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Analog Devices Inc. LTC1148CS#TRPBF
- Part No.:
- LTC1148CS#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC1148CS#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,200
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Product details
Overview
LTC1148CS#TRPBF from Analog Devices (formerly Linear Technology) is a synchronous step-down switching regulator controller driving external complementary MOSFETs in constant off-time current-mode architecture. It delivers up to 2A output current with >95% peak efficiency, 160µA light-load standby current, and supports 3.5V–20V input across fixed 3.3V or 5V output variants - used in battery-powered portable instruments and GPS systems.
For engineers reviewing the LTC1148CS#TRPBF datasheet, LTC1148CS#TRPBF pinout, LTC1148CS#TRPBF application, or LTC1148CS#TRPBF equivalent, key selection criteria include its adaptive nonoverlap gate drives, Burst Mode™ operation for micropower efficiency at low loads, 14-pin SOIC package thermal resistance (θJA = 110°C/W), and compatibility with external RSENSE-programmable current limits.
Technical Context
The LTC1148CS#TRPBF implements a constant off-time current-mode control architecture with programmable tOFF via external CT capacitor (e.g., 390pF yields ~5µs off time), enabling stable regulation down to 100% duty cycle in dropout. Its dual comparator system separates voltage regulation (via internal 1.25V reference and SENSE–/VFB feedback) from current sensing (25–170mV threshold across SENSE+ and SENSE–).
Burst Mode™ operation activates below ~300mA load, reducing quiescent current to 160µA by disabling switching and relying on output capacitance; recovery is triggered by output voltage hysteresis. Adaptive nonoverlap logic prevents shoot-through by enforcing sequencing between P-DRIVE and N-DRIVE outputs based on real-time pin state feedback.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.5V to 20V - supports wide-input industrial and battery systems including 12V nominal rails and 18V max transient tolerance. |
| Feedback Reference Voltage | 1.25V ±4% - sets regulated output via external resistor divider (adjustable version) or internal divider (fixed 3.3V/5V versions). |
| Current Sense Threshold | 25mV to 170mV - defines peak inductor current limit; enables RSENSE-based IMAX programming from 0.2A to 2A. |
| Standby Current | 160µA typical in Burst Mode - reduces no-load power dissipation to ~2mW at VIN = 10V, critical for always-on portable devices. |
| Shutdown Quiescent Current | <22µA - ensures ultra-low leakage during system sleep, compatible with CMOS-level SHUTDOWN pin (0.55–2V threshold). |
| Off-Time Accuracy | 3.8–6µs (CT = 390pF, ILOAD = 700mA) - determines minimum operating frequency and dropout behavior under light loads. |
| Thermal Resistance θJA | 110°C/W (14-pin SOIC) - defines junction-to-ambient temperature rise per watt; requires careful PCB copper area for >1W continuous operation. |
Pinout & Package
Package: 14-lead narrow SOIC (SO-14), surface-mount, JEDEC MS-012AC compliant, θJA = 110°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| P-DRIVE (Pin 1) | High-current gate driver output | Drives P-channel MOSFET source; swings from VIN to GND; requires low-inductance layout to minimize ringing. |
| NC (Pin 2) | No connection | May be tied to PGND or SGND for mechanical stability; not electrically functional. |
| VIN (Pin 3) | Main power supply input | Accepts 3.5–20V; must be decoupled with ≥1µF ceramic + bulk capacitor close to PGND. |
| CT (Pin 4) | Timing capacitor node | Sets off-time and operating frequency; discharge current scales with VOUT to maintain constant ripple current. |
| INTVCC (Pin 5) | Internal 3.3V LDO output | Powers internal circuitry; decouple to SGND with 1µF ceramic; do not load externally. |
| ITH (Pin 6) | Gain amplifier compensation node | Adjusts current comparator threshold; external RC network sets loop bandwidth and transient response. |
| SENSE– (Pin 7) | Inverting current sense / feedback node | Connects to internal resistive divider for fixed-output versions; also (–) input of current comparator. |
| SENSE+ (Pin 8) | Non-inverting current sense input | Paired with SENSE– to measure shunt voltage; built-in offset enables accurate low-current sensing. |
| VFB (Pin 9) | Feedback input (adjustable only) | Unused on LTC1148CS#TRPBF (fixed 5V version); NC on this variant per datasheet pinout table. |
| SHUTDOWN (Pin 10) | Logic-controlled enable/disable | Active-low: <0.8V = normal operation; >2V = shutdown with <22µA IQ; requires fast CMOS edge (<1µs). |
| SGND (Pin 11) | Small-signal ground reference | Must be routed separately from PGND to COUT(–); avoids noise coupling into feedback path. |
| PGND (Pin 12) | Power ground return | Connects to N-MOSFET source and CIN(–); high di/dt node requiring low-impedance copper pour. |
| NC (Pin 13) | No connection | May be tied to PGND or SGND; no electrical function. |
| N-DRIVE (Pin 14) | High-current gate driver output | Drives N-channel MOSFET source; swings from GND to VIN; matched drive strength to P-DRIVE. |
Key Features
| Feature | Design Value |
|---|---|
| Ultrahigh efficiency (>95%) | Achieved via synchronous FET switching and adaptive nonoverlap gate drives - eliminates body-diode conduction loss in N-MOSFET. |
| Burst Mode™ operation | Automatically engages below ~300mA load, reducing IQ to 160µA while maintaining regulation - extends battery life in idle states. |
| Constant off-time current-mode control | Provides inherent line/load transient immunity and stable operation across 3-decade load range without external compensation. |
| 100% duty-cycle dropout capability | Enables regulation down to VIN – VOUT ≈ 0V by holding P-MOSFET fully on - critical for Li-ion battery end-of-discharge support. |
| Short-circuit protection | Extends tOFF during overload to limit average short-circuit current to ~IMAX - prevents thermal runaway without external circuitry. |
Applications
| Portable Instrument Power Supply | Battery-Powered GPS Receiver |
|---|---|
|
Use Scenario: Handheld multimeter with 3.3V microcontroller, LCD, and analog front-end powered from two AA cells (1.8–3.2V) boosted to 5V then stepped down. IC Role / Device Role / Timing Role: LTC1148CS#TRPBF operates as fixed-5V synchronous buck controller, managing external Si4431DY/Si4412DY MOSFET pair with 390pF CT timing. Use Value: Delivers 92% efficiency at 100mA and 88% at 2A, while Burst Mode™ cuts no-load IQ to 160µA - enabling >1-year shelf life on alkaline batteries. |
Use Scenario: Automotive-grade GPS module requiring stable 5V rail from 9–16V vehicle battery with cold-crank immunity down to 6V. IC Role / Device Role / Timing Role: LTC1148CS#TRPBF configured as 5V regulator with 0.05Ω RSENSE, 62µH inductor, and 390µF output capacitor. Use Value: Maintains regulation during 6V cranking events via 100% duty cycle operation, while 110°C/W θJA allows operation within 85°C ambient without heatsink. |
| Notebook Subsystem Voltage Regulator | DC Power Distribution Node |
|
Use Scenario: Secondary 3.3V rail for USB interface ICs and SD card slot in ultraportable laptop, fed from main 12V bus. IC Role / Device Role / Timing Role: LTC1148CS#TRPBF (configured as LTC1148CS-3.3 variant) controls discrete P/N-MOSFETs with adaptive gate drive timing. Use Value: Achieves >94% efficiency at 1.5A and <50mV load regulation (5–2000mA), minimizing heat generation near sensitive RF sections. |
Use Scenario: Centralized 5V distribution point in industrial IoT gateway, powering multiple sensor nodes and wireless transceivers. IC Role / Device Role / Timing Role: LTC1148CS#TRPBF serves as high-reliability buck controller with external current limiting and short-circuit foldback. Use Value: Built-in short-circuit protection and 20V absolute max VIN rating ensure robustness against wiring faults and ESD transients in field-deployed equipment. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3502AEDD#TRPBF | Integrated power MOSFETs (no external FETs required); 3.3V/5V fixed outputs; 40V max VIN; higher IQ (2.5mA active). | Reduces BOM count and layout complexity but limits max output current to 1.2A and lacks Burst Mode™ efficiency at ultra-light loads. | Select when board space is constrained and 1.2A output suffices; avoid if >2A or sub-200µA standby is required. |
| TPS54202DDCR | Integrated FETs; 4.5–28V input; 2A output; 1.5MHz fixed frequency; no Burst Mode™ - uses pulse-skipping instead. | Higher switching frequency enables smaller magnetics but increases switching losses; pulse-skipping causes higher output ripple than Burst Mode™. | Prefer for compact designs needing 2A at 1.5MHz; choose LTC1148CS#TRPBF when >95% peak efficiency and <200µA IQ are mandatory. |
Compared with LT3502AEDD#TRPBF and TPS54202DDCR, the LTC1148CS#TRPBF offers superior light-load efficiency via true Burst Mode™ and higher current capability with discrete FET flexibility, at the cost of added external component count and layout sensitivity.
Availability
LTC1148CS#TRPBF is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered GPS receivers, and notebook subsystem power supplies requiring stable component supply with long-term industrial availability.
Supply support for LTC1148CS#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 (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision instrumentation, industrial automation, and aerospace markets.
The LTC1148 series was designed as a high-efficiency synchronous buck controller family targeting portable and battery-critical applications where micropower operation and wide input range are essential.
FAQ
What is the maximum output current supported by the LTC1148CS#TRPBF?
The LTC1148CS#TRPBF itself is a controller IC and does not define maximum output current directly - it depends on external MOSFET selection and RSENSE. With appropriate P/N-channel MOSFETs (e.g., Si4431DY/Si4412DY) and 0.05Ω sense resistor, the LTC1148CS#TRPBF supports up to 2A continuous output current while maintaining regulation and thermal safety in SOIC package.
Does the LTC1148CS#TRPBF include integrated power MOSFETs?
No, the LTC1148CS#TRPBF is a controller-only device and requires external complementary P-channel and N-channel power MOSFETs. This architecture enables optimization for specific voltage/current requirements and thermal management - unlike integrated DC/DC converters such as the LT3502AEDD#TRPBF.
How does Burst Mode™ operation improve efficiency in the LTC1148CS#TRPBF?
Burst Mode™ in the LTC1148CS#TRPBF disables switching and places the IC in micropower sleep (160µA IQ) when load current drops below ~300mA. During bursts, only the output capacitor supplies load current until voltage droop triggers a short switching cycle - reducing switching losses and achieving >90% efficiency even at 1mA load.
What is the purpose of the CT pin on the LTC1148CS#TRPBF?
The CT pin (Pin 4) on the LTC1148CS#TRPBF connects to an external timing capacitor that sets the off-time duration in its constant off-time architecture. A 390pF capacitor yields ~5µs off time, establishing operating frequency inversely proportional to VIN–VOUT - enabling stable regulation and predictable ripple current across input voltage variations.
Can the LTC1148CS#TRPBF operate with input voltages below 3.5V?
No - the absolute minimum input voltage for the LTC1148CS#TRPBF is 3.5V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Operation below this level risks improper startup, unstable regulation, or failure to engage the internal bias circuitry; for sub-3.5V applications, consider the LTC1148LCS variant rated down to 3.5V with tighter low-VIN validation.
LTC1148CS#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- 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):
- 3.5V ~ 20V
- 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:
- Surface Mount
- Supplier Device Package:
- 14-SO
LTC1148CS#TRPBF FAQ
1.How can I place an order for LTC1148CS#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1148CS#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 LTC1148CS#TRPBF reliable?
The price and inventory of LTC1148CS#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1148CS#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC1148CS#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1148CS#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1148CS#TRPBF?
LTC1148CS#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1148CS#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 LTC1148CS#TRPBF?
For technical support, including LTC1148CS#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1148CS#TRPBF requirements.
6.How does Aetrix verify that LTC1148CS#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC1148CS#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 LTC1148CS#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC1148CS#TRPBF?
All LTC1148CS#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1148CS#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 LTC1148CS#TRPBF part is unused and in its original packaging.
Return procedure for LTC1148CS#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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