LP2950 Datasheet, PDF (6/10 Pages) National Semiconductor (TI) – Series of Adjustable Micropower Voltage Regulators

LP2950 / LP2951
CORPORATION
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
LP2951 MINIMUM
OPERATING VOLTAGE
2.2
2.1
2.0
1.9
1.8
1.7
1.6
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (˚C)
1D-34
LP2951 ERROR
COMPARATOR OUTPUT
8
V_OUT = 5V
6
LP2951 FEEDBACK
BIAS CURRENT
20
10
0
–10
–20
–30
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (˚C)
1D-35
LP2951 COMPARATOR
SINK CURRENT
2.5
2.0
T_A = 125˚C
4
HYSTERESIS
2
0
NOTE: PULLUP RESISTOR
TO SEPARATE 5V SUPPLY
–2
0
1
2
3
4
INPUT VOLTAGE (V)
5
1D-37
1.5
T_A = 25˚C
1.0
T_A = –55˚C
0.5
0.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
OUTPUT LOW VOLTAGE (V)
1D-38
OUTPUT IMPEDANCE
10
5
I_O = 100µA
2
I_O = 1mA
1
I_O = 100mA
0.5
0.2
0.1
0.05
V_OUT = 5V
C_L = 1µA
0.02
0.01
10
100 1K 10K 100K 1M
FREQUENCY (Hz)
1D-40
250
200
150
100
50
0
–50
–100
100mA
100µA
LOAD TRANISENT
RESPONSE
C_L = 1µF
V_OUT = 5V
0
1
2
3
4
TIME (ms)
5
1D-43
RIPPLE REJECTION
90
80
70
60
I_L = 0
50
40
C_L = 1µF
I_L = 100µA
30 V_IN = 6V
20 ^{VOUT = 5V}
10¹ 10² 10³ 10⁴ 10⁵ 10⁶
FREQUENCY (Hz)
1D-41
80
60
40
20
0
–20
–40
–60
100mA
100µA
LOAD TRANSIENT
RESPONSE
C_L = 10µF
V_OUT = 5V
0
4
8 12 16
TIME (ms)
20
1D-44
LP2951 FEEDBACK
PIN CURRENT
50
PIN 7 DRIVEN BY
EXTERNAL SOURCE
0 (REGULATROR RUN
OPEN LOOP)
–50
–100
T_A = 125˚C
–150
–200
–250
–2.0
T_A = 25˚C
T_A = –55˚C
–1.5 –1.0 –0.5 0 0.5
FEEDBACK VOLTAGE (V)
1.0
1D-36
100mV
LINE TRANSIENT
RESPONSE
50mV
0
–50mV
8V
C_L = 1µA
I_L = 1mA
V_OUT = 5V
6V
4V
0
200 400 600
TIME (µs)
800
1D-39
RIPPLE REJECTION
90
C_L = 1µF
80
V_IN = 6V
70
I_L = 1mA
V_OUT = 5V
60
50
40
30
20
10¹
I_L = 10mA
10² 10³ 10⁴ 10⁵
FREQUENCY (Hz)
10⁶
1D-42
LP2951
ENABLE TRANSIENT
7
6
C_L = 1µF
5
4
3
I_L = 10mA
2
V_IN = 8V
C_L = 10µF
V_OUT = 5V
1
0
2
0
–2
–100 0 100 200 300 400 500 600 700
TIME (µs)
1D-45
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