| поискавой системы для электроныых деталей |
|
IR3088AM датащи(PDF) 22 Page - International Rectifier |
|
|
|||||||||||||||||||||||||||||
IR3088AM датащи(HTML) 22 Page - International Rectifier |
|
22 / 34 page ![]() IR3088A VDAC Slew Rate Programming Capacitor CVDAC and Resistor RVDAC From Figure 15 of IR3081 Data Sheet, the sink current of VDAC pin corresponding to 400kHz (ROSC=30.1kΩ) is 76uA. Calculate the VDAC down-slope slew-rate programming capacitor from the required down-slope slew rate. nF SR I C DOWN SINK VDAC 4 . 30 10 / 10 * 5 . 2 10 * 76 6 3 6 = = = − − − , Choose CVDAC=33nF Calculate the programming resistor. Ω = + = + = − − − 5 . 3 ) 10 * 33 ( 10 * 2 . 3 5 . 0 10 * 2 . 3 5 . 0 2 9 15 2 15 VDAC VDAC C R From Figure 15 of IR3081 Data Sheet, the source current of VDAC pin is 110uA. The VDAC up-slope slew rate is uS mV C I SR VDAC SOURCE UP / 3 . 3 10 * 33 10 * 110 9 6 = = = − − Over Current Setting Resistor ROCSET The room temperature is 25ºC and the target PCB temperature is 100 ºC. The phase IC die temperature is about 1 ºC higher than that of phase IC, and the inductor temperature is close to PCB temperature. Calculate Inductor DC resistance at 100 ºC, Ω = − ∗ + ∗ = − ∗ + ∗ = − − − m T T R R ROOM MAX L ROOM L MAX L 61 . 0 )] 25 100 ( 10 * 3850 1 [ 10 * 47 . 0 )] ( 10 * 3850 1 [ 6 3 _ 6 _ _ The current sense amplifier gain is 34 at 25ºC, and its gain at 101ºC is calculated as, 2 . 30 )] 25 101 ( 10 * 1470 1 [ 34 )] ( 10 * 1470 1 [ 6 _ 6 _ _ = − ∗ − ∗ = − ∗ − ∗ = − − ROOM MAX IC ROOM CS MIN CS T T G G Set the over current limit at 135A. From Figure 14 of IR3081 Data Sheet, the bias current of OCSET pin (IOCSET) is 41uA with ROSC=30.1kΩ. The total current sense amplifier input offset voltage is 0.55mV, which includes the offset created by the current sense amplifier input resistor mismatch. Calculate constant KP, the ratio of inductor peak current over average current in each phase, 3 . 0 6 / 135 ) 2 10 * 400 12 10 * 220 /( 33 . 1 ) 33 . 1 12 ( / ) 2 /( ) ( 3 9 = ∗ ∗ ∗ ∗ − = ∗ ∗ ∗ ∗ − = − n I f V L V V V K LIMIT SW I O O I P OCSET MIN CS TOFST CS P MAX L LIMIT OCSET I G V K R n R R / ] ) 1 ( [ _ _ _ ∗ + + ∗ ∗ = Ω = ∗ + ∗ ∗ = − − − k 3 . 13 ) 10 * 41 /( 2 . 30 ) 10 * 55 . 0 3 . 1 10 * 61 . 0 6 135 ( 6 3 3 No Load Output Voltage Setting Resistor RFB and Adaptive Voltage Positioning Resistor RDRP From Figure 14 of IR3081 Data, the bias current of FB pin is 41uA with ROSC=30.1kΩ. Ω = ∗ ∗ ∗ − ∗ = ∗ ∗ ∗ − ∗ = − − − − − − 365 10 * 61 . 0 10 * 41 10 * 91 . 0 6 10 * 55 . 0 10 * 20 10 * 61 . 0 3 6 3 3 3 3 _ _ _ _ MAX L FB O TOFST CS NLOFST O MAX L FB R I R n V V R R Ω = ∗ ∗ ∗ = ∗ ∗ ∗ = − − k R n G R R R O MIN CS MAX L FB DRP 21 . 1 10 * 91 . 0 6 2 . 30 10 * 61 . 0 365 3 3 _ _ Page 22 of 34 9/30/04 |
|
ссылки URL |
| Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | Ссылка на техническое описание | 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 |