參數(shù)資料
型號(hào): MC33761SNT1-29
廠商: ON SEMICONDUCTOR
元件分類: 基準(zhǔn)電壓源/電流源
英文描述: Ultra Low-Noise Low Dropout Voltage Regulator with 1V ON/OFF Control
中文描述: 2.9 V FIXED POSITIVE LDO REGULATOR, 0.25 V DROPOUT, PDSO5
封裝: SOT-23, TSOP-5
文件頁(yè)數(shù): 8/14頁(yè)
文件大?。?/td> 204K
代理商: MC33761SNT1-29
MC33761
http://onsemi.com
8
Understanding the Load Transient Improvement
The MC33761 features a novel architecture which allows
the user to easily implement the regulator in burst systems
where the time between two current shots is kept very small.
The quality of the transient response time is related to
many parameters, among which the closedloop bandwidth
with the corresponding phase margin plays an important
role. However, other characteristics also come into play like
the series pass transistor saturation. When a current
perturbation suddenly appears on the output, e.g. a load
increase, the error amplifier reacts and actively biases the
PNP transistor. During this reaction time, the LDO is in
openloop and the output impedance is rather high. As a
result, the voltage brutally drops until the error amplifier
effectively closes the loop and corrects the output error.
When the load disappears, the opposite phenomenon takes
place with a positive overshoot. The problem appears when
this overshoot decays down to the LDO steadystate value.
During this decreasing phase, the LDO stops the PNP bias
and one can consider the LDO asleep (Figure 8). If by
misfortune a current shot appears, the reaction time is
incredibly lengthened and a strong undershoot takes place.
This reaction is clearly not acceptable for line sensitive
devices, such as VCOs or other RadioFrequency parts.
This problem is dramatically exacerbated when the output
current drops to zero rather than a few mA. In this later case,
the internal feedback network is the only discharge path,
accordingly lengthening the output voltage decay period
(Figure 9).
The MC33761 cures this problem by implementing a
clever design where the LDO detects the presence of the
overshoot and forces the system to go back to steadystate
as soon as possible, ready for the next shot. Figure 10
and
11
show how it positively improves the response time and
decreases the negative peak voltage.
Figure 8. A Standard LDO Behavior when the Load
Current Disappears
Figure 9. A Standard LDO Behavior when the Load
Current Appears in the Decay Zone
Figure 10. Without Load Transient Improvement
Figure 11. MC33761 with Load Transient Improvement
相關(guān)PDF資料
PDF描述
MC33761SNT1-50 COMPACT FLASH CARD, 32MB
MC33761SNT1-50G Ultra Low-Noise Low Dropout Voltage Regulator with 1V ON/OFF Control
MC33761SNT1-28 Ultra Low-Noise Low Dropout Voltage Regulator with 1V ON/OFF Control
MC33761SNT1-30 Ultra Low-Noise Low Dropout Voltage Regulator with 1V ON/OFF Control
MC34271FB Internal power supply connectors (C-UL, TUV), Discrete wire connectors; HRS No: 680-1089-7 00; Connector Type: Wire; Contact Gender: Female; Termination Style: Crimping; Contact Mating Area Plating: Tin; Operating Temperature Range (degrees C): -35 to 85; General Description: Female contact
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC33762DM-2525R2 功能描述:低壓差穩(wěn)壓器 - LDO 2.5V 80mA Out Dual 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(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MC33762DM-2525RG 功能描述:低壓差穩(wěn)壓器 - LDO 2.5V 80mA Out Dual w/Enable Low Noise 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(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MC33762DM-2828R2 功能描述:低壓差穩(wěn)壓器 - LDO 2.8V 80mA Out Dual 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(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MC33762DM-2828RG 功能描述:低壓差穩(wěn)壓器 - LDO 2.8V 80mA Out Dual w/Enable Low Noise 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(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MC33762DM-3030R2 功能描述:低壓差穩(wěn)壓器 - LDO 3.0V 80mA Out Dual 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(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20