M30218 Datasheet, PDF (135/179 Pages) Mitsubishi Electric Semiconductor – M30218 Group

Pull-down
Mitsubishi microcomputers
M30218 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Power Dissipation Calculating Method
(Fixed number depending on microcomputer’s standard)
• VOH output fall voltage of high-breakdown port
2 V (max.); | Current value | = at 18 mA
• Resistor value = 68 kΩ (min.)
• Power dissipation of internal circuit (CPU, ROM, RAM etc.) = 5 V X 38 mA = 190 mW
(Fixed number depending on use condition)
• Apply voltage to VEE pin: Vcc – 50 V
• Timing number a; digit number b; segment number c
• Ratio of Toff time corresponding Tdisp time: 1/16
• Turn ON segment number during repeat cycle: d
• All segment number during repeat cycle: e (= a X c)
• Total number of built-in resistor: for digit; f, for segment; g
• Digit pin current value h (mA)
• Segment pin current value i (mA)
(1) Digit pin power dissipation
{h X b X (1–Toff / Tdisp) X voltage} / a
(2) Segment pin power dissipation
{i X d X (1–Toff / Tdisp) X voltage} / a
(3) Pull-down resistor power dissipation (digit)
{power dissipation per 1 digit X (b X f / b) X (1–Toff / Tdisp) } / a
(4) Pull-down resistor power dissipation (segment)
{power dissipation per 1 segment X (d X g / c) X (1–Toff / Tdisp) } / a
(5) Internal circuit power dissipation (CPU, ROM, RAM etc.) = 190 mW
(1) + (2)+ (3) + (4) + (5) = X mW
134