ISL97646 Просмотр технического описания (PDF) - Intersil
Номер в каталоге
Компоненты Описание
Список матч
ISL97646 Datasheet PDF : 15 Pages
| |||
Typical Application Diagram
VIN
C1
22µF
VIN2
C3
2.2nF COMP
R5
C4 10k
10nF SS
ISL97646
L1
10µH
BOOST
AVDD
R6
130k
R7
80k
VCOM
+4.0V
C6
0.1µF
ENABLE
FREQ-
VDPM
VFLK
C5
470P CE
RE
R3
2k POS
C11
1µF
NEG-
OUT
VIN1
AGND
GND
GPM
CIRCUIT
LDO
CONTROLLER
D1
LX
C2
47µF
FB
PGND
AVDD
R1
10k
C9 (OPTIONAL)
R2
1.3k
VGH
VON
VDD_1
VGH_M
VDD2
C10
2.2µF
TO ROW DRIVER
LDO_OUT
ADJ
VLOGIC
C7
4.7µF
FIGURE 14. TYPICAL APPLICATION DIAGRAM
Applications Information
The ISL97646 provides a complete power solution for TFT
LCD applications. The system consists of one boost
converter to generate AVDD voltage for column drivers, one
logic LDO regulator to provide voltage to logic circuit in the
LCD panel, one integrated VCOM buffer which can provide
up to 400mA peak current. This part also integrates a Gate
Pulse Modulator circuit that can help to optimize the picture
quality.
Enable Control
When enable pin is pulling down, the ISL97646 is shut down
reducing the supply current to <10µA. When the voltage at
enable pin reaches 2.2V, the ISL97646 is on.
Boost Converter
Frequency Selection
The ISL97646 switching frequency can be user selected to
operate at either constant 650kHz or 1.2MHz. Lower
switching frequency can save power dissipation, while
higher switching frequency can allow smaller external
components like inductor and output capacitors, etc.
Connecting FREQ pin to ground sets the PWM switching
frequency to 650MHz, or connecting FREQ pin to VIN for
1.2MHz.
Soft-Start
The soft-start is provided by an internal 2.5µA current source
to charge the external soft start capacitor. The ISL97646
ramps up current limit from 0A up to full value, as the voltage
at SS pin ramps from 0V to 1.2V. Hence the soft-start time is
4.8ms when the soft-start capacitor is 10nF, 22.6ms for 47nF
and 48ms for 100nF.
9
FN6265.1
December 14, 2007
Share Link: 