S-882Z Datasheet, PDF (14/24 Pages) Seiko Instruments Inc – ULTRA-LOW VOLTAGE OPERATION CHARGE PUMP IC FOR STEP-UP DC-DC CONVERTER STARTUP

ULTRA-LOW VOLTAGE OPERATION CHARGE PUMP IC FOR STEP-UP DC-DC CONVERTER STARTUP
S-882Z Series
Rev.1.2_00
„ Precautions
• If the consumption current (I_SSS) during shutdown 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 ≥ V_OFF
(2) V_IN + 1.0 V ≤ V_VM ≤ 3.0 V
• If the discharge start voltage (V_CPOUT1) of this IC is lower than the operating 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 Product and Startup Capacitor (C_CPOUT).)
• 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 Product and Startup Capacitor (C_CPOUT).)
• The discharge start delay time (t_OUT) is longer according to conditions (1), (2), and (3) below. Also note it is further
longer when these conditions are combined.
(1) The operating input voltage (V_IN) is low.
(2) The discharge start voltage (V_CPOUT1) is high.
(3) The startup capacitor value (C_CPOUT) is large.
• When stopping the discharge to OUT pin and recharging a startup capacitor (C_CPOUT), C_CPOUT is needed to be
charged until CPOUT pin voltage (V_CPOUT) is lowered less than discharge stop voltage (V_CPOUT2). In this case, set
the condition as follows:
Condition: OUT pin voltage (V_OUT)< Discharge stop voltage (V_CPOUT2)
• Note that the operation to restart a 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 state is released. This operation restarts if
V_CPOUT is lowered than V_CPOUT2 by discharge of a start-up capacitor (C_CPOUT).
• When designing for mass production using an application circuit described herein, the product deviation and
temperature characteristics should be taken into consideration. SII 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 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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Seiko Instruments Inc.