LT1083 Datasheet, PDF (4/12 Pages) Linear Technology – 3A, 5A, 7.5A Low Dropout Positive Fixed Regulators

LT1083/84/85 Fixed
ELECTRICAL CHARACTERISTICS
PARAMETER
Ripple Rejection
Temperature Stability
Long Term Stability
RMS Output Noise
(% of V_OUT)
Thermal Resistance
Junctrion-to-Case
CONDITIONS
LT1085-3.3
LT1085-3.6
LT1083/4/5-5
LT1083/4/5-12
f = 120Hz, C_OUT = 25µF Tantalum, V_IN = 6.3V, I_OUT = 3A
f = 120Hz, C_OUT = 25µF Tantalum, V_IN = 6.6V, I_OUT = 3A
V_IN = 8V (Note 5)
V_IN = 15V (Note 5)
T_A = 125°C, 1000 Hrs.
T_A = 25°C,
10Hz = ≤ f ≤ 10kHz
Control Circuitry/Power Transistor (See Applications Information)
LT1083
K Package
P Package
LT1084
K Package
P Package
T Package
LT1085
K Package
T Package
DD Package
MIN TYP MAX UNITS
q
60 72
dB
q
60 72
dB
q
60 68
dB
q
54 60
dB
q
0.5
%
0.03 1.0
%
0.003
%
0.6/1.6 °C/W
0.5/1.6 °C/W
0.75/2.3 °C/W
0.65/2.3 °C/W
0.65/2.7 °C/W
0.9/3.0 °C/W
0.7/3.0 °C/W
0.7/3.0 °C/W
The q denotes the specifications which apply over the full operating
temperature range.
Note 1: See thermal regulation specifications for changes in output voltage
due to heating effects. Load and line regulation are measured at a constant
junction temperature by low duty cycle pulse testing.
Note 2: Line and load regulation are guaranteed up to the maximum power
dissipation (60W for the LT1083, 45W for the LT1084 (K, P), 30W for the
LT1084 (T) and 30W for the LT1085). Power dissipation is determined by
the input/output differential and the output current. Guaranteed maximum
power dissipation will not be available over the full input/output range.
Note 3: I_{FULL LOAD} is defined in the current limit curves. The I_FULLLOAD
curve is defined as the minimum value of current limit as a function of
input to output voltage. Note that the 60W power dissipation for the
LT1083 (45W for the LT1084 (K, P), 30W for the LT1084 (T), 30W for the
LT1085) is only achievable over a limited range of input to output voltage.
Note 4: Dropout voltage is specified over the full output current range of
the device. Test points and limits are shown on the Dropout Voltage curve.
Note 5: For LT1083 I_{FULL LOAD} is 5A for – 55°C ≤ T_J ≤ – 40°C and 7.5A for
T_J ≥ – 40°C.
Note 6: 1.7V ≤ (V_IN – V_OUT) ≤ 25V for LT1084 at – 55°C ≤ T_J ≤ – 40°C.
Note 7: Dropout voltage 1.7V maximum for LT1084 at – 55 ≤ T_J ≤ – 40°C.
Note 8: Full load current is not available at all input-output voltages.
See Notes 2,3,5.
TYPICAL PERFORMANCE CHARACTERISTICS
LT1083 Dropout Voltage
2
INDICATES GUARANTEED TEST POINT
–40°C ≤ T_J ≤ 150°C
0°C ≤ T_J ≤ 125°C
1
T_J = 150°C
T_J = 25°C
T_J = –55°C
0
0 1 2 3 4 5 6 7 8 9 10
OUTPUT CURRENT (A)
LT1083/4/5 FIXED G01
LT1083 Short-Circuit Current
12
10
25°C
150°C
8
6
– 55°C
4
I_{FULL LOAD}
2
GUARANTEED
0
05
10 15 20 25 30 35
INPUT/OUTPUT DIFFERENTIAL (V)
LT1083/4/5 FIXED G02
LT1083 Load Regulation
0.10
∆I = 7.5A
0.05
0
– 0.05
– 0.10
– 0.15
– 0.20
–50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
LT1083/4/5 FIXED G03
4