- 您现在的位置：买卖IC网 > PDF目录225340 > TPS40003EVM (Texas Instruments, Inc.) TPS40003 Evaluation Module(TPS40003评估板) PDF资料下载
参数资料
| 型号： | TPS40003EVM |
| 厂商： | Texas Instruments, Inc. |
| 英文描述： | TPS40003 Evaluation Module(TPS40003评估板) |
| 中文描述： | TPS40003评估模块（TPS40003评估板） |
| 文件页数： | 15/17页 |
| 文件大小： | 339K |
| 代理商： | TPS40003EVM |
SLUU130A – September 2002 – Revised February 2003
7
TPS40003-Based 5-A Converter in Less Than One Square Inch
4.4
Output Capacitor Selection
Selection of the output capacitor is based on many application variables, including function, cost, size, and
availability. The minimum allowable output capacitance is determined by the amount of inductor ripple current
and the allowable output ripple in equation (3).
C
OUT(min) +
I
RIPPLE
8
f
V
RIPPLE
+
1.25 A
8
600 kHz
12 mV
+ 22 mF
In this design, COUT(min) is 22 F with VRIPPLE = 12 mV to allow for some margin. However, this only affects the
capacitive component of the ripple voltage. In addition, the voltage component due to the capacitor ESR must
be considered in equation (4).
ESR
Cout v
V
RIPPLE
I
RIPPLE
+ 0.012 V
1.25 A
+ 9.6 mW
For compactness while maintaining transient response capability, two 22-
F ceramic capacitors are fitted in
parallel. The total ESR of these capacitors is below 3 m
, and contributes only a few mV to the output voltage
ripple.
4.5
MOSFET Selection
The small physical size of this design requires the use of a single SO-8 package which contains dual N-channel
MOSFETs. MOSFETs with an RDS(on) of 18 m are selected to keep the conduction losses to a manageable
amount at full load.
4.6
Short Circuit Protection
The TPS40003 implements short circuit protection by comparing the voltage across the topside MOSFET while
it is on to a voltage dropped from VDD by RLIM due to an internal current source of 15 A inside pin 1. Due to
tolerances in the current source and variations in the power MOSFET on-voltage versus temperature, the short
circuit level can protect against gross overcurrent conditions only, and should be set higher than rated load. In
this particular case, RLIM is selected as:
R
LIM +
R1
+
2.5
I
OUT
0.018
W
15
mA
+ 15 kW
For this design, RLIM = 15 k, and the factor of 2.5 in the equation accounts for the variations in component
tolerances over temperature and output current ripple. The high currents that are switched under short circuit
conditions may cause SW pin 8 to be driven below ground several volts, possibly injecting substrate current
which can cause improper operation of the device. A 3.3-
resistor has been placed in series with this pin to
limit its excursion to safe levels.
(3)
(4)
(5)
相关PDF资料 |
PDF描述 |
|---|---|
| TPS40003 | Low Input Voltage Mode Synchronous Buck Controller |
| TPS40004 | "Low Input (2.25V-5.5V) 300 kHz Frequency |
| TPS40005 | "Low Input (2.25V-5.5V) 600 kHz Frequency |
| TPS5410MDREP | 4.6 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
| TPS54429ERSAT | 0.01 A SWITCHING REGULATOR, PQCC16 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TPS40004 | 制造商:TI 制造商全称:Texas Instruments 功能描述:LOW-INPUT VOLTAGE-MODE SYNCHRONOUS BUCK CONTROLLER |
| TPS40004DGQ | 功能描述:电压模式 PWM 控制器 Lo Input 300kHz Freq Synch Buck Cntrlr RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| TPS40004DGQG4 | 功能描述:电压模式 PWM 控制器 Lo Input 300kHz Freq Synch Buck Cntrlr RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| TPS40004DGQR | 功能描述:电压模式 PWM 控制器 Lo Input 300kHz Freq Synch Buck Cntrlr RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| TPS40004DGQRG4 | 功能描述:电压模式 PWM 控制器 Lo Input 300kHz Freq Synch Buck Cntrlr RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
发布紧急采购，3分钟左右您将得到回复。