ADS7852YB Burr-Brown Corporation, ADS7852YB Datasheet - Page 11

• Manufacturer Part Number: ADS7852YB
• Description: 12-Bit/ 8-Channel/ Parallel Output ANALOG-TO-DIGITAL CONVERTER
• Manufacturer: Burr-Brown Corporation

FIGURE 2. ADS7852 Write/Read Timing.
READING DATA
Data from the ADS7852 will appear at pins 15 through 26.
The MSB will output on pin 15 while the LSB will output
on pin 26. The outputs are coded in Straight Binary (with
0V = 000
BUSY pin will go HIGH. After BUSY has been HIGH for
at least t
LOW to enable the 12-bit output bus. CS and RD must be
held LOW for at least 25ns following BUSY HIGH. Data
will be valid 30ns after the falling edge of both CS and RD.
The output data will remain valid for 20ns following the
rising edge of both CS and RD. See Figure 2 for the read
cycle timing diagram.
Address
Bus
BUSY
Data
CLK
Bus
WR
CS
RD
14
H
seconds, the CS and RD pins may be brought
and 5V = FFF
t
1
HOLD
t
1
5
t
2
t
2
3
3
4
5
H
t
CKH
SYMBOL
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
). Following a conversion, the
CONV
ACQ
CKP
CKL
CKH
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
6
t
Address n + 1
CKL
Hi-Z
t
CONV
7
Conversion n
8
9
t
10
CKP
11
WR LOW After Rising Edge of CLK
CS LOW After Rising Edge of CLK
WR LOW Prior to Rising Edge of CLK
12
BUSY Delay After CS LOW
13
CLK LOW to BUSY HIGH
RD HIGH to CLK LOW
CS to RD Setup Time
Bus Relinquish Time
RD to CS Hold Time
14
Address Setup Time
Address Hold Time
BUSY to RD Delay
CS and RD HIGH
Bus Access Time
Conversion Time
Acquisition Time
DESCRIPTION
15
t
t
t
ACQ
Clock Period
7
9
t
t
Clock HIGH
Clock LOW
4
4
RD LOW
16
1
t
Valid
6
t
Data
8
2
11
3
Table I. Ideal Input Voltages and Output Codes.
4
DESCRIPTION
Least Significant
Bit (LSB)
Full Scale
Midscale
Midscale –1LSB
Zero Full Scale
t
10
5
6
Conversion n + 1
Address n + 2
7
8
MIN
125
40
40
35
20
20
25
20
25
30
10
50
5
5
5
0
0
0
9
Hi-Z
10
ANALOG INPUT
TYP
11
1.2207mV
4.99878V
2.49878V
12
2.5V
0V
MAX
5000
1.75
0.25
13
14
15
UNITS
ADS7852
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
16
s
s
1111 1111 1111
1000 0000 0000
0111 1111 1111
0000 0000 0000
BINARY CODE
Valid
Data
1
2
STRAIGHT BINARY
DIGITAL OUTPUT
3
4
5
Hi-Z
6
HEX CODE
7
FFF
7FF
8
800
000
®