LP3905 Datasheet, PDF (5/15 Pages) National Semiconductor (TI) – Power Management Unit For Low Power Handheld Applications

General Electrical Characteristics (Notes 2, 8, 9) (Continued)
Buck Regulator Electrical Characteristics
Buck 1 & 2 have a current rating of I_max= 600mA. Unless otherwise specified, limits are set with V_IN = V_EN1/2 = 3.8V, V_OUT-
(Buck1)= Vnom1 , V_OUT(Buck2)= Vnom2 and C_IN= C_OUT=10µF. Limits in standard typeface are for T_J = 25˚C. Limits in boldface
type apply over the full junction temperature range (−40˚C ≤ T_J ≤ +125˚C). Unless otherwise noted, specifications apply to the
LP3905 Typical Application Circuit (Figure. 1) (Notes 2, 8)
Symbol
Parameter
Condition
Min Typ Max Units
V_FB
V_OUT
Feedback Voltage
Line Regulation
R_{DSON (P)}
R_{DSON (N)}
I_LIM
F_OSC
η
Load Regulation
Pin-Pin Resistance for PFET
Pin-Pin Resistance for NFET
Switch Peak Current Limit
Internal Oscillator Frequency
Efficiency
(Note 16)
3.0V ≤ V_IN ≤ 5.5V
I_O = 1mA
100 mA ≤ I_O ≤ 600mA
V_IN= V_GS= 3.6V
V_IN= V_GS= 3.6V (Note 15)
Open Loop
PWM Mode
IOUT = 5mA, PFM mode (Note 15)
-4
+4
%
0.045
%/V
0.002
%/mA
380 500
mΩ
250 400
mΩ
650 1000 1220
mA
2
MHz
88
%
IOUT = 300mA, PWM mode (Note 15) 90
LDO Regulator Electrical Characteristics
The linear regulators have a current rating of I_max= 150mA with C_OUT = 1.0µF. A 100mA rating applies with C_OUT = 0.47µF.
Unless otherwise specified, limits are set with V_IN = 3.8V, V_EN1/2 = 3.8V, C_IN = 1µF, C_OUT = 0.47µF, I_OUT = 1.0mA. Limits in
standard typeface are for T_J = 25˚C. Limits in boldface type apply over the full junction temperature range (−40˚C ≤ T_J ≤
+125˚C). Unless otherwise noted, specifications apply to the LP3905 Typical Application Circuit (Figure. 1)(Notes 2, 8)
Symbol
Parameter
Conditions
Min
Typ
Max Units
∆V_OUT
I_LOAD
V_DO
I_SC
I_OUT
PSRR
Output Voltage Tolerance
Line Regulation Error
Load Regulation Error
Load Current
Dropout Voltage
Short Circuit Current Limit
Maximum Output Current
Power Supply Rejection Ratio
(Note 15)
e_n
Output Noise Voltage
(Note 15)
Over Full Line and Load Regulation
−3
3
%
V_IN = 3.8V to 5.5V,
I_OUT = 1mA
I_OUT = 1 mA to 100mA
(Notes 11, 15)
0.05
0.003
0
%/V
%/mA
mA
I_OUT = 100mA
(Note 13)
80
150
mV
300
500
mA
C_OUT = 1.0µF
150
f = 100Hz, I_OUT = 100mA
f = 1kHz, I_OUT = 100mA
f = 10kHz, I_OUT = 100mA
f = 50kHz, I_OUT = 100mA
f = 100kHz, I_OUT = 100mA
BW = 10Hz to
I_OUT = 1mA
100kHz, V_IN = 4.2V
Buck1 Turned ON
with I_LOAD= 0mA,
I_OUT = 100mA
Buck2 Turned OFF
90
90
60
35
25
13.5
15.5
mA
dB
µV_RMS
5
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