LMR38020 同步降压转换器用于在宽输入电压范围内进行调节,从而尽可能减少对外部浪涌抑制元件的需求。LMR38020 能够在输入电压突降至 4.2V 时根据需要以接近 100% 的占空比继续工作,因而是 宽输入电压范围工业应用和 MHEV/EV 系统的理想选择。
LMR38020 使用精密使能端,通过支持直接连接到宽输入电压或对器件启动和关断进行精确控制来提供灵活性。附带内置滤波和延迟功能的电源正常状态标志可提供系统状态的真实指示,免去了使用外部监控器的麻烦。该器件采用假随机展频,具有超低 EMI,并且开关频率可以在 200kHz 和 2.2MHz 之间配置,从而避开噪声敏感频带。另外,可以选择频率,从而在低工作频率下提高效率,或在高工作频率下缩小解决方案尺寸。
该器件具有内置的保护功能,例如逐周期电流限制、断续模式短路保护以及功耗过大情况下的热关断功能。LMR38020采用 8 引脚 HSOIC PowerPAD 集成电路封装。
Changes from Revision D (August 2023) to Revision E (September 2023)
Changes from Revision C (January 2022) to Revision D (August 2023)
Changes from Revision B (November 2021) to Revision C (January 2022)
Changes from Revision A (October 2021) to Revision B (November 2021)
ORDERABLE PART NUMBER | CURRENT | FPWM | SPREAD SPECTRUM |
---|---|---|---|
LMR38020SDDAR | 2 A | No | Yes |
LMR38020FDDAR | 2 A | Yes | No |
LMR38020FSDDAR | 2 A | Yes | Yes |
PIN | TYPE | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
GND | 1 | G | Power and analog ground terminal. All electrical parameters are measured with respect to this pin. Connect a high-quality bypass capacitor directly to this pin and VIN with short and wide traces. |
EN | 2 | A | Enable input to regulator. High = ON, low = OFF. Can be connected directly to VIN. Do not float. |
VIN | 3 | P | Input supply to the regulator. Connect a high-quality bypass capacitor or capacitors directly to this pin and GND with short and wide traces. |
RT/SYNC | 4 | A | Resistor timing or external clock input. An internal amplifier holds this pin at a fixed voltage when using an external resistor to ground to set the switching frequency. If the pin is pulled above the PLL upper threshold, a mode change occurs and the pin becomes a synchronization input. The internal amplifier is disabled and the pin is a high impedance clock input to the internal PLL. If clocking edges stop, the internal amplifier is re-enabled and the operating mode returns to frequency programming by resistor. |
FB | 5 | A | Feedback input to the regulator. Connect to tap point of the feedback voltage divider. Do not float. Do not ground. |
PG | 6 | A | Open-drain power-good flag output. Connect to a suitable voltage supply through a current limiting resistor. High = power OK, low = power bad. The flag pulls low when EN = low. Can be left open when not used. |
BOOT | 7 | P | Bootstrap supply voltage for the internal high-side driver. Connect a high-quality 100-nF capacitor from this pin to the SW pin. |
SW | 8 | P | Regulator switch node. Connect to a power inductor. |
EP | THERMAL PAD | Thermal | Connect to system ground. |
MIN | MAX | UNIT | ||
---|---|---|---|---|
Input voltage | VIN to PGND | –0.3 | 85 | V |
EN to PGND | –0.3 | VIN+0.3 | V | |
FB to PGND | –0.3 | 5.5 | V | |
RT/SYNC to PGND | –0.3 | 5.5 | V | |
Output voltage | BOOT to SW | –0.3 | 5.5 | V |
SW to PGND | –0.3 | 85 | V | |
SW to PGND less than 10-ns transients | –5.0 | 85.3 | V | |
PGOOD to PGND | –0.3 | 20 | V | |
Junction Temperature TJ | –40 | 150 | °C | |
Storage temperature, Tstg | –65 | 150 | °C |