L6560A STMicroelectronics, L6560A Datasheet - Page 4

• Manufacturer Part Number: L6560A
• Description: Power Factor Correction ICs Wide Input Voltage
• Manufacturer: STMicroelectronics

Specifications of L6560A

• Maximum Operating Temperature: + 150 C
• Mounting Style: Through Hole
• Package / Case: PDIP-8
• Minimum Operating Temperature: - 25 C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

L6560 - L6560A
ELECTRICAL CHARACTERISTICS (continued)
ZERO CURRENT DETECTOR
OUTPUT SECTION
OUTPUT OVERVOLTAGE SECTION
RESTART TIMER
OVER VOLTAGE PROTECTION OVP
The output voltage is expected to be kept by the
operation of the PFC circuits close to its reference
value that is set by the ratio of the two external re-
sistors R
eration that the non inverting input of the error
amplifier is biased inside the L6560 at 2.5V.
In steady state conditions, the current through R1
and R2 is:
and, if the external compensation network is
made only with a capacitor C, the current through
C is equal zero.
When the output voltage increases abruptly the
current through R1 becomes:
4/11
Symbol
Symbol
Symbol
Symbol
t
V
V
V
START
V
I
OVP
ZCD
ZCD
ZCD
t
t
GD
r
f
1
and R
Pin
Pin
Pin
Pin
5
5
5
7
7
7
2
I
SC
I
2
R1
Input Threshold Voltage Rising
Edge
Hysteresis
Clamp Voltage
Clamp Voltage
Dropout Voltage
Output Voltage Rise Time
Output Voltage Fall Time
OVP Triggering Current
Start Timer
(see fig. 2), taking into consid-
or I
V
V
SC
outsc
out
R1
R1
Parameter
Parameter
Parameter
Parameter
2.5
R2
2.5
2.5
I
I
I
I
I
I
CL = 1nF
CL = 1nF
ZCD
ZCD
GDsource
GDsource
GDsink
GDsink
= 3mA
= –3mA
= 200mA
= 20mA
Test Condition
Test Condition
Test Condition
Test Condition
Since the current through R2 doesn’t change, the
∆I current must flow through the capacitor C and
enter in the error amplifier.
This current is mirrored inside the L6560, and
compared with a precise internal reference of
40µA. Whenever such 40µA limit is exceed, the
OVP protection is triggered (Dynamic OVP), and
the external power transistor is switched off, until
the overvoltage situation disappears. However if
the overvoltage persists, before that the transient
condition of dynamic circuit exhausts, an internal
comparator (Static OVP) latches the OVP condi-
tion keeping the external power switch turned off
(see fig. 1).
The OVP value is threfore set by the equation
OVP = ∆Vout = R
Typical values for R
the application circuit. The overvoltage can be set
independently from the average output voltage.
The precision in setting the overvoltage threshold
is 7% of the overvoltage value (for instance ∆V =
60V
= 200mA
= 20mA
4.2V).
I
R1
V
outsc
1
+ ∆
40µA.
1
R1
, R
V
Min.
Min.
Min.
Min.
1.8
0.3
0.4
36
45
OUT
5
2
and C are reported in
− 2.5
Typ.
Typ.
Typ.
Typ.
0.5
5.7
0.7
1.2
0.7
50
40
40
60
= I
sc
Max.
Max.
Max.
Max.
120
100
2.3
0.7
6.4
1.5
0.3
44
+ ∆ I.
1
2
1
Unit
Unit
Unit
Unit
µ A
ns
ns
µs
V
V
V
V
V
V
V
V