My Inquiry
My Account
Analog Devices Inc. LTC3900HS8#PBF
- Part No.:
- LTC3900HS8#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Gate Drivers
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LTC3900HS8#PBF.pdf
- Description:
- IC GATE DRVR LOW-SIDE 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,435
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3900HS8#PBF from Analog Devices (formerly Linear Technology) is a secondary-side N-channel synchronous rectifier driver for isolated forward converters, featuring programmable timeout protection, reverse inductor current detection, 15ns rise/fall times at 5V VCC with 4.7nF load, 4.5V–11V supply range, and operation up to 150°C junction temperature. It drives external MOSFETs Q3 (forward) and Q4 (catch) using pulse transformer synchronization in telecom and industrial 36V–72V input DC/DC supplies.
For engineers reviewing the LTC3900HS8#PBF datasheet, LTC3900HS8#PBF pinout, LTC3900HS8#PBF application, or LTC3900HS8#PBF equivalent, key selection criteria include its –40°C to 150°C operating range, differential current sense threshold (10.5mV typ. for H-grade), SYNC edge-sensitive dual-comparator input (±1.4V thresholds), timer-based fault shutdown, and SO-8 package compatibility with thermal derating above 125°C.
Technical Context
The LTC3900HS8#PBF implements dual-edge–sensitive SYNC detection via separate S+ and S– comparators (±1.4V thresholds), enabling robust synchronization from pulse transformers even during power-up/down transients. Its timer circuit uses an external RTMR/CTMR network with internal 0.2×VCC timeout threshold and 200ns reset pulses on every SYNC negative edge.
Current sensing operates differentially across CS+/CS– with 10.5mV threshold (H-grade), active only 250ns after CG goes high to avoid turn-on ringing, and includes internal 11V clamp on CS+ and 0.5×VCC clamp on TIMER. Driver outputs FG and CG provide matched pull-up/pull-down resistance (1.2Ω/1.2Ω typ. for H-grade) and 2A peak current capability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Supply Range | 4.5V to 11V - supports bias from rectified secondary winding without external regulator |
| Operating Junction Temp | –40°C to +150°C - qualified for high-temp industrial and automotive under-hood applications |
| Current Sense Threshold | 10.5mV (typ.) - matches RDS(ON) TC of external MOSFETs to maintain accuracy over temperature |
| SYNC Input Thresholds | ±1.4V with ±0.2V hysteresis - enables reliable edge detection from pulse transformer signals |
| Driver Rise/Fall Time | 15ns (at VCC = 5V, CL = 4.7nF) - ensures fast MOSFET switching for high-frequency forward converters |
| UVLO Threshold | 4.1V rising, 3.6V falling - prevents erratic gate drive during brown-out or startup |
| Timer Timeout Accuracy | ±10% (RTMR = 4.7kΩ, CTMR = 1000pF) - provides configurable fault response time independent of VCC |
Pinout & Package
Package: 8-Lead Plastic Small Outline (SO-8), RoHS-compliant, rated for –40°C to +150°C junction temperature. Thermal resistance θJA = 130°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SYNC (Pin 8) | Synchronization Input | Edge-sensitive input accepting ±5V pulse transformer signals; triggers FG/CG state changes on positive/negative slews |
| TIMER (Pin 7) | Programmable Timeout Input | Connects to external RC network; resets on each SYNC negative edge; disables both drivers if voltage exceeds 0.2×VCC |
| GND (Pin 6) | Power Ground Reference | Return path for VCC bypass capacitor and internal logic; must be low-inductance connection to minimize noise coupling |
| FG (Pin 5) | Forward MOSFET Gate Driver | Drives gate of N-channel Q3; pulls high during positive SYNC edge, low during negative SYNC edge |
| CS+ (Pin 1), CS– (Pin 2) | Differential Current Sense Inputs | Monitor voltage across Q4's RDS(ON); trip at >10.5mV to shut off CG and prevent reverse inductor current damage |
| CG (Pin 3) | Catch MOSFET Gate Driver | Drives gate of N-channel Q4; pulls high during negative SYNC edge, low during positive SYNC edge |
| VCC (Pin 4) | Main Supply Input | Power source for drivers and internal circuitry; requires local 4.7µF ceramic bypass to GND |
Key Features
| Feature | Design Value |
|---|---|
| Pulse transformer synchronization | Supports isolated control via transformer-coupled SYNC signal, eliminating optocouplers and reducing latency |
| Reverse inductor current protection | Differential CS+ / CS– comparator shuts off CG within nanoseconds when Q4 conducts reverse current, preventing avalanche failure |
| Programmable timeout protection | External RTMR/CTMR sets fault response time; independent of VCC and immune to missing or malformed SYNC pulses |
| Matched temperature coefficient | 10.5mV current sense threshold has +0.33%/°C TC - tracks RDS(ON) drift of external MOSFETs for stable overcurrent protection |
| High-temperature qualification | –40°C to +150°C operation - validated for harsh environments including industrial motor drives and telecom rectifiers |
Applications
| 48V Telecom Rectifier | Industrial Forward Converter |
|---|---|
Use Scenario: 36V–72V input isolated DC/DC module delivering 3.3V/40A to base station processors. IC Role / Device Role / Timing Role: Secondary-side synchronous rectifier driver coordinating Q3/Q4 switching via pulse transformer sync from LT1952 primary controller. Use Value: Replaces Schottky diodes to reduce conduction loss by >60%, improving full-load efficiency from 85% to 92% at 48V input. |
Use Scenario: 400V DC input distributed power system stepping down to 12V/24V for PLC I/O modules in factory automation. IC Role / Device Role / Timing Role: Isolated forward converter driver managing dual N-MOSFET rectification with reverse-current shutdown during transient load dumps. Use Value: Enables continuous conduction mode operation across –25°C to +85°C ambient using programmable timer and TC-matched current sense. |
| Automotive Onboard Charger | High-Voltage Industrial PSU |
Use Scenario: Bidirectional OBC auxiliary supply using forward topology with 400V battery input and 12V/15A output for vehicle ECUs. IC Role / Device Role / Timing Role: High-temp-rated synchronous rectifier driver ensuring safe catch-FET turn-off during regenerative braking-induced reverse current events. Use Value: Prevents Q4 avalanche failure during rapid bus voltage collapse by detecting sub-10.5mV reverse RDS(ON) voltage within 250ns of CG activation. |
Use Scenario: 600V input industrial SMPS powering servo drives, requiring >90% efficiency and fault resilience in dusty, high-ambient-temperature enclosures. IC Role / Device Role / Timing Role: Robust secondary-side gate driver with UVLO hysteresis and timer-based lockout protecting MOSFETs during brown-out and sync loss. Use Value: Eliminates need for external watchdog ICs; single-chip solution reduces BOM count while maintaining 150°C junction reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous rectifier driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5112MY/NOPB | Single-channel high-speed gate driver; no integrated current sense or timer; requires external comparators and timing circuitry | Suitable for non-isolated or custom-synchronized designs where isolation barrier timing is managed externally | Choose LM5112MY/NOPB only when full system-level control of sync timing and current protection is implemented externally |
| UCC27524D | Dual-channel low-side driver with 5A peak current; lacks differential current sense, SYNC edge discrimination, and programmable timeout | Better suited for bootstrap-driven half-bridge topologies without isolation requirements | Select UCC27524D for cost-sensitive, non-isolated forward or LLC designs where protection logic resides in MCU or primary controller |
Compared with LTC3900HS8#PBF, LM5112MY/NOPB offers higher peak drive current but requires three additional ICs to replicate current sense, timer, and dual-edge sync functions; UCC27524D provides faster switching but cannot replace LTC3900HS8#PBF in isolated forward converters without major redesign of protection and synchronization architecture.
Availability
LTC3900HS8#PBF is available at Aetrix Electronics and suitable for 48V telecom rectifiers, industrial forward converters, automotive onboard chargers, and high-voltage distributed power systems requiring stable component supply across extended temperature ranges.
Supply support for LTC3900HS8#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 product support, datasheets, and application notes for the LTC portfolio. Linear's legacy precision analog and power management ICs remain industry benchmarks.
The LTC3900 family was designed specifically for high-efficiency isolated forward converters requiring robust secondary-side MOSFET control, fault protection, and transformer-based synchronization - targeting telecom, industrial, and automotive power systems.
FAQ
What is the maximum operating junction temperature for LTC3900HS8#PBF?
The LTC3900HS8#PBF is fully specified and tested over a junction temperature range of –40°C to +150°C. This H-grade qualification enables use in high-ambient environments such as enclosed industrial power supplies and automotive under-hood applications where thermal management is constrained. Derating guidelines apply above 125°C per datasheet Note 2.
How does the LTC3900HS8#PBF detect reverse inductor current?
The LTC3900HS8#PBF detects reverse inductor current by monitoring the voltage across the drain-source terminals of the catch MOSFET (Q4) via its differential CS+ and CS– inputs. When CS+ rises more than 10.5mV above CS– - indicating reverse current flow - the LTC3900HS8#PBF immediately pulls CG low to disable Q4, preventing avalanche failure. This function activates 250ns after CG goes high to avoid turn-on ringing artifacts.
Can LTC3900HS8#PBF operate without a pulse transformer on the SYNC pin?
Yes - the LTC3900HS8#PBF SYNC input accepts bipolar square-wave signals directly, provided the positive and negative amplitudes exceed ±1.4V with sufficient slew rate. Figure 8 in the datasheet shows a symmetrical drive circuit using 74HC14/132 gates. However, for isolated applications, pulse transformer coupling remains the recommended method to maintain galvanic separation and noise immunity.
What is the purpose of the TIMER pin on LTC3900HS8#PBF?
The TIMER pin on LTC3900HS8#PBF connects to an external RC network (RTMR, CTMR) that programs a fault timeout period. The internal timer resets on every negative SYNC edge; if SYNC pulses are missing or malformed, the timer voltage rises until it reaches 0.2×VCC, triggering simultaneous shutdown of FG and CG. This protects external MOSFETs during primary-controller faults or power-down sequences.
Does LTC3900HS8#PBF support continuous conduction mode (CCM) at no load?
The LTC3900HS8#PBF defaults to discontinuous conduction mode (DCM) at light loads due to its fixed 10.5mV current sense threshold. To enforce CCM at no load, external resistor dividers (RCS1/RCS2) can be added to the CS+ pin to raise the effective threshold - matching the expected RDS(ON) × negative peak current product - as detailed in the Applications Information section of the datasheet.
LTC3900HS8#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
- Programmable:
- Not Verified
- Driven Configuration:
- Low-Side
- Channel Type:
- Synchronous
- Number of Drivers:
- 2
- Gate Type:
- N-Channel MOSFET
- Voltage - Supply:
- 4.5V ~ 11V
- Logic Voltage - VIL, VIH:
- -
- Current - Peak Output (Source, Sink):
- 2A, 2A
- Input Type:
- Inverting, Non-Inverting
- High Side Voltage - Max (Bootstrap):
- -
- Rise / Fall Time (Typ):
- 15ns, 15ns
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO
LTC3900HS8#PBF FAQ
1.How can I place an order for LTC3900HS8#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3900HS8#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 LTC3900HS8#PBF reliable?
The price and inventory of LTC3900HS8#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3900HS8#PBF is usually 5 days.
3.What payment methods are accepted for LTC3900HS8#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3900HS8#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3900HS8#PBF?
LTC3900HS8#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3900HS8#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 LTC3900HS8#PBF?
For technical support, including LTC3900HS8#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3900HS8#PBF requirements.
6.How does Aetrix verify that LTC3900HS8#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3900HS8#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 LTC3900HS8#PBF meets industry standards.
7.What is the process for return or replacement of LTC3900HS8#PBF?
All LTC3900HS8#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3900HS8#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 LTC3900HS8#PBF part is unused and in its original packaging.
Return procedure for LTC3900HS8#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3900HS8#PBF Tags
-
ZXGD3009E6TA
Diodes Incorporated
-
1EDN7512BXTSA1
Infineon Technologies
-
UCC27517DBVR
Texas Instruments
-
MCP1416T-E/OT
Microchip Technology
-
MCP1402T-E/OT
Microchip Technology
-
MCP1415T-E/OT
Microchip Technology
-
MCP1401T-E/OT
Microchip Technology
-
IX4428NTR
Littelfuse Inc.
-
IRS2005STRPBF
Infineon Technologies
-
IRS2008STRPBF
Infineon Technologies
-
IX4310TTR
Littelfuse Inc.
-
2EDN7524RXTMA1
Infineon Technologies
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…
