ltc5100 Linear Technology Corporation, ltc5100 Datasheet - Page 32

• Manufacturer Part Number: ltc5100
• Description: 3.3v, 3.2gbps Vcsel Driver
• Manufacturer: Linear Technology Corporation

OPERATIO
LTC5100
Standalone Operation
On power-up the LTC5100 becomes an I
and attempts to load its configuration data from an exter-
nal EEPROM. If an EEPROM responds, the LTC5100 reads
16-bytes of data and transfers this data to the internal
register set. When a 16-byte transfer is completed without
error, the LTC5100 becomes ready to enable the transmit-
ter and begin driving the laser. If a bus error occurs during
this transfer, the load sequence is aborted and a
Mem_load_error is generated, preventing the transmitter
from being enabled until a successful memory load at-
tempt is completed or until an external agent sets the
Operating_mode bit. Every 64ms another attempt is made
to load the EEPROM until the memory is read or until
Table 5. EEPROM Memory Map
BYTE 7
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
32
Reserved
Ib_gain(4:0)/Apc_gain(4:0)
Reserved
T_nom(7:0)
Im_tc2(7:0)
Im_tc1(7:0)
Reserved
Im_nom(7:0)
Ib_tc2(7:0)/Imd_tc2(7:0)
Ib_tc1(7:0)/Imd_tc2(7:0)
Reserved
Ib_nom(7:0)/Imd_nom(7:0)
Reserved
Lpc_en
Reserved
Cml_en
U
6
Auto_shutdn_en Flt_pin_polarity Flt_pin_override Force_flt
Ib_limit
Md_polarity
5
Ext_temp_en
2
C bus master
4
Peaking (4:0)
Power_down_en Apc_en
BIT
Operating_mode = 1. Table 5 shows the memory map for
the EEPROM.
The LTC5100 generates I
binary) when accessing the EEPROM, making it compat-
ible with a wide range of EEPROM sizes. Table 6 details
how the LTC5100 interacts with EEPROMs from 128 bits
to 16k bits and from where it gets its data.
The LTC5100 supports hot plugging in standalone mode.
If the Soft_en bit is set in the EEPROM and the EN pin is
active, the LTC5100 loads its configuration data from the
EEPROM and immediately enables the transmitter. The
transmitter is typically enabled and settled within the
300ms t_init period required by the GBIC specification.
3
Imd_rng(1:0)
Im_rng(1:0)
Is_rng(1:0)
Rep_flt_inhibit Rapid_restart_en Flt_drv_mode
En_polarity
2
Im_gain(2:0)
Over_pwr_en
2
C address 0xAE (1010_1110
1
T_nom(9:8)
Im_nom(9:8)
Ib_nom(9:8)/Imd_nom (9:8)
Under_pwr_en Over_current_en
Soft_en
0
Operating_mode
sn5100 5100fs