UPD78F0138 NEC, UPD78F0138 Datasheet - Page 423

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

24.1 Outline of Regulator
output voltage, connect the REGC pin to V
regulator is 3.5 V (TYP.).
The 78K0/KE1 includes a circuit to realize constant-voltage operation inside the device. To stabilize the regulator
The supply voltage and oscillation frequency at which the regulator can be used are as follows.
• Power supply voltage: V
• Oscillation frequency: f
The regulator of the 78K0/KE1 stops operating in the following cases.
• During the reset period
• In STOP mode
• In HALT mode when the CPU is operating on the subsystem clock and when X1 oscillation is stopped
Figure 24-1 shows the block diagram of the periphery of the regulator.
Cautions 1. Directly connect the REGC pin of standard products and (A) grade products to V
2. The regulator cannot be used with (A1) and (A2) grade products. Be sure to connect the
regulator is not used.
REGC pin of these products directly to V
Bidirectional
level shifter
A/D converter
EV
X
DD
= 2.0 to 8.38 MHz
DD
Figure 24-1. Block Diagram of Regulator Periphery
AV
= 4.0 to 5.5 V
system I/O buffer
REF
CHAPTER 24 REGULATOR
X1, Ring,
sub
oscillator
SS
User’s Manual U16228EJ2V0UD
REGC
Internal digital circuits
via a capacitor (1
Regulator
1 F
( PD78F0134,
Flash memory
78F0138 only)
DD
.
V
DD
µ
F: recommended). The output voltage of the
V
PP
EV
DD
DD
when the
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