S-8424AAAFT-TB-X Datasheet, PDF (27/46 Pages) Seiko Instruments Inc – BATTERY BACKUP SWITCHING IC

Rev.3.0_01
BATTERY BACKUP SWITCHING IC
S-8424A Series
2. Load Transient Response Based on Output Current Fluctuation
The overshoot and undershoot are caused in the output voltage if the output current fluctuates between 10 μA and
50 mA (V_RO is between 10 μA and 30 mA) while the input voltage is constant. Figure 18 shows the output
voltage variation due to the output current. Figure 19 shows the test circuit for reference. The latter half of this
section describes ringing waveform and parameter dependency.
Output
current
Output
current
50 mA
10 μA
Overshoot
Undershoot
VIN
VOUT
S-8424A
Series
VSS
COUT
Oscilloscope
Figure 18 Output Voltage Variation due to
Output Current
Figure 19 Test Circuit
Figure 20 shows the ringing waveforms at the VOUT pin and Figure 21 shows the ringing waveforms at the VRO
pin due to the load variation, respectively.
VOUT pin
50 mA
Output current
10 μA
V_IN = 6.0 V, C_OUT = 22 μF, Ta = 25°C
50 mA
10 μA
Output voltage
(50 mV/div)
t (500 ms/div)
t (50 μs/div)
Figure 20 Ringing Waveform due to Load Variation (VOUT Pin)
VRO pin
30 mA
Output current
10 μA
V_IN=6.0 V, C_RO=22 μF, Ta=25°C
30 mA
10 μA
Output voltage
(20 mV/div)
t (20 ms/div)
t (50 μs/div)
Figure 21 Ringing Waveform due to Load Variation (VRO Pin)
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