M61880FP 参数 Datasheet PDF下载

M61880FP

7. VCC and GND pins

Power supply related pins are the VCC1 and VCC2 pins and the GND1 and GND2 pins. In terms of the internal

circuitry , these are connected as follows. (Basically, a single power supply should be used.)

VCC1, GND1: Connected to analog system.

VCC2, GND2: Connected to digital system.

The main points to be noted with regard to actual wiring are as follows.

(1) Make the wiring as wide as possible and avoid lengthy, circuitous wiring.

(2) Locate an electrolytic capacitor for voltage stabilization close to VCC1 and GND1.

(3) Locate a bypass capacitor close to VCC2 and GND2.

Also ensure that M61880 power is supplied while laser diode power is being supplied.

Note on Wiring of Peripheral Elements

Peripheral elements necessary for M61880 operation should be located as close as possible to the M61880.

Power Consumption Calculation Method

M61880 power consumption P is given approximately by the following equation:

P = Icc.×.Vcc.+.I(RO)

×.V(RO)

+.I(LD)

×V(LD)

where V(RO): RO pin voltage

V(LD): LD pin voltage

I(RO): RO pin load current I(LD): LD pin load current

For example, when VCC = 5.25 V, V(RO) = V(LD) = 2.5 V, and I(RO) = I(LD) = 100 mA, the power consumption

values when the laser is on and off are as follows.

(1) When laser is on, (DATA = “L”, ICC = 55 mA)

PON = 55.×.5.25.+.0 + 100

×.2.5

= 538.8 (mW)

(2) When laser is off, (DATA = “H”, ICC = 55 mA)

PON = 55.×.5.25.+.100

×.2.5

= 538.8 (mW)

Rev.1.0, Sep.19.2003, page 6 of 20