LT1508IN Linear Technology, LT1508IN Datasheet - Page 4

• Manufacturer Part Number: LT1508IN
• Description: IC PWM/POWER FACTOR CNTRLR 20DIP
• Manufacturer: Linear Technology

Specifications of LT1508IN

• Mode: Average Current
• Frequency - Switching: 100kHz
• Voltage - Supply: 27V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Startup: -

4
LT1508
V
outputs, unless otherwise noted.
PARAMETER
Soft Start Current
SS1 Current (PFC)
SS2 Current (PWM)
Comparators in PWM Section
I
Current Limit Comparator (CL) Threshold
GTDR2 Switching Off Threshold at V
V
PWMOK Comparator Low Threshold (in Terms of V
V
GTDR2 Turn-On Blanking Time
ELECTRICAL C
The
temperature range.
Note 1: Multiplier Gain Constant: K =
TYPICAL PERFORMANCE CHARACTERISTICS
LIM
CC
C
C
–20
100
Input Current
Pin High Voltage
80
60
40
20
Input Current
0
= 18V, R
10
denotes specifications which apply over the full operating
PFC Voltage Amplifier Open-Loop
Gain and Phase
100
SET
1k
= 15k to GND, C
FREQUENCY (Hz)
PHASE
GAIN
10k
HARA TERISTICS
100k
C
W
SET
or at SS2
1M
I
AC
= 1nF to GND, I
1508 G01
C
(VA
U
10M
I
OUT
M
0
–20
–40
–60
–80
–100
–120
– 2)
REF
)
2
AC
100
–20
80
60
40
20
= 100 A, I
0
CONDITIONS
SS1 = 2.5V
SS2 = 1V
I
V
I
V
1mA into V
10
LIM
LIM
PFC Current Amplifier Open-Loop
Gain and Phase
C
C
> 2.6V
= 0V
= 0V, V
= 0V
100
SENSE
C
C
1k
Pin
FREQUENCY (Hz)
= 1.6V
PHASE
GAIN
Note 2: GTDR2 (PWM) pulse is delayed by 53% duty cycle after GTDR1
(PFC) is set. See PFC/PWM Synchronization graph in the Typical
Performance Characteristics section.
= 0V, CA
10k
100k
OUT
= 3.5V, VA
1M
1508 G02
10M
0
–20
–40
–60
–80
–100
–120
OUT
= 5V, OVP = V
0.95
0.57
MIN
– 20
PFC/PWM Synchronization
6.2
5
5
1
53%
– 0.3
0.63
TYP
180
1.1
6.9
12
12
REF
PWM (GTDR2)
PFC (GTDR1)
. No load on any
TIME
MAX
1.20
0.70
– 80
7.5
30
30
– 2
UNITS
1508 G03
ns
A
A
A
V
V
A
V