MAX1554ETA+T Maxim Integrated Products, MAX1554ETA+T Datasheet - Page 9

• Manufacturer Part Number: MAX1554ETA+T
• Description: IC LED DRIVR WHITE BCKLGT 8-TDFN
• Manufacturer: Maxim Integrated Products
• Type: Backlight, White LEDr

Specifications of MAX1554ETA+T

• Constant Current: Yes
• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: White LED
• Voltage - Supply: 3.15 V ~ 5.5 V
• Voltage - Output: 40V
• Mounting Type: Surface Mount
• Package / Case: 8-TDFN Exposed Pad
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 970mA
• Internal Switch(s): Yes
• Number Of Segments: 10
• Operating Supply Voltage: 3.15 V to 5.5 V
• Maximum Power Dissipation: 1951 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency: -
• Efficiency: -
• Lead Free Status / Rohs Status: Details

Table 1. Component Suppliers
Ensure the diode’s average and peak current ratings
exceed the average output current and peak inductor
current. In addition, the diode’s reverse breakdown
voltage must exceed V
The MAX1553/MAX1554 have minimum input voltages
of 2.7V (MAX1553) and 3.15V (MAX1554). However,
lower battery voltages can still be boosted for LED
drive as long as V
range. Since most systems have a 3.3V system supply
active when the display is active and backlit, that logic
supply can be used to supply V
power connects directly to the boost inductor. No bat-
tery current is drawn when EN is low (Figure 4).
Due to fast-switching waveforms and high-current
paths, careful PC board layout is required. An evalua-
tion kit (MAX1553EVKIT) is available as an example of
a proper layout.
Central
Semiconductor
Kamaya
Murata
Nichia
Panasonic
Sumida
Taiyo Yuden
TDK
TOKO
SUPPLIER
Low Input-Voltage Applications
Applications Information
631-435-1110
260-489-1533
814-237-1431
248-352-6575
714-373-7939
847-956-0666
408-573-4150
847-803-6100
847-297-0070
_______________________________________________________________________________________
PHONE
CC
OUT
remains within the operating
.
www.centralsemi.com
www.kamaya.com
www.murata.com
www.nichia.com
www.panasonic.com
www.sumida.com
www.t-yuden.com
www.component.tdk.com
www.toko.com
Converters for 2 to 10 White LEDs
CC
PC Board Layout
, while the battery
WEBSITE
High-Efficiency, 40V Step-Up
When laying out a board, minimize trace lengths
between the IC and the inductor, diode, input capaci-
tor, output capacitor, and R1. Keep traces short, direct,
and wide. Keep noisy traces, such as the LX node
trace, away from FB. Place the V
(C1) as close to the IC as possible. The ground con-
nections of C1 and C2 should be as close together as
possible. Star connect the grounds for R1, R3, C3, and
the BRT voltage supply as close to the IC as possible.
The traces from V
from the LEDs to R1 can be longer if required.
TRANSISTOR COUNT: 740
PROCESS: BiCMOS
Figure 4. The MAX1553/MAX1554 can drive LEDs from battery
voltages that are lower than the device operating voltage
range by powering V
the boost inductor to the battery.
BATTERY
INPUT
4.7µF
C1
LOGIC
OFF
3.3V
0.1µF
0.1µF
ON
C4
C3
CC
CC
V
SS
EN
BRT
CC
from a logic supply and connecting
MAX1553
MAX1554
to C1, from C2 to the LEDs, and
L1
GND
OV
LX
FB
Chip Information
0.47µF
D1
CC
C2
bypass capacitor
R1
R2
R3
WHITE
LEDs
9