mic3003 Micrel Semiconductor, mic3003 Datasheet - Page 27

• Manufacturer Part Number: mic3003
• Description: Fom Management Ic With Internal Calibration
• Manufacturer: Micrel Semiconductor

Micrel, Inc.
Power On and Laser Start-Up
When power is applied, the MIC3003 initializes its
internal registers and state machine. This process takes
t
conversions begin, serial communication is possible, and
the POR bit and data ready bits may be polled. The first
set of analog data will be available t
MIC3003s are shipped from the factory with the output
enable bit, OE, set to zero, off. The MIC3003’s power-up
default state, therefore, is APC off, V
SHDN outputs disabled. V
floating (high impedance) and the laser diode, if
connected, will be off. Once the device is incorporated
into a transceiver and properly configured, then the
shutdown states of SHDN, V
determined by the state of the APC configuration and
OE bits. Tables 13, 14, and 15 illustrate the shutdown
states of the various laser control outputs versus the
control bits.
POR
May 2009
, about 50ms. Following t
Figure 8. V
MOD
Configured as Voltage Output
with Gain
BIAS
, V
BIAS
MOD
POR
, and V
, and SHDN will be
, analog-to-digital
CONV
BIAS
, V
MOD
after t
MOD
will be
, and
POR
.
27
In order to facilitate hot-plugging, the laser diode is not
turned on until t
assuming TXDISABLE is not asserted, the DACs will be
loaded with their initial values. Since t
than t
temperature,
compensation will be applied to the DAC values if
enabled. APC will begin if OE is asserted. (If the output
enable bit, OE, is not set, the V
outputs will float indefinitely.) Figure 9 shows the power-
up timing of the MIC3003. If TXDISABLE is asserted at
power-up, the V
shutdown states following MIC3003 initialization. A/D
conversions will begin, but the laser will remain off.
OE
OE
0
1
1
0
1
1
Configuration Bits
Configuration Bits
INIT2
Don’t Care
Don’t Care
Don’t Care
Configuration Bits
Table 13. Shutdown State of SHDN vs.
OE
, the first set of analog data, including
Table 14. Shutdown State of V
Table 15. Shutdown State of V
0
1
1
INV
Don’t Care
MODREF
is
INIT2
MOD
0
1
Configuration Bits
Configuration Bits
Configuration Bits
[e-mail]
available
after Power-On. Following t
Don’t Care
Don’t Care
BIASREF
and V
SPOL
0
1
0
1
BIAS
at
outputs will stay in their
V
V
Shutdown State
MOD
MOD
BIAS
t
INIT2
, V
Shutdown State
CONV
Shutdown State
SHDN
GND
BIAS
V DD
MOD
Hi-Z
or [phone]
M9999-052709-A
BIAS
.
V
GND
V DD
Hi-Z
V
GND
V DD
Hi-Z
MOD
BIAS
vs.
vs.
Temperature
, and SHDN
is much less
MIC3003
INIT2
, and