поискавой системы для электроныых деталей |
|
TC828A датащи(PDF) 4 Page - TelCom Semiconductor, Inc |
|
TC828A датащи(HTML) 4 Page - TelCom Semiconductor, Inc |
4 / 8 page 4 Switched Capacitor Voltage Converters TC828A TC828A-1 5/1/00 Capacitor Selection In order to maintain the lowest output resistance and output ripple voltage, it is recommended that low ESR capacitors be used. Additionally, larger values of C1 will lower the output resistance and larger values of C2 will reduce output ripple. (See Equation 1(b)). Table 1 shows various values of C1 and the correspond- ing output resistance values @ +25 °C. It assumes a 0.1Ω ESRC1 and 2Ω RSW. Table 2 shows the output voltage ripple for various values of C2. The VRIPPLE values assume 10mA output load current and 0.1 Ω ESRC2. Table 1. Output Resistance vs. C1 (ESR = 0.1 Ω) C1( µF) ROUT ( Ω) 0.1 850 1 100 3.3 42 10 25 47 18.3 100 17.3 Table 2. Output Voltage Ripple vs. C2 (ESR = 0.1 Ω) I OUT 10mA C2( µF) VRIPPLE (mV) 1 835 3.3 254 10 85 47 19.7 100 10.3 Input Supply Bypassing The VIN input should be capacitively bypassed to reduce AC impedance and minimize noise effects due to the switch- ing internal to the device. The recommended capacitor depends on the configuration of the TC828A. If the device is loaded from OUT to GND it is recom- mended that a large value capacitor (at least equal to C1) be connected from the input to GND. If the device is loaded from IN to OUT a small (0.1 µF) capacitor from IN to OUT is sufficient. Voltage Inverter The most common application for charge pump devices is the inverter (Figure 3). This application uses two external capacitors – C1 and C2 (plus a power supply bypass capacitor, if necessary). The output is equal to V– IN plus any voltage drops due to loading. Refer to Table 1 and Table 2 for capacitor selection. Cascading Devices Two or more TC828As can be cascaded to increase output voltage (Figure 4). If the output is lightly loaded, it will be close to (– 2 x VIN) but will droop at least by ROUT of the first device multiplied by the IQ of the second. It can be seen that the output resistance rises rapidly for multiple cascaded devices. For large negative voltage requirements see the TC682 or TCM680 data sheets. Paralleling Devices To reduce the value of ROUT, multiple TC828As can be connected in parallel (Figure 5). The output resistance will be reduced by a factor of N where N is the number of TC828As. Each device will require it’s own pump capacitor (C1), but all devices may share one reservoir capacitor (C2). However, to preserve ripple performance the value of C2 should be scaled according to the number of paralleled TC828As. Figure 3. Test Circuit C1 C1 C2 5 5 4 3 4 1 2 2 1 3 C2 V IN V OUT V OUT = –nVIN + TC828 “1” TC828 “N” . . . . . . Figure 4. Cascading TC828As to Increase Output Voltage 3 2 4 5 1 C3 10 µF* C1 10 µF* C2 10 µF* V IN V OUT R L TC828 C1– IN OUT C1+ GND Voltage Inverter |
Аналогичный номер детали - TC828A |
|
Аналогичное описание - TC828A |
|
|
ссылки URL |
Конфиденциальность |
ALLDATASHEETRU.COM |
Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | обмен ссыками | поиск по производителю All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |