TLV2548CPWR datasheet(4/48 Pages) TI1

4 / 48 page

TLV2544, TLV2548

2.7V TO 5.5V, 12BIT, 200KSPS, 4/8CHANNEL, LOW POWER

SERIAL ANALOGTODIGITAL CONVERTERS WITH AUTOPOWERDOWN

SLAS198E − FEBRUARY 1999 − REVISED JUNE 2003

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

Terminal Functions (Continued)

TERMINAL

NAME

NO.

I/O

DESCRIPTION

NAME

TLV2544

TLV2548

I/O

DESCRIPTION

SDO

The 3-state serial output for the A/D conversion result. SDO is kept in the high-impedance state

when CS is high and after the CS falling edge and until the MSB is presented. The output format

is MSB first.

When FS is not used (FS = 1 at the falling edge of CS), the MSB is presented to the SDO pin after

the CS falling edge, and successive data are available at the rising edge of SCLK and changed on

the falling edge.

When FS is used (FS = 0 at the falling edge of CS), the MSB is presented to SDO after the falling

edge of CS and FS = 0 is detected. Successive data are available at the falling edge of SCLK and

changed on the rising edge. (This is typically used with an active FS from a DSP.)

For conversion and FIFO read cycles, the first 12 bits are result from previous conversion (data)

followed by 4 don’t care bits. The first four bits from SDO for CFR read cycles should be ignored.

The register content is in the last 12 bits. SDO is 3-state (float) after the 16th bit. See the date code

information section, item (2).

REFM

External reference input or internal reference decoupling. Tie this pin to analog ground if internal

reference is used.

REFP

External reference input or internal reference decoupling. (Shunt capacitors of 10

µF and 0.1 µF

between REFP and REFM.) The maximum input voltage range is determined by the difference

between the voltage applied to this terminal and the REFM terminal when an external reference is

used.

VCC

Positive supply voltage

detailed description

analog inputs and internal test voltages

The 4/8 analog inputs and three internal test inputs are selected by the analog multiplexer depending on the

command entered. The input multiplexer is a break-before-make type to reduce input-to-input noise injection

resulting from channel switching.

converter

The TLV2544/48 uses a 12-bit successive approximation ADC utilizing a charge redistribution DAC. Figure 1

shows a simplified version of the ADC.

The sampling capacitor acquires the signal on Ain during the sampling period. When the conversion process

starts, the SAR control logic and charge redistribution DAC are used to add and subtract fixed amounts of charge

from the sampling capacitor to bring the comparator into a balanced condition. When the comparator is

balanced, the conversion is complete and the ADC output code is generated.

TLV2548CPWR Datasheet(PDF) 4 Page - Texas Instruments

TLV2548CPWR Datasheet(HTML) 4 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Datasheet Download

Link URL