SML2108
PRELIMINARY
PIN CONFIGURATION
48-Pin TQFP
MODN
MODN
BIASN
BIASN
A0
A1
A2
SDA
SCL
1
2
3
4
5
6
7
8
9
36
35
34
33
32
31
30
29
28
27
26
25
V
SS
V
AUTOMON
RDY#
ALERT#
EXT TEMP
CAP2
SS
V
SS
V
SS
BIASN
BIASN
MODN
MODN
10
11
12
CAP1
DETECT
2053 PCon 2.0
PIN DESCRIPTIONS
DETECT (12)
SDA, SCL (4 & 5)
This is the analog input from the laser monitor photodiode Data and Clock lines, respectively, whose function and
for the integrator circuit. There is an on-board resistance use are based on the industry standard I2C interface.
of 2MΩ between the DETECT input and CAP1 pin.
Lookup table values, configuration data, and D/A and A/D
registers may all be accessed via these two pins of the
SML2108. These pins have internal 100kΩ pullups.
CAP1 and CAP2 (11 & 10)
Capacitor inputs for an external capacitor in the feedback
loopoftheMeanPowerControlIntegrator. Thereisanon-
board capacitance of 500pF.
A0, A1, A2 (1, 2, & 3)
Address Pins for the interface provided to allow multiple
devices on a single bus. These pins have internal 100kΩ
pullups.
AUTOMON (6)
Active high input used to enable the internal auto-monitor
function, which provides automatic adjustments to the
RDY# (7)
modulationoutputcurrents(MODPandMODN)basedon Active low, open-drain output. This pin is driven low
the internal A/D output and the values stored in the whenever the internal A/D is performing a conversion, or
nonvolatile lookup table. This pin has an internal 100kΩ while the on-board EEPROM is being programmed.
pullup.
EXT TEMP (9)
ALERT# (8)
Temperature input (or no connection). This pin can be
Active low, open-drain output. This pin is driven low programmed as an input to the ADC and can interface a
wheneverthebiascurrentincreasesbeyondapredefined temperature sensor. The EXT TEMP pin is multiplexed
nonvolatile threshold. This can be used to predict laser with the bias current to provide a means of configuring the
failure.
inputtotheADC. WhenEXTTEMPisprogrammedasthe
SUMMIT MICROELECTRONICS, Inc.
2053 2.2 11/07/00
3
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
