參數(shù)資料
型號: L5989D
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: 5.06 A SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO16
封裝: ROHS COMPLIANT, HTSSOP-16
文件頁數(shù): 35/51頁
文件大?。?/td> 1947K
代理商: L5989D
Application information
L5989D
40/51
Doc ID 15778 Rev 3
HS switch delivering an impulsive extra current equal to ILOAD + IRIPPLE - IIN RMS and it is
recharged during the conduction time of the low side by the external power supply.
The golden rule is to reduce as much as possible the stray inductance of the path related to
the capacitor and VINto reduce injected noise: the suggested layout (see Figure 23 and
Figure 24) solves this matter placing the input filter just above the package of the device to
minimize noise. This placement offers the best filtering for the device and minimize the noise
injected by the pulsing current path. The additional stray inductance introduced in the path
from the switching node and the external inductor is not critical for the operation of the
device.
The pin 4 of the L5989D supplies most of the analog circuitry and MOSFET drivers so an
RMS current of few mA flows in its trace. A decoupling path between the power and signal
input reduces the issues induced by the switching noise: an RC network is helpful to filter
the signal supply from the noise generated by the switching activity and it becomes effective
when its time constant is bigger than two or three switching cycles. The pin 4 supplies the
drivers of the embedded MOSFET so the R value has to be kept limited to avoid voltage
spikes during the operation of the embedded driver (the maximum value is in the order of
few ohms).
The inductor current flows from power GND to the output capacitor during the conduction
time of the LS switch: the power ground plane and the signal ground are kept partitioned in
the PCB layout to minimize the injected noise on the signal ground. They are connected
together below the ground of the output capacitor which is the less noisy power component.
The connection of the external resistor divider to the feedback pin (FB) is an high
impedance node, so the interferences can be minimized placing the routing of feedback
node as far as possible from the high current paths. To reduce the pick up noise the resistor
divider has to be placed very close to the device.
Thanks to the exposed pad of the device, the ground plane helps to reduce the thermal
resistance junction to ambient; so a large ground plane enhances the thermal performance
of the converter allowing high power conversion.
Figure 23.
Top board layout
相關(guān)PDF資料
PDF描述
L5991D013TR 1.5 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO16
L6258EX STEPPER MOTOR CONTROLLER, 1.5 A, PDSO36
L6470PD STEPPER MOTOR CONTROLLER, 7 A, PDSO36
L6566BTR 0.8 A POWER FACTOR CONTROLLER, 900 kHz SWITCHING FREQ-MAX, PDSO16
L6706 SWITCHING REGULATOR, QCC40
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L5989DTR 功能描述:直流/直流開關(guān)調(diào)節(jié)器 4A cont 5A pulsed step-down sw RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
L5991 功能描述:電流型 PWM 控制器 Prog Current Mode RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
L5991_01 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:PRIMARY CONTROLLER WITH STANDBY
L5991A 功能描述:電流型 PWM 控制器 Prog Current Mode RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
L5991AD 功能描述:開關(guān)變換器、穩(wěn)壓器與控制器 Prog Current Mode RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關(guān)頻率:1 MHz 工作溫度范圍: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel