Datasheet
LP3872, LP3875
www.ti.com
SNVS227F –FEBRUARY 2003–REVISED APRIL 2013
ELECTRICAL CHARACTERISTICS – LP3872/LP3875
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, I
L
= 10 mA, C
OUT
= 10µF, V
SD
= 2V.
Typ
(1)
LP3872/5
(2)
Symbol Parameter Conditions Units
Min Max
Output Voltage Tolerance
(3)
-1.5 +1.5
V
O
V
OUT
+1V ≤ V
IN
≤ 7.0V, 10 mA ≤ I
L
≤ 1.5A 0 %
-3.0 +3.0
Output Voltage Line Regulation
(3)
0.02
ΔV
OL
V
OUT
+ 1V ≤ V
IN
≤ 7.0V %
0.06
ΔV
O
/ Output Voltage Load Regulation
(3)
0.06
10 mA ≤ I
L
≤ 1.5A %
ΔI
OUT
0.12
50
I
L
= 150 mA 38
60
V
IN
-
Dropout Voltage
(4)
mV
V
OUT
450
I
L
= 1.5A 380
550
9
I
L
= 150 mA 5
10
Ground Pin Current In Normal
I
GND
mA
Operation Mode
14
I
L
= 1.5A 6
15
Ground Pin Current In Shutdown V
SD
≤ 0.3V 0.01 10 µA
I
GND
Mode
-40°C ≤ T
J
≤ 85°C 50
I
O(PK)
Peak Output Current V
O
≥ V
O(NOM)
- 4% 1.8 A
Short Circuit Protection
I
SC
Short Circuit Current 3.2 A
Shutdown Input
Output = High V
IN
2
V
SDT
Shutdown Threshold V
Output = Low 0 0.3
T
dOFF
Turn-off delay I
L
= 1.5A 20 µs
T
dON
Turn-on delay I
L
= 1.5A 25 µs
I
SD
SD Input Current V
SD
= V
IN
1 nA
Error Flag
V
T
Threshold See
(5)
10 5 16 %
V
TH
Threshold Hysteresis See
(5)
5 2 8 %
V
EF(Sat)
Error Flag Saturation I
sink
= 100µA 0.02 0.1 V
Td Flag Reset Delay 1 µs
I
lk
Error Flag Pin Leakage Current 1 nA
I
max
Error Flag Pin Sink Current V
Error
= 0.5V 1 mA
AC Parameters
V
IN
= V
OUT
+ 1V, C
OUT
= 10µF
73
V
OUT
= 3.3V, f = 120Hz
PSRR Ripple Rejection dB
V
IN
= V
OUT
+ 0.5V, C
OUT
= 10µF
57
V
OUT
= 3.3V, f = 120Hz
ρ
n(l/f)
Output Noise Density f = 120Hz 0.8 µV
BW = 10Hz – 100kHz, V
OUT
= 2.5V 150
µV
e
n
Output Noise Voltage
(rms)
BW = 300Hz – 300kH, V
OUT
= 2.5V 100
(1) Typical numbers are at 25°C and represent the most likely parametric norm.
(2) Limits are specified by testing, design, or statistical correlation.
(3) Output voltage line regulation is defined as the change in output voltage from the nominal value due to change in the input line voltage.
Output voltage load regulation is defined as the change in output voltage from the nominal value due to change in load current. The line
and load regulation specification contains only the typical number. However, the limits for line and load regulation are included in the
output voltage tolerance specification.
(4) Dropout voltage is defined as the minimum input to output differential voltage at which the output drops 2% below the nominal value.
Dropout voltage specification applies only to output voltages of 2.5V and above. For output voltages below 2.5V, the drop-out voltage is
nothing but the input to output differential, since the minimum input voltage is 2.5V.
(5) Error Flag threshold and hysteresis are specified as percentage of regulated output voltage. See Application Hints.
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