EL7585AILZ-T13 Intersil, EL7585AILZ-T13 Datasheet - Page 12

• Manufacturer Part Number: EL7585AILZ-T13
• Description: IC POWER SUPPLY TFT-LCD 20-QFN
• Manufacturer: Intersil

Specifications of EL7585AILZ-T13

• Applications: Converter, TFT, LCD
• Voltage - Input: 3 ~ 5 V
• Number Of Outputs: 4
• Voltage - Output: 5.5 ~ 20 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-VQFN Exposed Pad, 20-HVQFN, 20-SQFN, 20-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

For the EL7585A, the minimum drive current is:
I_DRVL_min = 8mA
The minimum base-emitter resistor, R
calculated as:
R
1.25V/(8mA - 500mA/100) = 417Ω
This is the minimum value that can be used - so, we now
choose a convenient value greater than this minimum value;
say 500Ω. Larger values may be used to reduce quiescent
current, however, regulation may be adversely affected, by
supply noise if R
PG_LDON
0.9V
PG_LDOP
BL
0.4V
_min = V
FIGURE 22. V
FIGURE 21. V
GMN
+
-
+
GMP
-
+
-
BE
+
-
CLAMP
ESD
36V
_max/(I_DRVL_min - Ic/Hfe_min) =
BL
1: Nn
1: Np
LDO_OFF
OFF
is made too high in value.
ON
CLAMP
LDO_ON
ESD
36V
FUNCTIONAL BLOCK DIAGRAM
FUNCTIONAL BLOCK DIAGRAM
FBN
DRVN
12
R
3kΩ
DRVP
FBP
BN
R
7kΩ
BP
20kΩ
R
R
N2
N1
BL
20kΩ
V
R
R
REF
, can now be
V
Q2
P1
P2
BOOST
Q3
0.1µF
CP (TO 36V)
V
ON
CP (TO -26V)
V
0.1µF
OFF
(TO 35V)
0.1µF
C
(TO -20V)
ON
LX
0.1µF
C
LX
OFF
EL7585A
The V
of the row driver in the LCD panel. The DC-DC consists of an
external diode-capacitor charge pump powered from the
inductor (LX) of the boost converter, followed by a low
dropout linear regulator (LDO_ON). The LDO_ON regulator
uses an external PNP transistor as the pass element. The
onboard LDO controller is a wide band (>10MHz)
transconductance amplifier capable of 4mA drive current,
which is sufficient for up to 40mA or more output current
under the low dropout condition (forced beta of 10). Typical
V
+36V. A fault comparator is also included for monitoring the
output voltage. The under-voltage threshold is set at 25%
below the 1.2V reference.
The V
supply of the row driver in the LCD panel. The DC-DC
consists of an external diode-capacitor charge pump
powered from the inductor (LX) of the boost converter,
followed by a low dropout linear regulator (LDO_OFF). The
LDO_OFF regulator uses an external NPN transistor as the
pass element. The onboard LDO controller is a wide band
(>10MHz) transconductance amplifier capable of 4mA drive
current, which is sufficient for up to 40mA or more output
current under the low dropout condition (forced beta of 10).
Typical V
-5V to -20V. A fault comparator is also included for
monitoring the output voltage. The undervoltage threshold is
set at 200mV above the 0.2V reference level.
The V
within the LCD panel. The DC-DC may be powered directly
from the low voltage input, 3.3V or 5.0V, or it may be
powered through the fault protection switch. The
LDO_LOGIC regulator uses an external PNP transistor as
the pass element. The onboard LDO controller is a wide
band (>10MHz) transconductance amplifier capable of
16mA drive current, which is sufficient for up to 160mA or
ON
0.9V
PG_LDOL
FIGURE 23. V
voltage supported by EL7585A ranges from +15V to
LOGIC
ON
OFF
OFF
power supply is used to power the positive supply
+
GML
power supply is used to power the negative
-
power supply is used to power the logic circuitry
+
-
voltage supported by EL7585A ranges from
LOGIC
1: N1
LDO_LOG
FUNCTIONAL BLOCK DIAGRAM
DRVL
FBL
500Ω
R
BL
V
20kΩ
IN
R
R
(3V TO 6V)
L1
L2
OR V
Q5
(1.3V TO 3.6V)
PROT
V
LOGIC
March 9, 2006
C
10µF
FN7523.3
LOG