S-8426AAA-J8T1X Datasheet, PDF (21/37 Pages) Seiko Instruments Inc – BATTERY BACKUP SWITCHING IC

Rev.2.0_02
BATTERY BACKUP SWITCHING IC
S-8426A 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 (VRO is between 10 μA and 30 mA) while the input voltage is constant. Figure 37 shows the output voltage
variation due to the output current. Figure 38 shows the test circuit for reference. The latter half of this section
describes ringing waveform and parameter dependency.
Input ^{50 mA}
voltage
10 μA
Output
voltage
Overshoot
Undershoot
VIN
VOUT
S-8426A Series
VSS
COUT
Oscillo
scope
Figure 37 Output Voltage Variation due to Output Current
Figure 38 Test Circuit
2. 1 Load Variation
Figure 39 shows the ringing waveforms at the VOUT pin and Figure 40 shows the ringing waveforms at the VRO
pin due to the load variation, respectively.
VOUT pin
Output current
50 mA
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 39 Ringing Waveform due to Load Variation (VOUT Pin)
VRO pin
Output current
30 mA
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 40 Ringing Waveform due to Load Variation (VRO Pin)
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