TS8388BMFSB_Q Atmel Corporation, TS8388BMFSB_Q Datasheet - Page 36

• Manufacturer Part Number: TS8388BMFSB_Q
• Description: ADC 8-bit 1 Gsps.
• Manufacturer: Atmel Corporation

Figure 38. Differential Output: 50
Figure 39. Differential Output: Open Loaded
Out of Range Bit
Gray or Binary
Output Data
Format Select
36
75Ω
75Ω
-
-
TS8388B
VPLUSD = 2.4V
VPLUSD = 2.4V
DVEE
DVEE
11 mA
11 mA
1.6V
1.6V
75Ω
75Ω
An Out of Range (OR, ORB) bit is provided that goes to logical high state when the input
exceeds the positive full scale or falls below the negative full scale.
When the analog input exceeds the positive full scale, the digital output datas remain at high
logical state, with (OR, ORB) at logical one.
When the analog input falls below the negative full scale, the digital outputs remain at logical
low state, with (OR, ORB) at logical one again.
The TS8388B internal regeneration latches indecision (for inputs very close to latches thresh-
old) may produce errors in the logic encoding circuitry and leading to large amplitude output
errors.
This is due to the fact that the latches are regenerating the internal analog residues into logical
states with a finite voltage gain value (Av) within a given positive amount of time (t):
The TS8388B has been designed for reducing the probability of occurrence of such errors to
approximately 10
Av = exp( (t)/ ), with the positive feedback regeneration time constant.
+
+
Terminated
impedance
impedance
50Ω
75Ω
50Ω
75Ω
-13
(targeted for the TS8388B at 1 GSPS).
10 nF
50Ω
50Ω
Out
Out
OutB
OutB
Differential output:
+0.33V = 0.660V
(-1.2V below VPLUSD level)
Differential output:
+0.8V = 1.6V
(-1.2V below VPLUSD level)
Common mode level: -1.2V
Common mode level: -1.2V
1.38V/1.05V
1.05V/1.38V
1.6V/0.8V
0.8V/1.6V
2144C–BDC–04/03