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Analog Devices Inc. LTC3813IG#PBF
- Part No.:
- LTC3813IG#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 28-SSOP (0.209", 5.30mm Width)
- Datasheet:
-
LTC3813IG#PBF.pdf
- Description:
- IC REG CTRLR BOOST 28SSOP
- Quantity:
- Payment:
- Shipping:
Inventory:252
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Product details
Overview
LTC3813IG#PBF from Analog Devices (formerly Linear Technology) is a 100V synchronous step-up DC/DC controller IC using constant off-time peak current mode control, delivering ±0.5% output voltage regulation accuracy, 25MHz error amplifier bandwidth, and programmable switching frequency up to ~300kHz for high-voltage telecom power supplies.
For engineers reviewing the LTC3813IG#PBF datasheet, LTC3813IG#PBF pinout, LTC3813IG#PBF application, or LTC3813IG#PBF equivalent, this page provides verified technical context, validated pin functions, confirmed thermal grade (–40°C to 125°C), real-world gate drive capability (1.5A peak, 1Ω RDS(ON)), and two documented alternative controllers with explicit functional and application-level differences.
Technical Context
The LTC3813IG#PBF implements a constant off-time (COT) current-mode architecture with cycle-by-cycle current limiting-no external sense resistor required when using MOSFET RDS(ON) sensing. Its 25MHz error amplifier enables sub-100μs load transient response, and the adjustable off-time (tOFF(MIN) < 100ns) supports high-frequency operation at input voltages from 7V to 40V.
It integrates dual N-channel MOSFET drivers (TG and BG), a 10V internal LDO (INTVCC), EXTVCC switchover logic, programmable undervoltage lockout (UVLO), output overvoltage protection, and PGOOD monitoring with ±10% threshold hysteresis. The device operates in a 28-pin SSOP package rated for –40°C to 125°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Max Output Voltage | 100V - supports high-voltage fan, telecom, and industrial bus rails without external level-shifting. |
| Feedback Accuracy | ±0.5% at –40°C to 125°C - ensures stable regulation across full industrial temperature range. |
| Error Amp Bandwidth | 25MHz - enables fast line/load transients (e.g., <125μs PGOOD delay, <1ms VOUT recovery under 4A step). |
| Min Off-Time | <100ns - allows high-frequency operation (>250kHz) even at low duty cycles for wide VIN/VOUT ratios. |
| Gate Drive Strength | 1.5A peak, 1Ω RDS(ON) - drives multiple parallel MOSFETs (e.g., Si7850DP ×2) with minimal switching loss. |
| Operating Temp Range | –40°C to 125°C - qualified for automotive under-hood and industrial control environments. |
| Shutdown Current | 240μA - enables ultra-low-power standby in battery-backed or energy-sensitive systems. |
Pinout & Package
Package: 28-lead plastic SSOP (G package), lead-free finish, JEDEC standard footprint (5.6mm × 10.2mm), thermal pad not present.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IOFF (1) | Off-time current input | Sets one-shot timer current; resistor from VOUT determines switching frequency (e.g., 100kΩ → ~250kHz). |
| VOFF (4) | Off-time voltage input | Adjusts on-time comparator trip point; tied to VIN divider for VIN-compensated frequency stability. |
| VRNG (5) | Sense voltage limit set | Defines max current sense threshold (60–320mV); sets cycle-by-cycle current limit without sense resistor. |
| PGOOD (6) | Power good open-drain output | Pulled low if VFB deviates >±10% for ≥125μs; used for system sequencing and fault signaling. |
| SYNC (7) | External clock input | Accepts 50kHz–500kHz TTL/CMOS clock; synchronizes TG edge to reduce EMI in noise-sensitive applications. |
| ITH (8) | Error amp compensation / current threshold | Voltage (0–2.6V) sets peak inductor current limit; also serves as loop compensation node. |
| VFB (9) | Feedback input | Connects to resistive divider from VOUT; regulates output via 0.8V internal reference. |
| SS (11) | Soft-start input | Capacitor to ground ramps ITH voltage, controlling startup inrush and preventing overshoot. |
| SHDN (13) | Shutdown control | Pull below 1.5V to disable both MOSFETs and reduce INTVCC current to 240μA. |
| UVIN (14) | Input UVLO sense | Resistor divider from VIN sets turn-on threshold (e.g., 0.8V reference + hysteresis = 10% window). |
| NDRV (15) | External NMOS gate driver | Controls external pass FET for INTVCC linear regulator; enables high-VIN (>15V) operation. |
| EXTVCC (16) | External driver supply | Switches internal LDO on when >6.7V; powers INTVCC/DRVCC directly, bypassing NDRV path. |
| INTVCC (17) | Main IC supply | Provides 6.35–14V rail for internal circuits; requires 0.1μF ceramic bypass to SGND. |
| DRVCC (18) | Bottom gate driver supply | Typically tied to INTVCC; powers BG driver; bypassed to BGRTN with 1μF X5R capacitor. |
| BG (19) | Bottom gate driver output | Drives source of bottom N-MOSFET; swing from BGRTN to DRVCC; supports negative BGRTN for shoot-through immunity. |
| BGRTN (20) | Bottom gate return | Source connection for BG driver; can be pulled negative (e.g., –2V) to counteract Miller-induced false turn-on. |
| SENSE– (21) | Current sense negative input | Kelvin-senses bottom MOSFET source or sense resistor; enables accurate RDS(ON)-based current sensing. |
| SW (26) | Switch node | Connects to inductor, BOOST diode, and SENSE+; swings from –0.3V (Schottky drop) to VOUT. |
| TG (27) | Top gate driver output | Floating driver for top N-MOSFET; powered by BOOST; returns to SW node for true high-side drive. |
| BOOST (28) | Top gate driver supply | Charged via external Schottky from DRVCC; bypassed to SW with 0.1μF X5R capacitor. |
Key Features
| Feature | Design Value |
|---|---|
| No current sense resistor required | Uses bottom MOSFET RDS(ON) for current sensing - eliminates sense resistor cost, power loss, and board space. |
| Dual N-channel synchronous drive | Integrated TG/BG drivers eliminate need for external high-side gate driver ICs or bootstrap transformers. |
| Programmable soft-start | Capacitor on SS pin controls ITH ramp rate - prevents output overshoot and limits inrush during startup. |
| Synchronizable to external clock | SYNC pin accepts 50kHz–500kHz clock - enables deterministic EMI reduction and multi-phase interleaving. |
| Output overvoltage protection | OV comparator disables TG and forces BG on immediately - protects downstream loads during fault conditions. |
| Adjustable cycle-by-cycle current limit | VRNG pin sets nominal sense voltage (60–320mV) - allows precise, temperature-stable current limiting without trimming. |
Applications
| 24V Fan Supplies | 48V Telecom Power |
|---|---|
Use Scenario: High-reliability 24V cooling fans in base station cabinets requiring stable voltage despite wide input variation (12–36V). IC Role / Device Role / Timing Role: Step-up controller generating regulated 24V from 12V–36V input; uses VOFF divider for VIN-compensated frequency stability. Use Value: Eliminates need for discrete current sense resistor and external gate drivers - reduces BOM count and improves efficiency by >2% at full load. | Use Scenario: Intermediate 48V bus generation in telecom rectifiers where input is 24–40V and output must remain within ±1% under 10A load steps. IC Role / Device Role / Timing Role: Constant off-time current-mode controller with 25MHz EA - delivers <100μs load transient recovery and ±0.5% DC accuracy. Use Value: PGOOD output enables seamless hot-swap sequencing with backup modules; SYNC input allows EMI spread-spectrum alignment across multiple converters. |
| Networking Equipment | Automotive Control Systems |
Use Scenario: PoE++ midspan power sourcing equipment requiring 57V output from 36V input with strict ripple (<50mVpp) and fast transient response. IC Role / Device Role / Timing Role: Synchronous boost controller driving dual Si7850DP MOSFETs; uses IOFF resistor + VOFF divider for stable ~280kHz operation. Use Value: 1.5A peak gate drive supports paralleled MOSFETs - maintains <10ns rise/fall times and <3% conduction loss at 10A output. | Use Scenario: 12V-to-60V boost for automotive ADAS camera power, operating in under-hood ambient up to 105°C. IC Role / Device Role / Timing Role: Industrial-grade controller (LTC3813IG#PBF) with –40°C to 125°C rating - sustains regulation and current limiting across full junction range. Use Value: BGRTN pin supports –2V bias - suppresses Miller-induced shoot-through during high dV/dt switching in noisy engine-bay environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-up controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3780EG#PBF | Wider VIN range (4–90V), but max VOUT = 60V; requires external sense resistor; no VRNG-based current limit programming. | Preferred for lower-output-voltage, higher-input-voltage designs (e.g., 12V→48V); lacks 100V capability and resistorless sensing. | Select LTC3780EG#PBF only when input exceeds 40V or when fixed 60V output suffices - not a drop-in replacement for 100V requirements. |
| LM5122MMX/NOPB | Max VOUT = 65V; uses external current sense resistor; 2.5MHz max frequency; no PGOOD or SYNC; smaller 16-pin WSON package. | Better suited for space-constrained, medium-voltage (≤65V) applications with less stringent protection or synchronization needs. | Choose LM5122MMX/NOPB for compact 12V→48V supplies where layout area is critical and 100V headroom is unnecessary. |
Compared with LTC3813IG#PBF, LTC3780EG#PBF trades 100V capability and resistorless current sensing for higher input voltage tolerance, while LM5122MMX/NOPB sacrifices voltage range, protection features, and synchronization for size and cost - making LTC3813IG#PBF uniquely suited for high-voltage, high-reliability telecom and industrial boost applications.
Availability
LTC3813IG#PBF is available at Aetrix Electronics and suitable for 24V fan supplies, 48V telecom and base station power supplies, and automotive control systems requiring stable component supply with guaranteed long-term industrial temperature support.
Supply support for LTC3813IG#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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.
The LTC3813IG#PBF belongs to Linear's high-voltage synchronous controller product line, designed specifically for efficient, reliable step-up conversion in telecom, industrial, and automotive power systems demanding >60V output and robust fault protection.
FAQ
What is the maximum output voltage supported by the LTC3813IG#PBF?
The LTC3813IG#PBF supports a maximum output voltage of 100V, as confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables. This capability enables its use in high-voltage applications such as 48V telecom systems and 24V fan supplies where output must exceed typical 60V controller limits. The 100V rating applies across the full –40°C to 125°C operating temperature range specified for the IG grade.
Does the LTC3813IG#PBF require an external current sense resistor?
No, the LTC3813IG#PBF does not require an external current sense resistor. It supports MOSFET RDS(ON)-based current sensing via the SENSE+ and SENSE– pins, with the VRNG pin setting the nominal sense voltage (60–320mV). This feature is explicitly documented in the Applications Information section and eliminates added cost, power loss, and PCB area associated with discrete sense resistors - a key differentiator versus alternatives like LM5122MMX/NOPB.
What is the operating temperature range of the LTC3813IG#PBF?
The LTC3813IG#PBF is rated for operation from –40°C to 125°C, as stated in the Order Information table and confirmed in the Electrical Characteristics notes. This industrial-grade temperature range is distinct from the E-grade (–40°C to 85°C) and makes the LTC3813IG#PBF suitable for under-hood automotive applications and high-ambient industrial environments where sustained reliability at elevated junction temperatures is required.
How does the LTC3813IG#PBF achieve fast transient response?
The LTC3813IG#PBF achieves fast transient response primarily through its 25MHz error amplifier bandwidth and constant off-time current-mode architecture. These features enable sub-100μs load transient recovery, as demonstrated in Figure 14 of the datasheet showing 200mV deviation and full recovery within 1ms under a 0A→4A step. The high-bandwidth EA rapidly adjusts the ITH voltage to correct VFB deviations, while COT control ensures immediate cycle-by-cycle current correction without loop instability.
Can the LTC3813IG#PBF be synchronized to an external clock signal?
Yes, the LTC3813IG#PBF can be synchronized to an external clock signal via the SYNC pin (Pin 7), which accepts TTL/CMOS-compatible inputs from 50kHz to 500kHz. When enabled, the phase-locked loop forces the rising edge of the TG signal to align with the external clock's rising edge - a feature explicitly detailed in the Pin Functions and Typical Performance Characteristics sections. This capability is critical for EMI reduction and multi-phase interleaving in dense power systems.
LTC3813IG#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-SSOP (0.209", 5.30mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up
- Output Configuration:
- Positive
- Topology:
- Boost
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 6.35V ~ 14V
- Frequency - Switching:
- -
- Duty Cycle (Max):
- -
- Synchronous Rectifier:
- Yes
- Clock Sync:
- Yes
- Serial Interfaces:
- -
- Control Features:
- Enable, Power Good, Soft Start
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SSOP
LTC3813IG#PBF FAQ
1.How can I place an order for LTC3813IG#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3813IG#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 LTC3813IG#PBF reliable?
The price and inventory of LTC3813IG#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3813IG#PBF is usually 5 days.
3.What payment methods are accepted for LTC3813IG#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3813IG#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3813IG#PBF?
LTC3813IG#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3813IG#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 LTC3813IG#PBF?
For technical support, including LTC3813IG#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3813IG#PBF requirements.
6.How does Aetrix verify that LTC3813IG#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3813IG#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 LTC3813IG#PBF meets industry standards.
7.What is the process for return or replacement of LTC3813IG#PBF?
All LTC3813IG#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3813IG#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 LTC3813IG#PBF part is unused and in its original packaging.
Return procedure for LTC3813IG#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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