My Inquiry
My Account
Analog Devices Inc. LTC1504ACS8-3.3#PBF
- Part No.:
- LTC1504ACS8-3.3#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC1504ACS8-3.3#PBF.pdf
- Description:
- IC REG BUCK 3.3V 500MA 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:1,614
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC1504ACS8-3.3#PBF from Analog Devices (formerly Linear Technology) is a fixed-output 3.3V, 500mA synchronous buck DC/DC regulator in SO-8 package. It integrates dual on-chip 1.3Ω MOSFETs, delivers up to 92% peak efficiency at 5V→3.3V conversion, supports 100% duty cycle for low dropout, and operates from 4V to 10V input. It is used in portable digital systems requiring compact, high-efficiency local regulation.
For engineers reviewing the LTC1504ACS8-3.3#PBF datasheet, LTC1504ACS8-3.3#PBF pinout, LTC1504ACS8-3.3#PBF application, or LTC1504ACS8-3.3#PBF equivalent, key selection considerations include its fixed 3.3V output, internal current limit via IMAX resistor, soft-start control via SS pin, COMP-based loop compensation, and SO-8 thermal performance under 500mA continuous load.
Technical Context
The LTC1504ACS8-3.3#PBF implements a synchronous buck topology with integrated P-channel high-side and N-channel low-side MOSFETs, enabling bidirectional output current (source/sink) for tight regulation during load transients. Its internal 1.265V reference is trimmed to ±1%, and feedback is closed directly at the SENSE pin set to 3.3V - no external divider required.
Control architecture includes a 200kHz internal oscillator (150–250kHz over temperature), a transconductance error amplifier (gmV = 350–1100 µmho), and a dedicated current-limit loop that modulates COMP via SS pin voltage. Shutdown is active-low on SHDN, pulling SW low to actively disconnect output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±3% (3.20V–3.40V) - eliminates external feedback resistors and improves accuracy vs adjustable variants. |
| Max Output Current | 500mA continuous - supported by on-chip 1.3Ω switches and SO-8 thermal design (θJA = 90°C/W). |
| Peak Efficiency | 92% at 5V→3.3V/500mA - minimizes heat rise and extends battery life in portable applications. |
| Input Voltage Range | 4V to 10V - compatible with 5V rails and higher intermediate bus voltages; not rated below 4V. |
| Switching Frequency | 200kHz typical (150–250kHz over temp) - enables use of small, low-cost inductors (e.g., 47–100µH) with low EMI. |
| Duty Cycle Range | 0% to 100% - allows operation near dropout (e.g., VIN = 3.4V → VOUT = 3.3V) without regulation loss. |
| Current Limit | Adjustable via resistor from VCC to IMAX pin - sets threshold from ~100mA to >600mA using standard values (e.g., 47kΩ ≈ 300mA). |
Pinout & Package
Package: 8-lead plastic SO-8 (SOIC Narrow), exposed pad not present; θJA = 90°C/W; RoHS-compliant, Pb-free (PBF suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IMAX (Pin 1) | Current Limit Set Input | Internal 12µA sink pulls voltage across external RIMAX; sets peak switch current threshold - floating disables limit. |
| VCC (Pin 2) | Power Supply Input | 4V–10V main supply; requires low-ESR ceramic bypass (≥1µF) adjacent to pin for stable reference and switching. |
| SW (Pin 3) | Switch Node Output | Drives external inductor; carries pulsed high-current waveform (±1A peak); must avoid routing near sensitive analog traces. |
| GND (Pin 4) | Power Ground | Common return for VCC, SW, SENSE, and external capacitors; serves as primary thermal path - connect to large copper pour. |
| SENSE (Pin 5) | Output Voltage Sense | Direct connection to regulated 3.3V output node; internal divider fixes feedback point - no external resistors needed. |
| SHDN (Pin 6) | Shutdown Control | Active-low logic input (VIL ≤ 0.8V, VIH ≥ 2.4V); pulls SW low in shutdown to prevent backfeed from other supplies. |
| SS (Pin 7) | Soft Start Control | External capacitor (typically 0.1µF) sets ramp rate; also compensates current-limit loop - essential when IMAX is configured. |
| COMP (Pin 8) | Error Amplifier Output | High-impedance node for external RC compensation network; determines loop stability and transient response with output LC filter. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous Buck Architecture | Enables output current sinking during light loads - maintains regulation under dynamic load reversal (e.g., memory bus termination). |
| Integrated Power Switches | On-chip 1.3Ω P- and N-MOSFETs eliminate external FETs and gate drivers - reduces BOM count and layout area. |
| 100% Duty Cycle Operation | Supports ultra-low dropout (e.g., 3.4V→3.3V) - critical for battery-powered systems nearing end-of-life voltage. |
| Adjustable Current Limit | Single-resistor programming (VCC→IMAX) provides overload protection without sense resistor losses or PCB space. |
| Internal 1% Reference | Guarantees ±3% total output tolerance over line/load/temp - superior to typical ±5% of non-trimmed regulators. |
Applications
| Portable Digital Systems | Active Termination |
|---|---|
Use Scenario: Powering FPGA I/O banks or microcontroller peripherals in handheld test equipment with 5V input rail. IC Role / Device Role / Timing Role: Primary 3.3V point-of-load regulator delivering clean, fast-transient power with minimal external components. Use Value: Achieves 500mA at 92% efficiency in <100 mm² board area - extends battery runtime while meeting tight ripple (<20mVPP) requirements. | Use Scenario: Providing dynamically switched 3.3V termination voltage for high-speed parallel buses (e.g., PCI-X stubs). IC Role / Device Role / Timing Role: Regulator with sink capability actively clamps bus lines during idle cycles to maintain signal integrity. Use Value: Bidirectional current handling (source/sink) eliminates need for external termination FETs - reduces component count and improves timing margin. |
| Auxiliary Output Supplies | Minimum Part Count Switchers |
Use Scenario: Generating isolated 3.3V bias for analog front-end circuitry in industrial sensor nodes powered from 12V DC bus. IC Role / Device Role / Timing Role: Secondary regulator decoupled from main system rail - provides noise-isolated, low-quiescent power. Use Value: 0.3–0.6mA quiescent current in active mode and <20µA in shutdown - preserves system standby time without sacrificing startup speed. | Use Scenario: Replacing linear regulators (e.g., LM1117-3.3) in cost-sensitive consumer electronics where heat dissipation is constrained. IC Role / Device Role / Timing Role: Drop-in upgrade delivering 3.3V from 5V with only four external parts (CIN, COUT, L, CSS). Use Value: Reduces thermal load by >70% vs LDO at 500mA - eliminates heatsink requirement and enables thinner enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62067DSGR | 3.3V fixed, 600mA, 2.5V–6V input, 2.5MHz switching - smaller solution size but lower max input voltage. | Optimized for ultra-portable devices with Li-ion input (2.7–4.2V); not suitable for 5V/10V bus systems. | Select when board space is critical and input stays ≤6V; verify thermal performance at 500mA in DSGB package. |
| MP2307DN-LF-Z | 3.3V fixed, 3A, 4.75V–23V input, 340kHz - higher current, wider VIN, but requires external compensation and has looser output tolerance (±4%). | Targets industrial 12V/24V inputs; lacks integrated soft-start and precise current limit. | Choose for ruggedized 12V systems needing headroom above 500mA; accept trade-off in regulation accuracy and design simplicity. |
Compared with TPS62067DSGR and MP2307DN-LF-Z, the LTC1504ACS8-3.3#PBF offers superior output accuracy (±3% vs ±4%), built-in soft-start and current limit, and proven thermal reliability at 500mA in SO-8 - making it optimal for space-constrained 5V-input applications where precision and ease of use outweigh raw current headroom.
Availability
LTC1504ACS8-3.3#PBF is available at Aetrix Electronics and suitable for portable digital systems, active termination circuits, and auxiliary voltage supplies requiring stable component supply, long-term manufacturability, and consistent parametric performance across production lots.
Supply support for LTC1504ACS8-3.3#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 and maintains full technical and manufacturing continuity for legacy Linear power products.
The LTC1504A product line was designed specifically for compact, high-efficiency DC/DC conversion in space- and thermal-constrained applications - emphasizing integration, accuracy, and ease of implementation over raw power density.
FAQ
What is the maximum recommended input voltage for the LTC1504ACS8-3.3#PBF?
The absolute maximum input voltage (VCC to GND) for the LTC1504ACS8-3.3#PBF is 10V, and the device is specified for reliable operation across 4V to 10V. Operation below 4V is not guaranteed - Linear Technology notes that specifications at 2.7V require factory consultation. Exceeding 10V risks permanent damage to internal switches and reference circuitry.
Does the LTC1504ACS8-3.3#PBF require external feedback resistors?
No, the LTC1504ACS8-3.3#PBF does not require external feedback resistors. It features an internal resistor divider that fixes the SENSE pin reference to 3.3V, eliminating the need for external components to set output voltage - unlike the adjustable LTC1504ACS8 variant which uses the FB pin with external resistors.
How is current limit configured on the LTC1504ACS8-3.3#PBF?
Current limit on the LTC1504ACS8-3.3#PBF is configured by connecting a resistor between VCC and the IMAX pin. An internal 12µA current source pulls down IMAX, generating a voltage drop across the resistor that sets the current threshold - e.g., a 47kΩ resistor yields ~560mA limit. Leaving IMAX unconnected disables current limiting.
Can the LTC1504ACS8-3.3#PBF operate with 100% duty cycle, and what is its practical benefit?
Yes, the LTC1504ACS8-3.3#PBF supports 100% duty cycle operation, meaning the high-side switch remains continuously on when needed. This enables ultra-low dropout regulation - for example, maintaining 3.3V output from a 3.4V input - which is essential for battery-powered systems operating near end-of-discharge voltage.
What thermal considerations apply to the LTC1504ACS8-3.3#PBF at 500mA continuous load?
At 500mA continuous load with 5V input, the LTC1504ACS8-3.3#PBF dissipates ~0.85W (PLOSS ≈ (5V−3.3V)×0.5A×(1−0.92)). With θJA = 90°C/W and 25°C ambient, junction temperature rises ~77°C - reaching ~102°C. To stay within the 125°C TJMAX, ensure Pin 4 (GND) connects to ≥1 in² copper pour and minimize thermal resistance to ambient via airflow or heatspreading.
LTC1504ACS8-3.3#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 10V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 500mA
- Frequency - Switching:
- 200kHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO
LTC1504ACS8-3.3#PBF FAQ
1.How can I place an order for LTC1504ACS8-3.3#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC1504ACS8-3.3#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 LTC1504ACS8-3.3#PBF reliable?
The price and inventory of LTC1504ACS8-3.3#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC1504ACS8-3.3#PBF is usually 5 days.
3.What payment methods are accepted for LTC1504ACS8-3.3#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC1504ACS8-3.3#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC1504ACS8-3.3#PBF?
LTC1504ACS8-3.3#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC1504ACS8-3.3#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 LTC1504ACS8-3.3#PBF?
For technical support, including LTC1504ACS8-3.3#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC1504ACS8-3.3#PBF requirements.
6.How does Aetrix verify that LTC1504ACS8-3.3#PBF is sourced from the original manufacturer or authorized distributors?
All LTC1504ACS8-3.3#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 LTC1504ACS8-3.3#PBF meets industry standards.
7.What is the process for return or replacement of LTC1504ACS8-3.3#PBF?
All LTC1504ACS8-3.3#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC1504ACS8-3.3#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 LTC1504ACS8-3.3#PBF part is unused and in its original packaging.
Return procedure for LTC1504ACS8-3.3#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC1504ACS8-3.3#PBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
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…
