EL7640 INTERSIL [Intersil Corporation], EL7640 Datasheet - Page 16

• Manufacturer Part Number: EL7640
• Description: TFT-LCD DC/DC with Integrated Amplifiers
• Manufacturer: INTERSIL [Intersil Corporation]

Component Selection for Start-up Sequencing and
Fault Protection
The C
to stabilize the V
22nF to 1µF and should not be more than five times the
capacitor on C
REF
capacitor is typically set at 220nF and is required
DEL
REF
to ensure correct start-up operation.
output. The range of C
V
16
BOOST
V
V
V
CDLY
V
REF
OFF
ON
IN
REF
EL7640, EL7641, EL7642
FIGURE 23. START-UP SEQUENCE
is from
START-UP SEQUENCE
t
ON
TIMED BY C
t
DLY
DEL1
The C
range from 47nF minimum to several microfarads – only
limited by the leakage in the capacitor reaching µA levels.
C
above). Note with 220nF on C
typically 50ms and the use of a larger/smaller value will vary
this time proportionally (e.g. 1µF will give a fault time-out
period of typically 230ms).
DEL
t
DEL2
DEL
should be at least 1/5 of the value of C
capacitor is typically 220nF and has a usable
DEL
the fault time-out will be
REF
September 26, 2005
(see
FN7415.1