LT1377_15 Datasheet, PDF (3/12 Pages) Linear Technology – 500kHz and 1MHz High Efficiency 1.5A Switching Regulators

LT1372/LT1377
ELECTRICAL CHARACTERISTICS
The q denotes specifcatons which appy over the full operating temperature range, otherwise specifications are at T_A = 25°C.
V_IN = 5V, V_C = 0.6V, V_FB = V_REF, V_SW, S/S and NFB pins open, unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
Maximum Switch Duty Cycle
q 85
95
Switch Current Limit Blanking Time
130
260
BV
Output Switch Breakdown Voltage
V_SAT
Output Switch “On” Resistance
I_LIM
Switch Current Limit
LT1372/LT1377
LT1372HV
0°C ≤ T_J ≤ 125°C
– 40°C ≤ T_J < 0°C (I Grade)
I_SW = 1A
Duty Cycle = 50%
Duty Cycle = 80% (Note 2)
q 35
47
q 42
47
40
q
0.5
0.8
q 1.5
1.9
2.7
q 1.3
1.7
2.5
∆I_IN
Supply Current Increase During Switch On-Time
∆I_SW
Control Voltage to Switch Current
Transconductance
15
25
2
Minimum Input Voltage
q
2.4
2.7
I_Q
Supply Current
Shutdown Supply Current
Shutdown Threshold
Shutdown Delay
2.7V ≤ V_IN ≤ 25V
2.7V ≤ V_IN ≤ 25V, V_S/S ≤ 0.6V
0°C ≤ T_J ≤ 125°C
– 40°C ≤ T_J < 0°C (I Grade)
2.7V ≤ V_IN ≤ 25V
q
4
5.5
q
12
30
50
q 0.6
1.3
2
q5
12
25
S/S Pin Input Current
Synchronization Frequency Range
0V ≤ V_S/S ≤ 5V
LT1372
LT1377
q – 10
15
q 600
800
q 1.2
1.6
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: For duty cycles (DC) between 50% and 90%, minimum
guaranteed switch current is given by I_LIM = 0.667 (2.75 – DC).
UNITS
%
ns
V
V
V
Ω
A
A
mA/A
A/V
V
mA
µA
µA
V
µs
µA
kHz
MHz
TYPICAL PERFORMANCE CHARACTERISTICS
Switch Saturation Voltage
vs Switch Current
1.0
150°C
0.9
100°C
25°C
0.8
0.7
0.6
0.5
–55°C
0.4
0.3
0.2
0.1
0
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
SWITCH CURRENT (A)
LT1372 • G01
Switch Current Limit
vs Duty Cycle
3.0
2.5
25°C AND
2.0
125°C
–55°C
1.5
1.0
0.5
0
0 10 20 30 40 50 60 70 80 90 100
DUTY CYCLE (%)
LT1372 • G02
Minimum Input Voltage
vs Temperature
3.0
2.8
2.6
2.4
2.2
2.0
1.8
–50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
LT1372 • G03
3