LTC5100
6
sn5100 5100fs
ELECTRICAL CHARACTERISTICS
The ●denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA= 25°C. VDD = VDD(HS) = 3.3V, IS= 24mA; IM= 12mA (IMPP = 24mA); 49.9Ω, 1%
resistor from SRC (Pin 14) to MODA (Pin 11); 50Ω, 1% load AC coupled to MODB (Pin 10); 10nF, 10% capacitor from SRC (Pin 14) to
VSS; Cml_en = 0, Lpc_en = 1, transmitter enabled, unless otherwise noted. Test circuit in Figure 5.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: The quiescent V
DD
and V
DD(HS)
currents refer to the current with
zero SRC pin current (i.e., the laser is operating with zero bias current and
zero modulation current). The total power supply current is the quiescent
current plus the SRC pin current, I
S
, plus any current sinked from IN
+
and
IN
–
.
Note 3: The peak transient voltage at the IN
+
and IN
–
pins must not
exceed the range of –300mV to V
DD(HS)
+ 300mV.
Note 4: When Cml_en = 0 (not in CML mode), the termination is 100Ω
differential with 50k common mode to V
DD(HS)
/2.
Note 5: The common mode input resistance is measured relative to
V
DD(HS)
/2 with the inputs tied together.
Note 6: When Cml_en = 1 (CML mode), the termination is nominally 50Ω
to V
DD(HS)
on each of the IN
+
and IN
–
pins.
Note 7: The SRC pin current can be programmed to near zero in each
range, but the recommended minimum operating level is 1/16 of full scale.
Note 8: The laser bias current is the average current delivered to the laser.
It is equal to the SRC pin current minus the average modulation current at
the MODA and MODB pins, or I
B
= I
S
– I
M
. Full scale for the bias current
therefore depends on Is_rng and the actual modulation current.
Note 9: The MODA and MODB pins are connected on-chip. The modulation
current refers to the sum of the currents on these pins. I
M
refers to the
total average current at the MODA and MODB pins. I
MPP
refers to the total
peak-to-peak modulation current at the MODA and MODB pins. I
MPP
differs
from the laser modulation current, I
MOD
. I
MPP
splits between the laser and
the termination resistor according to I
MOD
= I
MPP
• R
T
/(R
T
+ R
LD
), where
R
T
is the value of the termination resistor and R
LD
is the dynamic
resistance of the laser diode.
PARAMETER CONDITIONS MIN TYP MAX UNITS
SCL, SDA
SCL, SDA Input Low Voltage, V
IL
–0.5 0.3 • V
V
DD
SCL, SDA Input High Voltage, V
IH
0.7 • V
DD
+V
V
DD
0.5
SCL, SDA Input Low Current (Note 21) V
SDA
, V
SCL
= 0.1 • V
DD
–100 µA
SCL, SDA Input High Current (Note 21) V
SDA
, V
SCL
= 0.9 • V
DD
–100 µA
SCL, SDA Output Low Voltage I
OL
= 3mA 0 0.4 V
Hysteresis 280 mV
Serial Interface Timing (Note 20)
SCL Clock Frequency 100 kHz
Hold Time (Repeated) START Condition. After This 4 µs
Period the First Clock Pulse is Generated
Low Period of the SCL Clock 4.7 µs
High Period of the SCL Clock 4µs
Set-Up Time for a Repeated START Condition 4.7 µs
Data Hold Time 0 3.45 µs
Data Set-Up Time 250 ns
Input Rise Time of Both SDA and SCL Signals 1000 ns
Output Fall Time of SCL and SDA from V
IH(MIN)
to 300 ns
V
IL(MAX)
with a Bus Capacitance from 10pF to 400pF
Set-Up Time for STOP Condition 4µs
Bus Free Time Between a STOP and START Condition 4.7 µs
Capacitive Load for Each Bus Line 400 pF
Noise Margin at the LOW Level for Each Connected 0.1 • V
Device (Including Hysteresis) V
DD
Noise Margin at the HIGH Level for Each Connected 0.2 • V
Device (Including Hysteresis) V
DD
