My Inquiry
My Account
Analog Devices Inc. LT1111CN8-12#PBF
- Part No.:
- LT1111CN8-12#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LT1111CN8-12#PBF.pdf
- Description:
- IC REG BUCK BOOST 12V 1.5A 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:135
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1111CN8-12#PBF from Analog Devices (formerly Linear Technology) is a micropower, fixed-output 12V step-up/step-down DC/DC converter IC with integrated 1.5A NPN power switch, 72kHz gated oscillator, and on-chip low-battery detector comparator. It operates from 2V to 30V input, delivers up to 200mA at 12V from 12V input in step-down mode, and requires only three external components. It is used in battery-backed memory supplies and portable instrumentation where compact size and ultra-low quiescent current (300µA) are critical.
For engineers reviewing the LT1111CN8-12#PBF datasheet, LT1111CN8-12#PBF pinout, LT1111CN8-12#PBF application, or LT1111CN8-12#PBF equivalent, this page provides verified package mapping (8-pin PDIP), confirmed pin functions (e.g., SW1 as collector, SW2 as emitter), exact output regulation spec (11.4–12.6V), thermal limits (0°C to 70°C), and two validated alternative parts for fixed 12V DC/DC conversion.
Technical Context
The LT1111CN8-12#PBF implements a gated-oscillator architecture: the 72kHz oscillator activates only when feedback voltage falls below 1.25V reference, minimizing quiescent current. Its internal NPN switch supports both step-up (boost) and step-down (buck) topologies via reconfigurable SW1/SW2 connections.
Pin 8 (FB/SENSE) connects directly to output in fixed versions; internal resistor divider sets 12V output with ±5% tolerance over temperature. The ILIM pin enables user-programmable current limiting (e.g., 400mA with 220Ω to VIN), and the A0/SET gain block serves as configurable comparator for undervoltage lockout or linear post-regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 12V ±5% (11.4V–12.6V) - guaranteed across full 0°C to 70°C operating range |
| Oscillator Frequency | 72kHz typical - optimized for standard surface-mount inductors; duty cycle adjusts dynamically (43–59% step-up, 24–50% step-down) |
| Switch Current Limit | 1.5A maximum - internal NPN transistor rated for 1.5A peak; programmable down to 400mA via ILIM resistor |
| Quiescent Current | 300µA typical (switch OFF) - enables >1-year battery life in low-duty-cycle remote sensors |
| Input Voltage Range | 2V to 30V - supports single-cell LiFePO₄ (2.5V min), multi-cell alkaline (up to 12V), and industrial 24V rails |
| Operating Temperature | 0°C to 70°C - commercial-grade rating; junction max 90°C with θJA = 130°C/W (N8 package) |
| Package | 8-lead plastic DIP (N8) - through-hole compatible; 0.3" wide body; RoHS-compliant #PBF finish |
Pinout & Package
LT1111CN8-12#PBF uses an 8-lead plastic DIP (N8) package with 0.3" width and standard 0.1" pin pitch. Pin 1 (ILIM) is bottom-left when notch faces up; pin 8 (FB/SENSE) is top-right.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: ILIM | Current limit programming input | Connect to VIN directly for full 1.5A switch current; add resistor to VIN to reduce limit (e.g., 220Ω → 400mA) |
| Pin 2: VIN | Main power supply input | Accepts 2V–30V; absolute max 36V; powers internal circuitry and switch base drive |
| Pin 3: SW1 | Collector of internal NPN power switch | In step-up: connects to inductor/diode node; in step-down: ties to VIN rail |
| Pin 4: SW2 | Emitter of internal NPN power switch | In step-up: connects to GND; in step-down: drives inductor; must not fall below –0.5V |
| Pin 5: GND | Analog and power ground reference | Common return for feedback, comparator, and oscillator; separate from high-current paths |
| Pin 6: A0 | Auxiliary gain block open-collector output | Sinks 300µA max; used for low-battery detection, error amplification, or UVLO with external pull-up |
| Pin 7: SET | Gain block inverting input | Connects to resistor divider from VIN for comparator trip point; referenced to 1.25V internal reference |
| Pin 8: FB/SENSE | Feedback input / fixed-voltage sense | On LT1111CN8-12#PBF: internally connected to 12V divider; must tie directly to VOUT for regulation |
Key Features
| Feature | Design Value |
|---|---|
| Three-component operation | Only inductor, diode, and output capacitor required - eliminates external feedback resistors for fixed 12V output |
| Topology flexibility | Single IC supports boost (2V→12V), buck (12V→12V), and inverting (±12V) configurations via pin wiring |
| Programmable current limit | Resistor-based ILIM control prevents inductor saturation and switch overstress across wide VIN ranges |
| Integrated low-battery detector | Comparator with 1.25V reference and 12.5mV hysteresis enables reliable brown-out detection without extra ICs |
| Micropower gated oscillator | 300µA quiescent current achieved by disabling oscillator and driver when regulation is met |
Applications
| Battery Backup Memory Supply | Portable Instrument Power |
|---|---|
|
Use Scenario: Providing regulated 12V VPP for Flash memory programming in handheld test equipment powered by 3.6V Li-ion. IC Role / Device Role / Timing Role: Step-up DC/DC converter generating stable 12V from declining battery voltage (3.0V–4.2V). Use Value: Enables in-system Flash reprogramming without external boost module; 300µA IQ extends battery runtime between charges. |
Use Scenario: Powering 12V analog front-end circuits (op-amps, ADC drivers) in battery-operated environmental sensors. IC Role / Device Role / Timing Role: Precision 12V regulator with <50mV load regulation (0–100mA) and low noise for signal chain integrity. Use Value: Eliminates need for separate LDO + boost stage; fixed 12V output avoids resistor tolerance errors in feedback network. |
| Laptop Peripheral Card | Uninterruptible Sensor Node |
|
Use Scenario: Generating 12V from 5V USB bus for legacy PCMCIA peripherals requiring auxiliary power. IC Role / Device Role / Timing Role: Step-down converter operating from 5V input to deliver 12V at 50mA (inverting topology with external diode). Use Value: Supports hot-plug operation with no inrush current surge; 72kHz frequency avoids audible noise in office environments. |
Use Scenario: Maintaining 12V output during AC mains failure using supercapacitor backup (2.7V–5.5V input range). IC Role / Device Role / Timing Role: Wide-input (2V–30V) buck-boost controller sustaining sensor telemetry during brownouts. Use Value: ILIM pin allows precise current limiting to match supercapacitor discharge profile; prevents premature shutdown. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output DC/DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1111CS8-12#PBF | Same electrical specs, but in 8-lead SOIC (S8) package - 150°C/W thermal resistance vs. 130°C/W for N8 | Preferred for automated SMT assembly; lower profile; unsuitable for through-hole prototyping | Select when board space is constrained and reflow capability exists; verify PCB pad layout matches S8 footprint. |
| MAX630CPA+ | Fixed 12V output, but 100kHz oscillator, 500mA switch, and no ILIM pin - lacks programmable current limit | Used in simpler cost-sensitive designs where input range is narrow and inductor saturation risk is low | Choose only if ILIM functionality is unnecessary and SOIC-8 or PDIP-8 mechanical compatibility is acceptable. |
Compared with LT1111CN8-12#PBF, the LT1111CS8-12#PBF offers identical regulation and topology support in a surface-mount package, while the MAX630CPA+ trades current-limit flexibility for lower BOM count in fixed-input applications - neither is pin-compatible, requiring layout changes.
Availability
LT1111CN8-12#PBF is available at Aetrix Electronics and suitable for battery backup supplies, portable instrumentation, laptop peripheral cards, and uninterruptible sensor nodes requiring stable component supply with long-term manufacturing continuity.
Supply support for LT1111CN8-12#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's legacy precision analog and power management ICs remain industry benchmarks for performance and reliability.
The LT1111 product line was designed for ultra-low-power, multi-topology DC/DC conversion in space-constrained portable and battery-powered systems - emphasizing micropower operation, minimal external parts, and flexible voltage generation.
FAQ
What is the output voltage tolerance of the LT1111CN8-12#PBF over temperature?
The LT1111CN8-12#PBF guarantees a 12V output within ±5% (11.4V to 12.6V) across its full 0°C to 70°C operating temperature range. This specification is confirmed in the Electrical Characteristics table under "VOUT, LT1111-12" with "G" (guaranteed) marking, and includes effects of reference drift, resistor divider tolerance, and comparator hysteresis.
Can the LT1111CN8-12#PBF be used in step-down mode from 24V input to 12V output?
Yes, the LT1111CN8-12#PBF supports step-down operation from inputs up to 30V. At 24V input, it delivers 12V at up to 200mA in buck mode. Key design requirements include connecting SW1 to VIN, SW2 to the inductor, using a Schottky catch diode (e.g., MBRS130T3), and ensuring SW2 does not swing below –0.5V - verified in the Absolute Maximum Ratings and Typical Performance Characteristics.
Does the LT1111CN8-12#PBF require external feedback resistors?
No, the LT1111CN8-12#PBF does not require external feedback resistors. Unlike the adjustable LT1111, the -12 suffix indicates internal resistor dividers set the output to 12V. Pin 8 (FB/SENSE) must be connected directly to the output node; adding external resistors would disrupt regulation and is not supported per the Functional Description and Block Diagrams.
What is the maximum continuous output current the LT1111CN8-12#PBF can deliver in step-up mode?
In step-up mode from 3V input, the LT1111CN8-12#PBF delivers 12V at up to 100mA continuously, as specified in the "Typical Application" section and confirmed by thermal limits (TJMAX = 90°C, θJA = 130°C/W). At higher loads, junction temperature exceeds safe limits unless derated - actual current depends on ambient temperature, PCB copper area, and airflow.
How does the ILIM pin function on the LT1111CN8-12#PBF?
The ILIM pin on the LT1111CN8-12#PBF programs the switch current limit by sensing a fraction of the main switch current. Connecting a resistor between ILIM and VIN sets the threshold - e.g., 220Ω limits peak current to ~400mA. This prevents inductor saturation and switch overstress when input voltage varies, as detailed in the "Using the ILIM Pin" application note and Typical Performance Characteristic curves.
LT1111CN8-12#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Boost
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2V
- Voltage - Input (Max):
- 30V
- Voltage - Output (Min/Fixed):
- 12V
- Voltage - Output (Max):
- -
- Current - Output:
- 1.5A (Switch)
- Frequency - Switching:
- 72kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LT1111CN8-12#PBF FAQ
1.How can I place an order for LT1111CN8-12#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1111CN8-12#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 LT1111CN8-12#PBF reliable?
The price and inventory of LT1111CN8-12#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1111CN8-12#PBF is usually 5 days.
3.What payment methods are accepted for LT1111CN8-12#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1111CN8-12#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1111CN8-12#PBF?
LT1111CN8-12#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1111CN8-12#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 LT1111CN8-12#PBF?
For technical support, including LT1111CN8-12#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1111CN8-12#PBF requirements.
6.How does Aetrix verify that LT1111CN8-12#PBF is sourced from the original manufacturer or authorized distributors?
All LT1111CN8-12#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 LT1111CN8-12#PBF meets industry standards.
7.What is the process for return or replacement of LT1111CN8-12#PBF?
All LT1111CN8-12#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1111CN8-12#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 LT1111CN8-12#PBF part is unused and in its original packaging.
Return procedure for LT1111CN8-12#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1111CN8-12#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…
