EDGE6435 데이터 시트보기 (PDF) - Semtech Corporation

부품명

상세내역

제조사

EDGE6435

Per-Pin Electronics Companion DAC

Semtech Corporation 

Edge6435/6436

TEST AND MEASUREMENT PRODUCTS

Circuit Description (continued)

Current Output DACs (Groups C, D)

Group C DACs

R_IGAIN_D is the value of an external resistor that

sets the output current range for Group D DACs

(78.12KΩ ≤ R_IGAIN_D ≤ 156.25KΩ)

The output current of each Group C Current DAC is a

function of an external resistor value (R_IGAIN_C), a

reference voltage level (VREF), contents of digital offset

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:

IOUT_C =

CODE

8192

*

50 x VREF

R_IGAIN_C

Equation 5.

IOUT_C is the output current of the Group C Current

DAC

VREF is an externally applied 2.5V reference voltage

R_IGAIN_C is the value of an external resistor that

sets the output current range for Group C DACs

(60.97KΩ ≤ R_IGAIN_C ≤ 250KΩ)

DATA is the base-10 value of the binary code loaded

into the DAC shift register (see Figures 4 and 5).

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.

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.

FORMAT

FORMAT Low selects the 4 pin channel format.

FORMAT High selects the 8 pin channel format.

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 (VREF) and the input code (DATA). The general

equation that describes the output current as a function

of these variables is presented below as Equation 6:

where:

IOUT_D

=

DATA

64

*

50 x VREF

R_IGAIN_D

Equation 6.

IOUT_D is the output current of the Group D DAC

VREF is an externally applied 2.5V reference voltage

 2006 Semtech Corp. / Rev. 3, 8/25/06

9

www.semtech.com

Share Link: