LP2954 Datasheet, PDF (4/13 Pages) National Semiconductor (TI) – 5V and Adjustable Micropower Low-Dropout Voltage Regulators

Electrical Characteristics (Continued)
Limits in standard typeface are for T_J = 25˚C, bold typeface applies over the −40˚C to +125˚C temperature range. Limits
are guaranteed by production testing or correlation techniques using standard Statistical Quality Control (SQC) methods. Un-
less otherwise noted: V_IN = 6V, I_L = 1 mA, C_L = 2.2 µF.
Symbol
Parameter
Conditions
Typical
2954AI
2954I
Units
Min
Max
Min
Max
Additional Specifications for the Adjustable Device (LP2954AIM and LP2954IM)
V_REF Reference Voltage
(Note 10)
1.230
1.215
1.245
1.205
1.255
V
1.205
1.255
1.190
1.270
∆V_REF/ Reference Voltage
V_IN=2.5V to
0.03
0.1
0.2
V_REF Line Regulation
VO(NOM)+1V
V_IN=2.5V to
VO(NOM)+1V to 30V
0.2
0.4
(Note 11)
∆V_REF/∆T Reference Voltage
(Note 3)
20
Temperature
Coefficient
ppm/˚C
I_B(FB)
Feedback Pin Bias
Current
20
40
40
nA
60
60
I_GND
Ground Pin Current V_SHUTDOWN≤1.1V
105
140
140
µA
at Shutdown (Note
6)
I_O(SINK) Output ″OFF″
Pulldown Current
(Note 12)
30
30
mA
20
20
Dropout Detection Comparator
I_OH
Output ″HIGH″
V_OH=30V
0.01
1
Leakage Current
2
1
µA
2
V_OL
Output ″LOW″
V_IN=V_O(NOM)−0.5V
150
250
250
mV
Voltage
I_O(COMP)=400µA
400
400
V_THR(MAX) Upper Threshold
Voltage
(Note 13)
−60
−80
−35
−80
−35
mV
−95
−25
−95
−25
V_THR(MIN) Lower Threshold
Voltage
(Note 13)
−85
−110
−55
−110
−55
mV
−160
−40
−160
−40
HYST Hysteresis
(Note 13)
15
mV
Shutdown Input
V_OS
Input Offset Voltage (Referred to V_REF)
±3
−7.5
7.5
−7.5
7.5
mV
−10
10
−10
10
HYST Hysteresis
6
mV
I_B
Input Bias Current
V_IN(S/D)=0V to 5V
10
−30
30
−30
30
nA
−50
50
−50
50
Note 1: Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the de-
vice 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:
.
Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The junction-to-ambient
thermal resistance of the TO-220 (without heatsink) is 60˚C/W, 73˚C/W for the TO-263, and 160˚C/W for the SO-8. If the TO-263 package is used, the thermal re-
sistance can be reduced by increasing the P.C. board copper area thermally connected to the package: Using 0.5 square inches of copper area, θ_JA is 50˚C/W; with
1 square inch of copper area, θ_JA is 37˚C/W; and with 1.6 or more square inches of copper area, θ_JA is 32˚C/W. The junction-to-case thermal resistance is 3˚C/W.
If an external heatsink is used, the effective junction-to-ambient thermal resistance is the sum of the junction-to-case resistance (3˚C/W), the specified thermal re-
sistance of the heatsink selected, and the thermal resistance of the interface between the heatsink and the LP2954. Some typical values are listed for interface ma-
terials used with TO-220:
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