MAX1513ETP+T Maxim Integrated Products, MAX1513ETP+T Datasheet - Page 19

• Manufacturer Part Number: MAX1513ETP+T
• Description: IC CNTRLR TFT-LCD PS 20-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1513ETP+T

• Applications: Controller, TFT, LCD
• Voltage - Input: 2.7 ~ 5.5 V
• Number Of Outputs: 1
• Voltage - Output: 2.7 ~ 50 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

5) If V
back signal is too high and can trip the current limit
before the full load current is delivered. Use the cur-
rent-sense configuration in Figure 9 to attenuate the
sense signal. Define the scale factor (SF) as:
Calculate R
6) If V
signal is low relative to the current-limit threshold. Use
the Figure 8 configuration, or, if good current-limit
accuracy is desired, use the optional current-sense
configuration in Figure 10 to increase the amplitude of
the sense signal. Calculate R
If the 2.2µH inductor used in the typical operating cir-
cuit (Figures 1 and 2) had a typical DCR of 24mΩ and a
maximum DCR of 30mΩ, the RC time constant of the
sense network would be:
Figure 8. Lossless Current Sensing with 80mV < V
V
IN
R
R
S
S
SENSE
SENSE
3
4
C
S+
=
=
S1
R
V
is greater than 100mV, the current-feed-
is less than 80mV, the current-feedback
MAIN
S
and R
MAX1513
MAX1514
-
R
C
______________________________________________________________________________________
R
R
L
S
S
-
S
S
V
3
SF
S2
V
1
2
IN MIN
MAIN
:
(
=
=
=
R
SF
R
C
)
V
GATE
100
S
GND
-
S-
S
1
-
SENSE
FB
S3
100
1
R
V
-
S
IN MIN
mV
×
and R
SF
TFT-LCD Power-Supply Controllers
(
mV V
SF
+
)
S4
SENSE
:
SENSE
×
< 100mV
R
V
S
MAIN
Select C
Assuming ∆T is 40°C and TC is 0.5%, the worst-case
high sense voltage over temperature is:
Because V
the circuit in Figure 8 should be used. The closest 1%
standard value for R
If the 2.2µH inductor used in the typical operating cir-
cuit (Figures 1 and 2) has a typical DCR of 45mΩ and a
maximum DCR of 56mΩ, the RC time constant of the
sense network is:
Select C
Assuming ∆T is 40°C and TC is 0.5%, the worst-case
high sense voltage over temperature is:
Figure 9. Lossless Current Sensing with V
V
SENSE
V
IN
S
S
=
C
S+
= 0.1µF and calculate R
= 0.1µF and calculate R
SENSE
2 6
.
A
R
R
MAX1513
MAX1514
τ
τ
×
S
S
would be between 80mV and 100mV,
R
C
=
L
S2
=
30
S
=
S
=
m
2 2
24
is 909Ω.
2 2
45
.
91 7
48 9
Ω
.
0 1
0 1
m
m
µ
.
.
µ
.
.
Ω
(
H
Ω
1 0 005
H
µ
µ
C
µ
µ
GATE
F
F
GND
+
S-
s
s
FB
=
=
R
S1
.
=
=
91 7
48 9
S
917
S
489
.
.
:
:
×
µ
SENSE
µ
s
Ω
Ω
s
40
°
C
> 100mV
)
=
93 6
.
V
MAIN
mV
19