MAX3946ETG+T Maxim Integrated Products, MAX3946ETG+T Datasheet - Page 19

• Manufacturer Part Number: MAX3946ETG+T
• Description: IC LASER DVR SFP 11.3GBPS 24TQFN
• Manufacturer: Maxim Integrated Products
• Type: Laser Diode Driverr

Specifications of MAX3946ETG+T

• Data Rate: 11.3Gbps
• Number Of Channels: 1
• Voltage - Supply: 2.85 V ~ 3.63 V
• Current - Supply: 68mA
• Current - Modulation: 80mA
• Current - Bias: 80mA
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 12-WFQFN, Exposed Pad
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Bits 7 to 0: SET_IMOD[8:1]. The modulation current DAC is controlled by a total of 9 bits. The SET_IMOD[8:1] bits
are used to set the modulation current with even denominations from 0 to 510 bits. The LSB (SET_IMOD[0]) is con-
trolled by the MODINC register and is used to set the odd denominations in the SET_IMOD[8:0]. Any direct write to
SET_IMOD[8:1] resets the LSB.
Bits 7 to 0: IMODMAX[7:0]. The IMODMAX register is an 8-bit register that can be used to limit the maximum modula-
tion current. IMODMAX[7:0] is continuously compared to SET_IMOD[8:1]. Any attempt to modify SET_IMOD[8:1] above
IMODMAX[7:0] is ignored and flags a warning at IMODERR.
Bits 7 to 0: IBIASMAX[7:0]. The IBIASMAX register is an 8-bit register that can be used to limit the maximum bias
current. IBIASMAX[7:0] is continuously compared to SET_IBIAS[8:1]. Any attempt to modify SET_IBIAS[8:1] above
IBIASMAX[7:0] is ignored and flags a warning at IBIASERR.
Bit 7: SET_IMOD[0]. This is the LSB of the SET_IMOD[8:0] bits. This bit can only be updated by the use of MODINC[4:0].
Bits 4 to 0: MODINC[4:0]. This string of bits is used to increment or decrement the modulation current. When written
to, the SET_IMOD[8:0] bits are updated. MODINC[4:0] are a two’s complement string.
Bit #
Name
Default Value
Bit #
Name
Default Value
Bit #
Name
Default Value
Bit #
Name
Default Value
1.0625Gbps to 11.3Gbps, SFP+ Laser Driver
with Laser Impedance Mismatch Tolerance
SET_IMOD
SET_IMOD
IMODMAX
IBIASMAX
[8] (MSB)
[7] (MSB)
[7] (MSB)
[0] (LSB)
______________________________________________________________________________________
7
0
7
0
7
0
7
0
SET_IMOD
IMODMAX
IBIASMAX
[7]
[6]
[6]
X
6
0
6
0
6
0
6
0
SET_IMOD
IMODMAX
IBIASMAX
[6]
[5]
[5]
X
5
0
5
1
5
1
5
0
SET_IMOD
IMODMAX
IBIASMAX
[4] (MSB)
MODINC
[5]
[4]
[4]
4
0
4
0
4
0
4
0
Maximum Modulation Current Setting Register (IMODMAX)
Modulation Current Increment Setting Register (MODINC)
SET_IMOD
IMODMAX
IBIASMAX
MODINC
Maximum Bias Current Setting Register (IBIASMAX)
[4]
[3]
[3]
[3]
3
0
3
0
3
0
3
0
Modulation Current Setting Register (SET_IMOD)
SET_IMOD
IMODMAX
IBIASMAX
MODINC
[3]
[2]
[2]
[2]
2
1
2
0
2
0
2
0
SET_IMOD
IMODMAX
IBIASMAX
MODINC
[2]
[1]
[1]
[1]
1
0
1
0
1
0
1
0
SET_IMOD
IMODMAX
IBIASMAX
[0] (LSB)
[0] (LSB)
MODINC
[0] (LSB)
[1]
0
0
0
0
0
0
0
0
ADDRESS
ADDRESS
ADDRESS
ADDRESS
H0x0A
H0x0B
H0x0C
H0x09
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