LT1950 Linear Technology, LT1950 Datasheet - Page 3

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

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ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifications are at T
= 0.1 F, SHDN = V
specified.
PARAMETER
Error Amplifier
FB Reference Voltage
FB Input Bias Current
Open Loop Voltage Gain
Unity Gain Bandwidth
COMP Source Current
COMP Sink Current
COMP High Level: V
COMP Active Threshold
COMP Low Level: V
Current Sense
I
I
Default Blanking Time
Adjustable Blanking Time
Blanking Override Voltage–
I
Turn-Off Delay to Gate
Slope Compensation (Note 4)
Internal Switcher
Boost Switch I
Boost Switch Off Time
V
V
V
V
GATE Driver Output
GATE Rise Time
GATE Fall Time
GATE Clamp Voltage
GATE Low Level
GATE High Level
Maximum Duty Cycle
SENSE
SENSE
SENSE
IN2
IN2
IN2
IN2
: Boost Disable
: Boost Disable Hysteresis
: Gate Enable
: Gate Enable Hysteresis
Maximum Threshold
Input Bias Current
Maximum Threshold
LIMIT
OL
OH
IN
, BLANK = 0V, I
SENSE
= 0V, V
CONDITIONS
3V < V
V
(Note 6)
FB = 1V, COMP = 1.6V
FB = 1.4V, COMP = 1.6V
FB = 1V, I
FB = 1.4V, I
Duty Cycle < 10%, COMP = V
COMP = 2.5V, I
FB = 1V, COMP = 2V, I
FB = 1V, COMP = 2V, I
BLANK = 75k to Ground
BLANK = Open, COMP = 2.5V (Note 4)
COMP = 2V
I
Default, R
2x Default, R
3x Default, R
V
V
FB = 1V, V
FB = 1V, V
I
I
I
I
I
FB = 1V, f
FB = FB Reference Voltage
Start of GATE Switching (Duty Cycle > 0%)
3V < V
3V < V
3V < V
3V < V
SENSE
GATE
GATE
GATE
GATE
GATE
OL
IN2
IN2
+ 0.2V < COMP < V
= 8V, 3V < V
= 8V, 3V < V
= 0 A, COMP = 2.5V, FB = 6V
= 20mA
= 200mA
= –20mA, V
= –200mA, V
IN
IN
IN
IN
IN
Max Threshold (DC < 10%) – (DC = 80%) (Note 4)
IN2
< 25V, V
< 10V
< 10V
< 10V, FB = 1V (Note 4)
< 10V, FB = 1V (Note 4)
COMP
OSC
SLOPE
IN2
IN2
= 15V, GATE = 1nF, BOOST = open, V
A
COMP
SLOPE
SLOPE
= 25 C. COMP = open, FB = 1.4V, R
= 12V, C
= 12V, C
= 200kHz
= – 250 A
SENSE
=
= 250 A
IN
IN
OL
IN2
The
= 8k
= 3.3k
IN2
< 10V
< 10V
+ 0.2V < COMP < V
= 12V, COMP = 2.5V, FB = 6V
= I
SENSE
SENSE
L
L
= 12V, COMP = 2.5V, FB = 6V
OH
= 1nF (Notes 3, 6)
= 1nF (Notes 3, 6)
SENSE
denotes the specifications which apply over the full operating
– 0.2
= 75mV
= 75mV
OH
Max Threshold
OH
– 0.2
IN
OSC
= 15V, V
= 249k, SYNC = 0V, SLOPE = open, V
SEC
1.205
–125
MIN
–0.3
11.5
9.75
250
9.5
7.0
65
90
15
70
10
90
8
= 0V, unless otherwise
1.230
–170
–0.6
TYP
–1.1
0.15
11.0
–1.0
0.25
–75
100
110
290
125
500
2.5
1.0
8.2
1.2
60
85
13
25
14
28
42
50
30
13
95
3
LT1950
1.254
11.75
–200
–250
MAX
1000
–1.8
9.27
14.5
1.75
110
180
0.4
40
97
sn1950 1950fs
UNITS
3
REF
MHz
mA
mA
mV
mV
mV
mV
mV
mA
nA
dB
ns
ns
ns
ns
ns
ns
%
V
V
V
V
A
V
V
V
V
V
V
V
V
V