My Inquiry
My Account
Analog Devices Inc. LT3751EFE#TRPBF
- Part No.:
- LT3751EFE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Management - Specialized
- Package:
- 20-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LT3751EFE#TRPBF.pdf
- Description:
- IC CTRLR CAP CHARGER 20-TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,440
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3751EFE#TRPBF from Analog Devices (formerly Linear Technology) is a high-input-voltage flyback controller designed for rapid, regulated high-voltage capacitor charging. It delivers precise output voltage control via external resistor networks, features an integrated 2A rail-to-rail MOSFET gate driver, supports VCC input from 4.75V to 24V, and achieves ≤1-second charge time for 1000µF to 500V in typical configurations - used in photoflash, strobe, and detonator power systems.
For engineers reviewing the LT3751EFE#TRPBF datasheet, LT3751EFE#TRPBF pinout, LT3751EFE#TRPBF application, or LT3751EFE#TRPBF equivalent, key selection considerations include its dual-mode operation (charge-only vs. low-noise regulation), user-programmable over/undervoltage lockouts on VCC and VTRANS, 106mV current-sense threshold accuracy, and TSSOP-20 package compatibility with industrial temperature range (–40°C to 125°C).
Technical Context
The LT3751EFE#TRPBF implements boundary-mode flyback control with start-up protection circuitry that prevents primary current runaway during low-output-voltage conditions. Its dual DCM comparator thresholds (VTH1/VTH2) enable seamless transition from startup to normal boundary-mode operation using a 26kHz one-shot clock and auxiliary current comparator.
It supports both primary-side and secondary-side output voltage sensing via RVTRANS/RVOUT pins, uses FB pin voltage hysteresis (55mV) to distinguish between charge mode (FB < 1.16V), regulation mode (1.16V–1.34V), and overvoltage shutdown (FB > 1.34V), and integrates independent UVLO/OVLO comparators for VCC and VTRANS with programmable trip points based on external resistors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.75V to 24V - enables direct use with 5V, 12V, or 24V industrial supplies without LDO pre-regulation. |
| Current Sense Threshold | 106mV ±6mV - sets accurate peak switch current limit with minimal RSENSE power loss (e.g., 106mV/12mΩ = 8.8A). |
| FB Pin Regulation Threshold | 1.22V ±0.03V - internal reference for stable low-noise output voltage feedback with 55mV hysteresis. |
| Gate Driver Output | 2A peak pull-up/pull-down - drives large NMOS gates efficiently; selectable 5.6V or 10.5V clamp via CLAMP pin. |
| Operating Temperature | –40°C to 125°C - qualified for automotive under-hood, industrial, and defense-grade environments. |
| DCM Detection Accuracy | ±10% over temperature - ensures reliable discontinuous conduction mode initiation across full junction range. |
| UVLO/OVLO Thresholds | 1.225V ±30mV base - allows precise VCC/VTRANS fault detection using standard 1% resistors (e.g., 191kΩ for 12V UVLO). |
Pinout & Package
LT3751EFE#TRPBF is housed in a 20-lead plastic TSSOP package (4.4mm × 6.5mm, 0.65mm pitch) with exposed pad (Pin 21) tied to GND for thermal management. The package supports reflow soldering and meets JEDEC MS-013AC standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| RVTRANS (Pin 1) | VTRANS supply sense input | Measures transformer auxiliary winding voltage; sets minimum VTRANS operating point (≥4.75V) and OVLO/UVLO thresholds. |
| UVLO1 (Pin 2) | VTRANS undervoltage detect | Triggers FAULT when VTRANS drops below 1.225V + 50µA·RUVLO1; requires external resistor for threshold setting. |
| OVLO1 (Pin 3) | VTRANS overvoltage detect | Shuts down switching if VTRANS exceeds 1.225V + 50µA·ROVLO1; enables robust protection against transformer faults. |
| FAULT (Pin 6) | Open-collector fault indicator | Drives low on VCC/VTRANS fault or internal UVLO; requires external pull-up for system-level fault signaling. |
| CHARGE (Pin 8) | Charge cycle initiator | Active-high enable: ≥1.5V starts charging; ≤0.3V forces shutdown; 20µs minimum low pulse width required. |
| HVGATE (Pin 15) | High-side NMOS gate driver output | Drives NMOS gate to VCC – 2V; must not be externally biased - risk of permanent damage if voltage/current applied. |
| GND (Pin 21) | Power and signal reference | Exposed pad must be soldered to PCB ground plane for thermal dissipation and noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 2A rail-to-rail gate driver | Enables direct drive of high-Qg NMOS switches without external buffers, reducing BOM count and layout complexity. |
| User-selectable 5.6V / 10.5V gate clamp | Configured via CLAMP pin tie to VCC (5.6V) or GND (10.5V); optimizes gate drive for low-VCC (<8V) or high-efficiency operation. |
| Programmable VCC/VTRANS UVLO & OVLO | Four independent comparators (UVLO1/OVLO1/UVLO2/OVLO2) allow custom fault thresholds for transformer and supply monitoring. |
| Dual-mode operation (charge/regulation) | Automatically transitions from fast capacitor charging (FB < 1.16V) to low-noise voltage regulation (1.16V–1.34V) without external mode control. |
| Start-up protection with auxiliary current comparator | Prevents primary current runaway at low output voltages by incrementing clock count until DCM detection is established. |
Applications
| Professional Photoflash Systems | Emergency Strobe Lighting |
|---|---|
Use Scenario: Rapid charging of 100–1000µF flash capacitors to 300–600V within sub-second intervals for studio and portable flash units. IC Role / Device Role / Timing Role: Flyback controller managing energy transfer from low-voltage DC bus to high-voltage storage capacitor via step-up transformer. Use Value: Achieves <1s charge time with tight output voltage regulation (±1%) and built-in overvoltage protection to prevent capacitor failure. |
Use Scenario: High-reliability strobe circuits in aircraft evacuation lighting, fire alarm beacons, and emergency vehicle warning systems. IC Role / Device Role / Timing Role: High-voltage capacitor charger providing consistent flash intensity across wide input voltage (12–24V) and temperature ranges. Use Value: Stable operation under no-load condition and rail-to-rail gate drive ensure reliable triggering even after long standby periods. |
| Security/Inventory Control Systems | Detonator Power Supplies |
Use Scenario: Compact, battery-powered laser rangefinders and RFID interrogators requiring pulsed high-voltage bias for avalanche photodiodes or RF power amplifiers. IC Role / Device Role / Timing Role: Regulated HV supply generator delivering precise 200–500V outputs with low ripple (<50mVpp) in low-noise regulation mode. Use Value: Low-noise output and FB pin hysteresis eliminate need for post-regulation filtering, reducing size and cost in space-constrained modules. |
Use Scenario: Safety-critical explosive initiation circuits where controlled, repeatable capacitor discharge is mandatory for pyrotechnic devices. IC Role / Device Role / Timing Role: Fault-tolerant HV charger with dual independent UVLO/OVLO monitoring on both VCC and VTRANS rails. Use Value: FAULT and DONE pins provide deterministic status signaling; latch-based shutdown prevents unintended firing during supply transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage capacitor charger controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3895EFE#TRPBF | Higher VCC max (100V), integrated boost regulator for gate drive, no DCM detection - optimized for synchronous flyback with higher efficiency at >100W. | Targets continuous high-power HV supplies (e.g., medical imaging), not rapid pulsed charging; lacks CHARGE/DONE/FAULT pin logic. | Select LTC3895EFE#TRPBF only when input voltage exceeds 24V or synchronous rectification is required; not drop-in for LT3751EFE#TRPBF designs. |
| MAX17596ATP+T | Fixed 500kHz frequency, no programmable UVLO/OVLO, lower gate drive (1.2A), no start-up protection circuitry - simpler architecture with fewer external components. | Suitable for fixed-output HV supplies (e.g., Nixie tube drivers), but cannot match LT3751EFE#TRPBF's sub-second charge performance or fault coverage. | Choose MAX17596ATP+T for cost-sensitive, non-safety-critical applications where 500kHz fixed frequency simplifies EMI filtering and layout. |
Compared with LTC3895EFE#TRPBF and MAX17596ATP+T, the LT3751EFE#TRPBF uniquely combines rapid capacitor charging capability, dual-mode regulation, comprehensive fault monitoring, and robust start-up protection - making it the preferred choice for pulsed high-voltage systems demanding reliability, speed, and design flexibility.
Availability
LT3751EFE#TRPBF is available at Aetrix Electronics and suitable for professional photoflash systems, emergency strobe lighting, and detonator power supplies requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LT3751EFE#TRPBF 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, documentation, and manufacturing continuity for all Linear ICs including the LT3751 family.
The LT3751 product line was designed specifically for high-voltage capacitor charging and regulated HV supply applications in safety-critical, pulsed-power systems - emphasizing precision, fault resilience, and fast transient response.
FAQ
What is the maximum safe VTRANS voltage for LT3751EFE#TRPBF?
The LT3751EFE#TRPBF has an absolute maximum RVTRANS pin voltage of 65V, enforced by an internal 60V clamp. For reliable operation, VTRANS should remain ≤60V with appropriate external resistor sizing to keep pin current within ±1mA. Exceeding this risks latch-up or permanent damage to the UVLO1/OVLO1 comparators.
Can LT3751EFE#TRPBF operate without an output capacitor?
No - the LT3751EFE#TRPBF requires an output capacitor for stable operation. Its control loop relies on capacitor voltage feedback via RVOUT/FB pins; open-circuit or ultra-low-capacitance conditions cause uncontrolled voltage rise, DCM detection failure, and potential FAULT latch activation. Minimum recommended COUT is 100µF for 500V operation.
How does the CLAMP pin affect gate drive behavior in LT3751EFE#TRPBF?
The CLAMP pin selects the internal gate driver clamp voltage: tied to GND enables 10.5V clamp (for VCC ≥ 12V), while tied to VCC enables 5.6V clamp (for VCC ≤ 8V). This optimizes NMOS gate overdrive and switching losses - incorrect configuration causes excessive gate dissipation or insufficient turn-on, degrading efficiency and reliability in LT3751EFE#TRPBF designs.
Is LT3751EFE#TRPBF pin-compatible with LT3751IFE#TRPBF?
Yes - LT3751EFE#TRPBF and LT3751IFE#TRPBF share identical pinout, package (20-lead TSSOP), and electrical specifications. The only difference is temperature grade: E-grade is specified from –40°C to 125°C (industrial), while I-grade is fully tested and guaranteed over the same range. Both are functionally interchangeable in LT3751EFE#TRPBF applications.
What happens if the FB pin is grounded in LT3751EFE#TRPBF?
Grounding the FB pin forces the LT3751EFE#TRPBF into permanent charge-only mode (FB ≈ 0V < 1.16V), disabling low-noise regulation. While functional for basic capacitor charging, this eliminates output voltage regulation, increases output ripple, and removes overvoltage protection - violating safe operating conditions for sensitive loads. Always connect FB via resistive divider or leave floating only during initial debug.
LT3751EFE#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Applications:
- Photoflash Capacitor Charger
- Current - Supply:
- 5.5mA
- Voltage - Supply:
- 4.75V ~ 24V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP-EP
LT3751EFE#TRPBF FAQ
1.How can I place an order for LT3751EFE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3751EFE#TRPBF 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 LT3751EFE#TRPBF reliable?
The price and inventory of LT3751EFE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3751EFE#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3751EFE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3751EFE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3751EFE#TRPBF?
LT3751EFE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3751EFE#TRPBF 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 LT3751EFE#TRPBF?
For technical support, including LT3751EFE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3751EFE#TRPBF requirements.
6.How does Aetrix verify that LT3751EFE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3751EFE#TRPBF 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 LT3751EFE#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3751EFE#TRPBF?
All LT3751EFE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3751EFE#TRPBF, 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 LT3751EFE#TRPBF part is unused and in its original packaging.
Return procedure for LT3751EFE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3751EFE#TRPBF Tags
-
TPS2511DGNR
Texas Instruments
-
UTC2000/MG
Microchip Technology
-
TUSB320HAIRWBR
Texas Instruments
-
TPS61252DSGR
Texas Instruments
-
PI5USB30216CXUAEX
Diodes Incorporated
-
SN6501DBVR
Texas Instruments
-
CYPD3177-24LQXQT
Infineon Technologies
-
SN6501QDBVRQ1
Texas Instruments
-
STUSB1600AQTR
STMicroelectronics
-
SN6505BDBVR
Texas Instruments
-
SN6501DBVT
Texas Instruments
-
TPS65150PWPR
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…
