TPS54040ADRCR

TPS54040A 器件是一款 42V、0.5A 降压稳压器，集成高侧 N 沟道 MOSFET。电流模式控制提供简单的外部补偿设计灵活性和器件选型灵活性。低纹波脉冲跳跃模式将无负载调节状态下的输入电源电流降至 116μA。通过使能引脚拉低，关断电源电流标称值降至 1.3μA。 欠压闭锁在内部设定为 2.5V，但可通过使能引脚提高该阈值。输出电压启动斜坡由缓启动引脚控制，该引脚还可配置用于电源排序或跟踪。开漏电源状态良好（PWRGD）信号在输出电压处于标称电压的 94% 至 107% 范围内时有效。 宽广的开关频率范围可对效率和外部元器件尺寸进行优化。频率折返和热关断功能在过载条件下对器件提供保护。 The TPS54040A device is a 42-V, 0.5-A, step-down (buck) regulator with an integrated high side n-channel MOSFET. To improve performance during line and load transients the device implements a constant frequency, current mode control which reduces output capacitance and simplifies external frequency compensation design. The wide switching frequency of 100 kHz to 2500 kHz 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 TPS54040A has a default start up voltage of approximately 2.5V. The EN pin has an internal pull-up current source that can be used to adjust the input voltage under voltage lockout (UVLO) threshold with two external resistors. In addition, the pull up current provides a default condition. When the EN pin is floating the device will operate. The operating current is 116μA when not switching and under no load. When the device is disabled, the supply current is 1.3μA. The integrated 200mΩ high side MOSFET allows for high efficiency power supply designs capable of delivering 0.5 amperes of continuous current to a load. The TPS54040A reduces the external component count by integrating the boot recharge diode. The bias voltage for the integrated high side MOSFET is supplied by a capacitor on the BOOT to PH pin. The boot capacitor voltage is monitored by an UVLO circuit and will turn the high side MOSFET off when the boot voltage falls below a preset threshold. The TPS54040A can operate at high duty cycles because of the boot UVLO. The output voltage can be stepped down to as low as the 0.8 V reference. The TPS54040A has a power good comparator (PWRGD) which asserts when the regulated output voltage is less than 92% or greater than 109% of the nominal output voltage. The PWRGD pin is an open drain output which deasserts when the VSENSE pin voltage is between 94% and 107% of the nominal output voltage allowing the pin to transition high when a pull-up resistor is used. The TPS54040A minimizes excessive output overvoltage (OV) transients by taking advantage of the OV power good comparator. When the OV comparator is activated, the high side MOSFET is turned off and masked from turning on until the output voltage is lower than 107%. The SS/TR (slow start/tracking) pin is used to minimize inrush currents or provide power supply sequencing during power up. A small value capacitor should be coupled to the pin to adjust the slow start time. A resistor divider can be coupled to the pin for critical power supply sequencing requirements. The SS/TR pin is discharged before the output powers up. This discharging ensures a repeatable restart after an over-temperatu

Applications

• 12V and 24V industrial and commercial low-power systems
• Automotive aftermarket accessories: video, GPS, entertainment

Key features

• 3.5V to 42V input voltage range
• 200mΩ high-side MOSFET
• High-efficiency Eco-mode™ at light loads with pulse skipping
• Tighter enable threshold than TPS54040
• Adjustable UVLO voltage and hysteresis for more precise UVLO voltage
• 116μA quiescent operating current
• 1.3μA shutdown current
• 100kHz to 2.5MHz switching frequency, synchronizable to external clock
• Adjustable soft-start/sequencing
• UV and OV power good output
• 0.8V internal voltage reference
• Available in MSOP-10 and VSON-10 packages
• Supported by WEBENCH and SwitcherPro software tools