MAX1543ETP+T Maxim Integrated Products, MAX1543ETP+T Datasheet - Page 14

• Manufacturer Part Number: MAX1543ETP+T
• Description: IC DC-DC CONV TFT-LCD 20-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1543ETP+T

• Applications: Controller, TFT, LCD
• Voltage - Input: 2.6 ~ 5.5 V
• Number Of Outputs: 2
• Voltage - Output: 2.6 ~ 13 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Thermal-overload protection prevents excessive power
dissipation from overheating the MAX1542/MAX1543.
When the junction temperature exceeds T
thermal sensor immediately activates the fault protec-
tion, which shuts down the device, allowing the IC to
cool. The input voltage must fall (below V
the fault latch and reactivate the controller.
Thermal-overload protection protects the controller in
the event of fault conditions. For continuous operation,
do not exceed the absolute maximum junction-temper-
ature rating of T
TFT LCD DC-to-DC Converter with
Operational Amplifiers
Figure 3. Functional Diagram
14
______________________________________________________________________________________
COMP
FREQ*
NEG1
OUT1
POS1
J
FB
= +150°C.
Thermal-Overload Protection
*MAX1543 ONLY.
5µA
OSCILLATOR
1.24V
ERROR
AMPLIFIER
COMPEN-
UVLO
SATION
J
SLOPE
DEL
= +160°C, a
5µA
) to clear
∑
SRC
(SEE FIGURE 4)
ERROR
COMPARATOR
CONTROL
SWITCH
COM
The primary considerations in inductor selection are
inductor physical shape, circuit efficiency, and cost.
The factors that determine the inductance value are
input voltage, output voltage, switching frequency, and
maximum output current. Final inductor selection
includes ensuring the chosen inductor meets the appli-
cation’s peak current and RMS current requirements.
Very high inductance values minimize the current ripple
and therefore reduce the peak current, which decreas-
es core losses in the inductor and I
cuit’s entire power path. However, large inductance
CLOCK
DRN*
AND DRIVER
CONTROL
CURRENT
LOGIC
SENSE
CTL
Applications Information
MAX1542
MAX1543
START
SOFT-
N
Inductor Selection
2
R losses in the cir-
IN
LX
PGND
AGND
SUP
EXT*
NEG2
OUT2
POS2