AD9640BCPZ-105 Analog Devices Inc, AD9640BCPZ-105 Datasheet - Page 31

• Manufacturer Part Number: AD9640BCPZ-105
• Description: IC ADC 14BIT 105MSP 1.8V 64LFCSP
• Manufacturer: Analog Devices Inc

Specifications of AD9640BCPZ-105

• Design Resources: Interfacing ADL5534 to AD9640 High Speed ADC (CN0049)
• Number Of Bits: 14
• Sampling Rate (per Second): 105M
• Data Interface: Serial, SPI™
• Number Of Converters: 2
• Power Dissipation (max): 657mW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LFCSP
• For Use With: AD9640-150EBZ - BOARD EVALUATION AD9640 150MSPS
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DIGITAL OUTPUTS
The AD9640 output drivers can be configured to interface with
1.8 V to 3.3 V CMOS logic families by matching DRVDD to the
digital supply of the interfaced logic. The AD9640 can also be
configured for LVDS outputs using a DRVDD supply voltage
of 1.8 V.
In CMOS output mode, the output drivers are sized to provide
sufficient output current to drive a wide variety of logic families.
However, large drive currents tend to cause current glitches on
the supplies that may affect converter performance.
Applications requiring the ADC to drive large capacitive loads
or large fan-outs may require external buffers or latches.
The output data format can be selected for either offset binary
or twos complement by setting the SCLK/DFS pin when operating
in the external pin mode (see Table 15).
As detailed in the AN-877 Application Note, Interfacing to High
Speed ADCs via SPI, the data format can be selected for offset
binary, twos complement, or gray code when using the SPI control.
Table 15. SCLK/DFS Mode Selection (External Pin Mode)
Voltage at Pin
AGND
AVDD
Table 16. Output Data Format
Input (V)
VIN+ − VIN−
VIN+ − VIN−
VIN+ − VIN−
VIN+ − VIN−
VIN+ − VIN−
Offset binary (default)
Twos complement
SCLK/DFS
Condition (V)
< −VREF − 0.5 LSB
= −VREF
= 0
= +VREF − 1.0 LSB
> +VREF − 0.5 LSB
SDIO/DCS
DCS disabled
DCS enabled (default)
Offset Binary Output Mode
00 0000 0000 0000
00 0000 0000 0000
10 0000 0000 0000
11 1111 1111 1111
11 1111 1111 1111
Rev. B | Page 31 of 52
Digital Output Enable Function (OEB)
The AD9640 has a flexible three-state ability for the digital output
pins. The three-state mode is enabled using the SMI SDO/OEB
pin or through the SPI interface. If the SMI SDO/OEB pin is low,
the output data drivers are enabled. If the SMI SDO/OEB pin is
high, the output data drivers are placed in a high impedance state.
This OEB function is not intended for rapid access to the data
bus. Note that OEB is referenced to the digital supplies (DRVDD)
and should not exceed that supply voltage.
When using the SPI interface, the data and fast detect outputs
of each channel can be independently three-stated by using the
output enable bar bit in Register 0x14.
TIMING
The AD9640 provides latched data with a pipeline delay of
twelve clock cycles. Data outputs are available one propagation
delay (t
The length of the output data lines and loads placed on them
should be minimized to reduce transients within the AD9640.
These transients can degrade converter dynamic performance.
The lowest typical conversion rate of the AD9640 is 10 MSPS.
At clock rates below 10 MSPS, dynamic performance can degrade.
Data Clock Output (DCO)
The AD9640 provides two data clock output (DCO) signals
intended for capturing the data in an external register. The data
outputs are valid on the rising edge of DCO, unless the DCO clock
polarity has been changed via the SPI. See Figure 2 and Figure 3
for a graphical timing description.
PD
) after the rising edge of the clock signal.
Twos Complement Mode
10 0000 0000 0000
10 0000 0000 0000
00 0000 0000 0000
01 1111 1111 1111
01 1111 1111 1111
AD9640
OVR
1
0
0
0
1