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Analog Devices Inc. LT3796HFE-1#TRPBF
- Part No.:
- LT3796HFE-1#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LT3796HFE-1#TRPBF.pdf
- Description:
- IC LED DRIVER CTRLR PWM 28TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,030
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Product details
Overview
LT3796HFE-1#TRPBF from Analog Devices (formerly Linear Technology) is a 100V constant-current/constant-voltage DC/DC controller optimized for dual-string LED driving and high-voltage battery/supercapacitor charging. It features dual current sense amplifiers, programmable analog dimming via CTRL pin (250 mV full-scale threshold), 100 kHz–1 MHz adjustable switching frequency, and integrated top-gate PMOS driver with independent TGEN enable. It operates across –40°C to +150°C junction temperature.
For engineers reviewing the LT3796HFE-1#TRPBF datasheet, LT3796HFE-1#TRPBF pinout, LT3796HFE-1#TRPBF application, or LT3796HFE-1#TRPBF equivalent, this page delivers verified technical context, validated pin functions, confirmed thermal rating (H-grade), real-world dimming performance (3000:1 PWM), and precise alternative selection guidance for LED driver and charger designs requiring high-side disconnect and dual-loop regulation.
Technical Context
The LT3796HFE-1#TRPBF implements fixed-frequency current-mode control with two independent feedback paths: FB1 regulates open-LED protection and CV mode at 1.25 V, while FB2 supports secondary voltage regulation or PMOS gate disable above 1.3 V. Its dual current sense architecture includes a rail-to-rail ISP/ISN amplifier (0–100 V common mode) and a separate high-side CSOUT amplifier configurable via external resistors.
Unlike the base LT3796, the -1 variant replaces SYNC with TGEN - an independent top-gate enable pin that forces TG high without disabling switching - enabling dynamic deactivation of a second LED string or extension of analog dimming range. The H-grade package guarantees operation up to 150°C junction temperature with thermal shutdown and fault latching via VMODE/FAULT pins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 6 V to 100 V input - supports wide-range industrial and automotive LED systems with transient tolerance. |
| Switching Frequency | 100 kHz to 1 MHz (RT-programmable) - enables optimization of efficiency vs. EMI and inductor size. |
| Current Sense Threshold | 250 mV full-scale (CTRL = 2.015 V) - sets precise LED current with ±7 mV accuracy over temperature. |
| Junction Temp Range | –40°C to +150°C - H-grade qualification ensures reliability in high-ambient lighting and charger applications. |
| Dimming Ratio | 3000:1 true-color PWM - achieved via dedicated PWM input with fast TG/GATE response and no color shift. |
| Top Gate Driver | PMOS driver with 7 V clamp and TGEN enable - allows safe high-side disconnect without affecting main loop stability. |
| FB Regulation Voltage | 1.25 V on FB1/FB2 - enables accurate constant-voltage regulation or open-LED detection with 10 mV hysteresis. |
Pinout & Package
LT3796HFE-1#TRPBF uses a 28-lead plastic TSSOP package with exposed pad (Pin 29) soldered to PCB ground for thermal management. Absolute maximum ratings include 100 V on VIN, ISP, ISN, CSP, CSN, and VS pins.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ISP (1) | Positive current sense input / TG supply rail | Serves as high-side reference for LED current sensing and powers TG driver; withstands up to 100 V. |
| ISN (2) | Negative current sense input | Completes ISP–ISN differential pair; referenced to GND; enables Kelvin sensing of LED string current. |
| TG (3) | Top gate driver output | Drives external PMOS switch between ISP and (ISP – 7 V); internal clamp prevents gate overvoltage. |
| GND (4,17,21,22,29) | Ground / current sense return | Multiple GND pins reduce noise; exposed pad (29) must be soldered for thermal conduction and low-impedance return. |
| ISMON (5) | Current monitor output | Reports ILED × RLED × 4 as voltage; sinks to GND during PWM low; used for system-level current telemetry. |
| FB2 (6) | Secondary voltage feedback | Regulates to 1.25 V; if driven >1.3 V, disables TG and pulls GATE low - enables overvoltage protection or secondary loop control. |
| FB1 (7) | Primary voltage feedback / open-LED detect | Regulates to 1.25 V; asserts VMODE when V(ISP–ISN) < 25 mV and FB1 > 1.19 V - signals open-circuit LED fault. |
| VC (8) | Error amplifier output | High-impedance during PWM low to retain demand state; requires RC compensation for loop stability. |
| CTRL (9) | Analog dimming threshold control | Sets V(ISP–ISN) threshold linearly (0.25 × VCTRL) from 16 mV to 250 mV - enables precise current scaling. |
| VREF (10) | 2.015 V reference output | Stable reference for CTRL divider; supplies ≤100 µA - used for temperature-compensated dimming or current limiting. |
| SS (11) | Soft-start / fault timer | 28 µA pull-up charges external cap; pulled down during faults (LED OC, INTVCC UVLO, thermal) - enables auto-restart delay. |
| RT (12) | Frequency programming | Resistor to GND sets oscillator frequency; 82.5 kΩ yields 105 kHz, 19.6 kΩ yields 400 kHz, 6.65 kΩ yields 1 MHz. |
| TGEN (13) | Top gate enable (LT3796-1 only) | Low signal forces TG high independently of PWM - enables selective deactivation of second current loop or extended analog dimming. |
| PWM (14) | Digital dimming input | Active-low signal halts switching, idles oscillator, disconnects VC, and pulls TG high - achieves 3000:1 dimming ratio. |
| FAULT (15) | Open-collector fault flag | Pulled low on FB1 OV (>1.3 V), INTVCC UVLO (<4 V), LED overcurrent (>375 mV), or thermal shutdown - latched until SS discharged. |
| VMODE (16) | Open-LED status flag | Pulled low when FB1 > 1.19 V and V(ISP–ISN) < 25 mV - indicates open LED string; updated only during PWM high phase. |
| SENSE (18) | Switch current sense input | Kelvin-connected to RSENSE positive terminal; monitors NMOS source current with 113 mV current limit threshold. |
| GATE (19) | NMOS gate driver output | Swings between INTVCC and GND; driven low during fault/idle - controls main power switch with 20 ns rise time. |
| INTVCC (20) | Internal LDO output | 7.7 V regulated supply for gate drivers and logic; bypassed with 4.7 µF ceramic; shuts down below 3.8 V UVLO. |
| VIN (23) | Main input supply | Accepts 6–100 V; local 0.22 µF bypass required; powers INTVCC LDO and internal circuitry. |
| EN/UVLO (24) | Enable and undervoltage lockout | 1.22 V falling threshold with programmable hysteresis; sub-µA bias above threshold - enables precise power sequencing. |
| VS (25) | Current sense amplifier supply | 3–100 V supply for ISP/ISN amplifier - enables high-side current monitoring without level-shifting. |
| CSN (26) | Current sense amplifier negative input | Common-mode input tied to VS in typical configurations; supports rail-to-rail sensing up to 100 V. |
| CSP (27) | Current sense amplifier positive input | Sinks current from external resistor network; sets CSOUT = V(ISP–ISN)/RIN1 - enables precision current reporting. |
| CSOUT (28) | Current sense amplifier output | Sources current proportional to V(ISP–ISN); typically connected to resistor-to-GND for voltage output scaling. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent current sense paths | ISP/ISN for primary LED string; CSP/CSN for secondary current/voltage monitoring - enables dual-string or charger+LED co-location. |
| TGEN-controlled top-gate enable | Independent PMOS gate control without disabling main regulator - allows dynamic reconfiguration of output topology during operation. |
| Programmable analog dimming (CTRL) | Linear 0.25×VCTRL scaling from 16 mV to 250 mV threshold - provides smooth, flicker-free dimming without PWM artifacts. |
| 150°C guaranteed junction operation (H-grade) | Validated thermal performance across full range - eliminates derating concerns in enclosed high-power LED fixtures and EV chargers. |
| C/10 battery charge detection | Comparator triggers at 25 mV V(ISP–ISN) with 200 mV hysteresis - enables accurate end-of-charge termination for Li-ion and supercapacitors. |
| Open-LED protection with VMODE flag | Asserts VMODE when FB1 > 1.19 V and V(ISP–ISN) < 25 mV - provides unambiguous fault signaling for system-level diagnostics. |
Applications
| High-Power Architectural LED Lighting | Automotive Exterior Lighting |
|---|---|
Use Scenario: Driving multiple high-voltage LED strings (e.g., 85 V, 400 mA) in commercial building façades with thermal constraints. IC Role / Device Role / Timing Role: Constant-current controller regulating two independent LED strings using ISP/ISN and FB2 loops; TGEN enables dynamic string disable for zoning. Use Value: 150°C H-grade operation ensures reliability in sealed enclosures; 3000:1 PWM dimming maintains color fidelity across brightness levels. |
Use Scenario: Adaptive front-lighting systems (AFS) requiring independent control of low-beam and high-beam LED arrays with fault reporting. IC Role / Device Role / Timing Role: Dual-loop controller managing separate current-regulated beams; VMODE/FAULT provide ASIL-B–compatible open-circuit and overcurrent flags. Use Value: TGEN allows real-time beam pattern reconfiguration; C/10 detection supports LED health monitoring over lifetime. |
| Battery & Supercapacitor Chargers | Industrial High-Voltage Power Supplies |
Use Scenario: Precision 48 V lithium-titanate or supercapacitor charger with CC/CV profile and end-of-charge cutoff. IC Role / Device Role / Timing Role: Constant-current/constant-voltage regulator using FB1 for voltage regulation and ISP/ISN for current control; C/10 comparator triggers termination. Use Value: 100 V input capability supports wide-input AC/DC front-ends; 25 mV C/10 threshold enables ±2% charge termination accuracy. |
Use Scenario: Programmable 100 V output supply for test equipment or plasma generators requiring stable current limiting. IC Role / Device Role / Timing Role: Accurate current-limited voltage regulator using FB2 for CV mode and SENSE for ILIM; RT sets 340 kHz switching for low-noise operation. Use Value: Dual current sense paths allow simultaneous load current monitoring and protection; 113 mV SENSE threshold ensures fast overcurrent shutdown. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar constant-current/constant-voltage controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3789EFE#TRPBF | Single-output synchronous buck-boost controller; no built-in top-gate driver or TGEN; max 40 V input; supports I²C configuration. | Lacks dual-string support and high-side PMOS control; suited for lower-voltage, digitally managed DC/DC converters. | Select LTC3789EFE#TRPBF only for compact, I²C-configurable buck-boost designs under 40 V input where TGEN and 100 V operation are unnecessary. |
| LT3762HFE#TRPBF | Single-string LED controller; no FB2 or TGEN; includes boost/buck-boost topology support; same 100 V rating and H-grade temp range. | Supports wider topology flexibility but lacks dual-loop regulation and independent top-gate enable for string multiplexing. | Choose LT3762HFE#TRPBF for high-efficiency single-string LED drivers where dual-loop functionality is not required and topology adaptability is critical. |
Compared with LTC3789EFE#TRPBF and LT3762HFE#TRPBF, the LT3796HFE-1#TRPBF uniquely integrates dual current sense paths, TGEN-enabled PMOS control, and guaranteed 150°C operation - making it the only option for thermally demanding, dual-string LED or charger applications requiring independent loop management.
Availability
LT3796HFE-1#TRPBF is available at Aetrix Electronics and suitable for high-power LED lighting, automotive exterior lighting, and battery/supercapacitor charging applications requiring stable component supply, long-term lifecycle assurance, and guaranteed high-temperature operation.
Supply support for LT3796HFE-1#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 its legacy of high-performance analog ICs for power management, signal conditioning, and timing.
The LT3796HFE-1#TRPBF belongs to Linear's LED driver and battery charger controller product line, designed specifically for high-voltage, high-reliability constant-current regulation with dual-loop flexibility and robust fault handling.
FAQ
What is the maximum operating junction temperature for the LT3796HFE-1#TRPBF?
The LT3796HFE-1#TRPBF is rated for continuous operation from –40°C to +150°C junction temperature. This H-grade qualification is verified per manufacturer specifications and distinguishes it from E- and I-grade variants limited to 125°C. Thermal shutdown activates above 165°C, and derating begins beyond 125°C to ensure long-term reliability in enclosed LED fixtures or high-ambient charger designs.
How does the TGEN pin differ from the PWM pin on the LT3796HFE-1#TRPBF?
The TGEN pin on the LT3796HFE-1#TRPBF provides independent control of the top-gate driver: pulling TGEN low forces TG high to disable a PMOS switch without halting switching operation or resetting the control loop. In contrast, the PWM pin disables the entire regulator - stopping oscillation, pulling GATE low, and placing VC in high-impedance storage mode. This makes TGEN ideal for dynamic string reconfiguration while maintaining system responsiveness.
Can the LT3796HFE-1#TRPBF drive two independent LED strings simultaneously?
Yes - the LT3796HFE-1#TRPBF supports dual-string operation via its dual current sense architecture: ISP/ISN regulates the primary string, while CSP/CSN (with external resistor network) and FB2 enable secondary current or voltage regulation. When combined with TGEN, one string can be dynamically disabled without affecting the other, enabling zoning, redundancy, or adaptive lighting patterns in architectural and automotive applications.
What is the purpose of the VMODE pin on the LT3796HFE-1#TRPBF?
The VMODE pin on the LT3796HFE-1#TRPBF is an open-collector output that asserts low when FB1 exceeds 1.19 V and V(ISP–ISN) falls below 25 mV - indicating an open LED condition. It updates only during PWM high time and latches during PWM low, providing a clean, debounced fault signal for microcontroller monitoring. An external pull-up resistor is required, and VMODE enables system-level diagnostics without interrupting regulation.
Does the LT3796HFE-1#TRPBF support C/10 battery charge termination?
Yes - the LT3796HFE-1#TRPBF includes a dedicated C/10 comparator that triggers when V(ISP–ISN) drops to 25 mV (typical) with 200 mV hysteresis. This function is enabled when VMODE is falling and FB1 = 1.25 V, allowing precise end-of-charge detection for lithium-based batteries and supercapacitors. The threshold is stable over temperature and independent of CTRL or analog dimming settings.
LT3796HFE-1#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- True Color PWM™
- Package/Case:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Controller
- Topology:
- SEPIC, Step-Down (Buck), Step-Up (Boost)
- Internal Switch(s):
- No
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 6V
- Voltage - Supply (Max):
- 100V
- Voltage - Output:
- -
- Current - Output / Channel:
- -
- Frequency:
- 100kHz ~ 1MHz
- Dimming:
- Analog, PWM
- Applications:
- -
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSSOP-EP
LT3796HFE-1#TRPBF FAQ
1.How can I place an order for LT3796HFE-1#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3796HFE-1#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 LT3796HFE-1#TRPBF reliable?
The price and inventory of LT3796HFE-1#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3796HFE-1#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3796HFE-1#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3796HFE-1#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3796HFE-1#TRPBF?
LT3796HFE-1#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3796HFE-1#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 LT3796HFE-1#TRPBF?
For technical support, including LT3796HFE-1#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3796HFE-1#TRPBF requirements.
6.How does Aetrix verify that LT3796HFE-1#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3796HFE-1#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 LT3796HFE-1#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3796HFE-1#TRPBF?
All LT3796HFE-1#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3796HFE-1#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 LT3796HFE-1#TRPBF part is unused and in its original packaging.
Return procedure for LT3796HFE-1#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3796HFE-1#TRPBF Tags
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BCR402RE6327HTSA1
Infineon Technologies
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BCR430UXTSA2
Infineon Technologies
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BCR420UE6433HTMA1
Infineon Technologies
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BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
-
CL2N8-G
Microchip Technology
-
BCR420UW6-7
Diodes Incorporated
-
BCR421UW6-7
Diodes Incorporated
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BCR420UFD-7
Diodes Incorporated
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BCR421UFD-7
Diodes Incorporated
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