Using De0 And De1 Inputs With The High Speed Tia; External Rtia Selection - Analog Devices ADuCM355 Hardware Reference Manual

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USING DE0 AND DE1 INPUTS WITH THE HIGH SPEED TIA

To use DE0 as the input of the high speed TIA, set the following register values:

DE0RESCON = value required to set R

HSRTIACON, Bits[3:0] = 0xF to disconnect R

DE1RESCON = 0xFF, to disconnect R
To use DE1 as the output of the high speed TIA, set the following register values:

DE1RESCON = value required to set R

HSRTIACON, Bits[3:0] = 0xF to disconnect R

DE1RESCON = 0xFF to disconnect R
High Speed TIA Current Limit Feature
As well as the protection diode, the high speed TIA also has a built in current limiting feature. If the current sourced or sunk from the
TIA is greater than the overcurrent limit protection, the amplifier clamps the current to this limit. The current clamp typically clamps at
approximately 17 mA. Refer to the
than specified in the data sheet.
EXTERNAL R SELECTION
TIA
The high speed TIA has the option of selecting an R
or DE1 pin can be connected to one side of the R
or AIN3/BUF_VREF1V8 pin can be connected to the other side of the external gain resistor, as shown in Figure 22.
To use the DE0 and AIN0 (input) pins to connect the high speed TIA with an R

DE0RESCON = 0x97 for 0 Ω R

DE1RESCON = 0xFF.

HSRTIACON, Bits[3:0] = 0xF.

Close the T1 and T10 switches (configure the TSWFULLCON register).
and R . See Table 120.
LOAD03 TIA2_03
from the high speed TIA.
TIA2
from the high speed TIA.
TIA2_05
and R . See Table 120.
LOAD05 TIA2_05
from the high speed TIA.
TIA2
from the high speed TIA.
TIA2_03
ADuCM355 data sheet for full specifications. Do not use this feature more frequently or for longer
instead of the internal R
TIA
. This R can be connected to the output of high speed TIA. The AIN0, AIN1, AIN2,
TIA TIA
and 0 Ω R in series with an external R
LOAD03 TIA2_03
AIN0 T1
EXTERNAL
R
TIA
R
DE0
LOAD03
Figure 22. Connecting External R
Rev. B | Page 104 of 312
ADuCM355 Hardware Reference Manual
, R , or R
TIA2 TIA2_03 TIA2_05
, set the following register values:
TIA
.
TIA
1.11V REFERENCE
HSTIA
HPTIA_P
T10 HPTIA_N
R
TIA2_03
Across the High Speed TIA
TIA
gain options. The DE0 pin