参数资料
型号: L6919CD
厂商: STMICROELECTRONICS
元件分类: 稳压器
英文描述: SWITCHING CONTROLLER, 200 kHz SWITCHING FREQ-MAX, PDSO28
封装: SO-28
文件页数: 4/32页
文件大小: 558K
代理商: L6919CD
L6919C
12/32
follow:
Since the current is read in differential mode, also negative current information is kept; this allow the device to
check for dangerous returning current between the two phases assuring the complete equalization between the
phase's currents. From the current information of each phase, information about the total current delivered (IFB
=IINFO1 +IINFO2) and the average current for each phase (IAVG =(IINFO1 +IINFO2)/2 ) is taken. IINFOX is then com-
pared to IAVG to give the correction to the PWM output in order to equalize the current carried by the two phases.
The transconductance resistor Rg can be designed in order to have current information of 25
A per phase at
full nominal load; the over current intervention threshold is set at 140% of the nominal (IINFOx = 35A). According
to the above relationship, the over current threshold (IOCPx) for each phase, which has to be placed at one half
of the total delivered maximum current, results:
Since the device senses the output current across the low-side mosfets (or across a sense resistors in series
with them) the device limits the bottom of the inductor current triangular waveform: an over current is detected
when the current flowing into the sense element is greater than IOCPx (IINFOx > 35A).
Introducing now the maximum ON time dependence with the delivered current (where T is the switching period
T=1/fSW):
This linear dependence has a value at zero load of 0.80T and at maximum current of 0.40T typical and results
in two different behaviors of the device:
1. TON Limited Output Voltage.
This happens when the maximum ON time is reached before the current in each phase reaches IOCPx (IINFOx
< 35
A).
Figure 6a shows the maximum output voltage that the device is able to regulate considering the TON limitation
imposed by the previous relationship. If the desired output characteristic crosses the TON limited maximum output
voltage, the output resulting voltage will start to drop after crossing. In this case, the device doesn't perform con-
stant current limitation but only limits the maximum ON time following the previous relationship. The output volt-
age follows the resulting characteristic (dotted in Figure 6b) until UVP is detected or anyway until IFB = 70A.
Figure 6. TON Limited Operation
I
IN FO x
R
SENSE
I
PHASE
R
g
----------------------------------------------
=
I
OCPx
35
ARg
R
SEN SE
---------------------------
=
Rg
I
OC P x
R
SE NSE
35
A
-------------------------------------------
=
T
ON,MAX
0.80
I
FB
5.73 k
() T
0.80
R
SENSE
Rg
----------------------
I
OUT
5.73k
T
0.80 T I
FB
0
A
=
0.40 T I
FB
70
A
=
==
a) Maximum output Voltage
b) TON Limited Output Voltage
0.80VIN
0.40VIN
VOUT
IOUT
IOCP=2IOCPx
(IFB=70A)
TON Limited Output
characteristic
0.80VIN
0.40VIN
VOUT
IOUT
IOCP=2IOCPx
(IFB=70A)
Desired Output
characteristic and
UVP threshold
Resulting Output
characteristic
相关PDF资料
PDF描述
L6919E SWITCHING CONTROLLER, PDSO28
L6920DTR 1.2 A SWITCHING REGULATOR, PDSO8
L6920D 1.2 A SWITCHING REGULATOR, PDSO8
L6920 1.2 A SWITCHING REGULATOR, PDSO8
L6924D013TR 1-CHANNEL POWER SUPPLY SUPPORT CKT, QCC16
相关代理商/技术参数
参数描述
L6919CDTR 功能描述:DC/DC 开关控制器 Prog Dual-Phase Cont RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK
L6919E 功能描述:DC/DC 开关控制器 5-Bit Dual Ph Contlr RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK
L6919ETR 功能描述:DC/DC 开关控制器 5-Bit Dual Ph Contlr RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK
L-692 制造商:RHOMBUS-IND 制造商全称:Rhombus Industries Inc. 功能描述:Common Mode Inductor
L6920 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:1V HIGH EFFICIENCY SYNCRONOUS STEP UP CONVERTER