My Inquiry
My Account
Analog Devices Inc. LTC3720EGN#PBF
- Part No.:
- LTC3720EGN#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Special Purpose Regulators
- Package:
- 28-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
LTC3720EGN#PBF.pdf
- Description:
- IC REG CTRLR INTEL 1OUT 28SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,834
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3720EGN#PBF from Analog Devices (formerly Linear Technology) is a valley-current-mode synchronous step-down controller designed for Intel VRM8.5-compliant CPU power supplies. It delivers 1.05V–1.825V output via 5-bit VID programming, supports 4V–36V input, achieves ≤100ns minimum on-time, and drives dual N-channel MOSFETs without requiring an external sense resistor - enabling high-efficiency, low-duty-cycle operation in Pentium®-based notebook and server power rails.
For engineers reviewing the LTC3720EGN#PBF datasheet, LTC3720EGN#PBF pinout, LTC3720EGN#PBF application, or LTC3720EGN#PBF equivalent, key selection criteria include VRM8.5 VID compatibility, ceramic-output-capacitor stability, active voltage positioning support, programmable current limit, and forced continuous/discontinuous mode control for transient noise management.
Technical Context
The LTC3720EGN#PBF implements a valley-current-mode architecture with a one-shot timer controlling top-MOSFET on-time, where tON is set by ION current and VON voltage - enabling near-constant switching frequency across VIN and VOUT variations. Its internal 0.8V reference exhibits ±1% accuracy over –40°C to 85°C, and the VID DAC provides ±0.25% output voltage accuracy across the 1.05V–1.825V range.
Fault protection includes foldback current limiting, ±7.5% PGOOD window detection, output overvoltage shutdown (M1 off/M2 latched on), and optional short-circuit shutdown timer. The controller supports both resistor-based and MOSFET RDS(ON)-based current sensing, with VRNG-programmable sense threshold scaling (50mV–200mV nominal) and true zero-current detection for discontinuous mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Range | 1.05V to 1.825V, set by 5-bit Intel VRM8.5 VID code - enables dynamic CPU core voltage scaling. |
| Input Voltage Range | 4V to 36V - supports wide-input industrial and server DC bus rails including 5V, 12V, and 24V systems. |
| Min On-Time | ≤100ns - enables stable regulation at very low duty cycles (e.g., 1.2V out from 24V in) without pulse-skipping. |
| Reference Accuracy | ±1% at 0.8V over full temperature range - ensures tight output voltage tolerance under thermal stress. |
| Current Sense Method | No external RSENSE required - uses bottom MOSFET RDS(ON) or optional sense resistor with VRNG-scalable threshold (79–214mV). |
| Switching Frequency | Externally adjustable via ION resistor - maintains stable frequency across line/load with implicit VIN/VOUT compensation. |
| PGOOD Threshold | ±7.5% window around regulated VOUT - provides precise power-rail monitoring for CPU reset sequencing. |
| Operating Temp | –40°C to +85°C (ambient) - qualified for extended-temperature industrial and computing environments. |
Pinout & Package
Package: 28-lead narrow plastic SSOP (GN package), RoHS-compliant, 0.635mm pitch, body size 7.6mm × 5.0mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RUN/SS (1) | Run enable & soft-start timing | Capacitor-to-ground sets ramp time (~3s/µF); <0.8V forces shutdown; rising edge above 1.5V initiates soft-start. |
| VON (2) | On-time comparator trip point | Adjusts tON vs VOUT - tie to output for constant-frequency operation; clamped at 0.7V/2.4V internally. |
| PGOOD (3) | Open-drain power-good flag | Pulled low when VFB exits ±7.5% window - interfaces directly with CPU RESET# or system supervisor ICs. |
| VRNG (4) | Sense voltage range select | Sets nominal current-sense threshold (50–200mV) via resistive divider from INTVCC - enables RSENSE or RDS(ON) scaling. |
| FCB (5) | Forced continuous mode control | Tie to GND for continuous conduction at light load (reduces noise); tie to INTVCC for discontinuous mode (improves light-load efficiency). |
| ITH (6) | Error amplifier output & current limit threshold | 0–2.4V control voltage sets valley current limit; also serves as compensation node for loop stability. |
| SGND (7,10) | Signal ground reference | Low-noise analog ground for feedback, compensation, and VID inputs - must be star-connected to PGND at single point. |
| ION (8) | Frequency-setting current input | Resistor from VIN sets tON; current scales inversely with VIN - enables auto-compensated constant-frequency operation. |
| VFB (9,11) | Feedback input & error amplifier inverting input | Connects to internal 0.8V reference; accepts external divider for non-VID applications or adds compensation network. |
| VOSENSE (12) | Output voltage sense input | Direct connection to regulated output - feeds internal VID DAC divider; enables remote sensing for improved load regulation. |
| VID0–VID4 (13–17) | Digital voltage identification inputs | 5-bit parallel code selects output voltage per VRM8.5 spec; internal 40kΩ pull-ups allow floating = highest voltage (1.825V). |
| VCC (18) | VID logic supply | 3.1V–5.5V supply for VID interface - decoupled separately to avoid digital noise coupling into analog control loop. |
| EXTVCC (19) | External gate-drive supply input | Switches internal LDO off when >4.7V - allows efficient 5V rail (e.g., secondary winding) to power drivers and logic. |
| VIN (20) | Main input supply | 4V–36V primary input - requires RC filter (1Ω + 0.1µF) to PGND for EMI suppression and bootstrap capacitor charging. |
| INTVCC (21) | Internal 5V regulator output | Supplies gate drivers and control circuitry; requires ≥4.7µF low-ESR tantalum capacitor to PGND for stability. |
| BG (22) | Bottom gate driver output | Drives bottom N-MOSFET gate from PGND to INTVCC - 1Ω pull-down resistance ensures fast turn-off. |
| PGND (23) | Power ground return | High-current return path for bottom MOSFET source, CIN(–), CVCC(–); must be low-inductance connection to minimize noise. |
| SENSE– (24) | Current sense comparator (–) input | Connected to PGND when using MOSFET RDS(ON); connects to sense-resistor low side for precision current limiting. |
| SENSE+ (25) | Current sense comparator (+) input | Connected to SW node for RDS(ON) sensing; connects to sense-resistor high side for discrete RSENSE implementation. |
| SW (26) | Switch node | Connects to inductor, bottom MOSFET drain, and bootstrap capacitor (–); swings from ~–0.3V to VIN during operation. |
| TG (27) | Top gate driver output | Drives top N-MOSFET gate with INTVCC-referenced swing - requires external Schottky diode and bootstrap capacitor. |
| BOOST (28) | Bootstrap capacitor (+) terminal | Swings from ~INTVCC–0.3V to VIN+INTVCC - powers TG driver during high-side conduction; requires low-ESR ceramic cap. |
Key Features
| Feature | Design Value |
|---|---|
| Valley current mode control | Enables stable operation at ultra-low duty cycles (<5%) without subharmonic oscillation or external slope compensation. |
| VRM8.5-compliant VID interface | Direct 5-bit digital interface to Intel CPUs - eliminates need for external DAC or microcontroller-based voltage control. |
| No RSENSE required | Uses bottom MOSFET RDS(ON) for current sensing - reduces BOM cost, PCB area, and conduction losses by up to 30%. |
| Ceramic output capacitor compatible | Stable with low-ESR ceramic COUT - enables compact, high-reliability designs without electrolytic capacitor aging concerns. |
| Active voltage positioning (AVP) | Supports AVP via ITH pin modulation - improves transient response and reduces required output capacitance in CPU power stages. |
| Programmable soft-start & current limit | External capacitor sets startup ramp; VRNG and ITH independently configure current limit threshold and foldback behavior. |
Applications
| Desktop & Server CPU Power | Notebook Processor Regulation |
|---|---|
|
Use Scenario: Primary 1.2V–1.5V core supply for Intel Pentium® III/IV processors in ATX desktop and 1U/2U rack servers. IC Role / Device Role / Timing Role: VRM8.5-compliant step-down controller managing dynamic VID updates, phase control, and multi-rail sequencing. Use Value: Delivers <100ns min-on-time and valley-current control to maintain regulation at 24V input → 1.25V/20A output with <±1% accuracy. |
Use Scenario: Compact, high-efficiency core voltage regulator in space-constrained notebook motherboards. IC Role / Device Role / Timing Role: Synchronous buck controller driving dual N-MOSFETs with ceramic output caps and integrated PGOOD signaling. Use Value: Eliminates external sense resistor and supports forced continuous mode to suppress audible noise during light-load video playback. |
| Industrial Embedded Computing | Networking Equipment Power |
|
Use Scenario: Reliable 1.5V/15A processor rail in fanless industrial PCs operating from 24VDC field buses. IC Role / Device Role / Timing Role: Wide-input (4V–36V), extended-temp (–40°C to +85°C) controller with robust fault protection and latchoff timer. Use Value: Maintains stable output under brownout conditions via 3.5V UVLO with hysteresis and survives 300°C solder reflow per JEDEC J-STD-020. |
Use Scenario: High-current core supply for network processor ASICs in enterprise switches and routers. IC Role / Device Role / Timing Role: Dual-MOSFET synchronous controller supporting active voltage positioning and fast transient response. Use Value: Achieves <50µs load-step recovery (0→15A) in forced continuous mode - critical for bursty packet-processing workloads. |
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 |
|---|---|---|---|
| ISL6522CRZ-T | Fixed 0.8V reference; no VID interface; supports only 3-bit PROCHOT# voltage scaling - lacks VRM8.5 compliance. | Targeted at non-Intel embedded processors; requires external DAC for multi-voltage operation. | Choose for cost-sensitive, fixed-output applications where VID flexibility is unnecessary. |
| TPS54620RGYT | Integrated FETs (30V, 6A); no VID interface; uses D-CAP2™ control - higher integration but lower max current. | Designed for point-of-load converters in telecom and FPGA power; not VRM8.5-certified. | Prefer for space-constrained, medium-current designs where board area outweighs CPU-specific feature needs. |
Compared with ISL6522CRZ-T and TPS54620RGYT, the LTC3720EGN#PBF uniquely combines VRM8.5 VID compliance, valley-current control for ultra-low duty cycles, and external MOSFET drive flexibility - making it irreplaceable for legacy Intel CPU power where dynamic voltage scaling and 20A+ capability are mandatory.
Availability
LTC3720EGN#PBF is available at Aetrix Electronics and suitable for desktop CPU power supplies, notebook motherboard designs, industrial embedded computing platforms, and networking equipment requiring stable component supply and long-term lifecycle assurance.
Supply support for LTC3720EGN#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. (including former Linear Technology products) is a global leader in high-performance analog, mixed-signal, and power management semiconductors - serving precision instrumentation, communications, and computing markets since 1965.
The LTC3720EGN#PBF belongs to Linear's high-efficiency DC/DC controller product line, engineered specifically for Intel VRM8.5-compliant CPU power delivery with emphasis on low-duty-cycle stability, ceramic-capacitor compatibility, and robust fault handling in demanding computing environments.
FAQ
What is the minimum on-time specification for the LTC3720EGN#PBF, and why does it matter?
The LTC3720EGN#PBF has a guaranteed minimum on-time of ≤100ns. This enables stable regulation at very low duty cycles - for example, generating 1.25V from a 24V input (5.2% duty cycle) without pulse-skipping or instability. Such performance is essential for high-input-voltage CPU power supplies where conventional controllers would fail to maintain regulation or exhibit poor transient response.
Does the LTC3720EGN#PBF require an external current sense resistor?
No, the LTC3720EGN#PBF does not require an external current sense resistor. It supports MOSFET RDS(ON)-based current sensing by connecting SENSE+ to the switch node (SW) and SENSE– to PGND. An optional sense resistor can be used for tighter current-limit accuracy, with VRNG pin programming to scale the sense threshold from 50mV to 200mV nominal.
How does the LTC3720EGN#PBF support Intel VRM8.5 compliance?
The LTC3720EGN#PBF supports Intel VRM8.5 compliance through its 5-bit VID interface (VID0–VID4), which directly programs output voltages from 1.05V to 1.825V in 25mV steps per the VRM8.5 specification. Its internal DAC achieves ±0.25% accuracy across this range, and the controller responds to real-time VID changes - enabling dynamic CPU voltage scaling during operation.
What is the purpose of the FCB pin on the LTC3720EGN#PBF?
The FCB (Forced Continuous) pin on the LTC3720EGN#PBF controls discontinuous vs. continuous conduction mode. When pulled to GND, it forces continuous operation at light loads - reducing output voltage ripple and RF emissions. When tied to INTVCC, it enables discontinuous mode for improved light-load efficiency. This dual-mode capability allows designers to optimize for either noise or efficiency based on system requirements.
Can the LTC3720EGN#PBF operate with ceramic output capacitors?
Yes, the LTC3720EGN#PBF is explicitly designed to be stable with low-ESR ceramic output capacitors. Its valley-current-mode architecture and internal compensation eliminate the need for the large ESR typically required by voltage-mode controllers - enabling smaller, more reliable, and longer-life ceramic-based output filters in space-constrained applications like notebooks and servers.
LTC3720EGN#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Applications:
- Controller, Intel Pentium®
- Voltage - Input:
- 4V ~ 36V
- Number of Outputs:
- 1
- Voltage - Output:
- 1.05V ~ 1.83V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SSOP
LTC3720EGN#PBF FAQ
1.How can I place an order for LTC3720EGN#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3720EGN#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 LTC3720EGN#PBF reliable?
The price and inventory of LTC3720EGN#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3720EGN#PBF is usually 5 days.
3.What payment methods are accepted for LTC3720EGN#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3720EGN#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3720EGN#PBF?
LTC3720EGN#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3720EGN#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 LTC3720EGN#PBF?
For technical support, including LTC3720EGN#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3720EGN#PBF requirements.
6.How does Aetrix verify that LTC3720EGN#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3720EGN#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 LTC3720EGN#PBF meets industry standards.
7.What is the process for return or replacement of LTC3720EGN#PBF?
All LTC3720EGN#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3720EGN#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 LTC3720EGN#PBF part is unused and in its original packaging.
Return procedure for LTC3720EGN#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3720EGN#PBF Tags
-
TPS51206DSQR
Texas Instruments
-
TPS51200DRCR
Texas Instruments
-
TPS51200DRCT
Texas Instruments
-
TPS62740DSSR
Texas Instruments
-
TPS51100DGQR
Texas Instruments
-
NCP51200MNTXG
onsemi
-
NCP51400MNTXG
onsemi
-
RT9026GSP
Richtek USA Inc.
-
LP2998MRX/NOPB
Texas Instruments
-
TPS51200QDRCRQ1
Texas Instruments
-
DPA423GN-TL
Power Integrations
-
LM10011SD/NOPB
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…
