STFPC320 STMicroelectronics, STFPC320 Datasheet - Page 66

• Manufacturer Part Number: STFPC320
• Description: Front Panel Controller/driver With Standby Power Management And Real-time Clock
• Manufacturer: STMicroelectronics

Electrical characteristics
17.3
66/75
Power consumption estimation
Maximum power consumption P
dissipation + dynamic power consumption
Where segment current = 3mA, grid current = 15mA and LED current = 20mA,
FIP driver dissipation = number of segments x 6 + number of grids/(number of grids + 1) x
30 (mW)
RL dissipation = (V
LED driver dissipation = number of LEDs x 20 (mW)
Dynamic power consumption = V
Example
Where VSS = -30 V, VDD = 3.3 V and in 16-segment and 12-digit modes,
FIP driver dissipation = 16 x 6 + 12/13 x 30 = 124
RL dissipation = 33.32/50 x 17 = 377
LED driver dissipation = 2 x 20 = 40
Dynamic power consumption = 3.3 x 5 = 16.5
Total = 557.5mW
DD
– V
SS
)
2
/50 x (segment + 1) (mW)
MAX
DD
x 5 (mW)
= VFD driver dissipation + R
L
dissipation + LED driver
STFPC320