ACS401 Semtech Corporation, ACS401 Datasheet - Page 7

• Manufacturer Part Number: ACS401
• Description: Optical Modem ic
• Manufacturer: Semtech Corporation

Single Fiber LED link
Link Budget Example (Rtrc set so LED launch current = 100 mApeak)
Fibertype
Fibersize
Minimum transmit couple power to fiber (µW)
Minimum LED responsivity (AW)
Minimum ACS401 sensitivity (nA)
Minimum input power to ACS401 amplifier (µW)
Link budget (dB)
VD+ pins 19, 20, 29 and 67.
GND pins 3, 10, 16, 17, 36, 41 and 43 .
All capacitors should be placed
very close to the ACS401.
TxD
TxCL and RxCL clock pulse widths
Transmit set-up and hold times
t
Plastic
1000 micron
0.01
50
13
TxCL
1000
500
t
wh
sut
GND
V+
Figure 4. 6 Full-duplex channels over a single fiber
+5V
ACS401
TxD1
RxD1
TxD2
RxD2
TxD3
RxD3
TxD4
RxD4
XO1
XO2
Glass
62.5 micron 50 micron
100
0.1
500
5
13
XI1
XI2
t
wl
47 µH
47 µH
µH
µH
t
ht
Glass
0.12
4.1
11
50
500
47 µH
ACS401 GND
Figure 3. Recommended power supply layout
Figure 2. Timing diagrams
µF
Single Fiber Link
100
nF
1
k
RxCL
Single Fiber Duplex LASER link
Link Budget Example (LASER launch power = 1 mW)
Fibertype
Fibersize
Minimum transmit couple power to fiber (µW)
Minimum PIN responsivity (AW)
Minimum ACS401 sensitivity (nA)
Minimum input power to ACS401 amplifier (µW)
Link budget (dB) (single mode fiber attenuation = 0.3 dB km)
RxD
10
100
nF
nF
GND
VG+
AGND
VA+
SETB
GND
VD+
RxD1
RxD2
RxD3
RxD4
ACS401
TxD1
TxD2
TxD3
TxD4
Digital Outputs rise and fall times
XO1
XO2
XI1
XI2
Receive set-up and hold times
ACS401
t
r
10 %
%
t
90 %
sur
%
4 * Synchronous
Channels
4 * Asynchronous
Channels
Channels
Channel
90 %
*Synchronous
*Asynchronous
%
10 %
CON1
CON2
CNT
TRC
%
t
t
hr
f
Pin 48 and Pin 51
should be connected
together
ACS401 GND
ACS401 GND
22-
100
Glass (single mode)
9 micron
1000
0.35
500
1.43
28.4
Rtrc > 800
nF