LT1950 Linear Technology, LT1950 Datasheet - Page 2

• Manufacturer Part Number: LT1950
• Description: Single Switch PWM Controller
• Manufacturer: Linear Technology

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LT1950
ABSOLUTE AXI U RATI GS
(Note 1)
BOOST ....................................................... –0.3V to 35V
V
FB, SYNC, V
COMP, BLANK .......................................... –0.3V to 3.5V
SLOPE ...................................................... –0.3V to 2.5V
I
R
V
Operating Junction Temperature Range
LT1950EGN/LT1950IGN (Notes 2, 5) ... – 40 C to 125 C
Storage Temperature Range ..................–65 C to 150 C
Lead Temperature (Soldering, 10 sec).................. 300 C
temperature range, otherwise specifications are at T
= 0.1 F, SHDN = V
specified.
PARAMETER
PWM Controller
Operating Input Voltage
Minimum Start-Up Voltage
V
V
Shutdown Threshold
Shutdown Pin Current
Shutdown Pin Current Hysteresis
V
V
V
Output Voltage
Line Regulation
Load Regulation
Oscillator
Frequency: f
Minimum Programmable f
Maximum Programmable f
SYNC Input Resistance
SYNC Switching Threshold
SYNC Frequency/f
f
V
2
ELECTRICAL CHARACTERISTICS
OSC
SENSE
IN
IN
IN2
IN2
REF
ROSC
IN
REF
OSC
Quiescent Current
Shutdown Current
, V
Quiescent Current
Shutdown Current
Line Reg
(External Output)
.................................................................... –10mA
.................................................................... –50 A
IN2
......................................................... –0.3V to 1V
, SHDN ......................................... –0.3V to 25V
OSC
SEC
OSC
........................................... –0.3V to 6V
IN
, BLANK = 0V, I
W
OSC
OSC
W W
SENSE
= 0V, V
CONDITIONS
I
I
I
SHDN = 0V
3V < V
SHDN = 70mV Above Threshold
SHDN = 100mV Below Threshold
I(V
SHDN = 0V, V
I
I
0 A < I
R
R
R
(R
3V < V
9.5V < V
VREF
VREF
VREF
VREF
VREF
OSC
OSC
OSC
OSC
IN2
REF
U
= 0 A
= 0 A
= 0 A, FB = 1V, I
= 0 A
= 0 A, 3V < V
= 249k, FB = 1V
= 499k
= 90.9k
) = 0 A, FB = 1V, I
IN
= 249k, f
IN
= 15V, GATE = 1nF, BOOST = open, V
A
VREF
IN2
< 25V
= 25 C. COMP = open, FB = 1.4V, R
< 25V
< 25V
< 2.5mA
IN2
The
OSC
= 2.7V (Boost Diode from V
IN
=200kHz), FB = 1V (Note 7)
denotes the specifications which apply over the full operating
< 25V
SENSE
SENSE
PACKAGE/ORDER I FOR ATIO
Consult LTC Marketing for parts specified with wider operating temperature ranges.
= 0.2V
= 0.2V
SLOPE
COMP
SHDN
SYNC
R
V
GND
OSC
16-LEAD NARROW PLASTIC SSOP
REF
FB
T
JMAX
1
2
3
4
5
6
7
8
JC
= 125 C,
GN PACKAGE
(PIN 8) = 30 C/W
TOP VIEW
IN
JA
= 3V)
IN
= 110 C/W,
OSC
16
15
14
13
12
11
10
= 15V, V
9
= 249k, SYNC = 0V, SLOPE = open, V
V
V
BOOST
PGND
GATE
V
I
BLANK
SENSE
SEC
IN
IN2
SEC
1.261
2.425
MIN
170
440
3.0
–7
85
4
= 0V, unless otherwise
U
GN PART MARKING
2.500
1.32
1.25
0.05
0.05
TYP
–10
500
200
100
500
ORDER PART
2.6
2.3
1.7
1.5
20
5
7
1
1
1
LT1950EGN
LT1950IGN
NUMBER
1950E
1950I
W
1.379
2.575
MAX
0.15
0.25
–13
700
230
115
560
3.0
3.0
2.5
2.2
1.5
25
20
10
5
5
sn1950 1950fs
UNITS
U
REF
%/V
%/V
kHz
kHz
kHz
mA
mA
mV
mV
k
V
V
A
V
A
A
A
V
V
V