MIC3000 Datasheet, PDF (6/68 Pages) Micrel Semiconductor – SFP Management IC

MIC3000
Pin Descriptions
Pin Number
11
Pin Name
TXDISABLE
12
DATA
13
CLK
14
VIN
15
RSIN
16
GNDD
17
NC
18
VDDD
19
RXLOS
20
RSOUT
21
COMP
22
VBIAS
23
VMOD–
24
VMOD+
Micrel
Pin Function
Digital Input; Active High. The transmitter is disabled when this line is high or
the STXDIS bit is set. The state of this input is always reflected in the TXDIS
bit.
Digital I/O; Open-drain. Bi-directional serial data input/output.
Digital Input; Serial bit clock input.
If bit 4 (IE) in USRCTL register is set to 0 (default), this pin is configured as
analog input. If IE bit is set to 1, this pin is configured as open-drain output.
Analog Input: Multiplexed A/D input for monitoring supply voltage. 0V to
5.5V input range.
Open-drain output: outputs the internally generated interrupt signal /INT.
Digital Input; Rate select input; ORed with rate select bit to determine the
state of the RSOUT pin. The state of this pin is always reflected in the RSEL
bit.
Ground return for digital functions.
No connection. This pin is used for test purposes and must be left uncon-
nected.
Power supply input for digital functions.
Digital Output; Active-High/Open-Drain. Indicates the loss of the received
signal as indicated by a level of received optical power below the pro-
grammed RXLOS comparator threshold; may be wire-ORed with external
signals. Low indicates normal operation. The LOS bit reflects the state of
RXLOS whether driven by the MIC3000 or an external circuit.
Digital Output. Open-Drain. This output is controlled by the SRSEL bit ORed
with RSIN input and is open drain only.
Analog Output, compensation terminal. Connect a capacitor between this pin
and GNDA or V_DDA with appropriate value to tune the APC loop time
constant to a desirable value.
Analog Output. Buffered DAC output capable of sourcing or sinking up to
10mA under control of the APC function to drive an external transistor for
laser diode D.C. bias. The output and feedback polarity are programmable to
accommodate either a NPN or an PNP transistor to drive a common anode
or common-cathode laser diode.
Analog Input. Inverting terminal of VMOD buffer op-amp. Connect to V_MOD+
(gain = 1) or feedback resistors network to set a different gain
Analog Output. Buffered DAC output to set the modulation current on the
laser driver IC. Operates with either a 0– V_REF or a (V_DD–V_REF) – V_DD
output swing so as to generate either a ground-referenced or a V_DD refer-
enced programmed voltage. A simple external circuit can be used to
generate a programmable current for those drivers that require a current
rather than a voltage input. See “Applications Information” section for more
details.
M9999-101204
6
October 2004