CR6842S Current-Mode SMPS PWM Controller SMD IC SOP-8

CR6842S Current-Mode SMPS PWM Controller SMD IC SOP-8 is a highly integrated, green-mode PWM controller specifically engineered for high-performance offline switch-mode power supply (SMPS) applications. This sophisticated IC utilizes a current-mode control scheme to provide excellent line and load regulation while ensuring high system stability. Furthermore, the CR6842S incorporates a proprietary green-mode function that reduces the switching frequency under light-load conditions, which significantly improves power conversion efficiency and minimizes standby power consumption. Consequently, it represents an ideal solution for designers aiming to meet strict global energy-efficiency standards. Therefore, you can rely on this controller to deliver a robust, cost-effective, and energy-efficient power stage for various consumer electronics.

Key Features:

• Low Startup Current: The device requires a very low startup current (typically 5 μA), allowing designers to use high-value startup resistors to reduce power loss.
• Green-Mode Operation: This feature automatically reduces the PWM frequency at light or no-load states to enhance overall system efficiency.
• Comprehensive Protection: The IC includes built-in Over-Temperature Protection (OTP), Over-Voltage Protection (OVP), and Over-Load Protection (OLP) to ensure high system reliability.
• Internal Slope Compensation: It integrates a slope compensation circuit that prevents sub-harmonic oscillation in continuous conduction mode (CCM) at high duty cycles.
• Leading-Edge Blanking (LEB): An internal LEB circuit filters out noise during the power MOSFET turn-on period, eliminating the need for an external RC filter.

Technical Specifications:

• Supply Voltage (V_DD): 12 V to 28 V (Max rating 30 V)
• Startup Current (I_DD-ST): ≈ 5 μA (Typical)
• Operating Supply Current: 3 mA (Typical)
• Programmable PWM Frequency: 50 kHz to 100 kHz (Set via external resistor)
• Gate Drive Output Voltage: 12 V to 18 V (Clamped)
• Operating Temperature: −40°C to +125°C
• Duty Cycle (Max): ≈ 75%

Mechanical Specifications:

• Package Type: SOP-8 (Surface Mount Device)
• Lead Material: Tinned Alloy for excellent solderability
• Encapsulation: Molded Plastic Compound (UL 94V-0 Rated)
• Thermal Resistance: ≈ 150°C/W (Junction to Ambient)

Dimensions:

• Body Length: ≈ 4.90 mm
• Body Width: ≈ 3.90 mm (Excluding leads)
• Total Width: ≈ 6.00 mm (Including leads)
• Body Height: ≈ 1.55 mm
• Lead Pitch: 1.27 mm (Standard SOP-8 pitch)

Pinout and Wiring:

• Pin 1 (GND): Connect to the primary-side ground of the power circuit.
• Pin 2 (FB): Feedback input pin; connect to an optocoupler to regulate the output voltage.
• Pin 3 (VIN): Startup voltage input pin; connect to the rectified line voltage through a high-value resistor.
• Pin 4 (RI): Frequency setting pin; connect a resistor to GND to determine the internal oscillation frequency.
• Pin 5 (RT): Temperature sensing pin; connect an NTC thermistor for over-temperature protection.
• Pin 6 (SENSE): Current sense input; connect to the source of the MOSFET to monitor peak current.
• Pin 7 (VDD): IC power supply pin; connect to the auxiliary winding of the transformer.
• Pin 8 (GATE): PWM output driver; connect directly to the gate of the power MOSFET.

Datasheet Reference:

• Download CR6842S PWM Controller Datasheet

Commonly Used in:

• Power Adapters: Providing high-efficiency power conversion for laptops and mobile device chargers.
• Open-Frame Power Supplies: Serving as the primary controller for industrial and telecommunication power modules.
• Battery Chargers: Managing the power stages of lead-acid and lithium-ion battery charging systems.

Applications:

• LCD Monitor Power Supplies: Operating the internal AC-DC converter stage for display panels.
• Set-Top Boxes: Providing stable voltage rails for digital media players and networking equipment.
• LED Lighting Drivers: Controlling the power delivery in high-wattage LED driver circuits.
• Auxiliary Power Units: Generating standby power for larger industrial machines and household appliances.

Equivalent Models:

• SG6842 (Fairchild/onsemi): A direct functional equivalent widely used in similar power designs.
• LD7552 (Leadtrend): A pin-compatible current-mode PWM controller with green-mode features.
• OB2269 (On-Bright): Often considered a functional replacement with similar low-startup current characteristics.

Package Includes:

• 1 x CR6842S Current-Mode SMPS PWM Controller SMD IC SOP-8