MAX1856:宽输入范围、可同步的、PWM SLIC电源

The MAX1856 offers a low-cost solution for generating a SLIC (ringer and off-hook) power supply. Using standard off-the-shelf transformers from multiple vendors, the MAX1856 generates various output voltages: -24V and -72V (dual output) for both ringer and off-hook supplies for voice-enabled broadband consumer premises equipment (CPE), -48V for IP phones and routers, -5V and -15V (single or dual output) for DSL CO line drivers, or negative voltages as high as -185V for MEMS bias supplies. The output voltages are adjusted with an external voltage divider. Due to its wide operating voltage range, the MAX1856 operates from a low-cost, unregulated DC power supply for cost-sensitive applications like xDSL, cable modems, set-top boxes, LMDS, MMDS, WLL, and FTTH CPE. The MAX1856 provides low audio-band noise for talk battery and a sturdy output capable of handling the ring trip conditions for ring battery. The operating frequency can be set between 100kHz and 500kHz with an external resistor in free-running mode. For noise-sensitive applications, the MAX1856's operating frequency can be synchronized to an external clock over its operating frequency range. The flyback topology allows operation close to 50% duty cycle, offering high transformer utilization, low ripple current, and less stress on input and output capacitors. Internal soft-start minimizes startup stress on the input capacitor, without any external components. The MAX1856's current-mode control scheme does not require external loop compensation. The low-side current-sense resistor provides accurate current-mode control and overcurrent protection.

关键特性
  • Low-Cost, Off-the-Shelf Transformer
  • 3V to 28V Input Range
  • Low Audio-Band Noise on Talk Battery
  • Effectively Handles Ring Trip Transients
  • Powers 2-, 4-, or 12-Line Equipment
  • High Efficiency Extends Battery Life During Life-Line Support Conditions
  • Adjustable 100kHz to 500kHz Switching Frequency
  • Clock Synchronization
  • Internal Soft-Start
  • Current-Mode PWM and Idle Mode™ Control Scheme
  • Logic-Level Shutdown
  • 10-Pin µMAX Package
功能框图
MAX1856:典型工作电路
产品应用
  • 电缆与DSL调制解调器
  • CO DSL线驱动器电源
  • FTTH
  • 工业电源
  • LMDS/MMDS
  • MEMS偏置电源
  • 路由器/交换机
  • 机顶盒
  • VoIP振铃与摘机电压发生器
  • 无线本地环路(WLL)
关键参数
Part NumberVIN
(V)
VIN
(V)
VOUT1
(V)
VOUT1
(V)
IOUT1
(A)
Output Adjust. MethodDC-DC OutputsOper. Freq.
(kHz)
Switch TypePackage/PinsBudgetary
Price
minmaxminmaxmaxSee Notes
MAX18563280-1850.3Resistor1500External
µMAX/10
$2.18 @1k
数据手册DataSheet
英文MAX1856.pdfRev 0; 03/2001
开发工具
技术资料
质量和环境数据
订购型号
型号状况推荐替代产品封装温度RoHS/无铅
MAX1856EUB生产中µMAX,;10引脚;15.4mm²-40°C至+85°CRoHS/无铅:否
MAX1856EUB+生产中µMAX,;10引脚;15.4mm²-40°C至+85°CRoHS/无铅:无铅
MAX1856EUB+T生产中µMAX,;10引脚;15.4mm²-40°C至+85°CRoHS/无铅:无铅
MAX1856EUB-T停止供货MAX1856EUB+TµMAX,;10引脚;15.4mm²-40°C至+85°CRoHS/无铅:否
MAX1856.pdf MAX1856
MAX1856.pdf MAX1856
MAX1856.pdf MAX1856
Flyback Transformer Design for MAX1856 SLIC Power Supplies MAX1856
Flyback Circuit Powers Broadband Phone Networks MAX1856
Selection of Ultra-Fast Recovery Diodes Used in Flyback Circuits MAX1856
Snubber Circuits Suppress Voltage Transient Spikes in Multiple Output DC-DC Flyback Converter Power Supplies MAX1856
Extending Soft-Start MAX4130
MAX1856.pdf MAX1856
MAX1856.pdf MAX1856