ADIADuM4471隔离DC-DC控制器参考设计方案
2013-07-22
作者:ADI
ADI公司的ADuM4471是一款内嵌MOSFET驱动器和校准器的四通道数字光电隔离DC-DC功率控制器,基于ADI先进iCoupler®技术,该控制器内部集成次边PWM光电隔离反馈补偿回路。有效减少了外部光电隔离电路和补偿回路的元器件,为实现小型化设计提供了基础。该控制器输入电压为5V或3V,输出电压范围为:3.3V-24V。单路输出功率可以达到2.5W。四通道可分别灵活独立配置,以满足用户不同的应用需要。本文介绍了DADuM4471芯片的主要特性、方框图、应用方向。评估板EVAL-ADuM5211EBZ的主要特性、电路图、材料清单和PCB元件布局图。
The ADuM4470/ADuM4471/ADuM4472/ADuM4473/ADuM44741 are quad-channel, digital isolators with a regulated dc-to-dc isolated power supply controller and an internal MOSFET driver. The dc-to-dc controller has an internal isolated PWM feedback from the secondary side, based on the iCoupler? chip scale transformer technology and complete loop compensation. This eliminates the need to use an optocoupler for feedback and compensates the loop for stability.
The ADuM447x isolators provide a more stable output voltage and higher efficiency compared to unregulated isolated dc- to-dc power supplies. The fully integrated feedback and loop compensation in a wide-body SOIC package provide a smaller form factor and 8.3 mm creepage distance solution.
The regulated feedback provides a relatively flat efficiency curve over the full output power range. The ADuM447x enable a dc-to-dc converter with a 3.3 V to 24 V isolated output voltage range from either a 5.0 V or a 3.3 V input voltage, with an output power of up to 2.5 W. The ADuM447x isolators provide four independent isolation channels in a variety of channel configurations and data rates.
ADuM4471主要特性:
Isolated PWM feedback with built in compensation
Primary side transformer driver for up to 2.5 W output power with 5 V input voltage
Regulated adjustable output: 3.3 V to 24 V
Up to 80% efficiency
Quad dc-to-25 Mbps (NRZ) signal isolation channels
200 kHz to 1 MHz adjustable oscillator
Soft start function at power-up
Pulse-by-pulse overcurrent protection
Thermal shutdown
5000 V rms isolation
High common-mode transient immunity: >25 kV/μs
20-lead SOIC package with 8.3 mm creepage
High temperature operation: 105°C
ADuM4471应用:
Power supply start-up bias and gate drives
Isolated sensor interfaces
Process controls
RS-232/RS-422/RS-485 transceivers
图1. ADuM4471方框图
EVAL-ADuM4471EBZ 主要特性:
ADuM447x circuits, including 5 kV rms isolated dc-to-dc converters
Single supply (default)
5 V input to 5 V output (regulated)
Reconfigurable to 5 V input to 3.3 V output or 3.3 V input to 3.3 V output
Double supply
5 V input to 15 V output (regulated) and 7.5 V output (unregulated)
Reconfigurable to 5 V input to 12 V output (regulated) and 6 V output (unregulated)
Footprints for Coilcraft, Inc., and Halo Electronics, Inc., transformer options
Multiple switching frequency options
EVAL-ADuM4471EBZ电路图:
图2. EVAL-ADuM4471EBZ电路图
EVAL-ADuM4471EBZ材料清单:
PCB元件布局图: