My Inquiry
My Account
Analog Devices Inc. LT3740EDHC#PBF
- Part No.:
- LT3740EDHC#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 16-WFDFN Exposed Pad
- Datasheet:
-
LT3740EDHC#PBF.pdf
- Description:
- IC REG CTRLR BUCK 16-DFN
- Quantity:
- Payment:
- Shipping:
Inventory:182
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3740EDHC#PBF from Analog Devices (formerly Linear Technology) is a synchronous step-down switching regulator controller driving dual N-channel MOSFETs in valley current mode, enabling 2.2V–22V input operation, no external sense resistor, 300kHz fixed-frequency control, and 0.8V feedback reference - used in high-ratio DC/DC conversion for portable computing power rails.
For engineers reviewing the LT3740EDHC#PBF datasheet, LT3740EDHC#PBF pinout, LT3740EDHC#PBF application, or LT3740EDHC#PBF equivalent, key selection considerations include valley-mode transient response, three selectable current limit thresholds (50/80/105mV), internal boost for gate drive above VIN, XREF-based output voltage tracking, and PGOOD monitoring with 720mV threshold.
Technical Context
The LT3740EDHC#PBF implements constant-frequency valley current mode control using internal ramp compensation synchronized to a 300kHz oscillator. It senses inductor current via SN+/SN– pins either across the bottom MOSFET's RDS(ON) or an external resistor, with slope compensation dynamically adjusted per RANGE pin selection (GND/open/VIN) to prevent subharmonic oscillation at high duty cycles.
Its integrated charge pump generates BIAS ≈ VIN + 7.8V to ensure robust top-gate drive down to 2.2V input; BGDP supplies bottom-gate bias, configurable to BIAS or VIN depending on input voltage level. Adaptive dead-time control prevents shoot-through, while reverse-current limiting triggers at 35mV to clamp negative inductor current during light-load or shutdown transients.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.2V to 22V - supports single-cell Li-ion up to 20V industrial rails without external LDO pre-regulation. |
| Switching Frequency | 300kHz (±10%) - enables compact magnetics and predictable EMI filtering with minimal layout sensitivity. |
| Feedback Reference | 0.800V (±8mV) - precise regulation point allowing ±1% output accuracy with standard resistor dividers. |
| Current Sense Thresholds | 50mV / 80mV / 105mV - pin-selectable limits directly set peak inductor current without calibration overhead. |
| PGOOD Threshold | 720mV to 765mV - ensures reliable power-good assertion only when regulated output is within ±5% of target. |
| BIAS–VIN Offset | 7.8V (typical) - guarantees sufficient gate overdrive for logic-level N-MOSFETs even at minimum 2.2V input. |
| SHDN Enable Threshold | 1.1V (min) - provides noise-immune enable control compatible with standard GPIO or supervisor outputs. |
Pinout & Package
LT3740EDHC#PBF is housed in a 16-lead 5mm × 3mm plastic DFN package with exposed thermal pad (Pin 17 = GND), optimized for high-power density and thermal performance in space-constrained applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SN– (1) | Negative current sense input | Connects to bottom MOSFET source or sense resistor low-side; enables No RSENSE™ operation. |
| PGND (2) | Power ground return | Low-impedance path for high di/dt switch node currents; must be tied directly to bottom FET source. |
| BGATE (3) | Bottom N-MOSFET gate driver | Provides 5.5V logic-high drive with 50ns fall time; controls synchronous rectification timing. |
| BGDP (4) | Bottom gate drive supply | Accepts 7V+ bias (from BIAS or VIN); determines minimum gate overdrive for RDS(ON)-based sensing. |
| SN+ (5) | Positive current sense input | Connects to bottom MOSFET drain or sense resistor high-side; completes differential current measurement. |
| SW (6) | Switch node connection | High dv/dt node shared by top/bottom MOSFETs; requires tight layout to minimize ringing and EMI. |
| TGATE (7) | Top N-MOSFET gate driver | Drives top FET gate to BIAS voltage; features adaptive dead-time to prevent shoot-through. |
| BIAS (8) | Top gate drive bootstrap supply | Output of internal boost converter; maintains ~7.8V above VIN for full top-FET enhancement. |
| SWB (9) | Internal boost switch node | Connects external boost inductor; critical for generating BIAS voltage from low VIN inputs. |
| VIN (10) | Main input supply | Primary power input; must be locally bypassed with low-ESR capacitor to handle pulsed current demands. |
| RANGE (11) | Current limit range select | GND = 50mV, open = 80mV, VIN = 105mV - sets both current limit and slope compensation gain. |
| PGOOD (12) | Open-collector power-good flag | Pulled low when FB < 720mV; requires external pull-up for system sequencing or fault reporting. |
| SHDN (13) | Shutdown/soft-start control | Logic-level enable; slow ramp enables controlled soft-start; fast transition ensures clean shutdown. |
| XREF (14) | External reference input | Overrides internal 0.8V reference with 0–0.8V signal for tracking, margining, or programmable soft-start. |
| FB (15) | Feedback voltage input | Regulated to 0.8V (or XREF value); connects to resistor divider from VOUT to set output voltage. |
| VC (16) | Error amplifier compensation | Connects RC network for loop stability; voltage modulates current comparator threshold. |
Key Features
| Feature | Design Value |
|---|---|
| No external sense resistor required | Enables high-efficiency, low-BOM-cost designs using bottom MOSFET RDS(ON) as current sensor - eliminates I²R loss and board area of shunt. |
| Valley current mode architecture | Delivers superior load transient response and inherent cycle-by-cycle current limiting without requiring slope compensation tuning. |
| Integrated boost converter for gate drive | Generates BIAS ≈ VIN + 7.8V internally - allows operation from 2.2V input while maintaining full N-MOSFET gate overdrive. |
| Three selectable current limit levels | Hardware-configurable thresholds (50/80/105mV) simplify design across multiple output current requirements without firmware or resistor changes. |
| XREF-based output voltage tracking | Allows real-time adjustment of regulated output voltage via analog signal - supports dynamic margining, sequencing, and soft-start control. |
Applications
| Notebook CPU Core Power | Portable Medical Instrument Supply |
|---|---|
Use Scenario: Delivering tightly regulated 1.0–1.8V at up to 10A to modern low-voltage CPU cores in ultraportable notebooks with 3–12V battery input. IC Role / Device Role / Timing Role: Synchronous step-down controller managing dual N-MOSFET power stage with valley-mode current sensing and 300kHz PWM timing. Use Value: Achieves >92% efficiency at 5V input/1.8V@10A while eliminating sense resistor losses and supporting rapid load transients from CPU burst activity. | Use Scenario: Generating stable 3.3V/5V rails for precision analog front-ends and microcontrollers in handheld diagnostic devices powered by 2-cell Li-ion (6–8.4V). IC Role / Device Role / Timing Role: High-efficiency DC/DC controller with PGOOD monitoring and XREF-based soft-start to ensure clean power-up of sensitive ADCs and sensors. Use Value: Guarantees monotonic startup, avoids brownout during battery sag, and maintains ±1% output regulation across temperature and load for clinical-grade accuracy. |
| Distributed Point-of-Load Converter | Industrial IoT Sensor Node Power |
Use Scenario: Local 12V-to-3.3V conversion at FPGA or ASIC load points in telecom baseband cards where space and thermal density are constrained. IC Role / Device Role / Timing Role: Valley-mode controller driving discrete N-MOSFETs with adaptive dead-time control and internal BIAS generation for compact, high-current POL design. Use Value: Enables 5mm × 3mm footprint with >90% efficiency at full load, reducing board area versus integrated PMICs while retaining design flexibility. | Use Scenario: Powering ultra-low-quiescent wireless sensor nodes (BLE/Zigbee) from primary 9V batteries or energy harvesters with wide input variation (2.2–9V). IC Role / Device Role / Timing Role: Wide-input synchronous buck controller with SHDN-controlled sleep mode and reverse-current limiting to extend battery life. Use Value: Maintains regulation down to 2.2V input, suppresses reverse current during deep sleep, and achieves <2.5μA shutdown current - doubling operational runtime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3891EMSE#PBF | Wider input range (4–60V), integrated gate drivers, but no internal boost - requires external bias for low-VIN operation. | Targeted at automotive and industrial 12/24V systems; lacks No RSENSE™ capability and valley-mode optimization for sub-3V inputs. | Select when input exceeds 4V and higher voltage robustness is needed; avoid for ≤3V battery-powered designs. |
| MP24894GQZ-P | Integrated MOSFETs, fixed 500kHz frequency, no XREF or RANGE pin - simpler but less flexible and lower efficiency at high step-down ratios. | Suitable for cost-sensitive consumer power supplies; cannot match LT3740EDHC#PBF's valley-mode transient response or multi-threshold current limiting. | Choose for compact, low-BOM-count solutions where 300kHz timing and analog tracking are not required. |
Compared with LTC3891EMSE#PBF and MP24894GQZ-P, the LT3740EDHC#PBF uniquely combines valley-mode control, internal boost for 2.2V start-up, No RSENSE™ operation, and XREF-based voltage tracking - making it optimal for high-performance, wide-input portable and POL applications where efficiency, transient response, and analog programmability are critical.
Availability
LT3740EDHC#PBF is available at Aetrix Electronics and suitable for notebook CPU core power, portable medical instrument supply, distributed point-of-load conversion, industrial IoT sensor node power, and high-ratio DC/DC applications requiring stable component supply across extended temperature ranges.
Supply support for LT3740EDHC#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 is a global leader in high-performance analog, mixed-signal, and power management semiconductors, formed through the acquisition of Linear Technology in 2017.
The LT3740EDHC#PBF belongs to Linear's high-efficiency DC/DC controller product line, designed specifically for synchronous step-down conversion in space- and thermally-constrained portable and industrial systems demanding wide input range and precision regulation.
FAQ
What is the minimum input voltage supported by the LT3740EDHC#PBF?
The LT3740EDHC#PBF supports a minimum input voltage of 2.2V, enabled by its internal boost converter that generates a BIAS voltage approximately 7.8V higher than VIN. This architecture ensures sufficient gate drive for N-channel MOSFETs even at the lowest operating input, making LT3740EDHC#PBF suitable for single-cell Li-ion and other low-voltage battery-powered applications.
How does the RANGE pin affect current limiting and stability in the LT3740EDHC#PBF?
The RANGE pin on the LT3740EDHC#PBF selects one of three current sense thresholds (50mV/GND, 80mV/open, 105mV/VIN) and simultaneously adjusts the slope compensation gain to match. This dual function ensures stable valley-mode operation across varying duty cycles - insufficient compensation at high VIN can cause subharmonic oscillation, which the RANGE pin mitigates by scaling compensation with the selected limit level in LT3740EDHC#PBF.
Can the LT3740EDHC#PBF operate without an external current sense resistor?
Yes, the LT3740EDHC#PBF supports No RSENSE™ operation by measuring voltage across the bottom MOSFET's RDS(ON) using SN+ and SN– pins. This eliminates I²R losses and PCB area associated with shunt resistors. However, designers must account for RDS(ON) variation with temperature and gate voltage - LT3740EDHC#PBF's three-range current limit helps accommodate this uncertainty while maintaining safe peak current control.
What is the function of the XREF pin in the LT3740EDHC#PBF, and how is it used in practice?
The XREF pin on the LT3740EDHC#PBF allows overriding the internal 0.8V feedback reference with an external 0–0.8V analog signal. It enables output voltage tracking (e.g., to match another rail), programmable soft-start (by ramping XREF), and dynamic margining. When XREF is ≥1V, LT3740EDHC#PBF reverts to its internal reference; below 0.8V, regulation follows XREF - providing analog control flexibility not found in most fixed-reference controllers.
Does the LT3740EDHC#PBF include protection against reverse inductor current?
Yes, the LT3740EDHC#PBF incorporates a dedicated reverse current comparator that triggers when (VSN+ – VSN–) reaches 35mV during bottom MOSFET conduction, forcing immediate turn-off. This protects against energy back-feeding from output capacitors or auxiliary supplies during light-load discontinuous operation, shutdown transients, or output overvoltage events - a critical feature for system reliability in LT3740EDHC#PBF-based designs.
LT3740EDHC#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-WFDFN Exposed Pad
- Packaging:
- Tube
- 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):
- 2.2V ~ 22V
- Frequency - Switching:
- 300kHz
- Duty Cycle (Max):
- -
- Synchronous Rectifier:
- Yes
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Power Good
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-DFN (5x3)
LT3740EDHC#PBF FAQ
1.How can I place an order for LT3740EDHC#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3740EDHC#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 LT3740EDHC#PBF reliable?
The price and inventory of LT3740EDHC#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3740EDHC#PBF is usually 5 days.
3.What payment methods are accepted for LT3740EDHC#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3740EDHC#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3740EDHC#PBF?
LT3740EDHC#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3740EDHC#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 LT3740EDHC#PBF?
For technical support, including LT3740EDHC#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3740EDHC#PBF requirements.
6.How does Aetrix verify that LT3740EDHC#PBF is sourced from the original manufacturer or authorized distributors?
All LT3740EDHC#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 LT3740EDHC#PBF meets industry standards.
7.What is the process for return or replacement of LT3740EDHC#PBF?
All LT3740EDHC#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3740EDHC#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 LT3740EDHC#PBF part is unused and in its original packaging.
Return procedure for LT3740EDHC#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3740EDHC#PBF 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…
