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參數(shù)資料
| 型號： | TPS618 |
| 英文描述： | PHOTOTRANSISTOR | NPN | 870NM PEAK WAVELENGTH | 50M | LED-7C |
| 中文描述： | 光電晶體管|叩| 870nm尖峰波長|五十米|發(fā)光二極管- 7C條 |
| 文件頁數(shù)： | 15/22頁 |
| 文件大?。?/td> | 392K |
| 代理商： | TPS618 |
TPS61000, TPS61001, TPS61002, TPS61003, TPS61004, TPS61005, TPS61006, TPS61007
SINGLE-AND DUAL-CELL BOOST CONVERTER WITH START-UP INTO FULL LOAD
SLVS279B – MARCH 2000 – REVISED AUGUST 2000
15
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
programming the low battery comparator threshold voltage
The current through the resistive divider should be about 100 times greater than the current into the LBI pin.
The typical current into the LBI pin is 0.01
μ
A. The voltage across R2 is equal to the reference voltage that is
generated on-chip, which has a value of 500 mV
±
15 mV. The recommended value for R2 is therefore in the
range of 500 k
. From that, the value of resistor R1, depending on the desired minimum battery voltage (V
BAT
),
can be calculated using the following equation:
R1
R2
VTRIP
VREF
1
500 k
VBAT
0.5 V
1
(2)
For example, if the low-battery detection circuit should flag an error condition on the LBO output pin at a battery
voltage of 1.0 V, a resistor in the range of 500 k
should be chosen for R1.
The output of the low battery comparator is a simple open-drain output that goes active low if the battery voltage
drops below the programmed threshold voltage on LBI. The output requires a pullup resistor with a
recommended value of 1M
, and should only be pulled up to the V
OUT
. If not used, the LBO pin can be left
floating.
inductor selection
The output filter of inductive switching regulators is a low pass filter of second order. It consists of an inductor and
a capacitor, often referred to as storage inductor and output capacitor.
To select an inductor, keep the possible peak inductor current below the current limit threshold of the power
switch in your chosen configuration. For example, the current limit threshold of the TPS61006’s switch is
1100 mA at an output voltage of 3.3 V. The highest peak current through the inductor and the switch depends on
the output load, the input (V
BAT
) and the output voltage (V
OUT
). Estimation of the maximum average inductor
current can be done using the following equation:
IL
IOUTx
VOUT
VBATx 0.8
(3)
For example, for an output current of 100 mA at 3.3 V, at least 515-mA current will flow through the inductor at a
minimum input voltage of 0.8 V.
The second parameter for choosing the inductor is the desired current ripple in the inductor. Normally it is advis-
able to work with a ripple of less than 20% of the average inductor current. A smaller ripple will reduce the mag-
netic hysteresis losses in the inductor as well as output voltage ripple and EMI. But in the same way, regulation
time at load changes will rise. In addition, a larger inductor will increase the total system costs.
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| TPS61000DGSR | SMPS Controller |
| TPS61001DGSR | SMPS Controller |
| TPS61002DGSR | SMPS Controller |
| TPS61003DGSR | SMPS Controller |
| TPS62100DR | Analog IC |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| TPS62000DGS | 功能描述:直流/直流開關(guān)調(diào)節(jié)器 Adj 600mA Hi-Eff Step-Down Converter RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| TPS62000DGS | 制造商:Texas Instruments 功能描述:BUCK CONVERTER ADJ O/P SMD 62000 |
| TPS62000DGS | 制造商:Texas Instruments 功能描述:HIGH EFFICIENCY STEP-DOWN CONVERTER :ROH |
| TPS62000DGSG4 | 功能描述:直流/直流開關(guān)調(diào)節(jié)器 Adj 600mA Hi-Eff Step-Down Converter RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| TPS62000DGSR | 功能描述:直流/直流開關(guān)調(diào)節(jié)器 Adj 600mA Hi-Eff Step-Down Converter RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
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