參數(shù)資料
型號: TPS75425QPWPREP
廠商: TEXAS INSTRUMENTS INC
元件分類: 固定正電壓單路輸出LDO穩(wěn)壓器
英文描述: 2.5 V FIXED POSITIVE LDO REGULATOR, PDSO20
封裝: PLASTIC, HTSSOP-20
文件頁數(shù): 9/31頁
文件大?。?/td> 608K
代理商: TPS75425QPWPREP
TPS75201EP, TPS75215EP, TPS75218EP, TPS75225EP, TPS75233EP WITH RESET
TPS75401EP, '75415EP, '75418EP, '75425EP, '75433EP WITH POWER GOOD
FAST TRANSIENT RESPONSE 2A LOW DROPOUT VOLTAGE REGULATORS
SGLS165 APRIL 2003
17
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
In most cases one can neglect the effect of inductive impedance ESL. Therefore, the following application focuses
mainly on the parasitic resistance ESR.
Figure 22 shows the output capacitor and its parasitic impedances in a typical LDO output stage.
LDO
VI
VESR
IO
RESR
CO
RLOAD
VO
+
Figure 22. LDO Output Stage With Parasitic Resistances ESR and ESL
In steady state (dc state condition), the load current is supplied by the LDO (solid arrow) and the voltage across the
capacitor is the same as the output voltage (V(CO) = VO). This means no current is flowing into the CO branch. If
IO suddenly increases (transient condition), the following occurs:
D The LDO is not able to supply the sudden current need due to its response time (t1 in Figure 24). Therefore,
capacitor CO provides the current for the new load condition (dashed arrow). CO now acts like a battery with
an internal resistance, ESR. Depending on the current demand at the output, a voltage drop will occur at RESR.
This voltage is shown as VESR in Figure 23.
D When CO is conducting current to the load, initial voltage at the load will be VO = V(CO) – VESR. Due to the
discharge of CO, the output voltage VO will drop continuously until the response time t1 of the LDO is reached
and the LDO will resume supplying the load. From this point, the output voltage starts rising again until it reaches
the regulated voltage. This period is shown as t2 in Figure 24.
The figure also shows the impact of different ESRs on the output voltage. The left brackets show different levels
of ESRs where number 1 displays the lowest and number 3 displays the highest ESR.
From above, the following conclusions can be drawn:
D The higher the ESR, the larger the droop at the beginning of load transient.
D The smaller the output capacitor, the faster the discharge time and the bigger the voltage droop during the LDO
response period.
相關PDF資料
PDF描述
TPSMC10A/7 1500 W, UNIDIRECTIONAL, SILICON, TVS DIODE, DO-214AB
TPSMC43A/7 1500 W, UNIDIRECTIONAL, SILICON, TVS DIODE, DO-214AB
TPSMC6.8A/7 1500 W, UNIDIRECTIONAL, SILICON, TVS DIODE, DO-214AB
TPT-MR-04-CCDF5 FIBER OPTIC TRANSCEIVER, 1529-1564nm, 11300Mbps(Tx), 11300Mbps(Rx), PANEL MOUNT, FC/UPC CONNECTOR
TPT-MR-04-CCDFF FIBER OPTIC TRANSCEIVER, 1529-1564nm, 11300Mbps(Tx), 11300Mbps(Rx), PANEL MOUNT, FC/UPC CONNECTOR
相關代理商/技術參數(shù)
參數(shù)描述
TPS75425QPWPRG4 功能描述:低壓差穩(wěn)壓器 - LDO Fast-Tran-Resp 2-A RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-20
TPS75433QPWP 功能描述:低壓差穩(wěn)壓器 - LDO Fast-Tran-Resp 2-A RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-20
TPS75433QPWPG4 功能描述:低壓差穩(wěn)壓器 - LDO Fast-Tran-Resp 2-A RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-20
TPS75433QPWPR 功能描述:低壓差穩(wěn)壓器 - LDO Fast-Tran-Resp 2-A RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-20
TPS75433QPWPRG4 功能描述:低壓差穩(wěn)壓器 - LDO Fast-Tran-Resp 2-A RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓(最大值):307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-20