MAX8901BETA+T Maxim Integrated Products, MAX8901BETA+T Datasheet - Page 8

• Manufacturer Part Number: MAX8901BETA+T
• Description: IC LED DRIVR WHITE BCKLGT 8-TDFN
• Manufacturer: Maxim Integrated Products
• Type: Backlight, White LEDr

Specifications of MAX8901BETA+T

• Constant Current: Yes
• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: White LED
• Frequency: 700kHz ~ 800kHz
• Voltage - Supply: 2.6 V ~ 5.5 V
• Voltage - Output: 24V
• Mounting Type: Surface Mount
• Package / Case: 8-TDFN Exposed Pad
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 25mA
• Internal Switch(s): Yes
• Efficiency: 91%
• Operating Supply Voltage: 2.6 V to 5.5 V
• Maximum Supply Current: 185 uA
• Maximum Power Dissipation: 953 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The high efficiency and tiny size of the MAX8901A/
MAX8901B WLED step-up converters make them ideally
suited for driving LCD backlighting in cell phones, PDAs,
and other portable and handheld devices. The
MAX8901_ drive from 2 to 6 series-connected WLEDs
with constant current for uniform WLED intensity and are
optimized for the highest possible efficiency (up to 91%)
over the full 1-cell Li+/Li-Poly battery range. These tiny
2mm x 2mm devices operate at a constant 750kHz
Highest Efficiency Supply for 2 to 6
Series WLEDs in a 2mm x 2mm TDFN Package
Figure 2. MAX8901A Block Diagram
8
_______________________________________________________________________________________
Detailed Description
SHUTDOWN
SHUTDOWN
750kHz OSC
MAX8901A
THERMAL
INTERNAL
TIMER
Gm
EP
D*0.5V
CONTROL
BOOST
LOGIC
REF
switching frequency, and use small external components
to achieve minimal input and output ripple while occupy-
ing the smallest possible footprint.
These converters use a single input (ON) to enable the IC
and to control WLED intensity. The MAX8901A requires a
direct PWM input to modulate WLED intensity, with WLED
current proportional to the PWM duty cycle. The
MAX8901B uses single-wire, serial-pulse dimming that
reduces the WLED intensity in 32 equal steps. Full-scale
WLED current for serial-pulse dimming is 24.75mA.
POWER
IC
PWM
COMP
PGND
GND
OVP
ON
CS
LX
IN