E6435BHFT Semtech Corporation, E6435BHFT Datasheet - Page 8

• Manufacturer Part Number: E6435BHFT
• Description: Per-pin Electronics Companion DAC
• Manufacturer: Semtech Corporation

Voltage Outputs DACs (Groups A, B, C)
The output voltage of each E6435/6436 V
function of external resistor values (R_MASTER, R_VGAIN
and R_OFFSET), a reference voltage level (V
of digital offset and gain registers, and the programmed
input code (DATA). The general equation that describes
the output voltage as a function of these variables is
presented below as Equation 1:
where:
As can be seen from Equation 1, the accuracy of the DAC
output voltage after calibration is dependent upon the
temperature coefficients of V
TEST AND MEASUREMENT PRODUCTS
Circuit Description (continued)
V OUT_[A:C] =
2006 Semtech Corp. / Rev. 3, 8/25/06
V OFFSET_[A:C] = – V REF
V
C Voltage DAC.
V
R_VGAIN[A:C] is the value of an external resistor used
to set the range for Group A, B, or C DACs
R_MASTER is the value of an external resistor that
sets the bias point/range for the voltage DACs
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 calibration
registers as shown in Figure 2.
V
programmed using an external resistor per group,
R_OFFSET[A:C] as follows:
OUT
REF
OFFSET[A:C]
[A:C] is the output voltage of a Group A, B, or
is an externally applied 2.5V reference voltage
8 * V REF
is the raw DAC offset voltage that is
*
Equation 1.
Equation 2.
R_VGAIN_[A:C]
R_MASTER
REF
R_OFFSET_[A:C]
R_MASTER
and the external resistors.
*
CODE
8192
REF
OUT
+ V OFFSET_[A:C]
), contents
DAC is a
8
Minimum / Maximum Output Voltages
See Table 2 for the minimum and maximum possible
voltages of a voltage output, where:
Resolution
The resolution of the DACs in Groups A, B and C is:
where V
Range
The range of the DACs in Groups A, B and C is:
External Resistors
Typically computed for R_MASTER = 100k .
V MAX_[A:C]
T
able 2. Minimum/Maximum Output Voltages
RANGE_[A:C]
V
OFFSET[A:C]
D
M
A
=
S
C
0
1
B
0
F
8 * V REF
S
. . .
0
F F
e
V
0
t t
H
H
RANGE_[A:C]
L
n i
S
B
g
is defined in Equation 4.
is defined in equation 2, and
Equation 3.
Equation 4.
*
Edge6435/6436
R_VGAIN_[A:C]
R_MASTER
V
V
O
O
V
/ (2
U
F F
M
T
A
[ _
S
X
T E
: A
[ _
13
[ _
] C
: A
: A
] C
(
C]
) V
*
– 1)
8191
8192
www.semtech.com
+ V OFFSET_[A:C]