S8880A Datasheet, PDF (8/30 Pages) Seiko Instruments Inc – ENERGY HARVESTING POWERED BY ULTRA-LOW POWER AND ULTRA-LOW VOLTAGE OPERATION BOOST CHARGE PUMP FOR STEP-UP DC-DC CONVERTER STARTUP

ENERGY HARVESTING POWERED BY ULTRA-LOW POWER AND ULTRA-LOW VOLTAGE OPERATION BOOST CHARGE PUMP FOR STEP-UP DC-DC CONVERTER STARTUP
S-8880A Series
Rev.1.0_01
 Example of Connection with Step-up DC-DC Converter
Figure 5 shows an example that a Schottky diode (SD1) is added between the output pin (VOUT) and the power supply
pin (VDD) of the step-up DC-DC converter to be started up in the S-8880A Series, and Figure 6 shows the timing chart.
As a result, it is possible to start up the step-up DC-DC converter by C_CPOUT with a small capacitance.
V_IN
C_CPOUT
CPOUT
OUT
VIN _{S-8880A Series}
VM
C_IN
VSS
SD1
VDD
C_VDD
VIN _{Step-up DC-DC converter} VOUT
VSS
V_VOUT
CL
Figure 5
V_IN
V_CPOUT
V_CPOUT1
V_CPOUT rises
due to rising V_VOUT of
DC-DC converter
V_OUT
t_OUT
Remark C_CPOUT = 10 μF, C_VDD = 1 μF
Figure 6
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