2-2
Functional Description
Figure 2-1. DAS-800 Series Functional Block Diagram
Analog Input Features
DAS-800 Series boards use a 12-bit, successive approximation
analog-to-digital converter (ADC) with integral sample and hold. The
ADC provides 12-bit resolution ±1 least significant bit (LSB), providing
an effective accuracy of 11 bits. The ADC converts one sample every
25
µ
s, providing a maximum conversion frequency of 40 kHz.
Clk 0
Gate 0
Out 0
Clk 2
Gate 2
Out 2
Clk 1
Gate 1
Out 1
Timer/
Counter
MUX
Clk 0
FIFO
INT_IN/XCLK
IP1/TRIG
Digital I/O
Analog In
Ch 0
Channel Select
& Scan Logic
Control Logic
Conversion
Clock Generate
& Control Logic
Interrupt
Control
12 Bit A/D
with
Sample/Hold
Ch 7
8 Channels
Gain
(DAS801/2)
Control
Clk 1
Gate 1
Gate 2
Gate 0
Out 0
Out 2
Out 1/CCLK
IP2
IP3
OP3
OP4
OP2
OP1
IBM PC XT/AT Bus
Status
Registers
Control
Registers
I/O
Buffers
Bus Interface
Address
Decode &
Internal Data Bus
Interrupt Select
(Jumper)
Levels 2-7
+5v
+12v
-12v
COM
Bus power for
Expansion & Interface
