- 您现在的位置：买卖IC网 > PDF目录199467 > TPS2394PWR (TEXAS INSTRUMENTS INC) 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO14 PDF资料下载
参数资料
| 型号： | TPS2394PWR |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | 电源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO14 |
| 封装： | PLASTIC, TSSOP-14 |
| 文件页数： | 3/18页 |
| 文件大小： | 356K |
| 代理商： | TPS2394PWR |
SENSE
IMAX
34 mV
R
I
RAMP
SENSE
(max)
11.3
C
=
di
100
R
dt
÷
è
www.ti.com
SLVSAA9 – AUGUST 2010
APPLICATION INFORMATION
Setting the Sense Resistor Value
Due to the current-limiting action of the internal LCA, the maximum allowable load current for an implementation
is easily programmed by selecting the appropriate sense resistor value. The LCA acts to limit the sense voltage
V(SENSE-SOURCE) to its internal reference. Once the voltage at the RAMP pin exceeds approximately 4 V, this
limit is the clamp voltage, VREF_K. Therefore; a maximum sense resistor value can be determined from
(1)
Where:
RSENSE is the sensing resistor value
IIMAX is the minimum desired current limit
When setting the sense resistor value, it is important to consider two factors, the minimum current limit that may
be imposed by the TPS2394, and the maximum load under normal operation of the module. For the first factor,
the specification minimum clamp value is used, as seen in Equation 1. Second factor is to ensure the peak
operating load current is less than IIMAX. One example of this is a switching converter which draws higher input
current, for a given power output, when the output is at the low end of its voltage range. To avoid current limit
operation under normal loading, some margin should be designed in between this maximum anticipated load and
For example, using a 10-m
Ω sense resistor for a nominal 2-A load application provides a minimum of 1.4 A of
overhead for load variance/margin. Typical bulk capacitor charging current during turn-on is 4.2 A
(42 mV/10 m
Ω).
Setting the Inrush Slew Rate
The TPS2394 device enables user-programming of the maximum current slew rate during load start-up events. A
capacitor tied to the RAMP pin (CRAMP in the typical application diagram) controls the di/dt rate. Once the sense
resistor value has been established, a value for CRAMP, in microfarads, can be determined from Equation 2.
(2)
Where:
RSENSE is the sense resistor value in Ω
(di/dt)(max) is the desired maximum slew rate in A/s
For example, if the desired slew rate for the typical application shown is 1500 mA/ms, the calculated value for
CRAMP is about 7500 pF. Selecting the next larger standard value of 8200 pF provides some margin for capacitor
and sense resistor tolerances.
Setting the Fault Timing Capacitor
The fault timeout period is established by the value of the capacitor connected to the FLTTIM pin, CFLT. The
timeout period permits riding out spurious current glitches and surges that may occur during operation of the
system, and prevents indefinite sourcing into faulted loads. However, to ensure smooth voltage ramping under all
conditions of load capacitance and input supply potential, the minimum timeout should be set to accommodate
these system variables. To do this, a rough estimate of the maximum voltage ramp time for a completely
discharged plug-in card provides a good basis for setting the minimum timer delay. This section presents a quick
procedure for calculating the timing capacitance requirement. However, for proper operation of the TPS2394,
there is an absolute minimum value of 0.01-F for CFLT. This minimum requirement overrides any smaller results
of Equation 7 and Equation 8.
Copyright 2010, Texas Instruments Incorporated
11
Product Folder Link(s): TPS2394
相关PDF资料 |
PDF描述 |
|---|---|
| TPS2816MDBVREP | 2 A BUF OR INV BASED MOSFET DRIVER, PDSO5 |
| TPS3305-33Y | 2-CHANNEL POWER SUPPLY MANAGEMENT CKT, UUC8 |
| TPS3807A30DCKT | 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5 |
| TPS40120PWRG4 | SPECIALTY ANALOG CIRCUIT, PDSO14 |
| TPS40222DRPTG4 | 3.5 A SWITCHING REGULATOR, 1500 kHz SWITCHING FREQ-MAX, PDSO6 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TPS2398D | 制造商:Texas Instruments 功能描述: |
| TPS2398DGK | 功能描述:热插拔功率分布 -48V Hot Swap Controller RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| TPS2398DGKG4 | 功能描述:热插拔功率分布 -48V Hot Swap Controller RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| TPS2398DGKR | 功能描述:热插拔功率分布 -48V Hot Swap Controller RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| TPS2398DGKRG4 | 功能描述:热插拔功率分布 -48V Hot Swap Controller RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
发布紧急采购，3分钟左右您将得到回复。