参数资料
型号: TPS2557DRB
厂商: TEXAS INSTRUMENTS INC
元件分类: 电源管理
英文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
封装: PLASTIC, SON-8
文件页数: 3/22页
文件大小: 942K
代理商: TPS2557DRB
0.947
ILIM
1.0028
ILIM
1.0708
ILIM
99038V
OSmax
R
k
111704V
OSnom
R
k
127981V
OSmin
R
k
I
(mA) =
I
(mA) =
I
(mA) =
W
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
20
30
40
50
60
70
80
90
100
110
120
130
140
150
R
– CurrentLimitResistor – k
ILIM
Current-LimitThreshold
mA
IOS(min)
IOS(typ)
IOS(max)
1.0708
ILIM
OSmin
127981V
OSmin
R
k
1
1.0708
ILIM
OSmin
ILIM
I
(mA) = 3000mA
I
(mA) =
127981V
R
(k ) =
I
mA
R
(k ) = 33.3k
W
÷
÷
÷
÷
è
www.ti.com
SLVS931 – NOVEMBER 2009
PROGRAMMING THE CURRENT-LIMIT THRESHOLD
The overcurrent threshold is user programmable via an external resistor. The TPS2556/57 uses an internal
regulation loop to provide a regulated voltage on the ILIM pin. The current-limit threshold is proportional to the
current sourced out of ILIM. The recommended 1% resistor range for RILIM is 20 k ≤ RILIM ≤ 187 k to ensure
stability of the internal regulation loop. Many applications require that the minimum current limit is above a certain
current level or that the maximum current limit is below a certain current level, so it is important to consider the
tolerance of the overcurrent threshold when selecting a value for RILIM. The following equations approximate the
resulting overcurrent threshold for a given external resistor value ILIM). Consult the Electrical Characteristics
table for specific current limit settings. The traces routing the RILIM resistor to the TPS2556/57 should be as short
as possible to reduce parasitic effects on the current-limit accuracy.
(1)
Figure 19. Current-Limit Threshold vs. RILIM
APPLICATION 1: DESIGNING ABOVE A MINIMUM CURRENT LIMIT
Some applications require that current limiting cannot occur below a certain threshold. For this example, assume
that 3 A must be delivered to the load so that the minimum desired current-limit threshold is 3000 mA. Use the
IOS equations and Figure 19 to select RILIM.
(2)
Select the closest 1% resistor less than the calculated value: RILIM = 33.2 k. This sets the minimum current-limit
threshold at 3000 mA . Use the IOS equations, Figure 19, and the previously calculated value for RILIM to
calculate the maximum resulting current-limit threshold.
Copyright 2009, Texas Instruments Incorporated
11
Product Folder Link(s): TPS2556 TPS2557
相关PDF资料
PDF描述
TPS2561DRC 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO10
TPS2561DRCT 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO10
TPS3305-20QDRQ1 2-CHANNEL POWER SUPPLY MANAGEMENT CKT, PDSO8
TPS3305-18QDRQ1 2-CHANNEL POWER SUPPLY MANAGEMENT CKT, PDSO8
TPS3306-20DRG4 2-CHANNEL POWER SUPPLY MANAGEMENT CKT, PDSO8
相关代理商/技术参数
参数描述
TPS2557DRBEVM-423 功能描述:交换机 IC 开发工具 Eval Mod for TPS2557 RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:USB Power Switches 工具用于评估:MAX4984E 工作电源电压:2.8 V to 5.5 V
TPS2557DRBR 功能描述:电源开关 IC - USB Prec Adj Current-Ltd Pwr-Dist Sw RoHS:否 制造商:Micrel 电源电压-最小:2.7 V 电源电压-最大:5.5 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:SOIC-8 封装:Tube
TPS2557DRBT 功能描述:电源开关 IC - USB Prec Adj Current-Ltd Pwr-Dist Sw RoHS:否 制造商:Micrel 电源电压-最小:2.7 V 电源电压-最大:5.5 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:SOIC-8 封装:Tube
TPS2557QDRBRQ1 功能描述:IC PWR DIST SWITCH ADJ 8SON 制造商:texas instruments 系列:汽车级,AEC-Q100 包装:剪切带(CT) 零件状态:有效 开关类型:通用 输出数:1 比率 - 输入:输出:1:1 输出配置:高端 输出类型:N 通道 接口:开/关 电压 - 负载:2.5 V ~ 6.5 V 电压 - 电源(Vcc/Vdd):不需要 电流 - 输出(最大值):5A 导通电阻(典型值):22 毫欧 输入类型:非反相 特性:压摆率受控型,状态标志 故障保护:限流(可调),超温,UVLO 工作温度:-40°C ~ 125°C (TJ) 封装/外壳:8-VDFN 裸露焊盘 供应商器件封装:8-SON(3x3) 标准包装:1
TPS2559DRCR 功能描述:IC PWR DIST SWITCH ADJ 10VSON 制造商:texas instruments 系列:- 包装:剪切带(CT) 零件状态:有效 开关类型:通用 输出数:1 比率 - 输入:输出:1:1 输出配置:高端 输出类型:N 通道 接口:开/关 电压 - 负载:2.5 V ~ 6.5 V 电压 - 电源(Vcc/Vdd):不需要 电流 - 输出(最大值):5.5A 导通电阻(典型值):13 毫欧 输入类型:非反相 特性:压摆率受控型,状态标志 故障保护:限流(可调),超温,UVLO 工作温度:-40°C ~ 125°C (TJ) 封装/外壳:10-VFDFN 裸露焊盘 供应商器件封装:10-VSON(3x3) 标准包装:1