S-8425AAAFT-TB-X Datasheet, PDF (22/45 Pages) Seiko Instruments Inc – BATTERY BACKUP SWITCHING IC

BATTERY BACKUP SWITCHING IC
S-8425 Series
Rev.3.1_01
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, VCH is between 10 μA and 10 mA) while the input voltage
is constant. Figure 20 shows the output voltage variation due to the output current. Figure 21 shows the
test circuit for reference. The latter half of this section describes ringing waveform and parameter
dependency.
Output
current
50 mA
10 μA
Overshoot
VIN
VOUT
S-8425 Series
VSS
C_OUT
Oscillo-
scope
O_Ou_ut_tp_pu_ut_t
c_vu_or_ltr_ae_gn_et
Undershoot
Figure 20 Output Voltage Variation
due to Output Current
Figure 21 Test Circuit
Figures 22 to 24 show the ringing waveforms at the VOUT, VRO, and VCH pins due to the load variation.
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 22 Ringing Waveform due to Load Variation (VOUT Pin)
22