CDK1304 Cadeka Microcircuits LLC., CDK1304 Datasheet - Page 10

• Manufacturer Part Number: CDK1304
• Description: 10-bit, 25 Msps 135mw A/d Converter
• Manufacturer: Cadeka Microcircuits LLC.

Data Sheet
Input Protection
All I/O pads are protected with an on-chip protection circuit
shown in Figure 6. This circuit provides ESD robustness
to 3.5kV and prevents latch-up under severe discharge
conditions without degrading analog transition times.
Power Supply Sequencing Considerations
All logic inputs should be held low until power to the
device has settled to the specific tolerances. Avoid power
decoupling networks with large time constants that could
delay VDD power to the device.
Clock Input
The CDK1304 is driven from a single-ended TTL-input
clock. Because the pipelined architecture operates on the
rising edge of the clock input, the device can operate over
a wide range of input clock duty cycles without degrading
the dynamic performance.
©2008 CADEKA Microcircuits LLC
Figure 7. On-Chip Protection Circuit
Digital Outputs
The digital outputs (D0–D10) are driven by a separate
supply (OVDD) ranging from +3 V to +5 V. This feature
makes it possible to drive the CDK1304 TTL/CMOS com-
patible outputs with the user’s logic system supply. The
format of the output data (D0–D9) is straight binary. (See
Table 3.) The outputs are latched on the rising edge of
CLK. These outputs can be switched into a tri-state mode
by bringing EN high.
Table 3. Output Data Information
(Ø indicates the flickering bit between logic 0 and 1.)
Overrange Output
The Overrange Output (D10) is an indication that the ana-
log input signal has exceeded the positive fullscale input
voltage by 1 LSB. When this condition occurs, D10 will
switch to logic 1. All other data outputs (D0 to D9) will
remain at logic 1 as long as D10 remains at logic 1.
This feature makes it possible to include the CDK1304 in
higher resolution systems.
Evaluation Board
The TBD evaluation board is available to aid designers
in demonstrating the full performance of the CDK1304.
This board includes a reference circuit, clock driver circuit,
output data latches, and an on-board reconstruction of
the digital data. An application note describing the opera-
tion of this board, as well as information on the testing
of the CDK1304, is also available. Contact the factory for
price and availability.
+F.S. + 1/2 LSB
+F.S. –1/2 LSB
+1/2 F.S.
+1/2 LSB
0.0V
Analog Input
Overrange D10
1
0
0
0
0
1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1Ø
ØØ ØØØØ ØØØØ
0 0 0 0 0 0 0 0 0 Ø
0 0 0 0 0 0 0 0 0 0
Output Code D9-D0
www.cadeka.com
10