TPS54478RTER

TPS54478 器件一款全功能6V、4A 同步降压电流模式转换器，具有两个集成的MOSFET。

TPS54478 集成了MOSFET、通过实施电流模式控制来减少外部组件数量、通过启用高达2MHz 的开关频率来减小电感器尺寸，并借助小型3mm×3mm 热增强型WQFN 封装尽量减小IC 封装尺寸，从而实现小型设计。

TPS54478 在工作温度范围内以精确 (±1%) 的电压基准 (V_REF) 为多种负载提供精准调节。通过集成的30mΩMOSFET 和典型值为525μA 的电源电流，效率得到最大限度提升。器件可利用使能引脚进入关断模式，关断电源电流可降至2.5μA。

欠压锁定在内部设定为2.6V，但可通过使能引脚上的电阻器网络来设定阈值，使之提高。输出电压启动斜坡由软启动引脚控制。一个开漏电源正常信号表示输出处于其标称电压值的93% 至107% 之内。

逐周期电流限制、断续过流保护和热关断功能在过流情况下可保护器件不受损坏。

The TPS54478 is a 6-V, 4-A, synchronous step-down (buck) converter with two integrated n-channel MOSFETs. To improve performance during line and load transients the device implements a constant frequency, peak current mode control which reduces output capacitance and simplifies external frequency compensation design. The wide switching frequency of 200kHz to 2000kHz allows for efficiency and size optimization when selecting the output filter components. The switching frequency is adjusted using a resistor to ground on the RT/CLK pin. The device has an internal phase lock loop (PLL) on the RT/CLK pin that is used to synchronize the power switch turn on to a falling edge of an external system clock.

The TPS54478 has a typical default start up voltage of 2.6V. The EN pin has an internal pull-up current source that can be used to adjust the input voltage under voltage lockout (UVLO) with two external resistors. In addition, the pull up current provides a default condition when the EN pin is floating for the device to operate. The total operating current for the TPS54478 is typically 525μA when not switching and under no load. When the device is disabled, the supply current is less than 2.5μA.

The integrated 30mΩ MOSFETs allow for high efficiency power supply designs with continuous output currents up to 4 amperes.

The TPS54478 reduces the external component count by integrating the boot recharge diode. The bias voltage for the integrated high side MO

• 两个可在4A 负载下获得高效率的30mΩ（典型值）MOSFET
• 200kHz 至2MHz 开关频率
• 在工作温度范围（-40°C 至 +150°C）内提供0.6V ± 1% 的电压基准
• 以预偏置电压启动
• 与外部时钟同步
• 可调慢速启动/排序
• 欠压(UV) 和过压(OV) 电源正常输出
• 逐周期电流限制和断续电流保护
• 热增强型3mm×3mm 16 引脚WQFN (RTE) 封装
• 与TPS54418 之间实现引脚兼容
• 使用TPS54478 并借助WEBENCH 电源设计器创建定制设计方案

• 低压、高密度电源系统
• 针对高性能DSP、FPGA、ASIC 和微处理器的负载点调节
• 宽带、网络及光纤通信基础设施