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Analog Devices Inc. LTC3544BEUD#PBF
- Part No.:
- LTC3544BEUD#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 16-WFQFN Exposed Pad
- Datasheet:
-
LTC3544BEUD#PBF.pdf
- Description:
- IC REG BUCK ADJ QUAD 16QFN
- Quantity:
- Payment:
- Shipping:
Inventory:6,282
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Product details
Overview
LTC3544BEUD#PBF from Analog Devices (formerly Linear Technology) is a quad-channel monolithic synchronous step-down DC/DC regulator IC with independent enable control per channel, delivering 300mA, 200mA, 200mA, and 100mA output currents respectively; operates from 2.25V to 5.5V input, features 2.25MHz fixed-frequency current-mode control, 0.8V feedback reference, and 100% duty-cycle low-dropout capability for Li-ion battery-powered portable electronics.
For engineers reviewing the LTC3544BEUD#PBF datasheet, LTC3544BEUD#PBF pinout, LTC3544BEUD#PBF application, or LTC3544BEUD#PBF equivalent, key selection considerations include per-channel current ratings, independent RUN pin control, thermal performance in 3mm × 3mm QFN, pulse-skipping mode for low-load ripple suppression, and compatibility with ceramic input/output capacitors in space-constrained designs.
Technical Context
The LTC3544BEUD#PBF implements four independent constant-frequency current-mode buck regulators sharing a single 2.25MHz oscillator but with separate RUN pins, SW nodes, and feedback inputs-enabling flexible power sequencing and dynamic channel enable/disable. Each regulator integrates matched P-channel high-side and N-channel synchronous rectifier MOSFETs with specified RDS(ON) (e.g., 0.55Ω/0.50Ω for 300mA channel at 25°C).
Control architecture includes internal soft-start (~1ms), overtemperature protection, undervoltage lockout (1.9V–2.25V), and pulse-skipping mode below ~10mA load to maintain sub-10mV output ripple while minimizing quiescent current (<1µA in shutdown). Feedback regulation uses a precision 0.8V reference with ±1.0% initial accuracy over temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.25V to 5.5V - supports single-cell Li-ion/polymer battery operation across full discharge curve. |
| Switching Frequency | 2.25MHz (typ) - enables use of compact 1µH–10µH inductors and low-ESR ceramic capacitors. |
| Output Current Capability | 300mA / 200mA / 200mA / 100mA - four independent channels with dedicated SW and RUN pins. |
| Feedback Reference Voltage | 0.8V ±1.0% - allows precise low-voltage outputs (e.g., 0.8V–3.3V) using standard resistor dividers. |
| Efficiency Peak | 95% - achieved at medium loads due to synchronous rectification and low RDS(ON) FETs. |
| Shutdown Current | <1µA - minimizes battery drain in standby or sleep modes. |
| Operating Temperature | –40°C to +85°C - qualified for industrial and portable consumer environments. |
Pinout & Package
Package: 16-lead (3mm × 3mm) plastic QFN with exposed pad (Pin 17 = GNDA), 0.75mm profile, RoHS-compliant lead-free finish (PBF).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VFB200B (1) | Feedback input for 200mA Channel B | Connects to resistive divider on VOUT200B to regulate output voltage via 0.8V reference. |
| VFB200A (2) | Feedback input for 200mA Channel A | Independent regulation path enabling distinct output voltages per channel (e.g., 1.2V, 1.5V, 1.8V). |
| RUN200A (3) | Enable input for 200mA Channel A | Logic-high (>1.0V) enables regulator; logic-low (<0.3V) forces shutdown with <1µA quiescent draw. |
| SW200B (4) | Switch node for 200mA Channel B | Drain connection of internal P/N-FET pair; requires external inductor and ceramic capacitor to ground. |
| SW200A (5) | Switch node for 200mA Channel A | Isolated switching node prevents crosstalk between channels during transient load steps. |
| PGND (6) | Power ground return | Common return for 300mA and both 200mA channels; must be low-impedance copper pour under exposed pad. |
| PVIN (7) | Power input supply | Input rail for 300mA and both 200mA regulators; requires ≥4.7µF ceramic decoupling to PGND. |
| SW300 (8) | Switch node for 300mA Channel | Highest-current switch node; designed for 600mA peak current handling (400mA continuous). |
| RUN300 (9) | Enable input for 300mA Channel | Independent control allows sequencing high-current rail before lower-current rails. |
| VFB300 (10) | Feedback input for 300mA Channel | Supports remote sensing; tolerates up to ±0.3V offset relative to VIN without damage. |
| VFB100 (11) | Feedback input for 100mA Channel | Enables ultra-low-power auxiliary rail (e.g., sensor bias, RTC, or interface I/O). |
| RUN100 (12) | Enable input for 100mA Channel | Allows fine-grained power gating of peripheral subsystems without affecting main rails. |
| SW100 (13) | Switch node for 100mA Channel | Optimized for low-RDS(ON) (0.8Ω/0.75Ω) despite smaller current rating. |
| GNDA (14, 17) | Analog ground / Exposed thermal pad | Reference ground for error amplifiers and VFB pins; exposed pad must be soldered to PCB ground for thermal and electrical integrity. |
| VCC (15) | Bias supply for control circuitry | Internal LDO output powers reference, oscillator, and logic; also serves as power path for 100mA regulator. |
| RUN200B (16) | Enable input for 200mA Channel B | Third independent enable pin enables asymmetric power-up sequences (e.g., RF + baseband before audio). |
Key Features
| Feature | Design Value |
|---|---|
| Four independent synchronous buck regulators | Eliminates need for four discrete converters; reduces BOM count, layout area, and design validation effort. |
| 2.25MHz fixed-frequency operation | Permits use of 2.2µH–4.7µH inductors (vs. 10µH+ at 500kHz), shrinking total solution size by >40%. |
| Pulse-skipping mode at light load | Maintains <10mVPP output ripple down to 100µA load while keeping efficiency >80% at 1mA. |
| 100% duty-cycle low-dropout mode | Extends usable battery life by regulating down to VIN – ILOAD×RDS(ON) (e.g., 0.8V out at 2.5V in). |
| Integrated high-side P-FET + low-side N-FET | Removes requirement for external Schottky diodes, improving efficiency by 3–5% and simplifying layout. |
| Thermally enhanced 3mm × 3mm QFN | θJA = 68°C/W enables 138mW total dissipation at 85°C ambient without heatsink or airflow. |
Applications
| Mobile Baseband Power | Digital Camera Core Logic |
|---|---|
Use Scenario: Powering application processor cores, memory interfaces, and DSP blocks in smartphones with dynamic voltage scaling. IC Role / Device Role / Timing Role: Quad-regulator delivers independently controlled 1.2V (core), 1.5V (I/O), 1.8V (memory), and 0.8V (low-power standby) rails from single Li-ion cell. Use Value: Enables simultaneous rail sequencing, eliminates cross-regulator load transients, and maintains <±1% output accuracy during 100mA–300mA load steps. | Use Scenario: Supplying image sensor, ISP, and LCD driver in compact digital still cameras. IC Role / Device Role / Timing Role: Provides 300mA main core rail (1.2V), dual 200mA rails (1.5V/1.8V) for analog front-end and display, and 100mA rail (3.3V) for SD card interface. Use Value: Pulse-skipping mode ensures clean 1.5V analog supply during image capture with <5mV ripple, avoiding sensor noise artifacts. |
| Wireless Modem Subsystem | Portable Medical Instrument |
Use Scenario: Powering LTE/Wi-Fi/BT combo modules requiring isolated, low-noise supplies with fast transient response. IC Role / Device Role / Timing Role: Four channels supply RF transceiver (1.8V), baseband (1.2V), PA bias (3.3V), and MCU (0.8V) with independent RUN control for power-state coordination. Use Value: Load-step response <20µs with <50mV undershoot enables reliable packet transmission during burst-mode operation. | Use Scenario: Powering ECG front-end, microcontroller, OLED display, and Bluetooth LE radio in handheld diagnostic devices. IC Role / Device Role / Timing Role: Delivers 200mA analog rail (2.5V), 100mA digital rail (1.8V), 300mA MCU rail (1.2V), and 200mA display rail (3.3V) from coin-cell or rechargeable battery. Use Value: Shutdown current <1µA extends battery life to >6 months in standby; 0.8V reference supports precise 2.5V analog rail calibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad-buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS65023RSBR | Triple buck + dual LDO; 3MHz switching; no pulse-skip mode; 0.6V reference; 16-pin QFN same footprint. | Optimized for OMAP/ARM processors with integrated LDOs; lacks fourth buck channel and low-ripple pulse-skip capability. | Select when system requires mixed buck/LDO architecture and higher switching frequency is acceptable. |
| ISL95210IRZ | Quad buck with DVS support; 1.2MHz max frequency; 0.6V reference; 32-pin QFN; no 100% duty cycle. | Targeted at Intel mobile platforms with dynamic voltage scaling; larger package and lower frequency increase solution size and reduce light-load efficiency. | Select when DVS interface (VID pins) is required and thermal budget allows larger 5mm × 5mm package. |
Compared with TPS65023RSBR and ISL95210IRZ, the LTC3544BEUD#PBF uniquely combines four true buck regulators, 2.25MHz operation, pulse-skipping for ultra-low ripple, and 100% duty-cycle dropout-making it optimal for compact, battery-sensitive applications demanding independent rail control and minimal EMI.
Availability
LTC3544BEUD#PBF is available at Aetrix Electronics and suitable for mobile baseband power, digital camera core logic, wireless modem subsystems, portable medical instruments, and industrial handheld terminals requiring stable component supply and long-term production continuity.
Supply support for LTC3544BEUD#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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors with expertise in precision regulation and energy-efficient conversion.
The LTC3544BEUD#PBF belongs to Linear's high-density power management IC family, engineered specifically for space-constrained portable electronics requiring multiple independent, low-noise, battery-optimized DC/DC rails.
FAQ
What is the maximum output current per channel for the LTC3544BEUD#PBF?
The LTC3544BEUD#PBF provides four independent output channels rated at 300mA (SW300), 200mA (SW200A), 200mA (SW200B), and 100mA (SW100) under typical conditions (TA = 25°C, VIN = 3.6V). Peak switch current limits are 600mA, 400mA, 400mA, and 300mA respectively. Derating applies at elevated temperatures or high duty cycles; full 300mA output requires adequate PCB copper area for thermal dissipation.
Does the LTC3544BEUD#PBF support independent voltage programming for each channel?
Yes, the LTC3544BEUD#PBF supports fully independent voltage programming via four separate feedback pins (VFB300, VFB200A, VFB200B, VFB100), each referenced to an internal 0.8V precision bandgap. Output voltage is set using external resistor dividers per channel (VOUT = 0.8V × (1 + R1/R2)), enabling distinct rails such as 1.2V, 1.5V, 1.8V, and 3.3V simultaneously from a single IC.
How does pulse-skipping mode operate in the LTC3544BEUD#PBF and what benefit does it provide?
Pulse-skipping mode activates automatically at light loads (<10mA per channel) to maintain regulation while minimizing output voltage ripple and quiescent current. Instead of forced PWM, the LTC3544BEUD#PBF skips entire switching cycles-reducing switching losses and maintaining <10mVPP ripple even at µA-level loads. This extends battery runtime in standby without compromising noise-sensitive analog rail integrity.
What thermal design considerations apply to the LTC3544BEUD#PBF in high-ambient environments?
The LTC3544BEUD#PBF uses a 3mm × 3mm QFN with exposed pad (GNDA, Pin 17) requiring solid solder connection to a thermal PCB plane. With θJA = 68°C/W, junction temperature is calculated as TJ = TA + PD × 68. At 85°C ambient and 138mW total dissipation (all channels active), TJ ≈ 94°C-well below the 125°C limit. Reduce RDS(ON)-related loss by minimizing trace resistance and ensuring adequate copper area under the exposed pad.
Can the LTC3544BEUD#PBF be used with ceramic capacitors on input and output?
Yes, the LTC3544BEUD#PBF is fully compatible with X5R/X7R ceramic capacitors on both input (≥4.7µF at PVIN) and output (≥4.7µF per channel). Its current-mode control loop does not rely on output capacitor ESR for stability, enabling ultra-low-ripple designs. However, avoid placing ceramic input caps directly after long-wire wall adapters to prevent ringing-induced VIN spikes that could exceed absolute maximum ratings.
LTC3544BEUD#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 4
- Voltage - Input (Min):
- 2.25V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 5.5V
- Current - Output:
- 100mA, 200mA(2), 300mA
- Frequency - Switching:
- 2.25MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-QFN (3x3)
LTC3544BEUD#PBF FAQ
1.How can I place an order for LTC3544BEUD#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3544BEUD#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 LTC3544BEUD#PBF reliable?
The price and inventory of LTC3544BEUD#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3544BEUD#PBF is usually 5 days.
3.What payment methods are accepted for LTC3544BEUD#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3544BEUD#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3544BEUD#PBF?
LTC3544BEUD#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3544BEUD#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 LTC3544BEUD#PBF?
For technical support, including LTC3544BEUD#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3544BEUD#PBF requirements.
6.How does Aetrix verify that LTC3544BEUD#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3544BEUD#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 LTC3544BEUD#PBF meets industry standards.
7.What is the process for return or replacement of LTC3544BEUD#PBF?
All LTC3544BEUD#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3544BEUD#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 LTC3544BEUD#PBF part is unused and in its original packaging.
Return procedure for LTC3544BEUD#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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