CR6850
30W flyback PWM controller with built-in HV startup, ideal for adapter and auxiliary power applications.
Product Overview
Description
30W flyback PWM controller with built-in HV startup. Current-mode control with 65kHz switching frequency.
SOP-8 package for compact designs. Green-mode operation for low standby power (<100mW).
In stock for adapter and auxiliary power applications. FAE support for power supply design and optimization.
Product Series
AC-DC
Primary Application
Key Features
- Built-in 700V high-voltage startup circuit
- Current-mode PWM control with 65kHz frequency
- Green-mode operation with frequency foldback
- Low standby power: <100mW at 230VAC
- Comprehensive protection: OCP, OVP, OTP, UVLO
- Soft-start and slope compensation
Specifications
| Voltage Rating | N/A |
|---|---|
| Current Rating | N/A |
| Temperature Range | N/A |
Applications
Power adapters
Industrial application for Power Management ICs CR6850
Auxiliary power supplies
Industrial application for Power Management ICs CR6850
Battery chargers
Industrial application for Power Management ICs CR6850
LED drivers
Industrial application for Power Management ICs CR6850
Industrial control
Industrial application for Power Management ICs CR6850
FAE Expert Insights
"Based on extensive field experience, this product delivers excellent performance across various operating conditions. The design incorporates proven architecture with robust protection features. Customers consistently report high satisfaction with reliability and ease of integration. In my professional experience, I highly recommend this CR Micro device for cost-sensitive applications where reliability is essential. I suggest implementing proper thermal management and considering the complete system requirements for optimal performance."
Reliable, good performance
— Senior FAE, BeiLuo
Frequently Asked Questions
What is the maximum output power of CR6850?
CR6850 can deliver up to 30W output power in a standard flyback configuration with universal input (85-265VAC). The actual maximum power depends on several factors: (1) Input voltage range - higher power at 230VAC than 115VAC. (2) Efficiency target - higher efficiency allows more output power. (3) Thermal design - adequate heatsinking for the external MOSFET. (4) Transformer design - proper core selection and winding design. For 5V output at 230VAC input, up to 6A (30W) is achievable. CR Micro provides reference designs for various output voltage and power combinations.
Contact our FAE team for power supply design support and transformer design guidelines.
How does the green-mode operation work in CR6850?
CR6850's green-mode operation reduces power consumption at light loads: (1) Frequency foldback - switching frequency decreases proportionally with load current below a threshold. (2) Burst mode - at very light loads or no load, the controller enters burst mode with intermittent switching. (3) Standby power - achieves <100mW standby power at 230VAC input with no load. The green-mode operation is automatic and requires no external components. The controller returns to normal PWM operation seamlessly when load increases.
Contact our FAE team for green-mode optimization and standby power reduction techniques.
What external components are required for CR6850?
CR6850 requires the following external components for a complete flyback converter: (1) External power MOSFET - select based on voltage rating (typically 600V for universal input) and current rating. (2) Current sense resistor - sets the peak current limit. (3) Transformer - flyback transformer with proper turns ratio and magnetizing inductance. (4) Output rectifier and filter - diode and capacitors for output voltage. (5) Feedback network - optocoupler and TL431 for isolated feedback, or resistor divider for non-isolated. (6) Startup and VCC components - minimal due to built-in HV startup. CR Micro provides detailed BOM and transformer specifications.
Contact our FAE team for complete BOM recommendations and transformer design support.
What is the switching frequency of CR6850 and can it be adjusted?
CR6850 has a fixed switching frequency of 65kHz. This frequency is internally set and cannot be adjusted externally. The 65kHz frequency provides a good balance between: (1) Magnetic component size - higher frequency allows smaller transformers and inductors. (2) Switching losses - lower frequency reduces switching losses in the MOSFET. (3) EMI - 65kHz is below common EMI regulatory bands, simplifying filtering. (4) Audible noise - above audible range to prevent acoustic noise. For applications requiring different frequencies, CR Micro offers other PWM controllers with adjustable or different fixed frequencies.
Contact our FAE team for frequency selection guidance and alternative controller recommendations.
How does the protection function work in CR6850?
CR6850 includes multiple protection functions: (1) Over-current protection (OCP) - cycle-by-cycle current limiting via current sense pin. (2) Over-voltage protection (OVP) - latches off when VCC exceeds threshold. (3) Over-temperature protection (OTP) - shuts down at excessive die temperature. (4) Under-voltage lockout (UVLO) - disables operation when VCC is too low. (5) Leading-edge blanking - prevents false triggering from switching noise. Most protections are automatic recovery except OVP which typically requires power cycling. These protections ensure safe operation under fault conditions.
Contact our FAE team for protection feature details and fault condition handling.
Can CR6850 be used for battery charger applications?
Yes, CR6850 can be used for battery charger applications with appropriate feedback and control circuitry. For battery charging: (1) Constant voltage (CV) mode - standard feedback maintains constant output voltage. (2) Constant current (CC) mode - additional current feedback circuit limits charging current. (3) Charge termination - voltage and current thresholds determine when to end charging. CR Micro provides reference designs for Li-ion and lead-acid battery chargers using CR6850. The controller's comprehensive protection features are beneficial for safe battery charging.
Contact our FAE team for battery charger reference designs and charging profile implementation.