LAN1032AT 48V Linear Constant Current IC – LED Automotive Driver – Wide Voltage Regulator – GS Micro
Keywords: LAN1032AT, 48V linear constant current IC, LED automotive driver chip, car light constant current IC, wide voltage regulator, SOT89-5L package, GS Micro
Product Key Parameters Summary: LAN1032AT is a 48V medium-voltage linear constant current IC designed by GS Micro for 9V/18V LEDs. It requires only one external resistor, integrates a 48V power MOSFET, 140°C over-temperature protection, high-voltage current foldback, and reverse polarity protection diode. It supports a wide 7V–48V input without LED off, with a low dropout voltage of just 1V @ 600mA. Max output current is 600mA. Ideal for automotive position lights, clearance lights, taillights, motorcycle lights, low-voltage LED strips, and DC LED lamps. A high‑reliability, low‑cost constant current solution, it perfectly replaces constant current diodes.
Overview:LAN1032AT is a 48V medium-voltage linear constant current IC specially designed for 9V/18V LEDs. LAN1032AT requires only one external resistor, integrates MOSFET, over-temperature protection, high-voltage current foldback, and reverse polarity protection. LAN1032AT supports a wide 7V–48V input without LED off, low dropout voltage of 1V, and is widely used in automotive lighting, low-voltage LED strips, and DC LED lamps. It perfectly replaces constant current diodes and is the preferred high‑reliability, low‑cost constant current solution.
LAN1032AT Product Overview
LAN1032AT is a medium-voltage constant current IC designed for 9V/18V LEDs, supporting high voltage differences. With only one external resistor, it forms a complete constant current drive circuit — extremely simple BOM, lower cost, and faster design.
LAN1032AT integrates 140°C over-temperature protection. When the temperature reaches the threshold, it automatically reduces output current, eliminating flicker at high temperatures, effectively controlling LED junction temperature and extending lifespan.
LAN1032AT features a built-in 48V power MOSFET with a maximum output current of 600mA. At 600mA, the dropout voltage is only 1V, achieving higher efficiency and lower heat generation.
LAN1032AT supports an ultra-wide 7V–48V input, compatible with both 12V and 24V vehicle systems. It maintains stable brightness under voltage fluctuations, automatically reduces current when voltage rises to prevent damage, and never turns off the LEDs. The built-in reverse polarity protection diode enhances reliability in automotive and industrial environments.
LAN1032AT Key Features
⚡ Single resistor sets current
Integrated 48V power MOSFET, 600mA Max
140°C over-temperature protection, no flicker at high temperatures
10V–48V wide input voltage, automatic current foldback at high voltage
Built-in reverse polarity protection diode
Low dropout voltage 1V @ 600mA, high efficiency
SOT89-5L high‑thermal package
Designed for automotive position lights / taillights / motorcycle lights
LAN1032AT Applications
Automotive Lighting: Position lights, clearance lights, taillights, motorcycle lights – all suitable for LAN1032AT. Low‑voltage Lighting: LED strips, light bars, wall washers, low‑voltage LED luminaires – all drivable by LAN1032AT. General DC LED lamps, industrial lighting, decorative lighting, and small constant current driver modules – LAN1032AT is the ideal solution.
LAN1032AT Internal Block Diagram
Internal block diagram: integrated reference source, current sense amplifier, over‑temperature protection logic, 48V power transistor, and reverse polarity protection unit. (Refer to datasheet for detailed diagram)
LAN1032AT Typical Application Circuit
Typical application schematic: VIN → LED+ → LED- → DR pin, CS pin connects external Rcs resistor to GND. Single resistor sets current Io = 0.3V / Rcs.
(For detailed circuit, refer to datasheet. Ensure the thermal pad is firmly attached to an aluminum or copper PCB.)
LAN1032AT Pin Configuration
Pin No.
Symbol
Description
1
NC
LAN1032AT No connect – reserved pin, leave floating
2
GND
LAN1032AT Ground and thermal pad
3
CS
LAN1032AT Current sense pin, connect external resistor to set current
4
DR
LAN1032AT LED constant current output, connect to LED cathode
5
VIN
LAN1032AT Power supply input
LAN1032AT Package Outline Drawing
SOT89-5L package outline (refer to datasheet for detailed dimensions)
60mA (low current, high voltage difference, no LED off)
12–14V
12V
Not recommended for strict low dropout applications
LAN1032AT Application Notes
Power Supply / Startup
Upon power‑up, LAN1032AT is powered via the VIN pin. The IC starts working when the input voltage exceeds 7V. To achieve optimal MOSFET drive voltage, VIN should be above 11V. LAN1032AT supports wide voltage operation from 10V to 48V at low currents, making it an ideal replacement for constant current diodes.
Output Current Setting
LAN1032AT output current is calculated by Io = 0.3V ÷ Rcs. By adjusting the external resistor at the CS pin, the output current can be precisely set.
Wide Voltage Protection Against Over‑Voltage
When the input voltage exceeds the output voltage significantly, the internal high‑voltage protection circuit automatically reduces the output current, preventing the chip from being damaged by over‑voltage while keeping the LEDs lit (not turning off) over the 10V–48V range.
Reverse Polarity Protection
LAN1032AT integrates a reverse polarity protection diode at the power input, preventing damage to the internal ESD protection devices when VIN and GND are reversed, thus improving circuit reliability.
Over‑Temperature Current Regulation
LAN1032AT features a built‑in 140°C over‑temperature protection circuit. When using 9‑10V LEDs with a 13.5V input (high voltage difference), the chip may generate significant heat. Once the chip temperature reaches 140°C (board temperature about 90°C), the LED junction temperature is kept below 125°C. LAN1032AT quickly reduces current during excessive heating, providing self‑protection, suitable for fan‑less small lights.
PCB Layout Guidelines
LAN1032AT uses an SOT89-5L package. The bottom thermal pad must be firmly soldered to an aluminum or copper PCB. Poor soldering may directly damage the chip. For thermal design, keep the chip away from LEDs if possible. Wide traces are recommended for high‑current paths, especially the DR pin (LED cathode) and input/output lines.
LAN1032AT Ordering Information
Part Number
Package
Marking
Packaging
LAN1032AT
SOT89-5L
32AT
Tape & Reel, 4000 pcs/reel
LAN1032AT chips are packed in moisture‑proof aluminum foil bags. After opening, they must be sealed and stored dry. Baking before use is recommended.
GS Micro Automotive Linear LED Driver IC Parameter Comparison
✅ Automatic current reduction within 48V, no LED off
❌ None, risk of damage at over‑voltage
❌ None, risk of damage at over‑voltage
Dropout Voltage
1V @ 600mA, high efficiency
1.2V @ 1A
0.8V @ 2.4A
Package
SOT89-5L (small size, low cost)
ESOP8
DFN
Automotive Suitability
Compatible with 12V/24V systems, perfect fit
Suitable only for stable low‑voltage environments
High‑current applications, higher cost
✅ LAN1032AT Key Advantages: Compared to SL7108 and OC7201C, LAN1032AT is the only one supporting 48V wide voltage, built‑in reverse polarity protection, 140℃ over‑temperature protection, and automatic current foldback without LED off. It is better suited for automotive voltage fluctuation environments, with minimal external components, lower BOM cost, and higher reliability.
LAN1032AT Replacement & Advantages
LAN1032AT can directly replace conventional constant current diodes, ordinary linear constant current ICs, and medium/low voltage LED driver chips.
1. LAN1032AT supports 48V high voltage and up to 600mA output – higher current and wider voltage range. 2. LAN1032AT integrates over‑temperature protection + high‑voltage current foldback – safer for automotive environments, no LED failure. 3. LAN1032AT single‑resistor design – extremely simple BOM, lower cost, faster production. 4. LAN1032AT built‑in reverse polarity protection, low dropout of only 1V – higher efficiency, lower heat. 5. LAN1032AT SOT89-5L high‑thermal, small‑footprint package – ideal for automotive and industrial high‑reliability applications.
Recommended Related Models
GS Micro's full range of automotive LED constant current ICs: LAN1032AT, LAN1032E, LAN1161ED, LAN1163E, LAN1165ED, LAN1165E, LAN1166ED, LAN1166E, LAN1168ED, LAN1053A, LAN1058A, covering 48V/100V/200V voltage ratings to meet all automotive headlight, taillight, and truck light applications.
LAN1032AT Frequently Asked Questions (FAQ)
1. What are the key advantages of LAN1032AT over conventional constant current diodes (CRD)?
LAN1032AT fully replaces traditional constant current diodes with benefits including: higher voltage rating (48V), adjustable output current from 60mA to 600mA (CRDs are usually fixed), ±3% current accuracy vs. CRD's ±15‑20%; integrated 140°C over‑temperature protection and high‑voltage current foldback, preventing LED damage under automotive voltage fluctuations and high temperatures; and built‑in reverse polarity protection – no external protection devices needed, significantly improving reliability.
2. Can LAN1032AT directly replace BCR401W / BCR420U or common SOT89 constant current ICs?
It can replace the constant current function. However, LAN1032AT uses an SOT89-5L package with different pin definitions (adding NC and CS) compared to standard SOT89-3L. PCB layout adjustments are required. If the original board uses a SOT89-3L constant current diode, you need to redesign the pad or use an adapter board.
3. How to calculate and set the output current of LAN1032AT?
Output current Iout = 0.3V / RCS, where RCS is the resistor from CS pin to GND. For example, for 300mA, RCS = 0.3V / 0.3A = 1Ω; for 500mA, RCS = 0.6Ω. Use a 1206 package resistor to withstand power dissipation.
4. Why does LAN1032AT keep LEDs lit (no off) over a 10V–48V wide input range?
The chip features a built‑in high‑voltage current foldback circuit. When input voltage rises excessively, the IC intelligently reduces output current, keeping LEDs dimly lit but not over‑voltage damaged. When voltage returns to normal, output current automatically recovers. The datasheet guarantees no LED off from 10V to 48V, making it ideal for automotive power (12V systems fluctuate 9V–14.5V, truck 24V systems fluctuate 18V–32V, and even 48V systems).
5. What PCB layout precautions should be taken when using LAN1032AT?
① The SOT89-5L bottom thermal pad must be firmly soldered to an aluminum or copper PCB – poor soldering may directly damage the chip. ② The CS resistor should be placed close to the CS and GND pins to minimize sense errors. ③ Input capacitor (10μF–100μF electrolytic) should be as close as possible to VIN and GND. ④ Widen high‑current traces, especially the DR pin (to LED cathode) and input/output lines, to handle up to 600mA.
6. How to request LAN1032AT samples or purchase?
GS Micro provides free samples (up to 5 pieces per order) and technical support. Please call the sales hotline at 18018703531 or add WeChat gsmicro_semi (remark LAN1032AT sample), or email sales@gs-micro.com. Standard bulk order packaging is 4000 pieces/reel, lead time approximately 3‑5 working days.
7. Does LAN1032AT support PWM dimming? How to connect?
Pin 1 of LAN1032AT is NC (reserved pin, recommended to float in the datasheet), and there is no standard PWM dimming interface. In practice, low‑frequency dimming can be achieved by toggling VIN, or by adding a MOSFET in series with the LED loop for PWM dimming (≤1kHz). For more detailed reference designs, please contact our technical support.
8. What is the over‑temperature protection threshold? Does it reduce current earlier?
The chip's internal over‑temperature protection circuit begins to reduce output current when the temperature reaches 140℃ (Datasheet Rev1.2). This mechanism effectively keeps LED junction temperature below 125℃, protecting the LEDs. Under standard thermal conditions (good aluminum PCB heat dissipation, ambient temperature 25℃, input 13V, output 600mA into 9V LEDs), the junction temperature is well below the protection threshold, allowing long‑term stable operation.
Company Profile
GS Micro Semiconductor (Shenzhen) Co., Ltd. (hereinafter referred to as “GS Micro”) was founded in 2023. Its predecessor, LUMENCHIP, was established in 2010. Headquartered in Shenzhen – the capital of technology – GS Micro has focused from its inception on analog and mixed‑signal IC technology and product implementation, promoting the development of green intelligent technologies as a leading analog IC integrated service brand.
GS Micro integrates domestic and international outstanding models and channels, breaking away from traditional independent distribution and agency models. It has created a unique dual model that combines hybrid agency distribution, market analysis and forecasting, technical solution services, and one‑stop supply. Our agency lines coexist with our own brands, and distribution lines coexist with supporting supplies – all three complement each other. Our only tenet is to serve you wholeheartedly, meet customer needs, provide innovative and customer‑oriented products and services to global customers, help customers achieve sustained profitability and success, and build the future of the customer market.
GS Micro offers the industry's most complete solutions and product lines, including MCUs, power management ICs, signal chain ICs, and power discrete devices. The product portfolio is comprehensive, covering signal processing, power management, automotive electronics, LED lighting, and more. With strong marketing planning capabilities and rich professional market operation experience, our authorized partners include DONGWOON (Korea), China Resources Microelectronics (PowTech, CR MICRO), CRHJ, APM, COOLSEMI, ANHI, Reasunos, OCX, MassChip, XLSEMI, Zhixin Semiconductor, NSIWAY, EGmicro, Ruimeng Technology, ChipWays, AISPEECH, Aerosemi, and others.
GS Micro adheres to the corporate values of “striving for the best, customer‑centric, and value contribution”. We focus on IC technology and product implementation, promoting the sustainable development of green intelligent technologies. Our distribution and application solutions lead the global semiconductor market in specialized segments.
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