My Inquiry
My Account
Analog Devices Inc. LTC1265IS#PBF
- Part No.:
- LTC1265IS#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC1265IS#PBF.pdf
- Description:
- IC REG BUCK BOOST ADJ 1.2A 14SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,606
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1265IS#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, and Burst Mode™ operation for ultra-low quiescent current. It delivers up to 1.2A output at 5V from 5.4V–12V input, achieves up to 95% efficiency, and features low-battery detection, short-circuit protection, and 100% duty-cycle dropout operation. It is used in battery-powered portable instruments and distributed power systems requiring high light-load efficiency.
For engineers reviewing the LTC1265IS#PBF datasheet, LTC1265IS#PBF pinout, LTC1265IS#PBF application, or LTC1265IS#PBF equivalent, key selection criteria include its 14-pin SO package, 160µA sleep-mode current, 5V fixed output (LTC1265-5 variant), internal current-sense threshold of 25–150mV, and CT-controlled constant off-time architecture enabling frequency scaling with input-output differential.
Technical Context
The LTC1265IS#PBF implements a constant off-time, current-mode control architecture where switching frequency varies inversely with (VIN – VOUT); off time is set by external capacitor CT (Pin 5), and peak inductor current is determined by voltage across RSENSE (Pins 7–8). The internal 1.25V reference and resistive divider on SENSE– (Pin 7) fix VOUT = 5V for this variant.
Burst Mode™ operation engages automatically below ~250mA load, disabling the power switch and reducing IQ to 160µA; during burst cycles, peak inductor current is clamped to 25mV/RSENSE. The low-battery comparator (Pins 3–4) triggers at 1.15–1.35V input threshold and sinks ≥0.5mA when active.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 5.0V ±2% (regulated at 800mA load; G-grade temp range) |
| Max Output Current | 1.2A continuous; peak switch current 1.6A |
| Input Voltage Range | 5.4V to 12V (absolute max −0.3V to 13V) |
| Quiescent Current | 160µA in sleep mode; <15µA in shutdown |
| Switch RDS(ON) | 0.3Ω typical at VIN = 10V, TJ = 25°C |
| Efficiency | Up to 95% at 800mA, VIN = 12V, VOUT = 5V |
| Operating Frequency | Variable: ~300–700kHz depending on VIN–VOUT and CT |
| Low-Battery Threshold | 1.15V to 1.35V (trip point at Pin 4; open-drain LBOUT on Pin 3) |
Pinout & Package
Package: 14-lead plastic SO (Small Outline), 1.27mm pitch, JEDEC MS-012AC, θJA = 110°C/W, rated for −40°C to +85°C (I-grade).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PWR VIN (Pins 1, 13) | Power MOSFET supply rail | Must be tied together and decoupled locally to PGND; supplies gate driver and high-side switch |
| VIN (Pin 2) | Control circuit supply | Provides bias for internal logic, reference, comparators; separate from PWR VIN |
| LBOUT (Pin 3) | Open-drain low-battery indicator | Sinks ≥0.5mA when LBIN (Pin 4) falls below 1.25V; high-Z in shutdown |
| LBIN (Pin 4) | Inverting input of low-battery comparator | Compares external resistor-divider voltage against internal 1.25V reference |
| CT (Pin 5) | Off-time timing capacitor node | External capacitor sets tOFF; discharge current scales with VOUT to stabilize frequency near dropout |
| ITH (Pin 6) | Current comparator threshold control | Voltage here sets trip point for current sense amplifier; decoupling improves stability |
| SENSE– (Pin 7) | Current comparator inverting input / VOUT divider tap | Connects to internal 5V feedback divider; also senses shunt voltage drop for current limiting |
| SENSE+ (Pin 8) | Current comparator non-inverting input | Paired with Pin 7 to measure RSENSE voltage; 1000pF cap required between Pins 7–8 |
| N/C, VFB (Pin 9) | No-connect (fixed-output version) | Not used on LTC1265-5; reserved for adjustable versions (LTC1265) |
| SHDN (Pin 10) | Active-high micropower shutdown | Logic high (>1.2V) disables switch and reduces IQ to <15µA; must not float |
| SGND (Pin 11) | Small-signal ground reference | Return for feedback, reference, and comparator circuits; routed separately from PGND |
| PGND (Pin 12) | Power ground return | Return for CIN, Schottky anode, and switch source; high di/dt path |
| SW (Pin 14) | Drain of internal P-channel MOSFET | Switching node connected to inductor and Schottky cathode; voltage swings from VIN to ~−0.3V |
Key Features
| Feature | Design Value |
|---|---|
| Burst Mode™ operation | Reduces sleep-mode IQ to 160µA while maintaining regulation; eliminates audible noise at light loads |
| Integrated 0.3Ω P-channel switch | Enables 1.2A output without external FET; eliminates gate drive complexity and layout sensitivity |
| Constant off-time architecture | Automatically adjusts frequency with input-output differential; avoids subharmonic instability without slope compensation |
| Low-battery detection with open-drain output | Allows system-level battery monitoring and graceful shutdown before cutoff; no external comparator needed |
| 100% duty-cycle dropout operation | Maintains regulation down to VIN ≈ VOUT; extends usable battery life in portable applications |
| Short-circuit protection | Extends off time under overload to limit average current; prevents thermal runaway during fault conditions |
Applications
| Portable Medical Instruments | Distributed Power Systems |
|---|---|
Use Scenario: Battery-powered handheld glucose meters and pulse oximeters requiring stable 5V rail from single Li-ion or dual alkaline cells. IC Role / Device Role / Timing Role: Primary step-down regulator delivering regulated 5V at ≤1A with ultra-low sleep current to maximize battery runtime. Use Value: 160µA quiescent current and Burst Mode™ extend shelf life and operational time; 5.4V–12V input accommodates varying battery states. |
Use Scenario: Intermediate bus conversion in industrial IoT gateways where 12V backplane supplies multiple 5V subsystems. IC Role / Device Role / Timing Role: Local point-of-load (POL) converter providing isolated 5V for microcontroller, sensor interface, and RF module rails. Use Value: High efficiency (>90% at 500mA) minimizes heat in dense layouts; CT-based frequency tuning simplifies EMI filtering design. |
| Cellular Telephone Peripherals | Memory Backup Supply |
Use Scenario: USB-powered accessories (e.g., LTE modems, GPS dongles) drawing bursty 5V loads from 5V USB host while maintaining low standby draw. IC Role / Device Role / Timing Role: Efficient buck converter with fast transient response to handle RF transmit current spikes without brownout. Use Value: Current-mode control ensures excellent line/load transient response; 1.2A peak supports short-duration 800mA bursts. |
Use Scenario: Maintaining SRAM or real-time clock (RTC) voltage during main power loss in embedded controllers using coin-cell backup. IC Role / Device Role / Timing Role: Low-quiescent, dropout-capable regulator sustaining 5V from depleting backup battery. Use Value: 100% duty cycle operation allows regulation down to VIN = VOUT; 160µA sleep current preserves coin-cell life for years. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down DC/DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1935ES5#TRMPBF | 500mA max output; 1.2MHz fixed frequency; no Burst Mode; 1.25V reference only | Lower current, higher frequency, no low-battery detection or 100% dropout | Select when board space is constrained and light-load efficiency is secondary to EMI control |
| TPS62130ARGTR | 3A output; 2.5V–6V input; DCS-Control™; 17µA IQ; no LB detector; 3mm × 3mm QFN | Higher current, wider input, smaller package, but lacks low-battery comparator and fixed 5V option | Select for higher-power, space-constrained designs where battery monitoring is handled externally |
Compared with LT1935ES5#TRMPBF and TPS62130ARGTR, the LTC1265IS#PBF uniquely combines 1.2A capability, integrated low-battery detection, 100% duty-cycle dropout, and Burst Mode™ IQ optimization - making it optimal for cost-sensitive, battery-life-critical 5V POL applications in industrial and portable equipment.
Availability
LTC1265IS#PBF is available at Aetrix Electronics and suitable for portable medical instruments, distributed power systems, cellular telephone peripherals, and memory backup supply designs requiring stable component supply, long-term lifecycle support, and guaranteed traceability.
Supply support for LTC1265IS#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 leader in high-performance analog, mixed-signal, and power management semiconductors.
The LTC1265IS#PBF belongs to Linear's legacy high-efficiency monolithic DC/DC converter family, designed specifically for battery-powered portable equipment demanding ultra-low quiescent current, robust protection, and seamless transition between continuous and burst-mode operation.
FAQ
What is the output voltage tolerance of the LTC1265IS#PBF under full temperature range?
The LTC1265IS#PBF is the I-grade (−40°C to +85°C) version of the LTC1265-5, specifying VOUT = 4.9V to 5.2V at 800mA load across the full operating temperature range. This ±2% tolerance is guaranteed by internal trimming of the SENSE– resistive divider and referenced to a 1.25V bandgap, ensuring stable 5V regulation without external components.
Does the LTC1265IS#PBF require an external current-sense resistor, and what value is recommended for 1A output?
Yes, the LTC1265IS#PBF requires an external RSENSE between SENSE+ (Pin 8) and SENSE– (Pin 7) to set current limit. For 1A maximum output, RSENSE = 100mV / IOUT(MAX) = 0.1Ω is recommended per the datasheet's design equation - matching the 0.1Ω IRC LRC2010-01-R100-J shown in Figure 1 and validated for 1.2A capability.
How does the LTC1265IS#PBF enter and exit Burst Mode™ operation?
The LTC1265IS#PBF enters Burst Mode™ automatically when load current drops below ~250mA, causing the output voltage to rise above regulation. The hysteretic voltage comparator then disables the power switch, letting the output capacitor supply load current while IQ drops to 160µA. It exits Burst Mode™ when VOUT sags by the comparator's hysteresis (≈50mV), re-enabling switching to restore regulation.
Can the LTC1265IS#PBF operate with input voltage below 5.4V, and what happens near dropout?
The absolute minimum input for functional operation is 5.4V per datasheet specifications, though the device can sustain regulation down to VIN ≈ VOUT via 100% duty-cycle operation. Below 5.4V, performance degrades: efficiency drops, CT discharge current increases to maintain frequency, and RDS(ON) rises with junction temperature - limiting safe operation in sustained dropout at high current.
What is the purpose of the 1000pF capacitor between SENSE+ and SENSE– (Pins 8 and 7) on the LTC1265IS#PBF?
The 1000pF capacitor between SENSE+ and SENSE– filters high-frequency noise on the current-sense path, preventing false triggering of the current comparator due to switching transients or PCB coupling. It is mandatory per the datasheet layout guidelines and must be placed as close as possible to Pins 7 and 8 to ensure accurate, stable current limiting and overcurrent protection for the LTC1265IS#PBF.
LTC1265IS#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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SO
LTC1265IS#PBF FAQ
1.How can I place an order for LTC1265IS#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1265IS#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 LTC1265IS#PBF reliable?
The price and inventory of LTC1265IS#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1265IS#PBF is usually 5 days.
3.What payment methods are accepted for LTC1265IS#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1265IS#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1265IS#PBF?
LTC1265IS#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1265IS#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 LTC1265IS#PBF?
For technical support, including LTC1265IS#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1265IS#PBF requirements.
6.How does Aetrix verify that LTC1265IS#PBF is sourced from the original manufacturer or authorized distributors?
All LTC1265IS#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 LTC1265IS#PBF meets industry standards.
7.What is the process for return or replacement of LTC1265IS#PBF?
All LTC1265IS#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1265IS#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 LTC1265IS#PBF part is unused and in its original packaging.
Return procedure for LTC1265IS#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1265IS#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…
