Datasheet

LP38842-ADJ
SNVS304A –FEBRUARY 2005–REVISED APRIL 2013 www.ti.com
ELECTRICAL CHARACTERISTICS
(1)
Limits in standard typeface are for T
J
= 25°C, and limits in boldface type apply over the full operating temperature range.
Unless otherwise specified: V
IN
= V
O
(NOM) + 1V, V
BIAS
= 4.5V, I
L
= 10 mA, C
IN
= 10 µF CER, C
OUT
= 22 µF CER, V
S/D
= V
BIAS
.
Min/Max limits are specified through testing, statistical correlation, or design.
Symbol Parameter Conditions MIN TYP
(2)
MAX Units
V
ADJ
Adjust Pin Voltage 10 mA < I
L
< 1.5A
0.552 0.568
V
O
(NOM) + 1V ≤ V
IN
≤ 5.5V 0.56 V
0.543 0.577
4.5V ≤ V
BIAS
≤ 5.5V
I
ADJ
Adjust Pin Bias Current 10 mA < I
L
< 1.5A
V
O
(NOM) + 1V ≤ V
IN
≤ 5.5V 1 µA
4.5V ≤ V
BIAS
≤ 5.5V
ΔV
O
/ΔV
IN
Output Voltage Line Regulation
(3)
V
O
(NOM) + 1V ≤ V
IN
≤ 5.5V 0.01 %/V
ΔV
O
/ΔI
L
Output Voltage Load Regulation
(4)
10 mA < I
L
< 1.5A 0.4
0.1 %/A
1.1
V
DO
Dropout Voltage
(5)
I
L
= 1.5A 175
115 mV
315
I
Q
(V
IN
) Quiescent Current Drawn from V
IN
10 mA < I
L
< 1.5A 35
30 mA
Supply 40
V
S/D
≤ 0.3V 1
0.06 µA
30
I
Q
(V
BIAS
) Quiescent Current Drawn from V
BIAS
10 mA < I
L
< 1.5A 4
2 mA
Supply 6
V
S/D
≤ 0.3V 1
0.03 µA
30
UVLO V
BIAS
Voltage Where Regulator
3.8 V
Output Is Enabled
I
SC
Short-Circuit Current V
OUT
= 0V 4 A
Shutdown Input
V
SDT
Output Turn-off Threshold Output = ON 0.7 1.3
V
Output = OFF 0.3 0.7
Td (OFF) Turn-OFF Delay R
LOAD
X C
OUT
<< Td (OFF) 20
µs
Td (ON) Turn-ON Delay R
LOAD
X C
OUT
<< Td (ON) 15
I
S/D
S/D Input Current V
S/D
=1.3V 1
µA
V
S/D
≤ 0.3V −1
θ
J-A
Junction to Ambient Thermal SO PowerPAD-8 Package
(6)
43 °C/W
Resistance
AC Parameters
PSRR (V
IN
) Ripple Rejection for V
IN
Input Voltage V
IN
= V
OUT
+1V, f = 120 Hz 80
V
IN
= V
OUT
+ 1V, f = 1 kHz 65
dB
PSRR (V
BIAS
) Ripple Rejection for V
BIAS
Voltage V
BIAS
= V
OUT
+ 3V, f = 120 Hz 58
V
BIAS
= V
OUT
+ 3V, f = 1 kHz 58
Output Noise Density f = 120 Hz µV/root−
1
Hz
e
n
Output Noise Voltage BW = 10 Hz − 100 kHz 150
µV (rms)
V
OUT
= 1.5V
BW = 300 Hz − 300 kHz 90
(1) If used in a dual-supply system where the regulator load is returned to a negative supply, the output pin must be diode clamped to
ground.
(2) Typical numbers represent the most likely parametric norm for 25°C operation.
(3) Output voltage line regulation is defined as the change in output voltage from nominal value resulting from a change in input voltage.
(4) Output voltage load regulation is defined as the change in output voltage from nominal value as the load current increases from no load
to full load.
(5) Dropout voltage is defined as the minimum input to output differential required to maintain the output with 2% of nominal value.
(6) For optimum heat dissipation, the ground pad must be soldered to a copper plane or connected using vias to an internal copper plane.
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