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Analog Devices Inc. LTC1143LCS#TRPBF
- Part No.:
- LTC1143LCS#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC1143LCS#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK/BCK-BST 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,656
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Product details
Overview
LTC1143LCS#TRPBF from Analog Devices (formerly Linear Technology) is a dual-channel, fixed-output (3.3V/5V), current-mode step-down switching regulator controller driving external P-channel MOSFETs. It features constant off-time architecture, Burst Mode™ operation for high light-load efficiency (>95% at full load), 160µA per channel standby current, and 3.5V–16V input range. It targets space-constrained dual-rail power supplies in portable computing and battery-powered instrumentation.
For engineers reviewing the LTC1143LCS#TRPBF datasheet, LTC1143LCS#TRPBF pinout, LTC1143LCS#TRPBF application, or LTC1143LCS#TRPBF equivalent, key selection criteria include its dual fixed-voltage control, SO-16 package footprint, 400kHz max switching frequency, 100% duty cycle low-dropout capability, and compatibility with standard external power stages using discrete P-MOSFETs and Schottky diodes.
Technical Context
The LTC1143LCS#TRPBF implements two independent constant off-time current-mode controllers, each with dedicated timing capacitor (CT) pins (6 & 14), current sense inputs (SENSE+/-), and P-drive outputs (4 & 12). Its Burst Mode™ operation disables switching below ~15mA load per channel, reducing quiescent current to 160µA per regulator block while maintaining regulation via output capacitor discharge.
Each channel uses an internal 1.25V reference and fixed resistor divider to set 3.3V (Pin 16) and 5V (Pin 8) outputs; feedback voltage accuracy is ±1.6% over temperature. The off-time is dynamically adjusted based on VOUT and VIN–VOUT differential to stabilize frequency near dropout and suppress audible noise.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Configuration | Dual fixed 3.3V and 5V outputs, each controlled independently with external P-MOSFET and diode |
| Input Voltage Range | 3.5V to 16V - supports wide battery and adapter inputs including Li-ion (3.7V nominal) and 12V industrial rails |
| Efficiency | >95% typical at full load; maintained across three decades of output current (5mA–2A) via Burst Mode™ |
| Quiescent Current | 160µA per channel in sleep mode - enables multi-day battery life in always-on portable devices |
| Switching Frequency | Up to 400kHz (set by CT pins); frequency decreases as VIN approaches VOUT to avoid audible noise |
| Current Sense Threshold | 130–170mV (typical) - sets peak inductor current; determines RSENSE value for target IOUT and ripple |
| Feedback Voltage Accuracy | ±1.6% over 0°C to 70°C - ensures stable 3.3V/5V rail tolerance without external trimming |
Pinout & Package
Package: 16-lead narrow SOIC (SO-16), 1.27mm pitch, JEDEC MS-012AC, θJA = 95°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (SENSE+1) | Current sense positive input - 3.3V section | Connects across RSENSE to detect inductor current; built-in offset sets trip threshold with Pin 16 |
| 2 (SHUTDOWN3) | Logic-controlled shutdown - 3.3V section | CMOS-compatible input; pull high ≥0.8V to disable 3.3V regulator and reduce supply current to 10µA |
| 3 (GND3) | 3.3V section ground return | Must be routed separately to COUT1(–) and D1 cathode to prevent noise coupling into current sense path |
| 4 (P-DRIVE1) | High-current gate driver - 3.3V section | Drives P-MOSFET gate from VIN1 to GND; swing amplitude matches input rail for full enhancement |
| 5 (VIN2) | 5V section input supply | Requires local 22µF/25V ceramic + bulk decoupling; maximum rating 16V absolute |
| 6 (CT2) | Timing capacitor connection - 5V section | 300pF typical sets ~400kHz; frequency scales inversely with CT and directly with VIN–VOUT |
| 7 (ITH2) | Gain amplifier decoupling - 5V section | Stabilizes current comparator threshold; connect 0.1µF ceramic to GND2 for noise immunity |
| 8 (SENSE–2) | Current sense negative / VFB reference - 5V section | Internal resistive divider sets 5V output; also (–) input of current comparator; connects to RSENSE low side |
| 9 (SENSE+2) | Current sense positive input - 5V section | Paired with Pin 8; built-in offset defines current trip point with external RSENSE |
| 10 (VFB2) | Feedback input - 5V section | Not used in LTC1143LCS#TRPBF (fixed 5V); tied internally to reference divider; not connected externally |
| 11 (GND2) | 5V section ground return | Independent ground path required to COUT2(–) and D2 cathode; prevents cross-regulator interference |
| 12 (P-DRIVE2) | High-current gate driver - 5V section | Drives P-MOSFET gate from VIN2 to GND; rated for 50mA peak sink/source |
| 13 (VIN1) | 3.3V section input supply | Separate input pin allows independent sourcing (e.g., different battery taps or LDO pre-regulation) |
| 14 (CT1) | Timing capacitor connection - 3.3V section | 300pF typical sets ~400kHz; independent frequency tuning per channel |
| 15 (ITH1) | Gain amplifier decoupling - 3.3V section | Stabilizes current comparator threshold; connect 0.1µF ceramic to GND3 |
| 16 (SENSE–1) | Current sense negative / VFB reference - 3.3V section | Internal resistive divider sets 3.3V output; also (–) input of current comparator; connects to RSENSE low side |
Key Features
| Feature | Design Value |
|---|---|
| Burst Mode™ Operation | Automatically switches to discontinuous conduction below ~15mA/channel, reducing total supply current to 320µA (both channels) |
| 100% Duty Cycle Low Dropout | Enables regulation down to VIN – VOUT ≈ RDS(ON) × ILOAD; no minimum input voltage limitation beyond MOSFET characteristics |
| Independent Channel Control | Separate VIN, CT, shutdown, and ground pins per channel allow asymmetric input sources, frequencies, and enable sequencing |
| Current Mode Stability | Eliminates need for external compensation; inherent loop stability across wide output capacitance and ESR ranges |
| Wide Input Range Support | 3.5V minimum start-up enables direct Li-ion (3.0–4.2V) operation without pre-regulation |
Applications
| Personal Digital Assistants | Notebook Computers |
|---|---|
Use Scenario: Dual-rail power management in handheld PDAs with separate 3.3V logic and 5V peripheral interfaces. IC Role / Device Role / Timing Role: Dual synchronous buck controller managing independent 3.3V/5V DC-DC converters with shared layout constraints. Use Value: 160µA/channel quiescent current extends battery runtime; Burst Mode™ maintains >85% efficiency at 10mA loads typical of standby states. | Use Scenario: Compact auxiliary power supply for embedded controllers, USB hubs, and display backlight drivers in ultraportable notebooks. IC Role / Device Role / Timing Role: Fixed-output dual controller replacing discrete linear regulators to reduce heat and board area. Use Value: SO-16 footprint integrates two regulators in space previously requiring two ICs plus discrete pass elements; 95% peak efficiency reduces thermal load on thin PCBs. |
| Battery-Operated Digital Devices | Portable Instruments |
Use Scenario: Powering microcontroller cores (3.3V) and analog front-ends (5V) in handheld test equipment with alkaline or Li-ion batteries. IC Role / Device Role / Timing Role: Dual-channel step-down controller enabling single-battery operation across mixed-voltage subsystems. Use Value: 3.5V minimum input allows operation down to single-cell Li-ion end-of-discharge (3.0V); 100% duty cycle sustains regulation during brownout conditions. | Use Scenario: Precision dual-rail supply for portable oscilloscopes and multimeters requiring clean, stable 3.3V digital and 5V analog rails. IC Role / Device Role / Timing Role: High-efficiency switching controller minimizing conducted EMI through constant off-time architecture and independent ground routing. Use Value: Separate GND1/GND2 paths and dedicated SENSE+/– inputs reduce ground bounce-induced output error to <±5mV under dynamic load steps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual fixed-output buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1143CS#TRPBF | Same architecture but higher minimum input voltage (4V vs 3.5V); lacks extended low-VIN optimization | Less suitable for single-cell Li-ion systems operating below 3.5V; otherwise pin- and function-compatible | Select LTC1143LCS#TRPBF when input must operate down to 3.5V or lower; use LTC1143CS#TRPBF only if VIN ≥4V guaranteed |
| TPS54202DRTT | Single-channel, integrated MOSFET, adjustable output; no dual fixed 3.3V/5V option; requires external feedback resistors | Cannot replace LTC1143LCS#TRPBF in dual-rail designs without adding second IC and redesigning layout | Only viable as partial replacement if system can accept single output + external LDO for second rail; not a functional substitute |
Compared with LTC1143CS#TRPBF, the LTC1143LCS#TRPBF delivers verified 3.5V start-up and optimized light-load efficiency below 4V input, while TPS54202DRTT offers integration at the cost of losing dual fixed outputs and requiring additional components for second rail generation.
Availability
LTC1143LCS#TRPBF is available at Aetrix Electronics and suitable for notebook computers, portable instruments, and battery-operated digital devices requiring stable component supply with long-term manufacturability and consistent electrical performance.
Supply support for LTC1143LCS#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 and maintains full product support, datasheets, and application engineering for legacy Linear parts including the LTC series.
The LTC1143L family was designed specifically for compact, high-efficiency dual-output DC-DC conversion in portable and battery-powered systems where board space, thermal budget, and light-load efficiency are critical constraints.
FAQ
What is the minimum input voltage required for reliable startup of the LTC1143LCS#TRPBF?
The LTC1143LCS#TRPBF guarantees operation down to 3.5V input across temperature. Startup is functional at 3.5V with both channels enabled; below this, undervoltage lockout may inhibit regulation. This makes LTC1143LCS#TRPBF suitable for single-cell Li-ion (3.0–4.2V) applications where minimum system voltage reaches 3.5V under load.
Does the LTC1143LCS#TRPBF support independent enable/disable of each output channel?
Yes. The LTC1143LCS#TRPBF provides separate shutdown pins: Pin 2 (SHUTDOWN3) controls the 3.3V channel and Pin 10 (SHUTDOWN5) controls the 5V channel. Each accepts CMOS-level signals; pulling either pin high disables its respective regulator and reduces that channel's supply current to 10µA.
Can the LTC1143LCS#TRPBF be used with N-channel MOSFETs instead of P-channel devices?
No. The LTC1143LCS#TRPBF P-DRIVE outputs (Pins 4 and 12) are designed exclusively for high-side P-channel MOSFETs, providing gate drive from VIN to GND. It lacks bootstrap circuitry or floating gate drivers required for N-MOSFET high-side configurations. Using N-MOSFETs would require fundamental redesign and is not supported.
What is the purpose of the ITH1 and ITH2 pins on the LTC1143LCS#TRPBF?
ITH1 (Pin 15) and ITH2 (Pin 7) are gain amplifier decoupling points for the 3.3V and 5V sections, respectively. They stabilize the current comparator threshold voltage against noise and supply ripple. A 0.1µF ceramic capacitor must be connected from each ITH pin to its corresponding ground (GND1 or GND2) to ensure accurate current sensing and prevent false triggering.
How does the LTC1143LCS#TRPBF maintain efficiency at very light loads?
The LTC1143LCS#TRPBF uses patented Burst Mode™ operation: below ~15mA per channel, it stops switching entirely, allowing the output capacitor to supply load current while internal circuitry enters micropower sleep (160µA/channel). When output voltage drops due to load, it resumes switching in short bursts to recharge the capacitor - sustaining >85% efficiency even at 1mA.
LTC1143LCS#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Down, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck, Buck-Boost
- Number of Outputs:
- 2
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 3.5V ~ 16V
- Frequency - Switching:
- Up to 400kHz
- Duty Cycle (Max):
- 100%
- Synchronous Rectifier:
- No
- 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:
- 16-SO
LTC1143LCS#TRPBF FAQ
1.How can I place an order for LTC1143LCS#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1143LCS#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 LTC1143LCS#TRPBF reliable?
The price and inventory of LTC1143LCS#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1143LCS#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC1143LCS#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1143LCS#TRPBF transactions.
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4.How is shipping managed for LTC1143LCS#TRPBF?
LTC1143LCS#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1143LCS#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 LTC1143LCS#TRPBF?
For technical support, including LTC1143LCS#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1143LCS#TRPBF requirements.
6.How does Aetrix verify that LTC1143LCS#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC1143LCS#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 LTC1143LCS#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC1143LCS#TRPBF?
All LTC1143LCS#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1143LCS#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 LTC1143LCS#TRPBF part is unused and in its original packaging.
Return procedure for LTC1143LCS#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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