HD6473847RHV Datasheet, PDF (391/546 Pages) Renesas Technology Corp – Renesas 8-Bit Single-Chip Microcomputer H8 Family / H8/300L Super Low Power Series

Section 15 Power Supply Circuit (H8/38104 Group Only)
Section 15 Power Supply Circuit
(H8/38104 Group Only)
This LSI incorporates an internal power supply step-down circuit. Use of this circuit enables the
internal power supply to be fixed at a constant level of approximately 3.0 V, independently of the
voltage of the power supply connected to the external V pin. As a result, the current consumed
CC
when an external power supply is used at 3.0 V or above can be held down to virtually the same
low level as when used at approximately 3.0 V. If the external power supply is 3.0 V or below, the
internal voltage will be practically the same as the external voltage. It is, of course, also possible to
use the same level of external power supply voltage and internal power supply voltage without
using the internal power supply step-down circuit.
15.1 When Using Internal Power Supply Step-Down Circuit
Connect the external power supply to the V_CC pin, and connect a capacitance of approximately 0.1
µF between CV_CC and V_SS, as shown in figure 15.1. The internal step-down circuit is made effective
simply by adding this external circuit. In the external circuit interface, the external power supply
voltage connected to V_CC and the GND potential connected to V_SS are the reference levels. For
example, for port input/output levels, the V_CC level is the reference for the high level, and the V_SS
level is that for the low level. The A/D converter analog power supply is not affected by the
internal step-down circuit.
V_CC
V_CC = 2.7 to 5.5 V
Step-down circuit
CV_CC
Internal
logic
Internal
power
supply
Stabilization
capacitance
(approx. 0.1 µF)
V_SS
Figure 15.1 Power Supply Connection when Internal Step-Down Circuit Is Used
PSCKT00A_000020020200
Rev. 7.00 Mar. 08, 2010 Page 359 of 510
REJ09B0024-0700