NJW4615A
Constant Current LED Driver with PWM Dimming Control
■
GENERAL DESCRIPTION
The NJW4615A is a constant current LED driver with PWM
dimming control. The output current can be set by external sensing
resister, and the NJW4615A can set up to 100mA.
Because the withstand voltage of the output (LED) pin is 35V, it
can series-connect the LED depending on forward voltage of the
LED.
The LED dimming control can be regulated via PWM duty cycle.
It is suitable for back light, light source and so on.
■
PACKAGE OUTLINE
NJW4615AF1
(SOT-23-6-1)
■
FEATURES
▪
Supply Voltage Range
2.5V to 35V
▪
Output Voltage
V
LED
= 35V max.
▪
Output Current
I
LED
= 5mA to 100mA
▪
Output Current Accuracy
1.2%
▪
To 10 of White LED can be operated. (at LED Vf=3.2V)
▪
Quiescent Current
370µA max.
▪
PWM Dimming Control
▪
Enable Function
▪
Over Current Protection (with Hysteresis)
▪
Thermal Shutdown Protection
▪
LED Short Protection
▪
Package
SOT-23-6-1
■
BLOCK DIAGRAM
V
DD
LED
V
REF
( 0.2V )
R
S
Current Limit
Thermal Shut Down
LED Short Protection
Control
Logic
GND
EN
PWM
Ver.2017-06-14
-1-
NJW4615A
■
PIN CONFIGURATION
PWM 1
GND 2
R
S
3
6 V
DD
5 EN
4 LED
■
PIN DESCRIPTIONS
Pin No.
Pin Name
1
2
3
4
5
6
PWM
GND
R
S
LED
EN
V
DD
I/O
I
-
O
O
I
-
Function
PWM signal input pin for dimming control.
The LED dimming control can be regulated by PWM duty cycle.
When this pin is open or input High level, I
LED
becomes set current by an external
resistor (R
S
).
Ground pin
Resistor connect pin of I
LED
setting.
The LED current can be set with connected resistor (R
S
) between R
S
pin and GND
pin. R
S
[Ω] = 0.2 [V] / I
LED
[A]
Constant current circuit output pin
Connect cathode pin of LED.
Standby control pin
Normal operation: High Level.
Standby mode: Low Level.
Power supply pin
-2-
Ver.2017-06-14
NJW4615A
■
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
Supply Voltage
V
DD
Output Voltage
V
LED
EN Pin Voltage
V
EN
PWM Pin Voltage
V
PWM
Power Dissipation
Junction Temperature Range
Operating Temperature Range
Storage Temperature Range
P
D
T
j
T
opr
T
stg
RATINGS
-0.3 to +40
-0.3 to +40
-0.3 to +40
-0.3 to +6
510 (*1)
710 (*2)
-40 to +150
-40 to +125
-50 to +150
(Ta=25 C)
UNIT
V
V
V
V
mW
C
C
C
(*1) Mounted on glass epoxy board based on EIA/JEDEC. (76.2 × 114.3 × 1.6mm: 2Layers FR-4)
(*2) Mounted on glass epoxy board based on EIA/JEDEC. (76.2 × 114.3 × 1.6mm: 4Layers FR-4), Internal Cu area: 74.2 × 74.2mm
■
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
Supply Voltage
V
DD
Output Current
I
LED
Output Voltage
V
LED
TEST CONDITIONS
MIN.
2.5
5
-
TYP.
-
-
-
MAX.
35
100
35
UNIT
V
mA
V
■
ELECTRICAL CHARACTERISTICS
(Unless otherwise noted, V
DD
= V
EN
=12V, V
LED
=1V, R
S
=10Ω, V
PWM
=OPEN, Ta=25 C)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN.
TYP. MAX. UNIT
Quiescent Current
I
DD
-
260
370
µA
Quiescent Current at OFF State
I
DD_OFF
V
EN
= GND
-
-
0.1
µA
Output Current Accuracy
-1.2
-
+1.2
%
I
LED
Output (LED) Pin
I
LEAK
1
V
EN
= GND, V
DD
= 35V, V
LED
= 35V
-
-
0.1
µA
Leak Current 1
Output (LED) Pin
I
LEAK
2
V
PWM
= GND V
DD
= 35V, V
LED
= 35V
-
-
0.1
µA
Leak Current 2
-
V
EN Pin ON Voltage
V
EN_ON
1.6
V
DD
I
LED
= OFF ON
-
V
EN Pin OFF Voltage
V
EN_OFF
0
0.3
I
LED
= ON OFF
-
V
PWM Pin ON Voltage 1
V
PWM_ON
1 V
DD
< 5V, I
LED
= OFF ON
0.7V
DD
V
DD
-
V
PWM Pin OFF Voltage 1
V
PWM_OFF
1 V
DD
< 5V, I
LED
= ON OFF
0
0.3V
DD
-
V
PWM Pin ON Voltage 2
V
PWM_ON
2 V
DD
5V, I
LED
= OFF ON
3.5
5.5
-
V
PWM Pin OFF Voltage 2
V
PWM_OFF
2 V
DD
5V, I
LED
= ON OFF
0
1.5
EN Pin Input Current
I
EN
V
EN
= 12V
-
7
-
µA
PWM Pin Pull Up Resistance
R
PWM
-
1
-
MΩ
R
S
Pin Output Current
I
OUT_RS
LED = OPEN
-
2.3
-
µA
3
PWM Pin ON Delay Time
t
PWM_ON
-
-
µs
V
PWM
= L H, I
LED
= OFF ON
1
PWM Pin OFF Delay Time
t
PWM_OFF
V
PWM
= H L, I
LED
= ON OFF
-
-
µs
LED Short Protection
V
LED_SHORT
17
20
23
V
Detect Voltage
Maximum Output Current
I
LED_MAX
R
S
= 0
Ω
100
170
-
mA
Ver.2017-06-14
-3-
NJW4615A
■
TYPICAL APPLICATIONS
V
DD
/ V
+
(*3)
V
DD
LED
I
LED
0
Output Current Wave Form
at PWM Dimming
V
REF
( 0.2V )
R
S
I
LED
Current Limit
Thermal Shut Down
LED Short Protection
Control
Logic
R
S
: Current Sense Resistor
GND
EN
PWM
H : ON
L : OFF
The R
s
Resistance Setting formula:
R
S
( )
0
.
2
(
V
)
I
LED
(
A
)
(*3) If the wiring from the power supply to the LED anode pin is long, the voltage may change due to the influence of the
parasitic elements.
As the countermeasure, it should connect a decoupling capacitor as close to the LED as possible.
-4-
Ver.2017-06-14
NJW4615A
■
TYPICAL CHARACTERISTICS
Quiescent Current vs. Supply Voltage
400
350
[V
EN
=V
DD
, V
LED
=1V, R
S
=10Ω, V
PWM
=OPEN]
Quiescent Current vs. Temperature
400
350
Quiescent Current : I
DD
[μA]
[V
DD
=12V, V
EN
=V
DD
, V
LED
=1V, R
S
=10Ω, V
PWM
=OPEN]
Quiescent Current : I
DD
[μA]
300
250
200
150
100
-40℃
300
250
200
150
100
50
0
-50
-25
0
25 50 75 100 125 150
Temperature : [ºC]
50
0
0
10
25℃
125℃
150℃
20
30
Supply Voltage : V
DD
[V]
40
Quiescent Current at OFF State：I
DD_OFF
[nA]
Quiescent Current at OFF State vs. Temperature
100
[V
EN
=GND, V
LED
=1V, R
S
=10Ω, V
PWM
=OPEN]
VDD=2.5V
VDD=12V
10
VDD=35V
1
0.1
-50
-25
0
25 50 75 100 125 150
Temperature : [ºC]
Output Pin Leak Current 1 vs. Temperature
VLED=1V
VLED=5V
VLED=35V
Output Pin Leak Current 2 vs. Temperature
Output Pin Leak Current 2 : I
LEAK
2 [nA]
Output Pin Leak Current 1 : I
LEAK
1 [nA]
1000
[V
DD
=35V, V
LED
=35V, V
EN
=GND, R
S
=10Ω, V
PWM
=OPEN]
1000
[V
DD
=35V, V
EN
=V
DD
, V
LED
=35V, R
S
=10Ω, V
PWM
=GND]
100
100
10
10
1
1
0.1
-50
-25
0
25 50 75 100 125 150
Temperature [ºC]
0.1
-50
-25
0
25 50 75 100 125 150
Temperature : [ºC]
Ver.2017-06-14
-5-
下载中心专版
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
