Microchip Technology CL1N8-G

Overview

CL1N8-G from Microchip Technology is a two-terminal, high-voltage, temperature-compensated constant-current source IC designed for LED biasing and industrial indicator loads. It delivers 20 mA ±5% at 45 V (VA–B), operates across 5–90 V input range, exhibits –8.5 µA/°C temperature coefficient, and requires no external components. It functions as either a constant-current sink or source in signage, automotive lamp indicators, and accent lighting.

For engineers reviewing the CL1N8-G datasheet, CL1N8-G pinout, CL1N8-G application, or CL1N8-G equivalent, this page provides verified electrical parameters, thermal behavior, parallel operation guidance, SOT-89 package layout, and real-world implementation constraints including junction temperature limits and dynamic resistance.

Technical Context

The CL1N8-G integrates a precision current-regulating control circuit with on-die temperature compensation to maintain stable output over voltage and temperature variations. Its internal architecture enables operation without external resistors or feedback networks, relying solely on internal trimming for 20 mA regulation at 45 V.

It supports both sink and source configurations via VA and VB terminals, with NC (Pin 3) unconnected. Power dissipation is limited to 1.3 W at 25°C ambient, and thermal resistance θ_JA is 133°C/W on FR4, requiring attention to PCB copper area and duty cycling above 45 V to avoid exceeding 125°C max operating junction temperature.

Key Specifications

Pinout & Package

CL1N8-G is housed in a Pb-free, RoHS-compliant 3-lead SOT-89 (TO-243AA) package with exposed tab for thermal conduction. Pin 1 (VB) serves as constant-current source terminal; Pin 2 (VA) is supply/sink terminal; Pin 3 (NC) is internally unconnected and must remain floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL5809-20E-7 and NSI45020AT1G, the CL1N8-G uniquely supports 90 V operation and parallel scalability while maintaining tight regulation across automotive and industrial temperature ranges-making it the only option for 72 V battery-powered signage or 120 V line-driven accent lighting with pulse operation.

Availability

CL1N8-G is available at Aetrix Electronics and suitable for automotive lamp indicators, industrial signage, and accent lighting requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for CL1N8-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 and global technical support.

The CL1 product line delivers simple, robust constant-current regulation for LED and indicator loads-designed specifically for applications where reliability, minimal external components, and wide input voltage tolerance outweigh programmability or digital interface needs.

FAQ

What is the maximum continuous operating voltage for CL1N8-G?

The CL1N8-G is rated for continuous operation up to 90 V (VA–B), with an absolute maximum rating of +100 V. Operation at 90 V requires careful thermal management-derating is necessary above 45 V to keep junction temperature below 125°C, especially with sustained DC bias. Pulse operation with controlled duty cycle is recommended for 120 V RMS-derived supplies.

Can CL1N8-G be used as both a current source and current sink?

Yes, the CL1N8-G functions as either a constant-current source or sink depending on connection: connect VB to LED cathode and VA to ground for sourcing; connect VA to LED anode and VB to ground for sinking. The internal circuitry supports both modes without external reconfiguration, and the datasheet confirms identical 20 mA regulation in both configurations.

How many CL1N8-G devices can be paralleled safely?

Multiple CL1N8-G units can be paralleled to achieve higher currents-e.g., two for 40 mA, three for 60 mA, four for 80 mA-as confirmed in Figure 3-4 of DS20006072A. Matching is inherent due to factory trimming; no external balancing resistors are needed. Ensure equal trace lengths and thermal coupling to maintain current sharing within ±5% tolerance.

What is the thermal resistance and recommended PCB layout for CL1N8-G?

The CL1N8-G has θ_JA = 133°C/W on a 25 mm × 25 mm × 1.57 mm FR4 board. To sustain 90 V operation at 25°C ambient, at least 25 mm² of 2-oz copper connected to the exposed tab is required. Avoid thermal isolation; use multiple vias under the tab to inner-layer ground planes for improved heat spreading in high-power deployments.

Does CL1N8-G require external components for basic LED driving?

No-CL1N8-G is a true two-terminal device requiring zero external components for basic constant-current LED operation. Its internal trimmed regulation and temperature compensation eliminate the need for sense resistors, bias networks, or feedback paths. Only the LED load and input supply are mandatory; optional capacitors may be added for EMI suppression but are not functionally required.