STFPC311(2012) View Datasheet(PDF) - STMicroelectronics

Part Name

Description

MFG CO.

STFPC311
(Rev.:2012)

Front panel controller/driver with standby power management

STMicroelectronics 

STFPC311

Maximum rating

10.1 Power consumption estimation

The maximum power consumption is comprised of the Vacuum Florescent Display (VFD)

driver dissipation, Load Resistance (RL), LED driver dissipation, and dynamic power

consumption.

PMAX = VFD + RL + LED + PDYN

Where,

● PMAX = maximum power consumption,

● VFD = Vacuum Florescent Display driver dissipation,

● RL = load resistance,

● LED = LED driver dissipation, and

) ● PDYN = dynamic power consumption.

t(s If the segment current (ISEG) = 3 mA, grid current (IGRID) = 15 mA, and the

c LED current = 20 mA, then:

u FIP = (#segments x 6) + [#grids/(#grids +1)] x 30 mW,

rod RL dissipation = (VDD – VSS)2 ÷ 50(segment + 1 mW),

P LED driver dissipation = #LEDs x 20 mW, and

te PDYN = VDD x 5 mW.

le To finish this example:

o FIP driver dissipation = 16 x 6 + 12/13 x 30 = 124mW

bs RL dissipation = 33.32/50 x 17 = 377 mW

O LED driver dissipation = 2 x 20 = 40

) - PDYN = 3.3 x 5 = 16.5 mW

t(s The maximum power consumption (Total) = 557.5 mW

c Where,

du VSS = –30 V,

Obsolete Pro VDD = 3.3 V, and the application is in 16-segment, 12-digit mode.

Doc ID 12324 Rev 2

29/39

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