MAX1882EUG Maxim Integrated, MAX1882EUG Datasheet - Page 28

• Manufacturer Part Number: MAX1882EUG
• Description: LCD Drivers Quad-Output TFT LCD DC-DC Converter with Buffer
• Manufacturer: Maxim Integrated

Specifications of MAX1882EUG

• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Package / Case: TSSOP-24
• Mounting Style: SMD/SMT

Quad-Output TFT LCD DC/DC
Converters with Buffer
MAX1778/MAX1880–MAX1885
28
Table 2. MAX1881/MAX1882/MAX1884/MAX1885 Component Values (f
*R
Table 3. Component Suppliers
Coilcraft
Coiltronics
Sumida USA
TOKO
AVX
KEMET
SANYO
Taiyo Yuden
Central
Semiconductor
International
Rectifier
Motorola
Nihon
Zetex
INDUCTORS
CAPACITORS
DIODES
COMP
SUPPLIER
I
MAIN(MAX)
and C
R
C
V
V
I
C
V
I
I
PEAK
COMP
COMP
MAIN
V
NEG
POS
NEG
R1
R2
POS
OUT
L
IN
COMP
are connected between the step-up converter’s output (V
847-639-6400
561-241-7876
847-956-0666
847-297-0070
803-946-0690
408-986-0424
619-661-6835
408-573-4150
516-435-1110
310-322-3331
602-303-5454
847-843-7500
516-543-7100
PHONE
CIRCUIT 6
49.9kΩ
100mA
309kΩ
4.7µH
4.7µF
None
None
2mA
2mA
3.3V
>1A
24V
-5V
9V
847-639-1469
561-241-9339
847-956-0702
847-699-1194
803-626-3123
408-986-1442
619-661-1055
408-573-4159
516-435-1824
310-322-3332
602-994-6430
847-843-2798
516-864-7630
FAX
CIRCUIT 7
49.9kΩ
100mA
309kΩ
10µH
None
None
10µF
2mA
2mA
3.3V
>1A
24V
-5V
9V
The charge pumps in the MAX1778/MAX1880–MAX1882
provide regulated output voltages by controlling the
voltage drop across the low-side n-channel MOSFET, so
they can be modeled as linear regulators followed by an
unregulated charge pump when determining the input
power requirements and efficiency.
The charge pump only provides charge to the output
capacitor during half the period (50% duty cycle), so
the input current is a function of the number of stages
and the load current:
for the positive charge pump, and:
for the negative charge pump, where N is the number
of charge-pump stages.
The efficiency characteristics of the MAX1778/
MAX1880–MAX1882 regulated charge pumps are simi-
lar to a linear regulator. It is dominated by quiescent
current at low output currents and by the input voltage
MAIN
) and FB.
CIRCUIT 8
I
I
SUPP
SUPP
200mA
49.9kΩ
309kΩ
10µH
None
None
10µF
3.3V
5mA
5mA
>1A
24V
-5V
9V
Charge-Pump Input Power and
=
=
I
I
POS
POS
Efficiency Considerations
OSC
(
(
N
N
+ 1
+ 1
)
)
= 500kHz)
CIRCUIT 9
200mA
49.9kΩ
200pF*
309kΩ
20kΩ*
Maxim Integrated
10µH
20µF
3.3V
5mA
5mA
>1A
24V
-5V
9V