LP2956A Datasheet, PDF (5/20 Pages) National Semiconductor (TI) – Dual Micropower Low-Dropout Voltage Regulators

Symbol
Parameter
Conditions
I_OH
Output “HIGH” Leakage
V_OL
Output “LOW” Voltage
I_B
Input Bias Current
GROUND PIN CURRENT
I_GND
Ground Pin Current
(Note 15)
I_GND
Ground Pin Current
at Dropout (Note 15)
I_GND
Ground Pin Current
at Shutdown (Note 15)
V_OH = 30V
V_IN (COMP) = 1.3V
V_IN (COMP) = 1.1V
I_O(COMP) = 400 μA
0 ≤ V_IN (COMP) ≤ 5V
I_L (Main Out) = 1 mA
I_L (Aux. Out) = 0.1 mA
I_L (Main Out) = 50 mA
I_L (Aux. Out) = 1 mA
I_L (Main Out) = 100 mA
I_L (Aux. Out) = 1 mA
I_L (Main Out) = 250 mA
I_L (Aux. Out) = 1 mA
I_L (Main Out) = 1 mA
I_L (Aux. Out) = 50 mA
I_L (Main Out) = 1 mA
I_L (Aux. Out) = 75 mA
V_IN = 4.5V
I_L (Main Out) = 0.1 mA
I_L (Aux. Out) = 0.1 mA
No Load on Either Output
I_{(SD IN}) ≥ 1 μA
Typical
0.01
150
10
LP2956AI
Min Max
1
2
250
400
−30 30
−50 50
LP2956I
Min Max
1
2
250
400
−30 30
−50 50
Units
μA
mV
nA
170
250
250
μA
280
280
1.1
2
2
2.5
2.5
3
6
6
8
8
16
28
28
mA
33
33
3
6
6
8
8
6
8
8
10
10
325
325
270
350
350
μA
120
180
180
200
200
Note 1: Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the
device outside of its rated operating conditions.
Note 2: The maximum allowable power dissipation is a function of the maximum junction temperature, T _J(max), the junction-to-ambient thermal resistance, θ _J-
A^{, and the ambient temperature, T}A^{. The maximum allowable power dissipation at any ambient temperature is calculated using: P(max) =}
.
Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. See Application Hints
for additional information on heat sinking and thermal resistance.
Note 3: When used in dual-supply systems where the regulator load is returned to a negative supply, the output voltage must be diode-clamped to ground.
Note 4: May exceed the input supply voltage.
Note 5: Output or reference voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
Note 6: Load regulation is measured at constant junction temperature using low duty cycle pulse testing. Two separate tests are performed, one for the range of
100 μA to 1 mA and one for the 1 mA to 250 mA range. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
Note 7: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a 1V differential.
At very low values of programmed output voltage, the input voltage minimum of 2V (2.3V over temperature) must be observed.
Note 8: Thermal regulation is the change in output voltage at a time T after a change in power dissipation, excluding load or line regulation effects. Specifications
are for a 200 mA load pulse at V_IN = 20V (3W pulse) for T = 10 ms on the Main regulator output. For the Auxiliary regulator output, specifications are for a 66 mA
load pulse at V_IN = 20V (1W pulse) for T = 10 ms.
Note 9: Connect a 0.1 μF capacitor from the output to the feedback pin.
Note 10: Load regulation is measured at constant junction temperature using low duty cycle pulse testing. Two separate tests are performed, one for the range
of 100 μA to 1 mA and one for the 1 mA to 75 mA range. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
Note 11: Dropout dectection comparator thresholds are expressed as changes in a 5V output. To express the threshold voltages in terms of a differential at the
Feedback terminal, divide by the error amplifier gain = V_OUT/V _REF.
Note 12: The shutdown input equivalent circuit is the base of a grounded-emitter NPN transistor in series with a current-limiting resistor. Pulling the shutdown
input high turns off the main regulator. For more details, see Application Hints.
Note 13: The auxiliary regulator output has foldback limiting, which means the output current reduces with output voltage. The tested limit is for V_OUT = 0V, so
the output current will be higher at higher output voltages.
Note 14: This test is performed with the auxiliary comparator output sinking 400 μA of current. At the upper trip point, the comparator output must be ≥2.4V. At
the low trip point, the comparator output must be ≤ 0.4V.
5
11339 Version 8 Revision 4 Print Date/Time: 2009/12/07 17:53:15
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