EVM6436 SEMTECH [Semtech Corporation], EVM6436 Datasheet - Page 9

• Manufacturer Part Number: EVM6436
• Description: Per-Pin Electronics Companion DAC
• Manufacturer: SEMTECH [Semtech Corporation]

Current Output DACs (Groups C, D)
Group C DACs
The output current of each Group C Current DAC is a
function of an external resistor value (R_IGAIN_C), a
reference voltage level (V
and gain registers, and the input code (DATA). The general
equation that describes the output current as a function
of these variables is presented below as Equation 5:
where:
Group D DACs
The output current of each group D DAC is a function of
an external resistor value (R_IGAIN_D), a reference voltage
level (V
equation that describes the output current as a function
of these variables is presented below as Equation 6:
where:
TEST AND MEASUREMENT PRODUCTS
Circuit Description (continued)
2006 Semtech Corp. / Rev. 3, 8/25/06
I
DAC
V
R_IGAIN_C is the value of an external resistor that
sets the output current range for Group C DACs
(60.97K
CODE is the base-10 value of the binary code (DATA)
loaded into the DAC shift register (see Figures 4 and
5) after it has been modified by the contents of the
digitally programmable offset and gain calibraiotn
registers as shown in Figure 2.
I
V
OUT_C
OUT_D
REF
REF
REF
is an externally applied 2.5V reference voltage
is an externally applied 2.5V reference voltage
is the output current of the Group C Current
is the output current of the Group D DAC
) and the input code (DATA). The general
R_IGAIN_C
Equation 5.
Equation 6.
REF
), contents of digital offset
250K )
Functional Description
Figure 1 provides a Functional Block Diagram. Figures 2
and 3 show details of the data latches and logic for the
DACs. The Edge6435/6436 features a serial data input
to program a channel or set of channel’s DACs and
functions. The Edge6435/6436 also features self-
calibrating DAC outputs via internal offset and gain
registers (Figure 2).
Figures 4 and 5 show the format of the Serial Input Data
for 4 pin channel and 8 pin channel formats.
Figure 6 shows the Serial Data Programming Sequence
Tables 3 and 4 provide the Address Maps for 4 pin channel
and 8 pin channel formats.
FORMAT
FORMAT Low selects the 4 pin channel format.
FORMAT High selects the 8 pin channel format.
R_IGAIN_D is the value of an external resistor that
sets the output current range for Group D DACs
(78.12K
DATA is the base-10 value of the binary code loaded
into the DAC shift register (see Figures 4 and 5).
9
R_IGAIN_D
Edge6435/6436
156.25K )
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