AD7677 Analog Devices, AD7677 Datasheet - Page 6

• Manufacturer Part Number: AD7677
• Manufacturer: Analog Devices

Specifications of AD7677

• Resolution (bits): 16bit
• # Chan: 1
• Sample Rate: 1MSPS
• Interface: Par,Ser
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref) p-p
• Adc Architecture: SAR
• Pkg Type: CSP,QFP

AD7677
Pin
No.
1
2
3,
40–42,
44–48
4
5
6
7
8
9, 10
11, 12
13
14
15
16
17
18
Mnemonic
AGND
AVDD
NC
BYTESWAP
OB/2C
WARP
IMPULSE
SER/PAR
DATA[0:1]
DATA[2:3] or
DIVSCLK[0:1]
DATA[4]
or EXT/INT
DATA[5]
or INVSYNC
DATA[6]
or INVSCLK
DATA[7]
or RDC/SDIN
OGND
OVDD
Type
P
P
DI
DI
DI
DI
DI
DO
DI/O
DI/O
DI/O
DI/O
DI/O
P
P
Description
Analog Power Ground Pin
Analog Power Pin. Nominally 5 V.
No Connect
Parallel Mode Selection (8-bit/16-bit). When LOW, the LSB is output on D[7:0] and the
MSB is output on D[15:8]. When HIGH, the LSB is output on D[15:8] and the MSB is
output on D[7:0].
Straight Binary/Binary Two’s Complement. When OB/2C is HIGH, the digital output is
straight binary; when LOW, the MSB is inverted resulting in a two’s complement output from
its internal shift register.
Mode Selection. When HIGH and IMPULSE LOW, this input selects the fastest mode, the
maximum throughput is achievable, and a minimum conversion rate must be applied in order to
guarantee full specified accuracy. When LOW, full accuracy is maintained independent of the
minimum conversion rate.
Mode Selection. When HIGH and WARP LOW, this input selects a reduced power mode.
In this mode, the power dissipation is approximately proportional to the sampling rate.
Serial/Parallel Selection Input. When LOW, the parallel port is selected; when HIGH, the
serial interface mode is selected and some bits of the DATA bus are used as a serial port.
Bit 0 and Bit 1 of the Parallel Port Data Output Bus. When SER/PAR is HIGH, these outputs
are in high impedance.
When SER/PAR is LOW, these outputs are used as Bit 2 and Bit 3 of the Parallel Port Data
Output Bus.
When SER/PAR is HIGH, EXT/INT is LOW and RDC/SDIN is LOW, which is the serial
master read after convert mode. These inputs, part of the serial port, are used to slow down if
desired the internal serial clock which clocks the data output. In the other serial modes, these
pins are high impedance outputs.
When SER/PAR is LOW, this output is used as the Bit 4 of the Parallel Port Data Output Bus.
When SER/PAR is HIGH, this input, part of the serial port, is used as a digital select input for
choosing the internal or an external data clock. With EXT/INT tied LOW, the internal clock
is selected on SCLK output. With EXT/INT set to a logic HIGH, output data is synchro-
nized to an external clock signal connected to the SCLK input.
When SER/PAR is LOW, this output is used as the Bit 5 of the Parallel Port Data Output Bus.
When SER/PAR is HIGH, this input, part of the serial port, is used to select the active state
of the SYNC signal. When LOW, SYNC is active HIGH. When HIGH, SYNC is active LOW.
When SER/PAR is LOW, this output is used as the Bit 6 of the Parallel Port Data Output Bus.
When SER/PAR is HIGH, this input, part of the serial port, is used to invert the SCLK sig-
nal. It is active in both master and slave mode.
When SER/PAR is LOW, this output is used as the Bit 7 of the Parallel Port Data Output Bus.
When SER/PAR is HIGH, this input, part of the serial port, is used as either an external data
input or a read mode selection input depending on the state of EXT/INT. When EXT/INT is
HIGH, RDC/SDIN could be used as a data input to daisy-chain the conversion results from
two or more ADCs onto a single SDOUT line. The digital data level on SDIN is output on
DATA with a delay of 16 SCLK periods after the initiation of the read sequence. When EXT/
INT is LOW, RDC/SDIN is used to select the read mode. When RDC/SDIN is HIGH, the
data is output on SDOUT during conversion. When RDC/SDIN is LOW, the data is output
on SDOUT only when the conversion is complete.
Input/Output Interface Digital Power Ground
Input/Output Interface Digital Power. Nominally at the same supply as the supply of the host
interface (5 V or 3 V).
PIN FUNCTION DESCRIPTIONS
–6–
REV. A