TLV5580

8BIT, 80 MSPS LOW POWER A/D CONVERTER

SLAS205B − DECEMBER 1998 − REVISED OCTOBER 2003

www.ti.com

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TLV5580 EVALUATION MODULE

POWER SUPPLIES

The board provides seven power supply connectors (see Table 2). For optimum performance, analog and digital

supplies should be kept separate. Using separate supplies for the digital logic portion of TLV5580 (DVDD) and

its output drivers (DRVDD) benefits dynamic performance, especially when DRVDD is put at the minimum

required voltage (3 V), while DVDD might be higher (up to 3.6 V). This lowers the switching noise on the die

caused by the output drivers.

Table 2. Power Supplies

SIGNAL

NAME

CONNECTOR

BOARD

LABEL

DESCRIPTION

DRV3

J1

3DRV

3.3 V digital supply for TLV5580 (digital output drivers)

DV3

J2

3VD

3.3 V digital supply for TLV5580 (digital logic) and peripherals

DV5

J3

5VD

5 V digital supply for D/A converter and peripherals

AV3

J4

3VA

3.3 V analog supply for TLV5580

AV5

J5

5VA

5 V analog supply for onboard reference circuit and D/A converter. Can be left unconnected if

internal references are used and no D/A conversion is required.

AV+12

J6

12VA

12 V analog supply for onboard reference circuit. Can be left unconnected if internal references

are used.

AV−12

J7

−12VA

−12 V analog supply for onboard reference circuit. Can be left unconnected if internal references

are used.

VOLTAGE REFERENCES

SW1 and SW2 switch between internal and external top and bottom references respectively. The external

references are onboard generated from a stable bandgap-derived 3.3 V signal (using TI’s TPS7133 and

quad-op amp TLE2144). They can be adjusted via potentiometers R6 (V(REFBI)) and R7 (V(REFTI)). It is advised

to power down the internal voltage references by asserting PWN_REF when onboard references are used.

The references are measured at test points TP3 (V(REFB)) and TP4 (V(REFT)).

DAC OUTPUT

The onboard DAC is a 10-bit 80 MSPS converter. It is connected back-to-back to the TLV5580. While the user

could use its analog output for measurements, the DAC output is directly connected to connector J8 and does

not pass through an analog reconstruction filter. So mirror spectra from aliased signal components feed through

into the analog output.

For this reason and to separate ADC and DAC contributions, performance measurements should be made by

capturing the ADC output data available on connector J11 and not by evaluating the DAC output.