Motor de Búsqueda de Datasheet de Componentes Electrónicos
  Spanish  ▼
ALLDATASHEET.ES

X  

ISL97650 Datasheet(PDF) 14 Page - Renesas Technology Corp

No. de pieza ISL97650
Descripción Electrónicos  4-Channel Integrated LCD Supply
Download  20 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricante Electrónico  RENESAS [Renesas Technology Corp]
Página de inicio  http://www.renesas.com
Logo RENESAS - Renesas Technology Corp

ISL97650 Datasheet(HTML) 14 Page - Renesas Technology Corp

Back Button ISL97650 Datasheet HTML 10Page - Renesas Technology Corp ISL97650 Datasheet HTML 11Page - Renesas Technology Corp ISL97650 Datasheet HTML 12Page - Renesas Technology Corp ISL97650 Datasheet HTML 13Page - Renesas Technology Corp ISL97650 Datasheet HTML 14Page - Renesas Technology Corp ISL97650 Datasheet HTML 15Page - Renesas Technology Corp ISL97650 Datasheet HTML 16Page - Renesas Technology Corp ISL97650 Datasheet HTML 17Page - Renesas Technology Corp ISL97650 Datasheet HTML 18Page - Renesas Technology Corp Next Button
Zoom Inzoom in Zoom Outzoom out
 14 / 20 page
background image
ISL97650
FN9198 Rev.4.00
Page 14 of 20
April 17, 2009
Rectifier Diode (Buck Converter)
A Schottky diode is recommended due to fast recovery and low
forward voltage. The reverse voltage rating should be higher
than the maximum input voltage. The peak current rating is 2A,
and the average current should be as shown in Equation 15:
Where Io is the output current of buck converter. Table 8 shows
some recommended diodes.
Output Capacitor (Buck Converter)
Four 10µF or two 22µF ceramic capacitors are recommended
for this part. The overshoot and undershoot will be reduced with
more capacitance, but the recovery time will be longer.
PI Loop Compensation (Buck Converter)
The buck converter of ISL97650 can be compensated by a RC
network connected from CM2 pin to ground. C9 = 4.7nF and
R2 = 2k RC network is used in the demo board. The larger
value resistor can lower the transient overshoot, however, at
the expense of stability of the loop.
The stability can be optimized in a similar manner to that
described in the section “PI Loop Compensation (Boost
Converter)” on page 12.
Bootstrap Capacitor (C16)
This capacitor is used to provide the supply to the high driver
circuitry for the buck MOSFET. The bootstrap supply is formed
by an internal diode and capacitor combination. A 1µF is
recommended for ISL97650. A low value capacitor can lead to
overcharging and in turn damage the part.
If the load is too light, the on-time of the low side diode may be
insufficient to replenish the bootstrap capacitor voltage. In this
case, if VIN-VBUCK < 1.5V, the internal MOSFET pull-up
device may be unable to turn-on until VLOGIC falls. Hence,
there is a minimum load requirement in this case. The
minimum load can be adjusted by the feedback resistors
to FBL.
The bootstrap capacitor can only be charged when the higher
side MOSFET is off. If the load is too light which can not make
the on time of the low side diode be sufficient to replenish the
boot strap capacitor, the MOSFET can’t turn on. Hence there is
minimum load requirement to charge the bootstrap capacitor
properly.
Charge Pump Controllers (VON and VOFF)
The ISL97650 includes 2 independent charge pumps (see
charge pump block and connection diagram, Figure 17). The
negative charge pump inverts the VSUP voltage and provides a
regulated negative output voltage. The positive charge pump
doubles or triples the VSUP voltage and provides a regulated
positive output voltage. The regulation of both the negative and
positive charge pumps is generated by internal comparator
that senses the output voltage and compares it with the
internal reference.
The pumps use pulse width modulation to adjust the pump
period, depending on the load present. The pumps can provide
30mA for VOFF and 20mA for VON.
Positive Charge Pump Design Consideration
The positive charge pump integrates all the diodes (D1, D2
and D3 shown in the “Block Diagram” on page 9) required for
x2 (VSUP doubler) and x3 (VSUP Tripler) modes of operation.
During the chip start-up sequence, the mode of operation is
automatically detected when the charge pump is enabled. With
both C7 and C8 present, the x3 mode of operation is detected.
With C7 present, C8 open and with C1+ shorted to C2+, the x2
mode of operation will be detected.
Due to the internal switches to VSUP (M1, M2 and M3), POUT
is independent of the voltage on VSUP until the charge pump is
enabled. This is important for TFT applications where the
negative charge pump output voltage (VOFF) and AVDD
supplies need to be established before POUT.
The maximum POUT charge pump current can be estimated
from the following equations assuming a 50% switching duty:
Note: VDIODE (2 • IMAX) is the on-chip diode voltage as a
function of IMAX and VDIODE (40mA) < 0.7V.
TABLE 8. BUCK RECTIFIER DIODE RECOMMENDATION
DIODE
VR/IAVG
RATING
PACKAGE
VENDOR
PMEG2020EJ
20V/2A
SOD323F Philips
Semiconductors
SS22
20V/2A
SMB
Fairchild
Semiconductor
TABLE 9. BUCK OUTPUT CAPACITOR RECOMMENDATION
CAPACITOR
SIZE
VENDOR
PART NUMBER
10µF/6.3V
0805
TDK
C2012X5R0J106M
10µF/6.3V
0805
Murata
GRM21BR60J106K
22µF/6.3V
1210
TDK
C3216X5R0J226M
100µF/6.3V
1206
Murata
GRM31CR60J107M
Iavg
1D
*I
o
=
(EQ. 15)
IMAX 2x
 min of 50mA or
2V
SUP
2
VDIODE 2IMAX
 VV
ON

22 rONH rONL
+


---------------------------------------------------------------------------------------------------------------------- 0.95A
IMAX 3x
 min of 50mA or
3V
SUP
3
VDIODE 2IMAX
 VV
ON

23 rONH 2r
ONL
+


---------------------------------------------------------------------------------------------------------------------- 0.95V
(EQ. 16)


Número de pieza similar - ISL97650

Fabricante ElectrónicoNo. de piezaDatasheetDescripción Electrónicos
logo
Intersil Corporation
ISL97650 INTERSIL-ISL97650 Datasheet
337Kb / 20P
   4-Channel Integrated LCD Supply
ISL97650 INTERSIL-ISL97650 Datasheet
353Kb / 20P
   4-Channel Integrated LCD Supply
ISL97650ARTZ-T INTERSIL-ISL97650ARTZ-T Datasheet
337Kb / 20P
   4-Channel Integrated LCD Supply
ISL97650ARTZ-T INTERSIL-ISL97650ARTZ-T Datasheet
353Kb / 20P
   4-Channel Integrated LCD Supply
ISL97650ARTZ-TK INTERSIL-ISL97650ARTZ-TK Datasheet
337Kb / 20P
   4-Channel Integrated LCD Supply
More results

Descripción similar - ISL97650

Fabricante ElectrónicoNo. de piezaDatasheetDescripción Electrónicos
logo
Renesas Technology Corp
ISL97651 RENESAS-ISL97651 Datasheet
845Kb / 20P
   4-Channel Integrated LCD Supply
logo
Intersil Corporation
ISL97650B INTERSIL-ISL97650B Datasheet
414Kb / 20P
   4-Channel Integrated LCD Supply
ISL97650 INTERSIL-ISL97650 Datasheet
337Kb / 20P
   4-Channel Integrated LCD Supply
ISL97650B INTERSIL-ISL97650B Datasheet
414Kb / 20P
   4-Channel Integrated LCD Supply
ISL97651 INTERSIL-ISL97651 Datasheet
330Kb / 19P
   4-Channel Integrated LCD Supply
logo
Renesas Technology Corp
ISL97650B RENESAS-ISL97650B Datasheet
921Kb / 20P
   4-Channel Integrated LCD Supply
logo
Intersil Corporation
ISL97650 INTERSIL-ISL97650_09 Datasheet
353Kb / 20P
   4-Channel Integrated LCD Supply
logo
Renesas Technology Corp
ISL98604 RENESAS-ISL98604 Datasheet
1Mb / 28P
   6-Channel Integrated LCD Supply
logo
Intersil Corporation
ISL97653A INTERSIL-ISL97653A Datasheet
752Kb / 18P
   5-Channel Integrated LCD Supply
ISL97653A INTERSIL-ISL97653A_08 Datasheet
530Kb / 18P
   5-Channel Integrated LCD Supply
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20


Datasheet Descarga

Go To PDF Page


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


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
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