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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > LED Drivers

Microchip Technology CL520K4-G

Name: CL520K4-G
Brand: Microchip Technology
SKU: CL520K4-G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: CL520K4-G

Manufacturer:: Microchip Technology

Category:: LED Drivers

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: CL520K4-G.pdf

Description:: IC LED DRIVER LINEAR 20MA TO252

Quantity:: RFQ Add To RFQ list

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Product details

Overview

CL520K4-G from Microchip Technology is a fixed-current linear LED driver delivering 20 mA ±10% constant output current with 1V dropout, operating across a 4.75V to 90V supply range and rated for 90V transient immunity. It functions as a high-voltage LED current sink in signage and specialty lighting systems driving single or multiple LEDs.

For engineers reviewing the CL520K4-G datasheet, CL520K4-G pinout, CL520K4-G application, or CL520K4-G equivalent, key selection criteria include its TO-252 (D-PAK) package, thermal resistance (θ_JA = 81°C/W), temperature-compensated current regulation, and suitability for ground-referenced or switched-LED topologies without external transient protection.

Technical Context

The CL520K4-G implements a linear constant-current regulator architecture with internal temperature compensation to maintain stable 20 mA output over –40°C to +125°C junction temperature. Its 90V absolute maximum supply rating enables direct operation from unregulated industrial or automotive-derived rails.

It features a 1V minimum dropout voltage, allowing efficient operation with higher LED string counts or lower input voltages, and includes fast turn-on/turn-off response (t_ON/t_OFF ≤ 100 µs) for PWM dimming compatibility. The device shuts off LED current when V_DD falls below 1V and draws ≤1 mA quiescent current.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Current	20 mA ±10% - precise, temperature-compensated current sink for consistent LED brightness
Supply Voltage Range	4.75V to 90V - supports wide-input industrial and signage power rails without pre-regulation
Dropout Voltage	1V - enables use with longer LED strings or lower supply margins while maintaining regulation
Transient Immunity	90V max rating - withstands load-dump and inductive switching transients without external TVS
Junction Temp Range	–40°C to +125°C - suitable for enclosed or high-ambient lighting enclosures
Thermal Resistance θ_JA	81°C/W (TO-252) - defines power dissipation limit on standard JEDEC test board
V_DD Bypass Capacitor	100 nF - required local decoupling to ensure stability and transient response

Pinout & Package

CL520K4-G is housed in a 3-lead TO-252 (D-PAK) surface-mount package with exposed thermal pad for enhanced heat dissipation. Pin 1 is VDD, Pin 2 is GND (circuit common, not for external connection), and Pin 3 is OUT (constant-current sink output).

Pin/Terminal	Circuit Role	Design Meaning
VDD	Supply input	Accepts 4.75–90V; must be bypassed with 100 nF capacitor to GND for stability
GND	Circuit common	Internal reference node; not intended for external current return path
OUT	Current sink output	Delivers regulated 20 mA to LED anode; connects to cathode of LED string

Key Features

Feature	Design Value
Temperature-compensated current	Maintains ±10% output accuracy across –40°C to +125°C, eliminating external thermal derating circuits
High-voltage transient tolerance	90V absolute max rating allows direct connection to 48V/72V industrial buses with no added TVS diodes
Low dropout operation	1V headroom enables use with up to 22 white LEDs (3.2V each) at 48V supply
Fast enable/disable timing	t_ON/t_OFF ≤ 100 µs supports high-frequency PWM dimming without current overshoot

Applications

Architectural Signage	Industrial Control Panels
Use Scenario: Illuminating channel letters and backlit acrylic signs powered from 24V–48V DC distribution rails. IC Role / Device Role / Timing Role: Constant-current sink regulating LED string brightness independent of forward voltage drift or temperature rise. Use Value: Eliminates need for individual LED resistors or switching regulators, reducing BOM count and thermal footprint in sealed enclosures.	Use Scenario: Driving status indicators and warning lights on factory HMIs and PLC I/O modules with variable input voltage (e.g., 24V ±20%). IC Role / Device Role / Timing Role: High-voltage tolerant current source enabling direct connection to unregulated control bus without protection components. Use Value: Withstands 90V transients from relay coil flyback or motor commutation, improving system reliability in electrically noisy environments.
Transportation Lighting	Emergency Exit Signs
Use Scenario: Powering interior cabin markers and door-edge lighting in buses and rail cars using 24V or 48V battery systems. IC Role / Device Role / Timing Role: Linear LED driver with shutdown threshold (V_DD(OFF) = 1V) enabling fail-safe LED extinguishment during low-battery conditions. Use Value: Prevents dim or flickering LEDs during brownout events, ensuring compliance with visibility safety standards.	Use Scenario: Maintaining illuminated exit path markings during AC mains failure using backup battery (e.g., 12V–48V). IC Role / Device Role / Timing Role: Fixed-current sink providing stable 20 mA to high-efficiency LED arrays under varying battery voltage discharge profiles. Use Value: Delivers consistent lumen output across full battery discharge curve without active feedback or microcontroller intervention.

Architectural Signage

Industrial Control Panels

Use Scenario: Illuminating channel letters and backlit acrylic signs powered from 24V–48V DC distribution rails.

IC Role / Device Role / Timing Role: Constant-current sink regulating LED string brightness independent of forward voltage drift or temperature rise.

Use Value: Eliminates need for individual LED resistors or switching regulators, reducing BOM count and thermal footprint in sealed enclosures.

Use Scenario: Driving status indicators and warning lights on factory HMIs and PLC I/O modules with variable input voltage (e.g., 24V ±20%).

IC Role / Device Role / Timing Role: High-voltage tolerant current source enabling direct connection to unregulated control bus without protection components.

Use Value: Withstands 90V transients from relay coil flyback or motor commutation, improving system reliability in electrically noisy environments.

Transportation Lighting

Emergency Exit Signs

Use Scenario: Powering interior cabin markers and door-edge lighting in buses and rail cars using 24V or 48V battery systems.

IC Role / Device Role / Timing Role: Linear LED driver with shutdown threshold (V_DD(OFF) = 1V) enabling fail-safe LED extinguishment during low-battery conditions.

Use Value: Prevents dim or flickering LEDs during brownout events, ensuring compliance with visibility safety standards.

Use Scenario: Maintaining illuminated exit path markings during AC mains failure using backup battery (e.g., 12V–48V).

IC Role / Device Role / Timing Role: Fixed-current sink providing stable 20 mA to high-efficiency LED arrays under varying battery voltage discharge profiles.

Use Value: Delivers consistent lumen output across full battery discharge curve without active feedback or microcontroller intervention.

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant-current LED driver applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
CL520N3-G	Same electrical specs but in TO-92 through-hole package (θ_JA = 132°C/W); no exposed thermal pad	Better suited for prototyping or low-power, manually assembled signage where thermal load is minimal	Select CL520N3-G only if manual assembly, lower cost per unit, or legacy TO-92 footprint is required
AL8862T-7	Switching buck LED driver (up to 1A), requires external inductor; 6–60V input; no 90V transient rating	Higher efficiency at >1W dissipation; unsuitable for direct 72V+ transient-prone rails without added protection	Choose AL8862T-7 when thermal management is critical and input voltage is stable and ≤60V

Compared with CL520N3-G, CL520K4-G offers superior thermal performance in surface-mount production environments; compared with AL8862T-7, it provides simpler layout, no EMI concerns, and inherent 90V transient robustness-critical for industrial signage where input rail integrity cannot be guaranteed.

Availability

CL520K4-G is available at Aetrix Electronics and suitable for architectural signage, industrial control panels, and transportation lighting requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for CL520K4-G 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

Microchip Technology is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and timing solutions, with ISO/TS-16949 certified manufacturing facilities.

The CL520K4-G belongs to Microchip's fixed-current linear LED driver product line, designed specifically for high-reliability, high-voltage signage and industrial indicator applications where simplicity, transient resilience, and thermal stability are prioritized over switching efficiency.

FAQ

What is the maximum continuous output current specification for CL520K4-G?

The CL520K4-G delivers a nominal output current of 20 mA with a tolerance of ±10%, verified across its full operating temperature range (–40°C to +125°C) and input voltage range (4.75V to 90V). This value is specified in the DC Electrical Characteristics table of the official Microchip datasheet DS20005805A, page 4, under "Current into OUT Pin" for CL520.

Does CL520K4-G require an external current-setting resistor?

No, CL520K4-G does not require an external current-setting resistor. It is a fixed-current linear regulator with internally trimmed 20 mA output. The current value is factory-set and temperature-compensated, eliminating design variability and PCB space associated with external precision resistors.

Can CL520K4-G drive multiple LEDs in series?

Yes, CL520K4-G can drive multiple LEDs in series, provided the total forward voltage (V_F) of the string remains within the device's output voltage capability (1V to 90V) and thermal limits are observed. For example, at 48V supply and 1V dropout, up to 14 white LEDs (3.2V each) can be driven continuously; higher counts require pulse operation per Microchip's application guidance on page 7.

What is the thermal resistance (θ_JA) of CL520K4-G and how is it measured?

The CL520K4-G has a junction-to-ambient thermal resistance (θ_JA) of 81°C/W, measured on a JEDEC-standard 2s2p test PCB (two signal layers, two power planes). This value assumes proper soldering of the exposed thermal pad to a copper pour and defines the maximum power dissipation before exceeding the +125°C maximum operating junction temperature.

Is CL520K4-G compatible with PWM dimming?

Yes, CL520K4-G supports PWM dimming via its VDD pin: applying a logic-level PWM signal to VDD enables rapid on/off control with t_ON and t_OFF ≤ 100 µs. This method avoids current ripple and maintains regulation integrity better than analog dimming, and is explicitly validated in Figures 3-1 through 3-3 of the CL520/CL525 datasheet.

CL520K4-G Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Linear

Topology:: -

Internal Switch(s):: -

Number of Outputs:: 1

Voltage - Supply (Min):: 4.75V

Voltage - Supply (Max):: 90V

Voltage - Output:: 1V ~ 90V

Current - Output / Channel:: 20mA

Frequency:: -

Dimming:: -

Applications:: Lighting, Signage

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: TO-252 (DPAK)

CL520K4-G FAQ

1.How can I place an order for CL520K4-G through Aetrix?

Please submit a Request for Quotation (RFQ) for CL520K4-G 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 CL520K4-G reliable?

The price and inventory of CL520K4-G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CL520K4-G is usually 5 days.

3.What payment methods are accepted for CL520K4-G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CL520K4-G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for CL520K4-G?

CL520K4-G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your CL520K4-G 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 CL520K4-G?

For technical support, including CL520K4-G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CL520K4-G requirements.

6.How does Aetrix verify that CL520K4-G is sourced from the original manufacturer or authorized distributors?

All CL520K4-G 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 CL520K4-G meets industry standards.

7.What is the process for return or replacement of CL520K4-G?

All CL520K4-G units undergo pre-shipment inspection (PSI). If there is an issue with CL520K4-G, 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 CL520K4-G part is unused and in its original packaging.

Return procedure for CL520K4-G:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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