GENERAL DESCRIPTION
The DT5548 is a high precision PSR constant current convertor for lighting LED driver applications. It operates in primary-side sense and regulation. Consequently, opto-coupler and TL431 could be eliminated. Moreover, The creative design of DT5548 makes it regulates the output current without any auxiliary windings or compensation circuitry, which drastically saving the cost and PCB space. The output current tolerance is as low as 3%.
The DT5548 offers comprehensive protection coverage with auto-recovery features including Cycle-by-Cycle current limiting, over voltage protection, feedback loop open protection, short circuit protection, under voltage lockout, thermal shutdown, etc.
The DT5548 is available in DIP8 package.
FEATURES
|
APPLICATIONS
|
TYPICAL APPLICATION CIRCUIT
PIN ASSIGNMENT
PIN DESCRIPTION
PIN No |
SYMBOL |
DESCRIPTTION |
||
1 |
FB |
Feed Back |
||
2 |
VCC |
Supply Input |
||
3 |
CS |
Current Sense |
||
4 |
COM |
Compensation Input |
||
5,6 |
SW |
Power MOSFET Output |
||
7,8 |
GND |
Ground |
ABSOLUTE MAXIMUM RATINGS (Note 1)
Sym |
Parameter |
Range |
Unit |
VCC |
Supply Voltage |
-0.3ï½?8 |
V |
FB,COM |
|
-0.3ï½?.0 |
V |
CS |
|
-0.3ï½?.0 |
V |
SW |
|
-0.3ï½?8 |
V |
PDMAX |
Maximum Power consumption(Note2) |
0.45 |
W |
PTR |
Thermal Resistance, SOP8(θJAï¼?/p> |
130 |
oC /W |
TJ |
Operating junction temperature |
-40ï½?50 |
oC |
TSTG |
Storage temperature range |
-55ï½?50 |
oC |
Note 2: The maximum power dissipation decrease if temperature rise, it is decided by TJMAX, θJA, and environment temperature (TA). The maximum power dissipation is the lower one between PDMAX = (TJMAX - TA)/ θJA and the number listed in the maximum table.
RECOMMENDED OPERATION CONDITION
Symbol |
Parameter |
Range |
Unit |
VCC |
Supply Voltage |
10~14 |
V |
fosc |
Operating Frequency |
20ï½?0 |
KHz |