L6668_06 STMICROELECTRONICS [STMicroelectronics], L6668_06 Datasheet - Page 2

• Manufacturer Part Number: L6668_06
• Description: SMART PRIMARY CONTROLLER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

L6668
2
L6668 is a current-mode primary controller IC, designed to build single-ended converters.
The IC drives the system at fixed frequency at heavy load and an improved Standby function causes a
smooth frequency reduction as the load is progressively reduced. At very light load the device enters a
special operating mode (burst-mode with fixed, externally programmed peak current) that, in addition to
the on-board high-voltage start-up and the very low quiescent current, helps keep low the consumption
from the mains and be compliant with energy saving regulations. To allow meeting compliance with these
standards in power-factor-corrected systems too, an interface with the PFC controller is provided that en-
ables to turn off the pre-regulator when the load level falls below a threshold.
The IC includes also a programmable soft-start, slope compensation for stable operation at duty cycles
greater then 50%, a disable function, a leading edge blanking on current sense to improve noise immunity,
latched disable for OVP or OTP shutdown and an effective two-level OCP able to protect the system even
in case the secondary diode fails short.
Table 2. Absolute Maximum Ratings
Note: 1. ESD immunity for pin 1 is guaranteed up to 900V (Human Body Model).
Table 3. Thermal Data
Figure 3. Pin Connection (Top view)
2/23
V
I
PFC_STOP
Symbol
Symbol
R
PFC_STOP
th j-amb
V
T
P
V
I
Description
---
HV
T
HV
stg
tot
cc
j
Thermal Resistance Junction to AmbientMax
Pin
14
14
5
1
1
IC Supply voltage (Icc = 20 mA)
High-voltage start-up generator voltage range
High-voltage start-up generator current
Analog Inputs & Outputs, except pin 14
Max. sink current (low state)
Max. voltage (open state)
Power Dissipation @Tamb = 50°C
Junction Temperature Operating range
Storage Temperature
HV
HV
HVS
HVS
GND
GND
OUT
OUT
Vcc
Vcc
N.C.
N.C.
DIS
DIS
VREF
VREF
Parameter
1
Parameter
RCT
RCT
S-COMP
S-COMP
PFC_STOP
PFC_STOP
STBY
STBY
ISEN
ISEN
SS
SS
COMP
COMP
SKIPADJ
SKIPADJ
Self-limited
Self-limited
-0.3 to 700
-25 to 150
-55 to 150
-0.3 to 8
Value
120
Value
0.75
16
2
°C/W
Unit
Unit
mA
°C
°C
W
V
V
A
V
V