mic3003gfltr Micrel Semiconductor, mic3003gfltr Datasheet - Page 27

• Manufacturer Part Number: mic3003gfltr
• 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 power-up default
state, therefore, is APC off, V
outputs disabled. V
(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
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.
July 2010
POR
, about 50ms. Following t
Figure 8. V
BIAS
, and V
MOD
BIAS
MOD
Configured as Voltage Output
, V
will be determined by the state of
with Gain
MOD
, and SHDN will be floating
BIAS
POR
, V
, analog-to-digital
MOD
CONV
, and SHDN
after t
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]
M9999-072910-A
BIAS
.
V
GND
V DD
Hi-Z
V
GND
V DD
Hi-Z
MOD
BIAS
MIC3003GFL
vs.
vs.
Temperature
, and SHDN
is much less
INIT2
, and