M61880FP Ver la hoja de datos (PDF) - MITSUBISHI ELECTRIC
Número de pieza
componentes Descripción
Fabricante
M61880FP Datasheet PDF : 11 Pages
| |||
MITSUBISHI < DIGITAL ASSP >
M61880FP
Laser-diode driver / controller
FUNCTION TABLE
Input
Switch condition
ENB S/H DATA Vm,Vr
H
X
X
X
SW1
OFF
SW2
OFF
L
H
X
X
OFF OFF
H
X
OFF OFF
L
L
Vm < Vr ON
OFF
L
Vm > Vr OFF
ON
X : Don't care
(2) APC Timing Chart
The following diagram is an APC timing chart, operation
of which is based on sample hold control signals.
Tr1
Output
ON Fixed to "L"
OFF High impedance state (hold)
OFF High impedance state (hold)
OFF Constant current sourcing (sample)
OFF Constant current sinking (sample)
Note that in the example it is assumed that the leak current
occurring at the CH pin under hold condition flows into
the M61880 (in the positive direction).
Vcc
ENB input
S / H input
sample
sample
sample
hold
hold
hold
DATA input
Laser drive current
∆I LD
An example of APC Timing Chart
7.Vcc and GND Pins
Pins related to the power supply function are Vcc1, Vcc2,
GND1, and GND2. The role of these pins in terms of the in-
ternal circuits are as follows.
Vcc1, GND1: connected to analog circuits
Vcc2, GND2: connected to digital circuits
In practical wiring, the following should be noted.
(1) Secure as much a width as possible for conductors and
avoid lengthy wiring.
(2) Allocate electrolytic capacitors for stable voltage near
Vcc1 and GND1.
(3) Allocate by-pass capacitors near Vcc2 and GND2.
Notes on the Wiring for Peripheral Components
Lay out peripheral components necessary for the M61880 to
operate in closest possible proximity to the M61880.
Calculation Method for Power Dissipation
The approximate power dissipation, P, of the M61880FP is
determined by the following equation.
P = Icc x Vcc + I(RO) x V(RO) + I(LD) x V(LD) where
V(RO):voltage at RO pin
V(LD): voltage at LD pin
I(RO): load current at RO pin
I(LD) : load current at LD pin
If, for example, Vcc = 5.25V, V(RO) = V(LD) = 2.5V, and I(RO)
= I(LD) = 100mA, power dissipation at times of turning laser
on and off will be as follows.
(1) Laser ON (DATA = "L" and Icc = 55mA)
PON = 55 x 5.25 + 0 + 100 x 2.5 = 538.8(mW)
(2) Laser OFF (DATA = "H" and Icc = 55mA)
POFF = 55 x 5.25 +0+100 x 2.5 = 538.8(mW)
( 4 / 11 )
Share Link: 