TLV5510

2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER

SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999

15

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

internal reference voltage conversion

Three internal resistors allow the device to generate an internal reference voltage. These resistors are brought

without the use of external resistors.

The internal resistors are provided to develop REFT and REFB as listed in Table 1 (bias option 1) with only two

connect REFT to REFTS and connect REFB to REFBS. For applications where the variance associated with

A second internal bias option (bias two option) is shown in Figure 22. Using this scheme REFB = AGND and

REFT is as shown in Table 1 (bias option 2). These bias voltage options can be used to provide the values listed

in the following table.

BIAS OPTION

VDDA

BIAS VOLTAGE

BIAS OPTION

VDDA

VREFB

VREFT

VREFT – VREFB

2.7 V

0.54

2.34

1.8

1

3 V

0.6

2.60

2

1

3.3 V

0.66

2.86

2.2

3.6 V

0.72

3.12

2.4

2.7 V

AGND

2.25

2.25

2

3 V

AGND

2.5

2.5

2

3.3 V

AGND

2.75

2.75

3.6 V

AGND

3

3

To use the internally-generated reference voltage, terminal connections should be made as shown in

Figure 21 or Figure 22.

R1

40

Ω NOM

Rref

200

Ω NOM

R2

60

Ω NOM

VDDA

REFTS

REFT

REFB

REFBS

AGND

TLV5510

16

17

22

21

23

18

0.1

µF

0.1

µF

2.63 V dc

Figure 21. External Connections Using the Internal Bias One Option