L4949 Datasheet, PDF (5/8 Pages) Motorola, Inc – MULTIFUNCTION VERY LOW DROPOUT VOLTAGE REGULATOR

L4949
TYPICAL CHARACTERIZATION CURVES (continued)
Figure 9. Sense Output versus
Sense Input Voltage
6.0
5.0 TJ = 25°C
4.0 _{Resistor 10 k}
from Sense Output
3.0 ^{to 5.0 V}
2.0
1.0
0
1.0 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4 1.45 1.5
VSI, SENSE INPUT VOLTAGE (V)
Figure 10. Sense Thresholds versus
Junction Temperature
1.4
1.38
1.36
Upper Threshold
1.34
1.32
1.3
1.28
1.26
Lower Threshold
1.24
1.22
1.2
–40 –20 0 20 40 60 80 100 120
TJ, JUNCTION TEMPERATURE (°C)
APPLICATION INFORMATION
Supply Voltage Transient
High supply voltage transients can cause a reset output
signal perturbation. For supply voltages greater than 8.0 V
the circuit shows a high immunity of the reset output against
supply transients of more than 100 V/µs. For supply voltages
less than 8.0 V supply transients of more than 0.4 V/µs can
cause a reset signal perturbation. To improve the transient
behavior for supply voltages less than 8.0 V a capacitor at Pin
3 can be used. A capacitor at Pin 3 (C3 ≤ 1.0 µF) reduces
also the output noise.
Figure 11. Application Schematic
C3
Vout _CO
VZ
(optional)
3
8
CT 4
Vbat
VCC
Preregulator
1
6.0 V
C_s
2.0 µA
Regulator
VCC
Si
2
1.23 Vref
NOTES: 1. For stability: Cs ≥ 1.0 µF, CO ≥ 4.7 µF, ESR < 10 Ω at 10 kHz
2. Recommended for application: Cs = CO = 10 µF
Reset
+
– ^{2.0 V}
Sense
+
– ^{1.23 V}
5 Gnd
Reset
6
10 kΩ
Vout
RSO 10 kΩ
S_o
7
MOTOROLA ANALOG IC DEVICE DATA
5