GOSTON ELECTRONICS CO.,LTD
SM2082B Single Channel LED Constant Current Driver v1.6
SM2082B
Features
Patented constant current control technology
Output current adjustable with range 5mA~60mA
Inter-chip output current deviation <±4% Over temperature protection Sharing PCB board with LED lamps Excellence EMI performance Simple circuit and low cost
Package:ESOP8、TO252-2
General Description
SM2082B is a single channel LED constant current driver which integrates patented constant current setting and control technology. The output current designed by external REXT is 5mA~60mA and it is invariant to OUT output voltage change, which has better constant current performance. It is a low cost circuit with simple circuit and less external components.
Pin Figure
Applications
T5/T8 LED tubes; LED street lighting; LED bulb lamp,LED ceiling lamp;
Diagram 1. SM2082B Each Package Pin Diagram
Pin Pin Function
OUT GND
Power input and constant current output GND
REXT
Output current setting port
Typical Schematic Circuit Diagram
220V~
Vin LED1
C2
LEDn
1 OUT
2 GND
3 REXT Rext
Diagram 2. SM2082B Typical Application Circuit In diagram 2, the power can be AC or DC.
SM2082B
Mail:
[email protected]
Tel: 0755 -27593075
Address: 3F,SSMEC Bldg.,15 South 1st Blvd.,South Area,Shenzhen H-igh tech Industrial Park,Nanshan Dist.,Shenzhen.
Note: The latest datasheet is subject to the web(www.dianyuanic.com).
-1-
Fax: 0755 -29031113
GOSTON ELECTRONICS CO.,LTD
SM2082B Single Channel LED Constant Current Driver v1.6
Limiting Values
The ambient temperature is 25°C if there is no special instruction.
Characteristic Parameters
Symbol
Output voltage
VOUT
Output current
IOUT
Operating current
TOPT
Storage temperature
TSTG
ESD withstand voltage
VESD
Range -0.5V ~ +250V 1mA ~ 60mA -40°C ~ +120°C -50°C ~ +150°C
2KV
Thermal Resistance Parameters
Symbol
Explanation
ESOP8
TO252-2
Unit
RTHJA
Thermal
89.2
74.9 ℃/W
resistance (1)*
Note(1)*:The chip should be mounted on PCB board with 200mm2 copper (35um thick) to dissipate heat.
Electrical Operating Parameters
The ambient temperature is 25°C if there is no special instruction.
Parameters
Symbol
Conditions
Min Typ
Output voltage
VOUT_MIN
IOUT = 30mA
--
Output withstand voltage
VOUT_BV
IOUT = 0
250 -
Output current
IOUT
-----
5-
Static current
VOUT = 10V,REXT no IDD - 0.16
connection
REXT output voltage
VREXT
VOUT = 10V
- 0.6
IOUT deviation
dIOUT
IOUT = 20mA
- ±4
Over-temperature Protection point(2)*
TSC
-
- 110
Note(2)*:When the junction temperature is over 110 ℃, the output current of SM2082B will be reduced.
Max 6.5
60 0.25 -
Unit V V mA mA V % ℃
Mail:
[email protected]
Tel: 0755 -27593075
Address: 3F,SSMEC Bldg.,15 South 1st Blvd.,South Area,Shenzhen H-igh tech Industrial Park,Nanshan Dist.,Shenzhen.
Note: The latest datasheet is subject to the web(www.dianyuanic.com).
-2-
Fax: 0755 -29031113
GOSTON ELECTRONICS CO.,LTD
SM2082B Single Channel LED Constant Current Driver v1.6
Output Current Characteristics
SM2082B output current formula : IOUT
V REXT rext
0.6V (A)。 rext()
Diagram 3. SM2082B The Relationship between Output Current and REXT
Diagram 4. SM2082B Constant Current Graph
Diagram 4 SM2082B constant current graph represents the lowest output voltage (VOUT_MIN:IOUT = 20mA, VOUT_MIN = 4.1V, IOUT = 30mA,VOUT_MIN = 4.6V;IOUT = 40mA,VOUT_MIN = 5.0V;IOUT = 50mA,VOUT_MIN = 5.5V) in normal temperature.
Mail:
[email protected]
Tel: 0755 -27593075
Address: 3F,SSMEC Bldg.,15 South 1st Blvd.,South Area,Shenzhen H-igh tech Industrial Park,Nanshan Dist.,Shenzhen.
Note: The latest datasheet is subject to the web(www.dianyuanic.com).
-3-
Fax: 0755 -29031113
GOSTON ELECTRONICS CO.,LTD
SM2082B Single Channel LED Constant Current Driver v1.6
Diagram 5. SM2082B Output Current Temperature Characteristics(IOUT = 20mA 40mA)
Temperature Compensation
High temperature inside the LED lamps will cause serious LED light decay, which deduces LED service life. Temperature compensation of SM2082 helps to decrease output current automatically when the inside temperature is more than 110 ºC. Therefore, temperature inside lamps can be reduced.
System Design
SM2082B
Vin LED1 LED2 Supply
GND
LEDn Rext
1 OUT 2 GND 3 REXT
Diagram 6. 82B Application Circuit
Efficiency Design
Diagram 6 below shows the application circuit efficiency formula:
PLED PIN
n * VLED * ILED VIN * I LED
n
* VLED VIN
Vin is system input power voltage. VLED is single LED drop voltage. ILED is LED current. It is can be seen that larger quantities of series LED in system brings higher efficiency.
In system design, SM2082B output operating voltage is based on application environment so that it
optimizes N value.
LED Series Number Design
Designing LED series number in the system should consider two aspects below:
In diagram 6, output voltage is VOUT = Vin – n*VLED.
Mail:
[email protected]
Tel: 07.