TDA8761 Datasheet, PDF (9/20 Pages) NXP Semiconductors – 9-bit analog-to-digital converter for digital video

Philips Semiconductors
9-bit analog-to-digital converter for
digital video
Preliminary specification
TDA8761
SYMBOL
PARAMETER
CONDITIONS
MIN. TYP.
MAX.
UNIT
3-state output delay times; see Fig.4
t_dZH
enable HIGH
t_dZL
enable LOW
t_dHZ
disable HIGH
t_dLZ
disable LOW
−
tbf
tbf
ns
−
tbf
tbf
ns
−
tbf
tbf
ns
−
tbf
tbf
ns
Notes
1. In addition to a good layout of the digital and analog ground, it is recommended that the rise and fall times of the clock
must not be less than 0.5 ns.
2. Analog input voltages producing code 0 up to and including code 511:
a) V_osB (voltage offset BOTTOM) is the difference between the analog input which produces data equal to 00 and
the reference voltage BOTTOM (V_RB) at T_amb = 25 °C.
b) V_osT (voltage offset TOP) is the difference between V_RT (reference voltage TOP) and the analog input which
produces data outputs equal to code 511 at T_amb = 25 °C.
3. Analog input voltage range can be derived from V_RT − V_RB difference. It is -⁽---V----^R----^T----^–----V-9----^R---^B----⁾----^×-----8--
4. GER = -⁽---V----⁵---¹--¹----^–--1---V.--5--⁰---⁾_V----^–-----1---.-5------V--- × 100
5. f_i = 11 MHz and f_clk = 30 MHz; f_i = 8 MHz and f_clk = 20 MHz.
6. The analog bandwidth is defined as the maximum input sine wave frequency which can be applied to the device. No
glitches greater than 2 LSBs, neither any significant attenuation are observed in the reconstructed signal.
7. The analog input settling time is the minimum time required for the input signal to be stabilized after a sharp full-scale
input (square-wave signal) in order to sample the signal and obtain correct output data.
8. Effective bits are obtained via a Fast Fourier Transform (FFT) treatment taking 8K acquisition points per equivalent
fundamental period. The calculation takes into account all harmonics and noise up to half of the clock frequency
(NYQUIST frequency). Conversion to signal-to-noise ratio: S/N = EB × 6.02 + 1.76 dB.
9. Intermodulation measured relative to either tone with analog input frequencies of 10.0 MHz and 10.10 MHz. The two
input signals have the same amplitude and the total amplitude of both signals provides full scale to the converter.
10. Measurement carried out using video analyser VM700A, where the video analog signal is reconstructed through a
digital-to-analog converter.
11. Output data acquisition: the output data is available after the maximum delay time of t_d.
1995 Mar 20
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