User’s Manual U15109EJ3V0UD
488
CHAPTER 15 REGULATOR
15.1 Outline
The V850/SC1, V850/SC2, and V850/SC3 incorporate a regulator to realize a 5 V single power supply, low power
consumption, and to reduce noise.
This regulator supplies a voltage obtained by stepping down the V
DD
power supply voltage to oscillation block and
on-chip logic circuits (excluding the A/D converter and output buffers). The regulator output voltage is set to 3.3 V.
Refer to
2.4 I/O Circuit Types, I/O Buffer Power Supply and Connection of Unused Pins
for the power supply
corresponding to each pin.
Figure 15-1. Regulator (
µµµµ
PD70F3089Y)
V
DD1
-system I/O buffer
PORTV
DD0
-system
I/O buffer
4.0 V to 5.5 V
4.0 V to 5.5 V
3.0 V
to
5.5 V
3.0 V to 5.5 V
3.0 V to 5.5 V
Internal digital circuit
(3.3 V)
Main/Sub
oscillator
Flash
memory
A/D converter
4.5 V to 5.5 V
ADCV
DD
V
DD1
PORTV
DD2
V
PP
PORTV
DD1
Regulator
V
DD0
CPUREG
1 F
(Recommended)
PORTV
DD0
PORTV
DD2
-system I/O buffer
PORTV
DD1
-system I/O buffer
ADCV
DD
-system
input buffer
µ
Remark
: Bidirectional level shifter
15.2 Operation
The regulator of the V850/SC1, V850/SC2, and V850/SC3 operates in every mode (STOP, IDLE, HALT).
For stabilization of regulator outputs, connect a capacitor of about 1
µ
F (recommended value) to the CPUREG pin.