MAX1885EUP-T Maxim Integrated, MAX1885EUP-T Datasheet - Page 35

• Manufacturer Part Number: MAX1885EUP-T
• Description: LCD Drivers Quad-Output TFT LCD DC-DC Converter with Buffer
• Manufacturer: Maxim Integrated

Specifications of MAX1885EUP-T

• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Package / Case: TSSOP-20
• Mounting Style: SMD/SMT

the Typical Operating Characteristics . Set the resistive-
divider to precharge BUFOUT, matching the buffer’s
output set voltage:
These resistor values are selected to charge the output
capacitor close to the output set voltage before the
buffer starts up:
Figure 11. VCOM Buffer Soft-Start
Maxim Integrated
R
C
3
BUFOUT
=
V
IN
INPUT
= 3.3V
R
4
⎡
⎢
⎢
⎣
(
⎛
⎜
⎝
R
4.7µF
V
3
C
BUFOUT
V
||
IN
SUPB
R
4
)
0.22µF
0.22µF
≈
C
C1
REF
⎞
⎟ −
⎠
5000
f
OSC
1
⎤
⎥
⎥
⎦
INTG
REF
IN
SHDN
PGND
MAX1778/MAX1880–MAX1885
MAX1778
Quad-Output TFT LCD DC/DC
6.8µH
L1
BUFOUT
BUF+
SUPB
BUF-
GND
LX
FB
Converters with Buffer
49.9kΩ
274kΩ
MAX1778
MAX1880
MAX1881
MAX1882
MAX1883
MAX1884
MAX1885
10kΩ
10kΩ
PART
R1
R3
R2
R4
FREQUENCY
SWITCHING
C
1.0µF
C
1.0µF
BUF
STEP-UP
R3 = R4
SUPB
500k
500k
500k
500k
(Hz)
C
(2) 4.7µF
1M
1M
1M
OUT
[(
V
V
BUFOUT
SUPB
MAIN
V
BUFFER OUTPUT
V
MAIN
BUFOUT
= 8V
)
CHARGE
-1
PUMPS
= V
Selector Guide
DUAL
]
SUPB
Yes
Yes
Yes
Yes
No
No
No
/2
REGUL ATO R
L IN EA R
Yes
Yes
Yes
Yes
No
No
No
35