My Inquiry
My Account
Analog Devices Inc. LTC1149CN-3.3#PBF
- Part No.:
- LTC1149CN-3.3#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
LTC1149CN-3.3#PBF.pdf
- Description:
- IC REG CTRLR BUCK 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,376
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1149CN-3.3#PBF from Analog Devices (formerly Linear Technology) is a synchronous step-down switching regulator controller designed for fixed 3.3V output, driving external complementary P-channel and N-channel MOSFETs. It operates from 9V to 48V input, delivers up to 2A load current, achieves up to 95% efficiency, and features Burst Mode™ operation for ultralow quiescent current in light-load conditions - ideal for portable instrumentation and battery-powered digital systems.
For engineers reviewing the LTC1149CN-3.3#PBF datasheet, LTC1149CN-3.3#PBF pinout, LTC1149CN-3.3#PBF application, or LTC1149CN-3.3#PBF equivalent, key selection criteria include its constant off-time current-mode architecture, 3.33V ±30mV output regulation at 700mA, 16-pin PDIP package, shutdown threshold of 0.8V on SHDN1 (Pin 10), and compatibility with external RSENSE down to 0.05Ω for peak-current sensing.
Technical Context
The LTC1149CN-3.3#PBF implements a constant off-time, current-mode control architecture with adaptive nonoverlap gate drives to prevent shoot-through. Its internal 10V low-dropout regulator powers gate drivers and control circuitry, while level-shifted PGATE (Pin 1) enables high-side P-MOSFET drive referenced to VIN.
Burst Mode™ operation activates below ~15mA load (IBURST ≈ 15mV/RSENSE), reducing supply current to 0.6–0.9mA and standby power to ~8mW at 12V input. The device supports short-circuit protection via current-sense comparator thresholds (130–170mV across RSENSE) and maintains 100% duty cycle in dropout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.33V ±65mV at 700mA load; tight regulation enables stable 3.3V logic rail generation. |
| Input Voltage Range | 9V to 48V (60V absolute max); supports wide industrial and telecom input rails. |
| Efficiency | Up to 95% at full load; maintained over wide current range due to synchronous FET switching and current-mode control. |
| Shutdown Current | 135–230µA at 12V input; enables ultra-low-power system sleep states. |
| Current Sense Threshold | 130–170mV (high threshold); sets precise peak inductor current limit for reliable overload protection. |
| Off-Time | 3.8–6µs (CT = 390pF); determines minimum switching frequency and ripple current scaling. |
| Operating Temperature | 0°C to 70°C (commercial grade); validated for embedded industrial and avionics environments. |
Pinout & Package
Package: 16-lead plastic DIP (N package), through-hole mounting, θJA = 70°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PGATE (1) | Level-shifted high-side gate drive | Swings from VIN to VIN – VCC; directly drives P-channel MOSFET gate with accurate timing reference. |
| VIN (2) | Main power input | Accepts 9–48V supply; feeds internal LDO and high-side driver; absolute max 60V. |
| VCC (3) | Internal 10V LDO output | Supplies gate drivers and control logic; rated 50mA continuous; not short-circuit protected. |
| PDRIVE (4) | High-current P-MOSFET gate driver | Ground-referenced output; drives P-FET gate via external level-shift network. |
| VCC (5) | Internal LDO input | Must be decoupled to PGND with ≥1µF ceramic capacitor for noise immunity. |
| CT (6) | Timing capacitor connection | External capacitor (e.g., 390pF) sets off-time and operating frequency; discharge current scales with VOUT. |
| ITH (7) | Gain amplifier compensation node | Connects to RC network for loop stability; adjusts current comparator threshold dynamically. |
| SENSE– (8) | Current sense (–) / internal divider tap | Internally connected to fixed 3.3V feedback divider; also (–) input of current comparator. |
| SENSE+ (9) | Current sense (+) | (+) input of current comparator; offset vs. Pin 8 sets 25mV/150mV trip thresholds across RSENSE. |
| SHDN1/VFB (10) | Logic shutdown / feedback input | In LTC1149CN-3.3#PBF: shutdown pin (0.5–2V threshold); must be grounded for normal operation. |
| SGND (11) | Small-signal ground | Separate return path for feedback and compensation; routed to COUT (–) to minimize noise coupling. |
| PGND (12) | Power ground | Return for CIN (–) and N-MOSFET source; separates high-di/dt paths from SGND. |
| NGATE (13) | N-channel MOSFET gate driver | Ground-referenced output (0–VCC swing); drives synchronous rectifier with fast 100–200ns transitions. |
| RGND (14) | LDO ground | Reference for internal 10V regulator; connects to PGND at single point near CIN. |
| SHDN2 (15) | Master shutdown | Shuts down entire IC including VCC; requires logic signal with tr/tf < 1µs; threshold 0.8–2V. |
| CAP (16) | Charge compensation | Capacitor to VCC supplies charge for P-drive level-shift capacitor during transients; must exceed PDRIVE capacitor value. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous FET switching | Eliminates Schottky diode loss; enables >95% efficiency and reduced thermal stress on N-MOSFET. |
| Burst Mode™ operation | Reduces quiescent current to 0.6mA at 12V input, enabling <8mW standby power for battery longevity. |
| Adaptive nonoverlap gate drives | Prevents shoot-through by enforcing dead time between P- and N-MOSFET conduction cycles. |
| Very low dropout (100% duty cycle) | Maintains regulation when VIN approaches VOUT; critical for brownout resilience in wide-input systems. |
| Ultrahigh input voltage capability | Operates up to 48V input (60V abs max); eliminates need for pre-regulator in 24/48V industrial bus designs. |
Applications
| Portable Instrumentation Power | Avionics DC-DC Conversion |
|---|---|
Use Scenario: Powering handheld test equipment with Li-ion battery input (9–16.8V) and strict 3.3V rail tolerance. IC Role / Device Role / Timing Role: Primary step-down controller managing synchronous buck conversion with Burst Mode™ for extended battery life. Use Value: Delivers 3.33V ±65mV at 2A with 93% efficiency at 12V input, reducing thermal load and enabling compact heatsink-free design. |
Use Scenario: Generating regulated 3.3V for flight control microcontrollers from 28V aircraft bus with EMI constraints. IC Role / Device Role / Timing Role: Fixed-output synchronous buck controller with constant off-time architecture for predictable EMI profile. Use Value: Maintains regulation down to 9V input and supports 48V transients; 16-pin PDIP simplifies conformal coating and mechanical ruggedization. |
| Industrial Sensor Node Supply | Telecom Line Card Bias |
Use Scenario: Providing isolated 3.3V bias to analog sensor front-ends in programmable logic controller (PLC) I/O modules. IC Role / Device Role / Timing Role: High-efficiency, low-noise DC-DC controller interfacing with external MOSFETs and precision RSENSE. Use Value: 130–170mV current sense threshold enables accurate 2A current limiting; SGND/PGND separation minimizes measurement noise. |
Use Scenario: Converting -48V telecom bus to +3.3V for FPGA configuration and management ICs in line cards. IC Role / Device Role / Timing Role: Wide-input synchronous buck controller supporting 48V nominal input with transient robustness. Use Value: Withstands 60V abs max input; Burst Mode™ reduces idle power draw during low-traffic periods without compromising startup reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1149CS-3.3#PBF | Same electrical specs; 16-lead SOIC package (θJA = 110°C/W), surface-mount compatible. | Preferred for space-constrained PCBs requiring automated assembly; higher thermal resistance requires careful layout. | Select when board real estate or reflow process mandates SOIC; verify thermal margin with 110°C/W θJA. |
| LTC3824-3.3 | Monolithic 3.3V buck regulator (integrated MOSFETs); 3–36V input; no external RSENSE; lower quiescent current (50µA). | Eliminates external MOSFETs and gate drive complexity; unsuitable where high-current discrete FETs or custom thermal management are required. | Choose for simplified BOM and faster prototyping; avoid when >2A peak current or >48V input is needed. |
Compared with LTC1149CS-3.3#PBF, the LTC1149CN-3.3#PBF offers superior thermal performance in through-hole layouts but requires manual assembly; versus LTC3824-3.3, it trades integration for higher input voltage headroom and discrete FET flexibility at the cost of design complexity.
Availability
LTC1149CN-3.3#PBF is available at Aetrix Electronics and suitable for portable instrumentation, avionics power systems, and industrial sensor node designs requiring stable component supply, long-term obsolescence management, and traceable sourcing.
Supply support for LTC1149CN-3.3#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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and aerospace markets.
The LTC1149 series belongs to Linear's legacy high-voltage synchronous buck controller product line, engineered specifically for wide-input industrial and telecom power conversion where discrete MOSFET control, burst-mode efficiency, and 48V+ operation are essential.
FAQ
What is the regulated output voltage accuracy of the LTC1149CN-3.3#PBF?
The LTC1149CN-3.3#PBF provides a fixed 3.33V output with guaranteed accuracy of ±65mV over 5mA–2A load and 0°C–70°C temperature range. At 700mA load and 9V input, the typical output is 3.33V with min/max bounds of 3.17V and 3.43V per datasheet specifications. This tight tolerance ensures reliable operation of 3.3V logic and analog circuits without external trimming.
How does the LTC1149CN-3.3#PBF enter and exit Burst Mode™ operation?
The LTC1149CN-3.3#PBF enters Burst Mode™ automatically when load current drops below IBURST ≈ 15mV/RSENSE, causing the voltage comparator to hold the P-MOSFET off and allow the timing capacitor to discharge fully. It exits Burst Mode™ when output voltage droops by the hysteresis band (set by internal comparator V), turning the P-MOSFET back on. During Burst Mode™, supply current drops to 0.6–0.9mA, reducing standby power to ~8mW at 12V input.
What are the key differences between SHDN1 (Pin 10) and SHDN2 (Pin 15) on the LTC1149CN-3.3#PBF?
SHDN1 (Pin 10) is a control-only shutdown pin that disables the PWM controller and gate drivers while leaving the internal 10V VCC regulator active; threshold is 0.5–2V, and it must be grounded for normal operation. SHDN2 (Pin 15) is the master shutdown pin that disables VCC and all internal circuitry; threshold is 0.8–2V and requires fast-edge logic signals (tr/tf < 1µs). Both pins are active-high, but SHDN2 provides deeper power savings.
Can the LTC1149CN-3.3#PBF operate with input voltages below 9V?
No - the LTC1149CN-3.3#PBF is specified for minimum 9V input voltage per Absolute Maximum Ratings and Electrical Characteristics tables. Operation below 9V risks failure to regulate or start-up, as the internal 10V LDO requires sufficient headroom (VIN – VCC ≥ 200mV dropout) and gate drive levels degrade. For sub-9V applications, consider the LTC1148 or monolithic alternatives like LTC3630A.
What is the recommended RSENSE value for a 2A maximum output application using the LTC1149CN-3.3#PBF?
For 2A maximum output, the recommended RSENSE is 0.05Ω, based on the formula RSENSE = 100mV/IMAX with margin. This yields a current sense threshold of 130–170mV, ensuring robust overload protection while keeping IRIPPLE(P-P) ≤ 25mV/RSENSE for stable Burst Mode™ entry. The datasheet confirms this value in Figure 2 and the typical application circuit (RSENSE** = 0.05Ω).
LTC1149CN-3.3#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- Up to 48V
- Frequency - Switching:
- Up to 250kHz
- Duty Cycle (Max):
- 100%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-PDIP
LTC1149CN-3.3#PBF FAQ
1.How can I place an order for LTC1149CN-3.3#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1149CN-3.3#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 LTC1149CN-3.3#PBF reliable?
The price and inventory of LTC1149CN-3.3#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1149CN-3.3#PBF is usually 5 days.
3.What payment methods are accepted for LTC1149CN-3.3#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1149CN-3.3#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1149CN-3.3#PBF?
LTC1149CN-3.3#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1149CN-3.3#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 LTC1149CN-3.3#PBF?
For technical support, including LTC1149CN-3.3#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1149CN-3.3#PBF requirements.
6.How does Aetrix verify that LTC1149CN-3.3#PBF is sourced from the original manufacturer or authorized distributors?
All LTC1149CN-3.3#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 LTC1149CN-3.3#PBF meets industry standards.
7.What is the process for return or replacement of LTC1149CN-3.3#PBF?
All LTC1149CN-3.3#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1149CN-3.3#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 LTC1149CN-3.3#PBF part is unused and in its original packaging.
Return procedure for LTC1149CN-3.3#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1149CN-3.3#PBF 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…
