Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
ISL97650 Datasheet(PDF) 16 Page - Renesas Technology Corp |
|
ISL97650 Datasheet(HTML) 16 Page - Renesas Technology Corp |
16 / 20 page ISL97650 FN9198 Rev.4.00 Page 16 of 20 April 17, 2009 The maximum VOFF output voltage of a single stage charge pump is: R6 and R7 in the “Typical Application Diagram” on page 10 determine VOFF output voltage. Improving Charge Pump Noise Immunity Depending on PCB layout and environment, noise pick-up at the FBP and FBN inputs, which may degrade load regulation performance, can be reduced by the inclusion of capacitors across the feedback resistors (e.g. in the Application Diagram, C21 and C22 for the positive charge pump). Set R6 • C20 = R7 • C19 with C19 ~ 100pF. VON Slice Circuit The VON Slice Circuit functions as a three way multiplexer, switching the voltage on COM between ground, DRN and SRC, under control of the start-up sequence and the CTL pin. During the start-up sequence, COM is held at ground via an NDMOS FET, with ~1k impedance. Once the start-up sequence has completed, CTL is enabled and acts as a multiplexer control such that if CTL is low, COM connects to DRN through a 30 internal MOSFET, and if CTL is high, COM connects to POUT internally via a 5MOSFET. The slew rate of start-up of the switch control circuit is mainly restricted by the load capacitance at COM pin as shown in Equation 22: Where Vg is the supply voltage applied to DRN or voltage at POUT, which range from 0V to 36V. Ri is the resistance between COM and DRN or POUT including the internal MOSFET rDS(On), the trace resistance and the resistor inserted, RL is the load resistance of switch control circuit, and CL is the load capacitance of switch control circuit. In the “Typical Application Diagram” on page 10, R10, R11 and C15 give the bias to DRN based on Equation 23: R12 can be adjusted to adjust the slew rate. FIGURE 17. NEGATIVE CHARGE PUMP BLOCK DIAGRAM FAULT 0.2V CLK EN VDD VSUP FBN NOUT PGND STOP PWM CONTROL VREF R6 40k C20 820pF C19 100pF R7 328k VOFF (-8V) C13 470nF D2 D3 C12 220nF A2 0.4V A1 M1 M2 1.2MHz VOFF_MAX 2x VSUP – VDIODE 2IOUT rON NOUT Hr ON NOUT L + ++ = (EQ. 20) VOFF VFBN 1 R7 R6 -------- + V REF – R7 R6 -------- = (EQ. 21) V t -------- Vg Ri RL C L ------------------------------------- = (EQ. 22) VDRN VON R11+AVDD R10 R10 R11 + --------------------------------------------------------------- = (EQ. 23) |
Número de pieza similar - ISL97650 |
|
Descripción similar - ISL97650 |
|
|
Enlace URL |
Política de Privacidad |
ALLDATASHEET.ES |
¿ALLDATASHEET es útil para Ud.? [ DONATE ] |
Todo acerca de Alldatasheet | Publicidad | Contáctenos | Política de Privacidad | Intercambio de Enlaces | Lista de Fabricantes 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 |