LP3941A Datasheet, PDF (12/32 Pages) National Semiconductor (TI) – Cellular Phone Power Management Unit

V_RTC LDO Electrical Characteristics
Unless otherwise noted, 2.5V < V_{BU_BAT} < 3.3V. Typical values and limits appearing in normal type apply for T_J = 25˚C. Limits
appearing in boldface type apply over the entire junction temperature range for operation, −40 to +125˚C. (Notes 2, 8, 9)
Symbol
V_OUT
Accuracy
I_Q
I_OUT
V_IN– V_RTC
PSRR
Parameter
Output Voltage
Quiescent Current
Output Current
Output Current Limit
Dropout Voltage
Power Supply Ripple
Rejection Ratio
Condition
I_OUT ≤ 50 µA, V_OUT = 1.8V
2.15V ≤ V_BU-BAT ≤ 3.3V
I_OUT = 6 µA
2.15V ≤ V_BU-BAT ≤ 3.3V
V_OUT = 0V
I_OUT = 50 mA
f = 100 Hz, C_OUT = 1.0 µF
Min
1.6
1000
Typ
1.8
2.6
10
2000
150
20
Max
2.0
6
50
10000
190
Units
V
µA
µA
mV
dB
C_OUT
Output Capacitance
1 mA ≤ I_OUT ≤ 200 mA
0.75
1.0
2.2
µF
Output Capacitor ESR
5
500
mΩ
Note: The RTC_LDO can be disabled via the I²C compatible interface by setting the corresponding disable bit. See Table 1 for further details.
Back-Up Charger Electrical Characteristics
Unless otherwise noted, V_IN = V_BATT = 3.6V. Typical values and limits appearing in normal type apply for T_J = 25˚C. Limits ap-
pearing in boldface type apply over the entire junction temperature range for operation, −40 to +125˚C. (Notes 2, 8, 9)
Symbol
Parameter
Condition
Min
Typ
Max
Units
V_IN
Operational Voltage Range
V_OUT
Accuracy
I_Q
I_OUT
Output Voltage
Quiescent Current
Output Current
Output Current Limit
PSRR
Power Supply Ripple
Rejection Ratio
I_OUT ≤ 50 µA, V_OUT = 3.15V
V_OUT + 0.4 ≤ V_BATT ≤ 5.5V
I_OUT < 50 µA
V_OUT + 0.4 ≤ V_BATT = V_IN ≤ 5.5V,
V_OUT = 3.0V
3.2V ≤ V_BATT = V_IN ≤ 5.5V
V_OUT = 0V
I_OUT ≤ 50 µA, V_OUT = 3.15V
V_OUT + 0.4 ≤ V_BATT = V_IN ≤ 5.5V
f < 10 kHz
V_OUT +
5.5
V
0.4
3.0
3.15
3.3
V
25
µA
70
150
µA
0.7
1.5
mA
2
15
dB
C_OUT
Output Capacitance
0 µA ≤ I_OUT ≤ 100 µA
0.1
µF
Output Capacitor ESR
5
500
mΩ
Note: The back-up battery charger can be disabled by setting the corresponding enable bit ‘0’ via the I²C interface. See Table 1 for further details.
Comparators’ Electrical Characteristics
Unless otherwise noted, V_BATT = +2.5V to 5.5V, V_O3 = 3.0V, V_CM = 0.27V. Typical values and limits appearing in normal type
apply for T_J = 25˚C. Limits appearing in boldface type apply over the entire junction temperature range for operation, −40 to
+125˚C. (Notes 2, 8, 9)
Symbol
Parameter
Condition
Min
Typ
Max
Units
V_T
I_B
I_OS
PSRR
V_OL
V_OH
t_PLH
t_PHL
t_LH
t_HL
Comparator Trip Voltage
Input Bias Current
Input Offset Current
Power Supply Rejection Ratio
Output Voltage Low
Output Voltage High
Propagation Delay Low to High
Propagation Delay High to Low
Rise Time Low to High
Fall Time High to Low
V_INV = 1.3V
2.7V ≤ V_BATT ≤ 5.5V
I_SINK = 1 mA
I_SOURCE = 1 mA
Overdrive = 100 mV (Note 10)
Overdrive = 100 mV (Note 10)
Overdrive = 100 mV
C_OUT = 10 pF (Note 10)
Overdrive = 100 mV
C_OUT = 10 pF (Note 10)
230
270
300
mV
0.01
0.15
µA
1
nA
50
dB
0.24
0.37
V
2.57 V_O3–0.25
3
V
5
µs
5
µs
5
ns
5
ns
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