TPS54225TPWPRQ1

TPS54225-Q1是一款自适应接通时间D-CAP2™模式同步降压型转换器。可帮助系统设计人员通过低成本、低组件数量的低待机电流解决方案来完成各种终端设备的电源总线调节器集。主控制环路采用D-CAP2™模式控制，无需外部补偿组件便可实现极快的瞬态响应。

此外，TPS54225-Q1的专有电路还有助于该器件适应诸如POSCAP或SP-CAP等低等效串联电阻(ESR)输出电容器以及超低ESR陶瓷电容器。该器件可在4.5V至18V VCC输入、及2V至18V VIN输入电源电压范围内工作。输出电压可在0.76V与5.5V之间进行编程。此外，该器件还支持可调慢启动时间与电源良好功能。TPS54225-Q1采用14引脚HTSSOP封装，设计用于在 -40°C至85°C的范围内工作。

The TPS54225-Q1 is a 2-A synchronous step-down (buck) converter with two integrated N-channel MOSFETs. It operates using D-CAP2™ mode control. The fast transient response of D-CAP2™ control reduces the output capacitance required to meet a specific level of performance. Proprietary internal circuitry allows the use of low ESR output capacitors including ceramic and special polymer types.

The main control loop of the TPS54225-Q1 is an adaptive on-time pulse width modulation (PWM) controller that supports a proprietary D-CAP2™ mode control. D-CAP2™ mode control combines constant on-time control with an internal compensation circuit for pseudo-fixed frequency and low external component count configuration with both low ESR and ceramic output capacitors. It is stable even with virtually no ripple at the output.

TPS54225-Q1 uses an adaptive on-time control scheme and does not have a dedicated on board oscillator. The TPS54225-Q1 runs with a pseudo-constant frequency of 700 kHz by using the input voltage and output voltage to set the on-time one-shot timer. The on-time is inversely proportional to the input voltage and proportional to the output voltage. The actual frequency may vary from 700 kHz depending on the off time, which is ended when the fed back portion of the output voltage falls to the VFB threshold voltage.

The soft start function is adjustable. When the EN pin becomes high, 2-μA current begins charging the capacitor which is connected from the SS pin to GND. Smooth control of the output voltage is maintained during start up. A unique circuit to prevent current from being pulled from the output during startup if the output is pre-biased.

• 符合汽车应用要求
• D-CAP2™模式支持快速瞬态响应
• 低输出纹波，支持陶瓷输出电容器
• 宽VCC输入电压范围：4.5V至18V
• 宽VIN输入电压范围：2V至18V
• 输出电压范围：0.76V至5.5V
• 高效集成FET，针对更低占空比应用进行优化
• 160mΩ（高侧）和110mΩ（低侧）
• 关断时的高效率，流耗不足10μA
• 初始带隙参考的高精度
• 可调软启动
• 预偏置软启动
• 700kHz开关频率(fSW)
• 逐周期过流限制
• 电源良好输出

• 低电压系统的广泛应用
• 数字电视电源
• 高清蓝光光盘播放器
• 网络家庭终端设备
• 数字机顶盒(STB)