S-8340A25AFT-T2-X Datasheet, PDF (26/55 Pages) Seiko Instruments Inc – SWITCHABLE SWITCHING REGULATOR CONTROLLER

STEP-UP, 600 kHz, PWM CONTROL OR PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
S-8340/8341 Series
Rev.4.0_01
 Precautions
 Mount the external capacitors, diode, coil, and other peripheral parts as close to the IC as possible, and make a one-
point grounding.
 Characteristic ripple voltage and spike noise occur in IC containing switching regulators. Moreover rush current flows
at the time of a power supply injection. Because these largely depend on the coil, the capacitor and impedance of
power supply used, fully check them using an actually mounted model.
 Make sure that dissipation of the switching transistor especially at high temperature will not surpass the power
dissipation of the package.
 To stabilize operation, use a capacitor with a low ESR as a bypass capacitor between the VDD and VSS pins of the IC,
and install and wire it with a short distance and a low impedance. Connect CVREF to the VSS pin.
 The main circuit of the IC operates on the internal power supply connected to the CVREF pin. CVREF is a bypass
capacitor that stabilizes the internal power supply. Use a 0.01 to 1 μF ceramic capacitor as CVREF and install and wire
it to assure a short distance and a low impedance.
 Switching regulator performance varies depending on the design of PC patterns, peripheral circuits and parts.
Thoroughly evaluate the actual device when setting. When using parts other than those which are recommended,
contact the SII Semiconductor Corporation marketing department.
 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.
26