Designers are confronted with the task of supplying power to a wide range of devices that include ASICs, processors, memories, and FPGAs employed in data centers and telecom systems. Responding to the need for this powering flexibility are configurable digital multiphase PWM controllers with associated external Smart Power Stages that combine to support loads from 10A to 450A.
国际公司’s digital multiphase PWM controllers and their associated Smart Power Stages provide a scalable output of 10A to 450A. These digital PWM controllers include PMBus v1.3 and Adaptive Voltage Scaling Bus (AVSBus) that supports dynamic power minimization.
这些数字多相控制器之一是ISL68134，可以作为单个输出x+y = <4进行编程，例如作为4+0，双输出3+1或2+2相操作。还支持在两个输出之间使用少于四个阶段的操作。在典型的应用中，PWM输出驱动ISL99227智能电源阶段in a multiphase configuration.Fig. 1is a simplified diagram of the ISL68134 showing its four outputs configured as 2+2.
Another digital multiphase controller is theISL68137, a X+Y=<7 PWM controller you can program for single output 7+0, dual output 6+1, 5+2, or 4+3 phase operation. Operation using less than seven phases between two outputs is also supported. The ISL68137 supports up to two regulated outputs through seven assignable phases. Either output is capable of controlling up to seven phases in any arbitrary mix.图2说明了简化的6+1配置和Fig. 3shows a demo board with a similar arrangement.
与多个PMBus设备通信时a single bus, each device must have its own unique address so the host can distinguish between the devices. The device address can be set using a 1% resistor on the SA pin according to the pin-strap options.
Although the ISL68137 supports arbitrary phase assignment, it is good practice to assign phases to Output 1 in descending sequential numerical order starting from Phase 6. For example, a 4-phase rail could consist of phases 6, 5, 4, and 3. For Output 0, phases would be assigned starting from Phase 0 in ascending sequential numerical order.
To produce optimal efficiency across a wide range of output loading, the ISL68134 and ISL68137 support optional automatic phase dropping. Enabling automatic phase dropping causes the number of active phases at any time to be determined solely by load current. By shedding phases when the load is idling, the system can save power by not switching unnecessary power stages. Adjustment on where phases are added and dropped can be controlled precisely by the user.
ISL68134和ISL68137均采用专有的线性合成电流调制方案，可改善瞬态性能。这是一个唯一的恒定频率，双边PWM调制方案，PWM引导和后侧边缘都被独立移动，以提供对瞬态载荷的最佳响应。当前平衡是法规方案的固有部分。调制方案能够重叠脉冲，如果负载轮廓需要此类操作，从而可以快速瞬态响应和节省输出电容。此外，调制器能够响应调节需求而从给定循环中添加或去除脉冲，同时仍管理恒定频率。
Enhancement Features
ISL68134 and ISL68137 features include:
- AVSBus control
- Diode braking for overshoot reduction
- Current sense support
- 负载线调节
- 多种温度传感选择
- User-configurable switching frequency from 200 kHz to 1 MHz
- Current balancing across all frequencies and slew rates
These ICs feature on-chip nonvolatile memory (NVM) to store up to eight unique configurations, allowing the user to select via pin-strap—giving system designers increased power density to configure and deploy multiple configurations.
Use of the AVSBus in both controllers complements the PMBus by providing a common interface that accelerates point-to-point communication between the controller and the load to statically and dynamically control processor voltage, thus delivering a balanced and power efficient solution. AVSBus can be used exclusively once the device is configured via PMBus.
The AVSBus is a 50-MHz bus that connects directly to a processor to communicate telemetry data and deliver efficiency savings through adaptive voltage positioning. The ISL68134 and ISL68137 controllers and ISL99227 60A smart power stage support CPU core voltages, memory, and auxiliary power rails. This enables designers to customize their solution to meet any rail requirements.
Adaptive Voltage Scaling (AVS) is a closed-loop dynamic power minimization technique that reduces power based on the ICs actual operating conditions. Typically, most ICs operate so that they meet their most demanding application throughput requirements under worst-case operating conditions. This can waste power because most ICs do not always operate under typical operating conditions. AVS continually adjusts IC operating voltage, which minimizes power consumption.
ISL68134和ISL68137提供全面的故障管理：
- Pulse-by-pulse phase current limiting
- Total output current protection
- Output and input OV/UV
- Open voltage sense detect
- Black box recording capability for faults
- 主动温度监测
Fault monitors trigger configurable protective measures to prevent damage to a load. In addition, Power-Good indicators (PG0/PG1) can link to external system monitors. Faults may be enabled or disabled individually. Each fault type can also be configured to either latch off or retry indefinitely.
Doubling Phases
Intersil的专有ISL6617A可以将3.3V多相控制器支持的阶段数量增加一倍。例如，它可以将7相ISL68137转换为14阶段，同时平衡每对的电流。它最小化了高相计数可扩展应用程序中控制器和驱动程序之间接口的模拟信号数量。它不需要通常用于常规级联配置中的通用COMP信号，从而改善了噪声免疫并简化了布局。此外，ISL6617A比常规级联技术提供了低零件数量和低成本优势。
ISL6617A还具有识别高阻抗状态的三态输入和输出，与Intersil多相PWM控制器和功率阶段一起工作，以防止暂停操作时受控输出电压的负瞬变。此功能消除了对电源系统中使用的Schottky二极管的需求，以保护负载免受过度负输出电压损坏。
To facilitate configuration development for the ISL68134 and ISL68137, the PowerNavigator GUI provides a step-by-step arrangement for setup and parametric adjustment. This software allows simple configuration and monitoring of multiple digital-DC devices using a PC with a USB interface. Combined with the drag-and-drop GUI interface, it simplifies configuration and changes parameters, telemetry, or rail sequencing of a digital power supply design. PowerNavigator software supports Intersil’s portfolio of PMBus-enabled digital power products, including digital regulators, controllers, multiphase devices, power modules, and digital power monitors.
Once a configuration has been set, the user may employ PowerNavigator to monitor telemetry or use a direct PMBus interface based on the supported command set. Thresholds for automatic phase add/drop are user-programmable using the PowerNavigator GUI.
智能电源阶段
ISL99227和ISL99227B是高密度同步DC/DC功率转换的优化驱动程序和功率阶段解决方案。ISL99227适用于3.3V PWM逻辑，ISL99227B适用于5V PWM逻辑。它们包括高性能驱动器，作为自举二极管发挥作用的N通道MOSFET，以及针对高开关频率降压电压调节器进行了优化的MOSFET对。该电路实际上是熟悉的DRMOS模块的增强版本。图4shows the smart power stage circuit and interface.
ISL9922760A Smart Power Stage Features
- 4.5V至18V输入范围
- 60A current capability with 25V rated synchronous MOSFETs
- 200 kHz至2 MHz操作
- Integrated current sensing, 3% accuracy across line, load and temperature
- Differential current reporting at 5mV/A eliminating DCR error and noise
- 3.3V compatible tri-state PWM input
- 通过故障监测进行集成温度传感
- Accurate current outputs
- Thermal reporting outputs
- High MOSFET overcurrent protection
- High MOSFET short circuit protection
- Over-temperature protection
- VCC undervoltage lockout (UVLO)
- VIN UVLO
ISL99227和ISL99227B使用死亡时间控制ptimized for high efficiency and prevents simultaneous conduction of both MOSFETs. Should the driver have no bias voltage applied and be unable to actively hold the MOSFETs off, an integrated 20kΩ resistor from the upper MOSFET gate-to-source will aid in keeping the upper MOSFET device in its off state. This can be especially critical in applications where the input voltage rises prior to the ISL99227, ISL99227B supplies.
ISL99227支持3.3V PWM三级输入，并且与数字多相控制器兼容。如果该设备保留在三态窗口中，则固定时间，则驾驶员将迫使两个MOSFET到其关闭状态。当PWM信号在关闭窗口外移动时，驾驶员立即根据PWM命令恢复驾驶MOSFET。PWM控制器使用此功能作为强迫两个MOSFET的方法。如果将PWM输入保持浮动，将销钉内部拉入三态窗口，从而将两个MOSFET迫使安全状态。
Lower MOSFET current is monitored and a signal proportional to that current is the output on the IMON pin (relative to the REFIN pin). The IMON and REFIN pins are connected to the current sense inputs on the multiphase controller. This method eliminates the need for external RSENSE or DCR sensing of the inductor current while providing an accurate, temperature-compensated current signal.
ISL9927/b为其多芯片模块采用5×5 mm PQFN软件包。PQFN具有20英里厚的铜铅帧和焊料模具的较高的热性能。小占地面积为多芯片电源IC产品提供了一种具有成本效益的区域效率解决方案。
Digital Family Members
The ISL68137 and ISL68134 are just the first members of Intersil’s digital controller family. There are other controllers that utilize the AVSBus to power and communicate with ARM-based processors in network routers, switches, servers, storage, and wireless telecom equipment. Two general-purpose controllers (ISL68127 and ISL68124) are intended for power network processors, FPGAs, SoCs, and graphics accelerators. Plus, eight controllers (ISL69147/44, ISL69137/34, ISL69128/27, and ISL69125/24) add a secondary high-speed interface (SVID or SVI2) to power the latest Intel and AMD processors in cloud computing applications that make up the Internet of Things (IoT) backbone.
