My Inquiry
My Account
Analog Devices Inc. LTC1147IS8-5#TRPBF
- Part No.:
- LTC1147IS8-5#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC1147IS8-5#TRPBF.pdf
- Description:
- IC REG CTRLR BUCK 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,686
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1147IS8-5#TRPBF from Analog Devices (formerly Linear Technology) is a high-efficiency, constant off-time current-mode step-down switching regulator controller driving an external P-channel MOSFET. It delivers regulated 5V output up to 2A with input voltage range 3.5V–16V, 95% peak efficiency, 160µA light-load quiescent current, and micropower shutdown (<20µA). It is used in portable battery-powered systems requiring compact, high-efficiency DC/DC conversion.
For engineers reviewing the LTC1147IS8-5#TRPBF datasheet, LTC1147IS8-5#TRPBF pinout, LTC1147IS8-5#TRPBF application, or LTC1147IS8-5#TRPBF equivalent, key selection criteria include its fixed 5V output, 8-pin SOIC package, Burst Mode™ operation for ultra-low IQ, programmable current sense threshold (25–170mV), and compatibility with external P-MOSFETs like Si4431DY.
Technical Context
The LTC1147IS8-5#TRPBF implements a constant off-time (COT) current-mode architecture where switching frequency varies inversely with input voltage, and off-time is set by an external CT capacitor (e.g., 470pF yields ~400kHz at VIN=10V). Its internal gain block and voltage comparator regulate output via SENSE–/SENSE+ differential sensing across RSENSE, while ITH pin enables dynamic current threshold scaling.
Burst Mode™ operation activates below ~300mA load, disabling switching and reducing IQ to 160µA; shutdown reduces IQ further to <20µA. The device supports 100% duty cycle for low-dropout operation and includes short-circuit protection via extended tOFF during overload, limiting average short-circuit current to ~IMAX.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.05V (typ) at 700mA load; ±100mV line/load regulation ensures stable rail under varying input and load conditions. |
| Input Voltage Range | 3.5V to 16V; supports wide battery and industrial supply rails including 5V, 9V, and 12V nominal sources. |
| Quiescent Current | 160µA (sleep mode), <20µA (shutdown); enables multi-day battery life in always-on portable instruments. |
| Current Sense Threshold | 25mV to 170mV (adjustable via RSENSE); sets peak inductor current and maximum output (e.g., RSENSE = 0.05Ω → IMAX ≈ 2A). |
| Off-Time | 4–6.5µs (CT = 390pF, ILOAD = 700mA); determines minimum on-time and dropout behavior; scales with VOUT to maintain COT stability. |
| Efficiency | ≥95% at 1A (VIN = 10V); sustained over three decades of load (0.001A–2A) due to Burst Mode™ and low gate drive losses. |
| Shutdown Threshold | 0.5–2.0V on SHDN pin; compatible with standard CMOS logic; requires tr/tf < 1µs to prevent false triggering. |
Pinout & Package
Package: 8-lead plastic SOIC (S8), RoHS-compliant, θJA = 150°C/W, rated for –40°C to +85°C operating ambient temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Main power input | Accepts 3.5V–16V; must be decoupled with ≥100µF low-ESR capacitor close to pin and GND. |
| CT (Pin 2) | Timing capacitor connection | Sets off-time and operating frequency; discharge current proportional to VOUT enables COT behavior. |
| ITH (Pin 3) | Current threshold control | Voltage applied here scales current comparator threshold linearly-used for adaptive current limiting. |
| SENSE– (Pin 4) | Inverting current sense input | Connects to internal resistive divider; also serves as (–) input to current comparator for RSENSE monitoring. |
| SENSE+ (Pin 5) | Non-inverting current sense input | (+) input to current comparator; built-in 25–150mV offset with Pin 4 sets trip point for inductor peak current. |
| SHDN/VFB (Pin 6) | Shutdown control / feedback reference | Logic-level input: <0.5V = normal operation, >2V = shutdown; on LTC1147-5, not used as feedback (fixed 5V). |
| GND (Pin 7) | Analog and power ground | Two independent ground paths required: one to COUT (–) and one to diode cathode/CIN (–) to minimize noise coupling. |
| PDRIVE (Pin 8) | High-current P-MOSFET gate driver | Swings from VIN to GND; drives external P-channel MOSFET (e.g., Si4431DY) with 100–200ns transition times. |
Key Features
| Feature | Design Value |
|---|---|
| Constant off-time current-mode control | Enables fast transient response, inherent stability without loop compensation, and natural dropout behavior (100% duty cycle). |
| Automatic Burst Mode™ operation | Reduces IQ to 160µA at light loads and eliminates switching losses-critical for battery runtime in standby states. |
| Logic-controlled micropower shutdown | IQ < 20µA in shutdown; allows system-level power gating with no external circuitry or leakage concerns. |
| Short-circuit protection | Extends off-time during overload to limit average short-circuit current to IMAX, preventing thermal runaway. |
| Wide input voltage range (3.5V–16V) | Supports single-cell Li-ion (3.0–4.2V), dual-cell alkaline (2.4–3.6V with boost), and 5V/12V industrial rails without external regulators. |
Applications
| Portable Medical Monitors | Industrial Handheld Scanners |
|---|---|
Use Scenario: Battery-powered ECG or pulse oximeter with continuous sensor readout and Bluetooth LE transmission. IC Role / Device Role / Timing Role: Primary 5V DC/DC controller supplying analog front-end, microcontroller, and RF transceiver from 3.7V Li-ion cell. Use Value: Burst Mode™ extends battery life beyond 72 hours per charge; 160µA sleep current minimizes self-discharge during idle periods. |
Use Scenario: Ruggedized barcode scanner operating from 4xAA batteries (6V fresh, down to 4.2V depleted). IC Role / Device Role / Timing Role: Fixed 5V buck controller powering CMOS image sensor, laser diode driver, and ARM Cortex-M4 MCU. Use Value: 3.5V minimum VIN enables full functionality until battery depletion; 95% efficiency preserves runtime during burst scanning cycles. |
| GPS Navigation Units | Wireless Sensor Node Transceivers |
Use Scenario: Automotive-grade GPS receiver with cold-start acquisition and real-time position logging. IC Role / Device Role / Timing Role: Regulates clean 5V rail for GPS baseband IC and flash memory from 9–16V vehicle supply. Use Value: Wide 3.5–16V input range accommodates cranking dips and alternator surges; low-noise PDRIVE minimizes RF interference. |
Use Scenario: LoRaWAN node powered by primary lithium thionyl chloride (3.6V) with 10-year shelf life requirement. IC Role / Device Role / Timing Role: Step-down controller enabling 5V USB-compatible charging interface and sensor biasing during wake-up bursts. Use Value: <20µA shutdown current prevents measurable battery drain during 99.9% sleep time; supports energy harvesting integration via ITH pin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC1148CS8-5#PBF | Higher peak efficiency (>96%), lower IQ (120µA sleep), integrated soft-start; same pinout and 5V fixed output. | Better suited for noise-sensitive RF applications due to reduced switching jitter and tighter VOUT tolerance (±1%). | Select when higher precision, lower EMI, or longer battery life is prioritized over cost sensitivity. |
| TPS54202DRCT | Integrated 2A N-MOSFET; 4.5–17V input; 5V adjustable via resistor divider; no Burst Mode, uses D-CAP2 control. | Reduces BOM count but lacks micropower sleep (<100µA only in EN = low); less suitable for sub-100µA always-on nodes. | Choose for simplified layout and higher integration where IQ >100µA is acceptable and external MOSFET is undesirable. |
Compared with LTC1147IS8-5#TRPBF, LTC1148CS8-5#PBF offers superior light-load efficiency and tighter regulation but at higher unit cost; TPS54202DRCT eliminates external MOSFET and gate drive complexity but sacrifices ultra-low-IQ operation and true micropower shutdown capability.
Availability
LTC1147IS8-5#TRPBF is available at Aetrix Electronics and suitable for portable medical monitors, industrial handheld scanners, GPS navigation units, and wireless sensor node transceivers requiring stable component supply across long production lifecycles.
Supply support for LTC1147IS8-5#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.
The LTC1147 series was designed specifically for high-efficiency, low-quiescent-current step-down regulation in space-constrained, battery-operated systems-emphasizing Burst Mode™, wide VIN range, and external P-MOSFET flexibility.
FAQ
What is the function of the ITH pin on the LTC1147IS8-5#TRPBF?
The ITH pin on the LTC1147IS8-5#TRPBF controls the current comparator threshold voltage. Applying a voltage to this pin linearly scales the 25–170mV sense threshold, enabling adaptive current limiting or dynamic load matching. In standard fixed-output configurations, it is typically bypassed to GND via a small capacitor for noise immunity.
Can the LTC1147IS8-5#TRPBF operate with an input voltage below 3.5V?
No-the LTC1147IS8-5#TRPBF has a specified minimum input voltage of 3.5V. Operation below this level is not guaranteed and may result in loss of regulation, failure to start, or erratic Burst Mode™ behavior. For sub-3.5V applications, consider the LTC1147L variant or alternative controllers such as the LTC3642.
Does the LTC1147IS8-5#TRPBF require external compensation components?
No-the LTC1147IS8-5#TRPBF uses constant off-time current-mode control, which provides inherent loop stability without external compensation networks. The application circuit in the datasheet (Figure 1) operates reliably with only the recommended RSENSE, CT, L, CIN, and COUT components.
What is the maximum output current supported by the LTC1147IS8-5#TRPBF?
The LTC1147IS8-5#TRPBF supports up to 2A output current when paired with a suitable external P-channel MOSFET (e.g., Si4431DY), 50µH inductor, and 0.05Ω current sense resistor. Peak current is limited by RSENSE value and thermal design; IMAX ≈ 100mV / RSENSE provides a practical design margin.
How does Burst Mode™ operation affect output voltage ripple on the LTC1147IS8-5#TRPBF?
In Burst Mode™, the LTC1147IS8-5#TRPBF disables switching and supplies load current from COUT until VOUT drops by comparator hysteresis (~20–50mV), then delivers a short energy burst. This results in low-frequency, higher-amplitude ripple (typically ≤50mVP-P at ILOAD = 0A), distinct from high-frequency ripple in continuous mode.
LTC1147IS8-5#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-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 ~ 14V
- Frequency - Switching:
- -
- Duty Cycle (Max):
- 100%
- Synchronous Rectifier:
- No
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO
LTC1147IS8-5#TRPBF FAQ
1.How can I place an order for LTC1147IS8-5#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1147IS8-5#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 LTC1147IS8-5#TRPBF reliable?
The price and inventory of LTC1147IS8-5#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1147IS8-5#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC1147IS8-5#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1147IS8-5#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1147IS8-5#TRPBF?
LTC1147IS8-5#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1147IS8-5#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 LTC1147IS8-5#TRPBF?
For technical support, including LTC1147IS8-5#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1147IS8-5#TRPBF requirements.
6.How does Aetrix verify that LTC1147IS8-5#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC1147IS8-5#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 LTC1147IS8-5#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC1147IS8-5#TRPBF?
All LTC1147IS8-5#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1147IS8-5#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 LTC1147IS8-5#TRPBF part is unused and in its original packaging.
Return procedure for LTC1147IS8-5#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1147IS8-5#TRPBF 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…
