|
|
PDF NCS29001 Data sheet ( Hoja de datos )
| Número de pieza | NCS29001 | |
| Descripción | LED Backlight Driver | |
| Fabricantes | ON Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de NCS29001 (archivo pdf) en la parte inferior de esta página. Total 16 Páginas | ||
|
No Preview Available !
NCS29001
LED Backlight Driver
The NCS29001 is an integrated LED driver used in LCD display
backlighting applications. A configurable bill of materials allows the
designer to create a highly ef ficient solution for a variety of LCD
screen sizes. The NCS29001 uses a boost type converter to deliver
constant current in a string of LEDs. High accuracy PWM dimming is
supported for a frequency up to 500 Hz . The integrated soft start
function provides excellent control during the power up sequence to
avoid current overshoot. The device protects against output
overvoltage, open / short LED, and thermal overload. The NCS29001
is offered in the cost effective SOIC−14 package.
Features
• 8.5 V to 18 V Input Voltage Range
• ±1% Vref Voltage Accuracy to set LED Current
• PWM Controlled Dimming
• Soft Start Limits In−Rush Current
• Open Feedback Protection
• Open LED Protection
• Short LED Protection
• LED String Cathode Short to ground Protection
• Max Duty Cycle Above 90%
• SOIC−14 Package
• This is a Pb−Free Device
Typical Application
• TFT−LCD TV Panels
• LCD Monitor Panels
http://onsemi.com
14
1
SOIC−14 NB
CASE 751A
MARKING
DIAGRAM
14
NCS29001G
AWLYWW
1
NCS29001= Specific Device Code
A = Assembly Location
WL = Wafer Lot
Y = Year
WW = Work Week
G = Pb−Free Package
PIN CONNECTIONS
VIN 1
14 GATE
Vref 2
13 CS
GND 3
PWMin 4
NCS29001
12 PGND
11 PWMout
RT 5
10 FBN
FBP 6
9 COMP
STBY 7
8 OVP
ORDERING INFORMATION
See detailed ordering and shipping information on page 15 of
this data sheet.
© Semiconductor Components Industries, LLC, 2013
October, 2013 − Rev. 1
1
Publication Order Number:
NCS29001/D
http://www.Datasheet4U.com
1 page  
NCS29001
ELECTRICAL SPECIFICATIONS VIN = 12 V, TAMB = –40°C to 85°C; typical values are at 25°C
Symbol
Parameter
Condition
Min
VIN (VIN Pin)
IVIN Operating Supply Current
VIN = 12 V; PWMin = 5 V; no load,
STBY = 5 V
ISHUTDOWN Shutdown Mode Supply Current
PWMin = GND
Ambient temperature 25°C
STBY = 5 V
UVLO
Under Voltage Lockout
Threshold
VIN Rising
7.5
DUVLO
Tstartup
UVLO Hysteresis
Startup time
Time from standby falling edge to
steady−state Vboost operation with 30%
dimming pattern − (Note 6)
VREF (VREF Pin)
VREF
Vref voltage
REF bypassed with a 1 mF capacitor to
GND
4.95
Line_Reg
Load_Reg
Line Regulation
Load Regulation
VIN = 8.5 V to 24 V at I_REF = 10 mA
0 mA < I_REF < 10 mA at VIN = 12 V
ICC (Vref)
Iref output current
VREF bypassed with a 1 mF capacitor
to GND
GATE (GATE, RT Pins)
VOH_GATE
ISOURCE
ISINK
TRISE
GATE output high voltage
GATE short circuit current
GATE sinking current
GATE output rise time
VIN = 12 V
7.5
Output voltage rise−time @ CL = 1 nF,
10−90% of output signal (Note 6)
−
TFALL
GATE output fall time
Output voltage fall−time @ CL = 1 nF,
90−10% of output signal (Note 6)
−
ROH
ROL
DLSS_MAX
FOSC
Source resistance
Sink resistance
Maximum Duty Cycle
Boost Switching Frequency
range
(Note 6)
93
100
±DFOSC
Frequency Accuracy
VRT RT pin output voltage
PWM DIMMING (PWMin, PWMout Pins)
−10
0.85
VOH_PWMout
DD_DIM
PWMout output high voltage
PWMout/PWMin Duty cycle
Tolerance
VIN = 12 V
7.5
0.98
TRISE
PWMout output rise time
Output voltage rise−time
10−90% of output
@sigCnaLl=
1
nF,
−
TFALL
PWMout output fall time
Output voltage fall−time @ CL = 1 nF,
90−10% of output signal
−
ISOURCE
PWMout short circuit current
ISINK
PWMout sinking current
ROH
Source resistance
ROL Sink resistance
6. Guaranteed by characterization and design
Typ
8
475
5
0.08
10
0.33
0.33
40
20
13
6.0
95
1
10
1
−
−
15
15
270
230
Max Unit
5 mA
12 uA
8.5 V
mV
100 ms
5.05 V
0.20 %
0.6 mV/mA
10 mA
15 V
0.45 A
0.45 A
ns
ns
W
W
%
500 kHz
+10 %
1.15 V
15 V
1.02 %
2 us
2 us
20 mA
20 mA
W
W
http://onsemi.com
5
5 Page 
NCS29001
VREF REFERENCE VOLTAGE
The device contains an accurate 5 V reference that can supply up to 10 mA and can be accessed through the VREF pin. It
can be used to program the LED feedback voltage by using a resistor divider on the FBP pin. This reference is only active when
STBY = low. When the device is in standby mode the VREF pin voltage will drop to 4.2V typical with a minimum of 3.5V.
The VREF will return to 5 V immediately when STBY is driven high.
MINIMUM ON & OFF TIME
If the steady state duty cycle and switching frequency combintoe generate short Ton times (low VOUT/VIN converter ratio),
the converter will skip some cycles to regulate VOUT which will increase output voltage ripple. The timing limit is set by the
intrinsic loop propagation delay and the switching frequency will be limited by the minimum ON time and OFF time.
THE INDUCTOR SELECTION
For a given application, it is necessary to know the input voltage at the inductor (VININDUCTOR), the output current (IOUT)
set by RFBN and the voltage on the FBP pin, and the switching frequency s(wF). The inductor can be chosen using the formula
below:
ǒ ǓLmax t 2
1
Fsw
IOUT
VIN
VOUT
2
ǒVOUT * VINǓ
(eq. 1)
The minimal inductor value is determined with the desired peak current flowing through the inductor. Using the chosen
inductor value the steady state duty cycle and peak inductor current can be calculated:
Ǹ2 L Fsw IOUT ǒVOUT * VINǓ
D+
VIN
And the inductor peak current is now:
(eq. 2)
ǸIpeak
+
VIN
L
D
Fsw +
2
IOUT (VOUT * VIN)
L Fsw
(eq. 3)
THE CURRENT SENSE RESISTOR
Set a current limit between 2 and 2.5 times the peak inductor current to account for inductor tolerance:
Ilimit + 2.5 Ipeak
(eq. 4)
The current limit reference fixed on the ove-rcurrent protection comparator is VCS = 0.5 V and the resistance can be calculated
using following the equation:
RCS
+
2.5
VCS
Ipeak
(eq. 5)
SLOPE COMPENSATION
After the current sense resistor is calculated additional calculations are needed for the external slope compensation ramp. Using
the RSENSE value the typical slope of the compensation ramp can be calculated:
Mramp
+
1
2
RSENSE
VOUT *
L
VIN
(eq. 6)
Using the typical value for , the external compensation resistor can be calculated as follows:
RSC
+
MRAMP
IRAMP
(eq. 7)
The slope compensation ramp has an offset current, , which is used to calculate the peak ramp current and finally the adjusted
current sense resistor.
IRAMP,peak
+
IOFF
)
D
IRAMP
RSW
(eq. 8)
RCS
+
VCS * RCS IRAMP,peak
Ilimit ) IRAMP,peak
(eq. 9)
http://onsemi.com
11
11 Page | ||
| Páginas | Total 16 Páginas | |
| PDF Descargar | [ Datasheet NCS29001.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| NCS29001 | LED Backlight Driver | ON Semiconductor |
| 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 |