www.ti.com

DEFINITION OF SPECIFICATIONS

SNR + 10log10

P

S

P

N

(1)

ADS5440

SLAS467 – JULY 2005

DEVICE INFORMATION (continued)

TERMINAL FUNCTIONS (continued)

TERMINAL

DESCRIPTION

NAME

NO.

2, 7, 9, 12, 15, 18, 20,

GND

22, 24, 26, 28, 30, 32, Ground

34, 36, 38, 40, 52, 65

VREF

6

Reference voltage

CLK

10

Differential input clock (positive). Conversion initiated on rising edge

CLK

11

Differential input clock (negative)

AIN

16

Differential input signal (positive)

AIN

17

Differential input signal (negative)

Over range indicator LVDS output. A logic high signals an analog input in excess of the

OVR, OVR

42, 41

full-scale range.

D0, D0

50, 49

LVDS digital output pair

D1–D6, D1–D6

53–64

LVDS digital output pairs

D7–D11, D7–D11

67–76

LVDS digital output pairs

D12, D12

78, 77

LVDS digital output pair, most-significant bit (MSB

DRY, DRY

80, 79

Data ready LVDS output pair

NC

4, 5, 29, 33, 43–48

No connect

Analog Bandwidth The analog input frequency at which the power of the fundamental is reduced by 3 dB with respect to the

low frequency value.

Aperture Delay The delay in time between the rising edge of the input sampling clock and the actual time at which the

sampling occurs.

Aperture Uncertainty (Jitter) The sample-to-sample variation in aperture delay.

Clock Pulse Width/Duty Cycle The duty cycle of a clock signal is the ratio of the time the clock signal remains at a logic

high (clock pulse width) to the period of the clock signal. Duty cycle is typically expressed as a percentage. A

perfect differential sine wave clock results in a 50% duty cycle.

Maximum Conversion Rate The maximum sampling rate at which certified operation is given. All parametric testing is

performed at this sampling rate unless otherwise noted.

Minimum Conversion Rate The minimum sampling rate at which the ADC functions.

Differential Nonlinearity (DNL) An ideal ADC exhibits code transitions at analog input values spaced exactly 1 LSB apart.

The DNL is the deviation of any single step from this ideal value, measured in units of LSB.

Integral Nonlinearity (INL) The INL is the deviation of the ADCs transfer function from a best fit line determined by a least

squares curve fit of that transfer function. The INL at each analog input value is the difference between the

actual transfer function and this best fit line, measured in units of LSB.

Gain Error

The gain error is the deviation of the ADCs actual input full-scale range from its ideal value. The gain error is

given as a percentage of the ideal input full-scale range.

Offset Error

Offset error is the deviation of output code from mid-code when both inputs are tied to common-mode.

Temperature Drift Temperature drift (with respect to gain error and offset error) specifies the change from the value at the

the power at dc and the first five harmonics.

SNR is either given in units of dBc (dB to carrier) when the absolute power of the fundamental is used as the

reference, or dBFS (dB to full scale) when the power of the fundamental is extrapolated to the converter’s

full-scale range.

7