimizes backup battery drain. Use Value: 160µA sleep current enables >5-year backup from CR2032; fixed 5V output matches standard SRAM VCC requirements without trimming. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1935ES5#TRMPBF | 500mA max output; 1.2MHz fixed frequency; no Burst Mode™; 2.5µA shutdown current | Lower current capability; better suited for compact, low-noise 3.3V/5V point-of-load rails where size > efficiency | Select if board space is constrained and 500mA suffices; avoid for >800mA loads or battery longevity-critical use |
| TPS62130ARGTR | 3A output; 2.5V–6V input; DCS-Control™ topology; 17µA quiescent in PWM mode; no low-battery detector | Higher current, wider input range, but lacks integrated battery monitoring - requires external comparator | Choose for higher-power applications needing 3A or tighter output accuracy; add discrete LB circuit if battery cutoff needed |
Compared with LT1935ES5#TRMPBF and TPS62130ARGTR, the LTC1265CS#PBF uniquely combines 1.2A capability, Burst Mode™ for µA-level light-load efficiency, and built-in low-battery detection in a single SOIC-14 package - making it optimal for long-life, battery-fed 5V systems where feature integration outweighs raw current headroom.
Availability
LTC1265CS#PBF is available at Aetrix Electronics and suitable for portable medical monitors, industrial handheld scanners, wireless sensor nodes, memory backup supplies, and battery-powered instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.
Supply support for LTC1265CS#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; Linear pioneered high-performance analog ICs including precision regulators, data converters, and power management solutions.
The LTC1265CS#PBF belongs to Linear's legacy high-efficiency DC/DC converter family, designed specifically for battery-powered portable equipment demanding extended runtime, robust transient response, and integrated system monitoring functions.
FAQ
What is the exact output voltage tolerance of the LTC1265CS#PBF over temperature?
The LTC1265CS#PBF is the fixed 5V version (LTC1265-5). Its output voltage is specified as 4.9V to 5.2V at 800mA load across the full operating temperature range (0°C to 70°C for the 'C' grade), corresponding to ±2% tolerance. This is achieved via an internal resistive divider referenced to a trimmed 1.25V bandgap, with no external components required for regulation.
Does the LTC1265CS#PBF require an external feedback resistor network?
No, the LTC1265CS#PBF does not require an external feedback resistor network. As the fixed-output 5V variant (LTC1265-5), it uses an internal resistive divider connected to SENSE– (Pin 7) to set regulation. Pin 9 (VFB) is NC (no connect) in this version - unlike the adjustable LTC1265, which requires external R1/R2 on Pin 9 to set VOUT.
How does the LTC1265CS#PBF achieve low quiescent current in light-load conditions?
The LTC1265CS#PBF achieves 160µA quiescent current in light-load conditions through automatic entry into Burst Mode™ operation. When load current drops below the threshold for continuous conduction, the device disables gate drive, enters sleep mode, and relies on output capacitance to supply the load until output voltage droop triggers reactivation - reducing average supply current by >90% versus active mode.
What is the maximum allowable input voltage for the LTC1265CS#PBF?
The absolute maximum input voltage for the LTC1265CS#PBF is 13V applied to Pins 1, 2, or 13. However, the recommended operating range is 5.4V to 12V. Exceeding 13V risks permanent damage; note that SW (Pin 14) must never exceed VIN by more than 0.3V - a condition that can occur during battery disconnect and requires external Schottky clamping per Figure 5 in the datasheet.
Can the LTC1265CS#PBF be used in dropout mode, and what happens to efficiency?
Yes, the LTC1265CS#PBF supports 100% duty cycle operation in dropout mode when VIN approaches VOUT. In this state, the internal P-channel MOSFET remains fully enhanced, minimizing conduction loss. Efficiency remains high - dominated by I²R losses in RDS(ON) (0.3Ω typical) - e.g., at VIN = 5.1V, VOUT = 5V, and IOUT = 1A, efficiency exceeds 98%, far surpassing linear regulators at similar conditions.
LTC1265CS#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Buck-Boost, SEPIC
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 13V
- Voltage - Output (Min/Fixed):
- 1.25V
- Voltage - Output (Max):
- 13V
- Current - Output:
- 1.2A (Switch)
- Frequency - Switching:
- Up to 700kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SO
LTC1265CS#PBF FAQ
1.How can I place an order for LTC1265CS#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1265CS#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 LTC1265CS#PBF reliable?
The price and inventory of LTC1265CS#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1265CS#PBF is usually 5 days.
3.What payment methods are accepted for LTC1265CS#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1265CS#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1265CS#PBF?
LTC1265CS#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1265CS#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 LTC1265CS#PBF?
For technical support, including LTC1265CS#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1265CS#PBF requirements.
6.How does Aetrix verify that LTC1265CS#PBF is sourced from the original manufacturer or authorized distributors?
All LTC1265CS#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 LTC1265CS#PBF meets industry standards.
7.What is the process for return or replacement of LTC1265CS#PBF?
All LTC1265CS#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1265CS#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 LTC1265CS#PBF part is unused and in its original packaging.
Return procedure for LTC1265CS#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1265CS#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…
