参数资料
型号: TPS72525KTT
厂商: Texas Instruments, Inc.
英文描述: LOW INPUT VOLTAGE, 1-A LOW-DROPOUT LINEAR REGULATORS WITH SUPERVISOR
中文描述: 低输入电压,1低压差线性稳压器与督导员
文件页数: 2/18页
文件大小: 535K
代理商: TPS72525KTT
www.ti.com
Regulator Protection
THERMAL INFORMATION
P
D
max + VI(avg) * VO(avg)
I
O(avg) )
V
I(avg)
x I
(Q)
(3)
TPS72501
TPS72515, TPS72516
TPS72518, TPS72525
SLVS341D – MAY 2002 – REVISED MARCH 2004
APPLICATION INFORMATION (continued)
The TPS725xx pass element has a built-in back diode that safely conducts reverse current when the input
voltage drops below the output voltage (e.g., during power down). Current is conducted from the output to the
input and is not internally limited. If extended reverse voltage is anticipated, external limiting might be
appropriate.
The TPS725xx also features internal current limiting and thermal protection. During normal operation, the
TPS725xx limits output current to approximately 1.6 A. When current limiting engages, the output voltage scales
back linearly until the overcurrent condition ends. While current limiting is designed to prevent gross device
failure, care should be taken not to exceed the power dissipation ratings of the package. If the temperature of the
device exceeds 165
°C, thermal-protection circuitry shuts it down. Once the device has cooled down to below
145
°C, regulator operation resumes.
The amount of heat that an LDO linear regulator generates is directly proportional to the amount of power it
dissipates during operation. All integrated circuits have a maximum allowable junction temperature (TJmax)
above which normal operation is not assured. A system designer must design the operating environment so that
the operating junction temperature (TJ) does not exceed the maximum junction temperature (TJmax). The two
main environmental variables that a designer can use to improve thermal performance are air flow and external
heatsinks. The purpose of this information is to aid the designer in determining the proper operating environment
for a linear regulator that is operating at a specific power level.
In general, the maximum expected power (PD(max)) consumed by a linear regulator is computed as:
Where:
VI(avg) is the average input voltage.
VO(avg) is the average output voltage.
IO(avg) is the average output current.
I(Q) is the quiescent current.
For most TI LDO regulators, the quiescent current is insignificant compared to the average output current;
therefore, the term VI(avg) x I(Q) can be neglected. The operating junction temperature is computed by adding the
ambient temperature (TA) and the increase in temperature due to the regulator's power dissipation. The
temperature rise is computed by multiplying the maximum expected power dissipation by the sum of the thermal
resistances between the junction and the case (RθJC), the case to heatsink (RθCS), and the heatsink to ambient
(RθSA). Thermal resistances are measures of how effectively an object dissipates heat. Typically, the larger the
device, the more surface area available for power dissipation and the lower the object's thermal resistance.
Figure 20 illustrates these thermal resistances for (a) a SOT223 package mounted in a JEDEC low-K board, and
(b) a DDPAK package mounted on a JEDEC high-K board.
10
相关PDF资料
PDF描述
TPS726126 "Single Output LDO
TPS726126DCQ LOW INPUT VOLTAGE, 1-A LOW-DROPOUT LINEAR REGULATORS WITH SUPERVISOR
TPS726126DCQR LOW INPUT VOLTAGE, 1-A LOW-DROPOUT LINEAR REGULATORS WITH SUPERVISOR
TPS72615KTTR LOW INPUT VOLTAGE, 1-A LOW-DROPOUT LINEAR REGULATORS WITH SUPERVISOR
TPS72615KTTT LOW INPUT VOLTAGE, 1-A LOW-DROPOUT LINEAR REGULATORS WITH SUPERVISOR
相关代理商/技术参数
参数描述
TPS72525KTTR 功能描述:低压差稳压器 - LDO Low Input Voltage Any Cap 1-A RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
TPS72525KTTRG3 功能描述:低压差稳压器 - LDO Low Input Voltage Any Cap 1-A RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
TPS72525KTTT 功能描述:低压差稳压器 - LDO Low Input Voltage Any Cap 1-A RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
TPS72525KTTTG3 功能描述:低压差稳压器 - LDO Low Input Voltage Any Cap 1-A RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
TPS726126DCQ 功能描述:低压差稳压器 - LDO Low Input Voltage Any Cap 1A RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20