參數(shù)資料
型號(hào): L6917BD
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: SWITCHING CONTROLLER, 600 kHz SWITCHING FREQ-MAX, PDSO28
封裝: SO-28
文件頁(yè)數(shù): 5/33頁(yè)
文件大?。?/td> 631K
代理商: L6917BD
Obsolete
Product(s)
- Obsolete
Product(s)
13/33
L6917B
Integrated Droop Function
The device uses a droop function to satisfy the requirements of high performance microprocessors, reducing
the size and the cost of the output capacitor.
This method "recovers" part of the drop due to the output capacitor ESR in the load transient, introducing a de-
pendence of the output voltage on the load current
As shown in figure 6, the ESR drop is present in any case, but using the droop function the total deviation of the
output voltage is minimized. In practice the droop function introduces a static error (Vdroop in figure 6) propor-
tional to the output current. Since the device has an average current mode regulation, the information about the
total current delivered is used to implement the Droop Function. This current (equal to the sum of both IINFOx)
is sourced from the FB pin. Connecting a resistor between this pin and Vout, the total current information flows
only in this resistor because the compensation network between FB and COMP has always a capacitor in series
(See fig. 7). The voltage regulated is then equal to:
VOUT = VID - RFB IFB
Since IFB depends on the current information about the two phases, the output characteristic vs. load current is
given by:
Figure 6. Output transient response without (a) and with (b) the droop function
Figure 7. Active Droop Function Circuit
The feedback current is equal to 50
A at nominal full load (IFB = IINFO1 + IINFO2) and 70A at the OC threshold,
so the maximum output voltage deviation is equal to:
VFULL_POSITIVE_LOAD = +RFB 50A
VPOSITIVE_OC_THRESHOLD = +RFB 70A
Droop function is provided only for positive load; if negative load is applied, and then IINFOx < 0, no current is
sunk from the FB pin. The device regulates at the voltage programmed by the VID.
V
OUT
VID
R
FB
R
SENSE
Rg
----------------------
I
OUT
=
VMAX
VMIN
VNOM
(a)
(b)
ESR DROP
VDROOP
V
PROG
COMP
FB
To VOUT
I
FB
R
FB
相關(guān)PDF資料
PDF描述
L6917BDTR SWITCHING CONTROLLER, 600 kHz SWITCHING FREQ-MAX, PDSO28
L6917D SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO28
L6918ADTR SWITCHING CONTROLLER, 1200 kHz SWITCHING FREQ-MAX, PDSO28
L6918AD SWITCHING CONTROLLER, 1200 kHz SWITCHING FREQ-MAX, PDSO28
L6919CD SWITCHING CONTROLLER, 200 kHz SWITCHING FREQ-MAX, PDSO28
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L6917BDTR 功能描述:DC/DC 開關(guān)控制器 Prog Dual-Phase Cont RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
L6917D 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
L6917DTR 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
L6918 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5 BIT PROGRAMMABLE MULTIPHASE CONTROLLER
L6918A 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5 BIT PROGRAMMABLE MULTIPHASE CONTROLLER