MIC3000 Datasheet, PDF (5/68 Pages) Micrel Semiconductor – SFP Management IC

MIC3000
Pin Configuration
FB
VMPD
GNDA
VDDA
VILD–
VILD+
24 23 22 21 20 19
1
18
2
17
3
16
4
15
5
14
6
13
7 8 9 10 11 12
VDDD
NC
GNDD
RSIN
VIN
CLK
Micrel
24-Lead MLF™
Pin Descriptions
Pin Number
1
Pin Name
FB
2
VMPD
3
GNDA
4
VDDA
5
VILD–
6
VILD+
7
SHDN
8
VRX
9
XPN
10
TXFAULT
Pin Function
Analog Input. Feedback voltage for the APC loop op-amp . Polarity and
scale are programmable via the APC configuration bits. Connect to V_BIAS if
APC is not used.
Analog Input. Multiplexed A/D converter input for monitoring transmitted
optical power via a monitor photodiode. In most applications, VMPD will be
connected directly to FB. The input range is 0 - V_REF or 0 - V_REF/4 depend-
ing on the setting of the APC configuration bits.
Ground return for analog functions.
Power supply input for analog functions.
Analog Input. Reference terminal for the multiplexed pseudo-differential A/D
converter inputs for monitoring laser bias current via a sense resistor (VILD+
is the sensing input). Tie to V_DD or GND to reference the voltage sensed on
VILD+ to V_DD or GND respectively. Limited common-mode voltage range,
see “Applications Information” section for more details.
Analog Input. Multiplexed A/D input for monitoring laser bias current via a
sense resistor (signal input); accommodates inputs referenced to V_DD or
GND (see pin 5 description). Limited common-mode voltage range, see
“Applications Information” section for more details.
Digital output; Programmable polarity. Asserted at the detection of a fault
condition that can be used to activate a second series transistor in the laser
current path, enhancing protection against single-point failures.
Analog Input. Multiplexed A/D converter input for monitoring received optical
power. The input range is 0 to V_REF.
Analog Input/Output. Optional connection to an external PN junction for
sensing temperature at a remote location. The Zone bit in OEMCFG1
determines whether temperature is measured using the on-chip sensor or
the remote PN junction.
Digital Output; Open-Drain. A high level indicates a hardware fault impeding
transmitter operation. The state of this input is always reflected in the TXFLT
bit.
October 2004
5
M9999-101204