|
|
PDF MAX8728 Data sheet ( Hoja de datos )
| Número de pieza | MAX8728 | |
| Descripción | Low-Cost - Multiple-Output Power Supply for LCD Monitors/TVs | |
| Fabricantes | Maxim Integrated | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de MAX8728 (archivo pdf) en la parte inferior de esta página. Total 29 Páginas | ||
|
No Preview Available !
19-3910; Rev 0; 1/06
www.DataSheet4U.com
Low-Cost, Multiple-Output
Power Supply for LCD Monitors/TVs
General Description
The MAX8728 generates all the supply rails for thin-film
transistor (TFT) liquid-crystal display (LCD) panels in TVs
and monitors. It includes step-down and step-up regula-
tors, positive and negative charge pumps, and a dual-
mode, logic-controlled high-voltage switch control block.
The MAX8728 can operate from input voltages from 7V to
13.2V and is optimized for LCD TV panel and LCD moni-
tor applications running directly from 12V supplies.
The step-up and step-down regulators feature internal
power MOSFETs and high-frequency operation allow-
ing the use of small inductors and capacitors, resulting
in a compact solution. Both switching regulators use
fixed-frequency, current-mode control architectures,
providing fast load-transient response and easy com-
pensation. The positive and negative charge-pump reg-
ulators provide TFT gate-driver supply voltages. Both
output voltages can be adjusted with external resistive
voltage-dividers.
The MAX8728 is available in a small (5mm x 5mm), low-
profile (0.8mm), 32-pin TQFN package and operates
over the -40°C to +85°C temperature range.
LCD Monitors
Applications
LCD TVs
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
PACKAGE
CODE
MAX8728ETJ+
-40°C to +85°C
32 TQFN-EP*
5mm x 5mm
T3255-4
+Denotes lead-free package.
*EP = Exposed pad.
Pin Configuration
TOP VIEW
24 23 22 21 20 19 18 17
GND2 25
16 DRVP
LX2 26
15 GNDP
GATE 27
14 FBP
EN 28
MODE 29
MAX8728
13 REF
12 GND
DEL 30
11 SHDN
COMP 31
FB1 32
10 VCC
9 VL
1 2345678
Features
♦ Optimized for 10.8V to 13.2V Input Supply
♦ 7V to 13.2V Input Supply Range
♦ Selectable Frequency (500kHz/1MHz/1.5MHz)
♦ Current-Mode Step-Down Regulator
14V Internal n-Channel MOSFET
1.5% Accurate Output
♦ Current-Mode Step-Up Regulator
19V Internal n-Channel MOSFET
1% Accurate Output
True Shutdown™ (Output Goes to Zero)
♦ 180° Out-of-Phase Switching
♦ Adjustable Positive/Negative Charge Pumps
♦ Soft-Start and Timer Delay Fault Latch for All
Outputs
♦ Logic-Controlled, High-Voltage Switches
♦ Power-Up and Power-Down Sequences
♦ Thermal-Overload Protection
Simplified Operating Circuit
VIN AVDD
OUT1
VGOFF
VL
VL INL GATE
LX2
GND2
FB2
BST COMP
IN
LX1
GND1
SHDN
EN
DEL
OUT1 MAX8728 CTL
THR
FBI
FSEL
VL VCC
REF
MODE
DRN
GON
SRC
GND
FBN
DRVN
SUPP
FBP
DRVP
ON/OFF
LCD ENABLE
FROM TCON
VIN
VGON
TQFN
True Shutdown is a trademark of Maxim Integrated Products, Inc.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1 page  
www.DataSheet4U.com
Low-Cost, Multiple-Output
Power Supply for LCD Monitors/TVs
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, VIN = VINL = VSUPP = 12V, VOUT1 = +3.3V, VSRC = 28V, GND1 = GND2 = GNDP = GND = 0, IREF = 0, TA = 0°C
to +85°C. Typical values are at TA = +25°C, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
DEL, EN Discharge Switch
On-Resistance
SHDN = low or fault tripped
20 Ω
FBN Discharge Switch
On-Resistance
EN = low or fault tripped
5 kΩ
POSITIVE GATE-DRIVER TIMING AND CONTROL SWITCHES
CTL Input Low Voltage
0.6 V
CTL Input High Voltage
2.0 V
CTL Input Leakage Current
-1 +1 µA
CTL-to-GON Rising Propagation 1kΩ from DRN to GND, 1.5nF from GON to
Delay
GND
100
ns
CTL-to-GON Falling Propagation 1kΩ from DRN to GND, 1.5nF from GON to
Delay
GND
250
ns
SRC Input Voltage Range
SRC Input Current
DRN Input Current
SRC Switch On-Resistance
SRC Switch Saturation Current
VMODE = VREF, VDEL = VCTL = 3V
VMODE = VREF, VDEL = 3V, VCTL = 0
VMODE = VREF, VDRN = 8V, VDEL = 3V,
VGON > VDRN, VCTL = 0
VMODE = VREF, VDEL = VCTL = 3V
VMODE = VREF, VDEL = VCTL = 3V,
VSRC - VGON > 5V
38
1.5 2.0
0.14 0.20
01
15 30
260
V
mA
µA
Ω
mA
DRN Switch
On-Resistance
VMODE = VREF, VDEL = 3V, VCTL = 0, VGON
= 28V, VTHR = 1.4V
25 50
Ω
DRN Switch Saturation Current
MODE Switch On-Resistance
VMODE = VREF, VDEL = 3V, VCTL = 0, VGON
= 28V, VTHR = 1.4V, VGON - VDRN > 5V
SHDN = GND
100
1
mA
kΩ
MODE Current-Source Stop
Voltage Threshold
MODE rising
1.2 1.4 1.6
V
MODE Charge Current
Operating mode 2, VMODE = 0.7V
MODE Voltage Threshold
Enabling DRN switch control in mode 2
THR to GON Voltage Gain
FAULT DETECTION
Duration to Trigger Fault
Thermal Shutdown Threshold 15°C typical hysteresis
SWITCHING-FREQUENCY SELECTION
FSEL = VCC (1MHz)
FSEL Input Levels
FSEL = REF (0.5MHz)
FSEL = GND (1.5MHz)
FSEL Input Current
Forced to VCC
40 50
0.8 1.0
9.4 10.0
50
+160
VCC - 0.4
1.65
10
60
1.2
10.6
2.35
0.5
µA
V
V/V
ms
°C
V
µA
_______________________________________________________________________________________ 5
5 Page 
www.DataSheet4U.com
Low-Cost, Multiple-Output
Power Supply for LCD Monitors/TVs
Typical Operating Characteristics (continued)
(Circuit of Figure 1. VIN = VINL = VSUPP = 12V, AVDD = 13.5V, VGON = 28V, VGOFF = -6V, VOUT1 = 3.3V, FSEL = GND, TA = +25°C,
unless otherwise noted.)
NEGATIVE CHARGE-PUMP
LOAD TRANSIENT RESPONSE
VGOFF, AC,
50mV/div
POWER-UP SEQUENCE
VGON, 20V/div, 10kΩ LOAD
AVDD, 5V/div, 150Ω LOAD
OUT1, 5V/div,
100Ω LOAD
EN, CEN = 0.01μF,
2V/div
40μs/div
IVGOFF,
50mA/div
VGOFF, 5V/div,
10kΩ LOAD
2ms/div
DEL,
CDEL = 0.01μF
2V/div
INL SUPPLY CURRENT vs. INL VOLTAGE
10
EN = GND
8
6
4
2 EN = GND
0
7 8 9 10 11 12 13
INL VOLTAGE (V)
HIGH-VOLTAGE SWITCH
CONTROL (MODE 1)
VCTL, 5V/div
0V
VMODE, 2V/div
0V
VGON, 10V/div
INL SUPPLY CURRENT vs. TEMPERATURE
7
EN = VL
6
5
4
3
2 EN = GND
1
0
-40
-15 10 35 60
TEMPERATURE (°C)
85
HIGH-VOLTAGE SWITCH
CONTROL (MODE 2)
VCTL, 5V/div
0V
VMODE, 2V/div
0V
VGON, 10V/div
0V 0V
2μs/div
2μs/div
______________________________________________________________________________________ 11
11 Page | ||
| Páginas | Total 29 Páginas | |
| PDF Descargar | [ Datasheet MAX8728.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MAX872 | Precision Voltage References | Maxim Integrated |
| MAX872 | 10A / Low-Dropout / Precision Voltage References | Maxim Integrated |
| MAX872-MAX874 | 10A / Low-Dropout / Precision Voltage References | Maxim Integrated |
| MAX8720 | Dynamically Adjustable 6-Bit VID Step-Down Controller | Maxim Integrated |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |