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Analog Devices Inc. LT1956IFE#TRPBF
- Part No.:
- LT1956IFE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LT1956IFE#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 1.5A 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,237
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Product details
Overview
LT1956IFE#TRPBF from Analog Devices (formerly Linear Technology) is a high-voltage, current-mode 500kHz synchronous step-down switching regulator with 5.5V–60V input range, 1.5A peak switch current, and fixed 5V output. It integrates a 0.2Ω NPN power switch, internal error amplifier, and cycle-by-cycle current limiting-designed for industrial power supplies, battery chargers, and distributed power systems requiring stable 5V regulation under transient input conditions.
For engineers reviewing the LT1956IFE#TRPBF datasheet, LT1956IFE#TRPBF pinout, LT1956IFE#TRPBF application, or LT1956IFE#TRPBF equivalent, key selection criteria include its guaranteed –40°C to 125°C operating junction temperature, thermally enhanced 16-pin TSSOP package with exposed pad, 5V fixed SENSE interface, and 580kHz–700kHz external synchronization capability.
Technical Context
The LT1956IFE#TRPBF employs a constant-frequency current-mode architecture with dual feedback loops: one sensing inductor current on a cycle-by-cycle basis, the other using the SENSE pin (internally tied to 5V output) to regulate voltage. Its patented slope compensation cancellation maintains 1.5A peak switch current across full duty cycle range (up to 90%), eliminating typical current-limit roll-off above 50% duty.
Thermal performance is enabled by the FE-package exposed thermal pad soldered to ground plane (θJC = 10°C/W), while efficiency at light loads is improved via BIAS pin operation-allowing internal circuitry to draw current from the regulated 5V output instead of VIN when VIN ≫ 5V. The BOOST pin drives an external capacitor-diode network to saturate the internal NPN switch, achieving FET-like conduction loss (0.2Ω typical).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 5.5V to 60V - supports wide-range industrial and automotive battery inputs including 24V/48V systems and transient-tolerant 12V rails. |
| Output Voltage | Fixed 5V - internally trimmed SENSE pin eliminates external resistor divider; ±2% accuracy over temperature and line. |
| Switch Current Limit | 1.5A (min), 2A (typ) - maintained across full duty cycle range, enabling reliable operation up to 90% duty without current derating. |
| Switch On Resistance | 0.2Ω (typ) - achieved via BOOST-driven saturation of internal NPN switch, reducing conduction loss vs. standard bipolar designs. |
| Switching Frequency | 500kHz (±10%) - fixed internal oscillator; externally synchronizable from 580kHz to 700kHz for EMI reduction or multi-rail coordination. |
| Shutdown Current | 25µA (max) - ultra-low quiescent draw enables always-on monitoring circuits in battery-powered systems. |
| Operating Junction Temp | –40°C to +125°C - fully specified and guaranteed over this range, validated for harsh industrial and automotive under-hood environments. |
Pinout & Package
LT1956IFE#TRPBF is housed in a 16-lead plastic TSSOP package with exposed thermal pad (FE package). The exposed pad must be soldered to a PCB ground plane for thermal and electrical integrity (θJC = 10°C/W, θJA = 45°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pins 1, 8, 9, 16) | Power and signal reference ground | Four dedicated GND pins minimize ground impedance; exposed pad must be connected to same ground plane as these pins for thermal and regulation stability. |
| SW (Pin 2) | Emitter of internal NPN power switch | Connects to inductor node; swings from near 0V (off) to VIN (on); requires low-inductance path to catch diode and input capacitor. |
| VIN (Pin 4) | Collector of internal NPN switch & primary bias source | Supplies internal control circuitry when BIAS pin is unconnected; high dI/dt node requiring short, low-inductance routing. |
| BOOST (Pin 6) | Switch driver boost supply input | Accepts voltage ≥ VIN + 2V (min) from external boost capacitor/diode; enables NPN saturation and 0.2Ω RCE(sat). |
| SHDN (Pin 15) | Enable/disable control with UVLO | Two thresholds: 2.38V (UVLO enable), 0.4V (deep shutdown); internal bias allows floating for default-on operation. |
| SYNC (Pin 14) | External oscillator synchronization input | Logic-compatible (1.5V–2.2V min amplitude); accepts 580–700kHz square wave; tie to GND if unused. |
| SENSE (Pin 12) | 5V output voltage sense input | Internally connected to 5V output; no external divider needed; functions as fault monitor (foldback below 0.8V). |
| VC (Pin 11) | Error amplifier output / current limit setpoint | Provides loop compensation node; also serves as current clamp; voltage ranges ~1V (light load) to ~2V (full load). |
| BIAS (Pin 10) | Efficiency-optimized bias supply input | When connected to 5V output, shifts internal bias current from VIN to VOUT, improving efficiency at high VIN/low IOUT. |
Key Features
| Feature | Design Value |
|---|---|
| Patented duty-cycle-independent current limit | Maintains 1.5A peak switch current up to 90% duty cycle-enables high-VIN/low-VOUT conversion (e.g., 48V→5V) without current derating. |
| Integrated BOOST drive architecture | Reduces effective switch resistance to 0.2Ω via external boost capacitor, delivering FET-level conduction efficiency in a bipolar process. |
| Dual-threshold SHDN pin | 2.38V UVLO prevents startup until input stabilizes; 0.4V deep shutdown reduces supply current to 25µA-ideal for battery backup systems. |
| Frequency and current foldback protection | Automatically reduces switching frequency (5:1) and peak current limit when SENSE < 0.8V or < 0.6V-limits power dissipation during short-circuit faults. |
| Thermally enhanced FE package | Exposed pad with θJC = 10°C/W enables >2W continuous power dissipation at TA = 85°C-critical for high-input-voltage, high-duty-cycle operation. |
Applications
| Industrial Power Supply | Battery Charger Control |
|---|---|
Use Scenario: Regulating 48V DC bus down to stable 5V for PLC I/O modules, sensors, and communication interfaces in factory automation cabinets. IC Role / Device Role / Timing Role: Primary buck controller providing isolated 5V rail with transient immunity against 60V surges and brownouts. Use Value: Guaranteed –40°C to 125°C operation and 60V absolute max input withstand capability ensure reliability in uncontrolled cabinet environments. | Use Scenario: Charging lead-acid or LiFePO4 batteries from variable solar or vehicle alternator sources where input may swing 9V–60V. IC Role / Device Role / Timing Role: Constant-voltage stage controller delivering precise 5V to charge management ICs or microcontrollers in multi-stage chargers. Use Value: Fixed 5V SENSE interface eliminates calibration drift; BOOST-assisted saturation ensures >90% efficiency even at 48V→5V conversion. |
| Distributed Power System | Automotive Body Electronics |
Use Scenario: Local point-of-load regulation in telecom or server backplanes where 12V or 48V intermediate bus powers multiple 5V subsystems. IC Role / Device Role / Timing Role: Compact, synchronized buck converter enabling phase-aligned switching across multiple rails to reduce input ripple and EMI. Use Value: 580–700kHz SYNC capability allows interleaving with adjacent converters; TSSOP package fits dense board layouts. | Use Scenario: Powering infotainment head units, ADAS cameras, or gateway ECUs from 12V vehicle battery with load dump tolerance up to 60V. IC Role / Device Role / Timing Role: Main 5V system rail generator with built-in undervoltage lockout and thermal protection for under-hood deployment. Use Value: Dual SHDN thresholds provide robust start-up sequencing; exposed thermal pad sustains 125°C junction temperature during sustained high-power operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3642EMSE#TRPBF | 40V max input, 500kHz, 1.2A output, integrated MOSFETs; requires external feedback resistors even for 5V. | Lower input voltage ceiling; lacks BOOST architecture-higher dropout and lower efficiency at high VIN. | Choose LTC3642 for space-constrained designs needing integrated high-side/low-side FETs, but only if VIN ≤ 40V and efficiency at 48V→5V is not critical. |
| MP2451DT-LF-Z | 36V max input, 500kHz, 1.5A, fixed 5V output; no BOOST pin; uses standard CMOS process with higher RDS(on). | No high-voltage boost capability-RDS(on) rises significantly above 24V input, reducing efficiency and thermal margin. | Choose MP2451 for cost-sensitive 12V/24V applications where 60V input tolerance and 0.2Ω switch performance are unnecessary. |
Compared with LTC3642EMSE#TRPBF and MP2451DT-LF-Z, LT1956IFE#TRPBF uniquely delivers 60V input tolerance, BOOST-enabled 0.2Ω switch conduction, and guaranteed 1.5A current limit across full duty cycle-making it the only option qualified for 48V→5V industrial and automotive power conversion with minimal thermal derating.
Availability
LT1956IFE#TRPBF is available at Aetrix Electronics and suitable for industrial power supplies, battery chargers, and automotive body electronics requiring stable component supply with extended temperature qualification and long-term lifecycle support.
Supply support for LT1956IFE#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, Inc. (ADI) is a global semiconductor leader specializing in high-performance analog, mixed-signal, and power management ICs for precision, industrial, automotive, and communications applications.
The LT1956IFE#TRPBF belongs to ADI's legacy Linear Technology high-voltage DC/DC converter product line, engineered specifically for ruggedized 5V point-of-load regulation in harsh environments where input transients, wide temperature ranges, and thermal constraints demand proven reliability.
FAQ
What is the maximum input voltage rating for the LT1956IFE#TRPBF?
The LT1956IFE#TRPBF has an absolute maximum input voltage rating of 60V on the VIN pin, with guaranteed operation from 5.5V to 60V. This makes LT1956IFE#TRPBF suitable for 48V industrial buses and automotive load-dump tolerant designs. Exceeding 60V risks permanent damage per Absolute Maximum Ratings.
Does the LT1956IFE#TRPBF require external feedback resistors to set the 5V output?
No, the LT1956IFE#TRPBF features a fixed 5V output configuration with internal resistor divider-its SENSE pin (Pin 12) connects directly to the internal 5V reference and requires no external components. This eliminates resistor tolerance errors and simplifies layout versus adjustable versions like the LT1956.
How does the BOOST pin function in the LT1956IFE#TRPBF, and what external components are required?
The BOOST pin in LT1956IFE#TRPBF supplies gate drive voltage above VIN to saturate the internal NPN switch, achieving 0.2Ω on-resistance. It requires an external flying capacitor (typically 100nF ceramic) and Schottky diode (e.g., MMSD914) from SW to BOOST. Without this network, switch conduction loss increases significantly.
What thermal design considerations apply to the LT1956IFE#TRPBF's FE-package exposed pad?
The LT1956IFE#TRPBF's exposed thermal pad must be soldered to a solid copper ground plane with ≥4 thermal vias (0.3mm diameter) to achieve θJC = 10°C/W. Inadequate pad connection raises junction temperature, potentially triggering thermal shutdown or degrading long-term reliability-especially at high duty cycles and 60V input.
Can the LT1956IFE#TRPBF be synchronized to an external clock, and what is the valid frequency range?
Yes, the LT1956IFE#TRPBF supports external synchronization via the SYNC pin (Pin 14) with logic-level input (1.5V–2.2V min amplitude, 10%–90% duty cycle). Valid synchronization range is 580kHz to 700kHz-enabling EMI reduction and multi-rail phase alignment. If unused, SYNC must be tied to GND.
LT1956IFE#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 5.5V
- Voltage - Input (Max):
- 60V
- Voltage - Output (Min/Fixed):
- 1.219V
- Voltage - Output (Max):
- 54V
- Current - Output:
- 1.5A (Switch)
- Frequency - Switching:
- 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP-EP
LT1956IFE#TRPBF FAQ
1.How can I place an order for LT1956IFE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1956IFE#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 LT1956IFE#TRPBF reliable?
The price and inventory of LT1956IFE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1956IFE#TRPBF is usually 5 days.
3.What payment methods are accepted for LT1956IFE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1956IFE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1956IFE#TRPBF?
LT1956IFE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1956IFE#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 LT1956IFE#TRPBF?
For technical support, including LT1956IFE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1956IFE#TRPBF requirements.
6.How does Aetrix verify that LT1956IFE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT1956IFE#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 LT1956IFE#TRPBF meets industry standards.
7.What is the process for return or replacement of LT1956IFE#TRPBF?
All LT1956IFE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1956IFE#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 LT1956IFE#TRPBF part is unused and in its original packaging.
Return procedure for LT1956IFE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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