OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

MAX8727ETB+TG104

P1-P3P4-P6P7-P9P10-P12P13-P13
MAX8727
TFT-LCD Step-Up DC-DC Converter
4 _______________________________________________________________________________________
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
SHDN
= 3V, FREQ = GND, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER CONDITIONS
MIN
TYP
MAX
UNITS
CONTROL INPUTS
SHDN, FREQ Input Low Voltage V
IN
= 2.6V to 5.5V
0.3 ×
V
IN
V
SHDN, FREQ Input High Voltage
V
IN
= 2.6V to 5.5V
0.7 ×
V
IN
V
EFFICIENCY vs. LOAD CURRENT
(1.2MHz OPERATION)
MAX8727 toc01
LOAD CURRENT (mA)
EFFICIENCY (%)
10010
60
70
80
90
100
50
11000
L = 3.6
μ
H
V
IN
= 5.0V
V
IN
= 3.3V
EFFICIENCY vs. LOAD CURRENT
(640kHz OPERATION)
MAX8727 toc02
LOAD CURRENT (mA)
EFFICIENCY (%)
10010
60
70
80
90
100
50
1 1000
L = 6.8
μ
H
V
IN
= 5.0V
V
IN
= 3.3V
LOAD REGULATION
MAX8727 toc03
LOAD CURRENT (mA)
LOAD REGULATION (%)
10010
-1.5
-1.0
-0.5
0
0.5
-2.0
1 1000
V
IN
= 5.0V
V
IN
= 3.3V
SWITCHING FREQUENCY
vs. INPUT VOLTAGE
MAX8727 toc04
INPUT VOLTAGE (V)
SWITCHING FREQUENCY (kHz)
5.04.54.03.53.0
600
700
800
900
1000
1100
1200
1300
1400
500
2.5 5.5
FREQ = IN
FREQ = GND
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX8727 toc05
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
5.04.54.03.53.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0
2.5 5.5
SWITCHING
NONSWITCHING
SUPPLY CURRENT vs. TEMPERATURE
(SWITCHING)
MAX8727 toc06
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
806040200-20
1
2
3
4
5
0
-40 100
V
IN
= 5.0V
V
IN
= 3.3V
Typical Operating Characteristics
(Circuit of Figure 1. V
IN
= 5V, V
MAIN
= 15V, T
A
= +25°C unless otherwise noted.)
MAX8727
TFT-LCD Step-Up DC-DC Converter
_______________________________________________________________________________________ 5
SOFT-START
(R
LOAD
= 30Ω)
MAX8727 toc07
1ms/div
OA
INDUCTOR
CURRENT
1A/div
OV
V
OUT
5V/div
LOAD-TRANSIENT RESPONSE
(I
LOAD
= 50mA TO 550mA)
MAX8727 toc08
1
μ
s/div
OA
INDUCTOR
CURRENT
1A/div
50mA
15V
V
OUT
5mV/div
AC-COUPLED
I
OUT
500mA/div
PULSED LOAD-TRANSIENT RESPONSE
(I
LOAD
= 100mA TO 1.1A)
MAX8727 toc09
1
μ
s/div
OA
INDUCTOR
CURRENT
1A/div
0.1A
15V
V
OUT
5mV/div
AC-COUPLED
I
OUT
1A/div
SWITCHING WAVEFORMS
(I
LOAD
= 600mA)
MAX8727 toc10
1
μ
s/div
OA
INDUCTOR
CURRENT
1A/div
OV
LX
10V/div
Typical Operating Characteristics (continued)
(Circuit of Figure 1. V
IN
= 5V, V
MAIN
= 15V, T
A
= +25°C unless otherwise noted.)
MAX8727
TFT-LCD Step-Up DC-DC Converter
6 _______________________________________________________________________________________
PIN
NAME
FUNCTION
1
COMP
Compensation Pin for Error Amplifier. Connect a series RC from COMP to ground. See the Loop
Compensation section for component selection guidelines.
2FB
Feedback Pin. The FB regulation voltage is 1.24V nominal. Connect an external resistive voltage-divider
between the step-up regulator’s output (V
OUT
) and GND, with the center tap connected to FB. Place the
divider close to the IC and minimize the trace area to reduce noise coupling. Set V
OUT
according to the
Output Voltage Selection section.
3
SHDN
Shutdown Control Input. Drive SHDN low to turn off the MAX8727.
4
GND
Ground. Connect pins 4 and 5 directly together.
5
GND
Ground. Connect pins 4 and 5 directly together.
6LX
Switch Pin. LX is the drain of the internal MOSFET. Connect the inductor/rectifier diode junction to LX and
minimize the trace area for lower EMI. Connect pins 6 and 7 directly together.
7LX
Switch Pin. LX is the drain of the internal MOSFET. Connect the inductor/rectifier diode junction to LX and
minimize the trace area for lower EMI. Connect pins 6 and 7 directly together.
8 IN Supply Pin. Bypass IN with a minimum 1µF ceramic capacitor directly to GND.
9
FREQ
Frequency-Select Input. When FREQ is low, the oscillator frequency is set to 640kHz. When FREQ is high, the
frequency is 1.2MHz. This input has a 5µA pulldown current.
10 SS
Soft-Start Control Pin. Connect a soft-start capacitor (C
SS
) to this pin. Leave open for no soft-start. The soft-
start capacitor is charged with a constant current of 4.5µA. Full current limit is reached after t = 2.5 × 10
5
C
SS
.
The soft-start capacitor is discharged to ground when SHDN is low. When SHDN goes high, the soft-start
capacitor is charged to 0.4V, after which soft-start begins.
Pin Description
LX LX
FB
GND
GND
FREQ
IN
COMP
SS
1
4
5
2
3
9
8
67
10
V
OUT
15V/600mA
V
IN
4.5V TO 5.5V
SHDN
MAX8727
C1
10μF
6.3V
R3
10Ω
C3
1μF
C6
33nF
C4
330pF
C5
39pF
L1
3.6μH
D1
R2
28.0kΩ
1%
R4
100kΩ
R1
309kΩ
1%
C2
4.7μF
25V
C7
4.7μF
25V
C8
4.7μF
25V
Figure 1 Typical Operating Circuit
P1-P3P4-P6P7-P9P10-P12P13-P13

MAX8727ETB+TG104

Mfr. #:
Buy MAX8727ETB+TG104
Manufacturer:
Maxim Integrated
Description:
LCD Drivers TFT-LCD Step-Up DC/DC Converter
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet