S8880A Datasheet, PDF (14/30 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
 Precautions
• If the consumption current during power-off (I_SSS) needs to be kept at 0.8 μA or lower, set the VM pin voltage (V_VM)
so that conditions (1) and (2) below are satisfied.
(1) V_VM ≥ Power-off voltage (V_OFF)
(2) Operation input voltage (V_IN) + 1.0 V ≤ V_VM ≤ 3.0 V
• If the discharge start voltage (V_CPOUT1) of the S-8880A Series is lower than the operation voltage of the step-up
DC-DC converter to be started, the step-up DC-DC converter may not start up. When selecting products, fully check
them using an actually mounted model. Refer to " Selection of Startup Capacitor (C_CPOUT)" for details.
• Select a capacitor with a sufficiently large capacitance for the startup capacitor. In the case of a capacitor with
insufficient capacitance, the step-up DC-DC converter may not start up. When selecting products, fully check them
using an actually mounted model. Refer to " Selection of Startup Capacitor (C_CPOUT)" for details.
• The discharge start delay time (t_OUT) will be longer according to conditions (1), (2), and (3) below. Also note it will be
further longer when these conditions are combined.
(1) The operation input voltage (V_IN) is low.
(2) The discharge start voltage (V_CPOUT1) is high.
(3) The capacitance of startup capacitor (C_CPOUT) is large.
• When stopping the discharge to the OUT pin and recharging the startup capacitor (C_CPOUT), C_CPOUT needs to be
discharged until CPOUT pin voltage (V_CPOUT) decreases to discharge stop voltage (V_CPOUT2) or lower. In this case,
set the condition as follows:
Condition: OUT pin voltage (V_OUT) < V_CPOUT2
• When not using the VM pin in actual use, be sure to connect it to the VSS pin. If the VM pin is left open, it may cause
malfunctions.
• Note that the operation to restart the step-up DC-DC converter does not start when CPOUT pin voltage (V_CPOUT)
exceeds the discharge stop voltage (V_CPOUT2) even if the power-off status is released. The operation to restart the
step-up DC-DC converter restarts if V_CPOUT decreases to V_CPOUT2 or lower by discharge of the startup capacitor
(C_CPOUT).
• Do not connect a high resistance to the VM pin. Note that the VM pin input current (I_VM) max. may not flow if a high
resistance is connected.
• The S-8880A Series can start up the step-up DC-DC converter more reliably as the discharge start voltage (V_CPOUT1)
is higher and the capacitance of the startup capacitor (C_CPOUT) is larger. However, note that the time from when the
power is input until the step-up DC-DC converter starts becomes longer in this case.
• In the S-8880A Series, the capacitance of the startup capacitor (C_CPOUT) can be more lowered as the discharge start
voltage (V_CPOUT1) is higher, but note that if V_CPOUT1 > 2.0 V, the minimum operation input voltage (V_IN min.) (the
minimum input voltage value required for power to be output from the OUT pin of the S-8880A Series) rises from
0.37 V to 0.39 V (Refer to Table 10).
• When the capacitance of the startup capacitor (C_CPOUT) is lower, the discharge operation may start if the ripple
voltage of the CPOUT pin reaches the discharge start voltage (V_CPOUT1). The influence of the ripple voltage can be
reduced by setting C_CPOUT larger in this case.
• Do not connect a load other than a capacitance to the CPOUT pin. Note that the discharge operation may not be
performed if a resistance, etc. is connected.
• When the operation input voltage (V_IN) is higher or the OUT pin current is extremely low, the CPOUT pin voltage
(V_CPOUT) equal to or more than the discharge start voltage (V_CPOUT1) may be output.
• When designing for mass production using the application circuit described herein, the product deviation and
temperature characteristics should be taken into consideration. SII Semiconductor Corporation shall not bear any
responsibility for the products on the circuits described herein.
• Do not apply an electrostatic discharge to this IC that exceeds the performance ratings of the built-in electrostatic
protection circuit.
• SII Semiconductor Corporation claims no responsibility for any disputes arising out of or in connection with any
infringement by products including this IC of patents owned by a third party.
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