Manual

MAX3795
1Gbps to 4.25Gbps Multirate VCSEL Driver
with Diagnostic Monitors
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.97V to +3.63V, T
A
= -40°C to +85°C. Typical values are at V
CC
= +3.3V, TC1 and TC2 are shorted, PEAKSET open, T
A
=
+25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Bias Current During Fault
I
BIAS_OFF
Current out of the BIAS pin 1.5 10 µA
1mA < I
BIAS
< 3mA 0.0875 0.105 0.1375
BIASMON Gain
G
BIASMON
I
BIASMON
/ I
BIAS
3mA ≤ I
BIAS
< 15mA 0.085 0.105 0.125
mA/mA
BIASMON Stability (Notes 2, 4) -10
+10
%
AUTOMATIC POWER CONTROL (APC)
MD Nominal Voltage V
MD
APC loop is closed 1
V
REF
-
0.2
2V
Voltage at REF V
REF
1.2 1.8 2.2 V
MD Voltage During Fault 0V
MD Input Current Normal operation (FAULT = low) -2 0.7 +2 µA
APC Time Constant C
COMP
= 0.047µF, ∆I
PD
/ ∆I
LASER
= 0.02 90 µs
PWRMON Nominal Gain V
PWRMON
/ (V
REF
- V
MD
)
1.85 2.15 2.45
V/V
LASER MODULATOR (Load is 50Ω AC-Coupled to OUT+)
Minimum
0.25
Differential Input Voltage V
ID
Maximum 2.4
V
P-P
Input Common-Mode Voltage V
CM
1.75
V
Differential Input Resistance R
IN
85 100
115
Ω
Single-Ended Input Return Loss S11 f < 4GHz
12.7
dB
Differential Input Return Loss
SDD11
f < 4GHz 11 dB
Minimum 2
Modulation Current I
MOD
Current into OUT+
R
LOAD
≤ 50Ω
Maximum 15
mA
Laser Modulation During Fault or
Squelch Active
I
MOD_OFF
DC tested 15 50
µA
P-P
Tolerance of Programmed
Modulation Current
TC1 is shorted to TC2 -10
+10
%
Minimum Peaking Current R
PEAKSET
= 10kΩ 0.2 mA
Maximum Peaking Current R
PEAKSET
= 1kΩ 2mA
Peaking Current Duration 75 ps
Output Resistance
R
OUT
Single-ended resistance 42 50 58 Ω
Minimum Programmable
Temperature Coefficient
0
ppm/°C
Maximum Programmable
Temperature Coefficient
Temperature range 0°C to +70°C
+5000
ppm/°C
- 40°C to + 85° C
49 72
t
R
50Ω load, no peaking,
5mA ≤ I
MOD
≤ 15mA
+100°C 58
- 40°C to + 85° C
56 79
Modulation Transition Time
(Note 2)
t
F
50Ω load, no peaking,
5mA ≤ I
MOD
≤ 15mA
+100°C 64
ps