KODENSHI SN8500D

SN8500D
Semiconductor
Switching Type (Buck) LED Driver IC
http:// www.auk.co.kr
◈ Description
The SN8500D is a high power PWM LED driver IC using a buck converter topology that is capable of driving up
to 1.5A of output current. it operates from an input voltage range of
3Vdc to 40Vdc and generates a regulated
programmable constant output current for high power LEDs. external resistor controlled the maximum output
current to single LED or a LED string.
◈ Features
• Operation from 3.0V to 40V input.
• Low Standby Current
• High efficiency
• Output Switch Current to 1.5A
• Halogen-Free Package is Available
◈ Application
• Automotive and Marine Lighting
• High Power LED Driver
• Constant Current Source
◈ Pin Assignment & Description (Top View)
OSC
5
Pin
Symbol
Description
OUT
4
1
VCC
Input Voltage
2
CS
Peak Current Sense Pin
GND
3
3
GND
Ground
CS
2
4
OUT
Output Pin
VCC
1
5
OSC
Oscillator Timing pin
Package : TO-252-5L
◈ Ordering Information
Package Type
Device Name
Marking
TO-252-5L
SN8500D
SN8500---(1)
YYWW---(2)
(1) Device Code, (2) Year & Week Code
KSD-I6T002-000
1
SN8500D
◈ Absolute maximum ratings
[Ta=25℃]
Characteristic
Symbol
Rating
Unit
Power Supply Voltage
VCC(MAX)
40
V
Output Current
IOUT(MAX)
1.5
A
Thermal Resistance Junction-Ambient
Rth(j-a)*
96.1
℃/W
Power Dissipation
PD*
1.3
W
Operating Temperature Range
Topr
-40 ~ +85
℃
Storage Temperature Range
Tstg
-55 ~ +150
℃
* Mounted on a glass epoxy circuit board of 30x30mm Pad dimension of 50mm2
◈ Recommended operating conditions
Characteristic
Symbol
Power Supply Voltage
Rating
Unit
Min
Max
VCC
7
40
V
Output Current
IOUT
-
1.5
A
Dimming Frequency
FDIM
-
10
kHz
◈ Electrical Characteristics (Ta=25℃, unless otherwise noted.)
Characteristic
Symbol
Condition
Min. Typ. Max. Unit
Supply Current 1
ICC1
VCC=4V, Out=open
-
2.0
4.0
mA
Supply Current 2
ICC2
VCC=40V, Out=open
-
2.0
4.0
mA
Dropout Voltage
Vdrop
VCC=10V, Iout=1A
-
1
1.3
V
270
300
330
mV
Current Sense Voltage
VCS
VCC=10V, Rout=820kΩ
Maximum duty cycle
TDC
-
-
85
-
%
VCC=40V, VOSC=1.5V
-
200
1000
µA
Current Sense Off Current
ICS(OFF)
OSC ON Voltage
VOSC(on)
VCC=4V~40V
-
-
0.5
V
OSC OFF Voltage
VOSC(off)
VCC=4V~40V
1.5
-
-
V
OSC Charge Current
ICH
Vcc=5V, VOSC=0.5V
24
35
42
µA
OSC Discharge Current
IDCH
Vcc=5V, VOSC=1.5V
140
180
260
µA
KSD-I6T002-000
2
S8500D
◈ Functional block diagram
OUT
CS
+
0.3V
CONTROL
VCC
Driver
OSC
OSC
SN8500
GND
◈ Typical Application
L
CS
RSENSE
OUT
SN8500
Supply Voltage
7~40V
VCC
DF
Power LED
OSC
CIN
GND
+
CT
KSD-I6T002-000
3
SN8500D
◈ Application Information
1) Input Capacitor
The input capacitor (CIN) reduces the ripple of the input current drawn from the input supply
and reduces noise injection into the IC. The reflected ripple voltage will be smaller when an
input capacitor with larger capacitance is used. The capacitors should be placed close to the
VCC and GND.
2) Current-Sense Resistor
The snese resistor Rsense can be obtained as follows
Rsense = 300mV / (IAVG + 0.5 x IRIPPLE)
Thus target average LED current 700mA and ripple current 100mA then the result
Rsense= 300mV/ (700mA + 0.5 x 100mA) = 0.4Ω
When selecting the sense resistor, low–inductance resistors, such as surface–mount metal
film resistors, are preferred.
3) Output inductor
The value of the inductor is not fixed and can be adjusted freely in order to make tradeoffs
among size, cost, and efficiency. Although lower inductor values will minimize size and cost,
they will also reduce efficiency due to higher peak currents. On the other hand, higher
inductor values will increase efficiency, but at some point the resistive losses due to the extra
turns of wire will exceed the benefit gained from lower AC current levels. Also, high
inductor values can affect the load–transient response of the converter.
4) Freewheeling diode
The schottky barrier diode SDB30A40(40V, 3A) was recommended for freewheeling diode
KSD-I6T002-000
4
SN8500D
◈ Application Guide
L=220uH
CS
RSENSE
OUT
SN8500
Supply Voltage
7~40V
Power LED x n
VCC
OSC
CIN=47uF
GND
DF
(SDB30A40)
+
CT=470pF
<Application 1. Constant Current Power LED Driver Circuit in Series>
L=220uH
CS
RSENSE
OUT
Power LED x n
SN8500
Supply Voltage
7~40V
VCC
OSC
CIN=47uF
GND
DF
(SDB30A40)
+
CT=470pF
<Application 2. Constant Current Power LED Driver Circuit in Parallel>
KSD-I6T002-000
5
SN8500D
◈ Application Guide
L=220uH
CS
RSENSE
OUT
Supply Voltage
7~40V
SN8500
VCC
Power LED
ENABLE
SDS511
OSC
GND
DF
(SDB30A40)
+
CT=470pF
CIN=47uF
<Application 3. LED Driver Circuit with PWM Dimming Function >
IPK
SDB30A40
OUT
RSENSE
Supply Voltage
12Vac
SN8500
L=220uH
VCC
DF
(SDB30A40)
CIN=47uF
+
Power LED
(MR16)
CT
GND
CT=470pF
<Application 4. Constant Current LED Driver Circuit for MR16>
KSD-I6T002-000
6
SN8500D
◈ Electrical Characteristic Curves
Fig.2 ICC vs TA
5
20
16
12
8
4
0
-4
-8
-12
-16
-20
V C C =10V
Supply Current – ICC [mA]
Current Sense Voltage Change – VCS [%]
Fig.1 VCS vs TA
V C C =5V
4
3
2
1
0
-50 -25
0
25
50
75
100 125 150
-50 -25
25
50
75
100 125 150
Ambient Temperature - TA [℃]
Ambient Temperature - TA [℃]
Fig.4 LED Current vs PWM Duty
Fig.3 Dropout Voltage vs TA
3.0
350
V C C =10V
I O U T =1A
2.5
2.0
1.5
1.0
0.5
LED Current- ILED[mA]
Dropout Voltage- VDROP[V]
0
0.0
300
Vc c =1 5 V
fD I M =1 KH z
250
CT=4 7 0 pF
L= 2 2 0 u H
R s = 0 .9 9 Ω
200
150
100
50
0
-50 -25
0
25
50
75
100 125 150
Ambient Temperature - TA [℃]
0
20
40
60
80
100
PWM Duty Cycle [%]
KSD-I6T002-000
7
SN8500D
◈ Electrical Characteristic Curves
Fig.5 Start-up Waveform
Fig.6 Normal Operating Waveform
VCC=15V
VCC=15V
Ch1►
Ch1►
Ch2►
Ch2►
Ch3►
Ch3►
Ch4►
Ch4►
Ch1 : OSC, 2V/Div
Ch1 : OSC, 2V/Div
Ch2 : IIN, 80mA/Div
Ch2 : IIN, 50mA/Div
Ch3 : VOUT, 10V/Div
Ch3 : VOUT, 10V/Div
Ch4 : IOUT, 200mA/Div
Ch4 : IOUT, 200mA/Div
Fig.7 Dimming Waveform
fosc=100Hz
Ch1►
Ch2►
Ch3►
Ch4►
Ch1 : OSC, 5V/Div
Ch2 : IIN, 80mA/Div
Ch3 : VLED, 3V/Div
Ch4 : ILED, 200mA/Div
KSD-I6T002-000
8
SN8500D
◈ TO-252-5L Outline Dimension
(Unit : mm)
θ
θ
※ Recommend PCB solder land
[Unit: mm]
2.00
7.20
11.00
5.60
5.60
1.27
KSD-I6T002-000
0.60
9
SN8500D
The AUK Corp. products are intended for the use as components in general electronic
equipment (Office and communication equipment, measuring equipment, home
appliance, etc.).
Please make sure that you consult with us before you use these AUK Corp. products
in equipments which require high quality and / or reliability, and in equipments which
could have major impact to the welfare of human life(atomic energy control, airplane,
spaceship, transportation, combustion control, all types of safety device, etc.). AUK
Corp. cannot accept liability to any damage which may occur in case these AUK Corp.
products were used in the mentioned equipments without prior consultation with AUK
Corp..
Specifications mentioned in this publication are subject to change without notice.
KSD-I6T002-000
10