MAX1880EUG Maxim Integrated Products, MAX1880EUG Datasheet - Page 28

• Manufacturer Part Number: MAX1880EUG
• Description: DC/DC Switching Converters
• Manufacturer: Maxim Integrated Products

Specifications of MAX1880EUG

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Quad-Output TFT LCD DC-DC
Converters with Buffer
28
Table 2. MAX1881/MAX1882/MAX1884/MAX1885 Component Values (f
*R
Table 3. Component Suppliers
INDUCTORS
Coilcraft
Coiltronics
Sumida USA
Toko
CAPACITORS
AVX
Kemet
Sanyo
Taiyo Yuden
DIODES
Central
Semiconductor
International
Rectifier
Motorola
Nihon
Zetex
COMP
SUPPLIER
______________________________________________________________________________________
I
and C
MAIN(MAX)
R
C
V
V
I
C
V
I
I
PEAK
COMP
COMP
MAIN
NEG
V
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
100mA
49.9kΩ
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
100mA
49.9kΩ
309kΩ
10µH
None
None
10µF
3.3V
2mA
2mA
>1A
24V
-5V
9V
The charge pumps in the MAX1778/MAX1880/
MAX1881/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/MAX1881/MAX1882 regulated charge
pumps are similar to a linear regulator. It is dominated
by quiescent current at low output currents and by the
MAIN
) and FB.
CIRCUIT 8
I
I
SUPP
SUPP
49.9kΩ
200mA
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*
10µH
20µF
5mA
5mA
3.3V
>1A
24V
-5V
9V