技术资料.pdf - 第25页
25 34980A Sys tem Control Mod ules 34950A 64 - bit di gital I/ O with mem ory and c ounter This modu le can be used t o simulate or detec t digital patterns . It has eight 8 - bit digital I/O cha nnels wit h handshak ing…
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34945EXT switch drive (64 channels, low side drive mode)
General specifications
Driver off voltage (max)
30 V
Driver off leakage current
500 μA
Driver on current (max)
600 mA
Driver on voltage (max)
0.5 V @ 600 mA
34945EXT switch drive (64 channels, TTL drive mode)
Hi output voltage
3 V @ Iout = 2 mA
Lo output voltage
0.4 V @ Iin = 20 mA
Lo input Current
20 mA
34945EXT position indicator sense inputs
Channels
64
Lo input voltage (max)
0.8 V
Hi input voltage (min)
2.5 V
Input resistance
> 100 kΩ @ Vin ≤ 5 V
> 20 kΩ @ Vin > 5 V
Maximum input voltage
30 V
34945EXT switch drive power supply (34945EXT powered by 34945A)
Voltage
24 V nominal (external power supply required for switches needing more than
24 V)
Current
100 mA continuous + 200 mA (15 msec pulse, 25% duty cycle)
34945EXT external power connection
Voltage range
4.75 V to 30 V
Current limit
2 A
LED indicator (Current mode divers)
Channels
64
Supply voltage
5 V nominal
LED drive current
5 mA nominal, (prog 1-20 mA)
Driver compliance voltage
0.8 V
34945EXT dimensions
Dimensions
11.2" x 4.5" x 1.5" high with distribution boards installed
Maximum of eight 34945EXT’s per mainframe
Switch drive control is also available in L4445A and L4490A/91A RF Switch Platform.
Note: See Configuration Guide, “34945A, L4445A, L4490A/L4491A” literature number 5989-2272EN, for configuration details.
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34980A System Control Modules
34950A 64-bit digital I/O with memory and counter
This module can be used to simulate or detect digital patterns. It has eight 8-bit digital I/O channels with
handshaking, pattern memory, two 10 MHz counters with gate functions, and programmable clock output.
Digital input/output
The digital I/O bits are organized into two banks of 32-bits. The I/O bits can be configured and
programmed as inputs or outputs in 8-bit channels. The digital outputs can be configured as active drive
or open-drain outputs with a 10 kΩ pull up. User-supplied pull-up resistors for up to 5 V outputs are also
acceptable. The digital inputs have programmable thresholds up to 5 V for compatibility with most digital
logic standards.
The onboard pattern memory can be used to select and output digital stimulus or bit-stream patterns or to
capture external digital data. Each bank has independent memory and directional control so that one
bank can output data while the other captures data. The memory can be divided up to 64 Kbytes per 8-bit
channel.
Specifically, the digital I/O channels also have:
•
Variable active high drive output from 1.65 V to 5 V or open-drain
•
Variable input thresholds from 0 V to 5 V
•
Configurable handshaking protocols, including synchronous and strobe
•
Programmable polarity
•
Source or sink up to 24 mA with an Imax of 400 mA per module.
•
Internal alarming for maskable pattern match
•
1 hardware pattern interrupt per bank
•
Connections via standard 78-pin Dsub cables or detachable terminal block
Frequency counter/totalizer
The two channels can be used to count digital events, frequency, period, duty cycle, totalize, and pulse
width. The counter/totalizer also includes:
•
Programmable gate functionality
•
Programmable input thresholds levels 0 V to 3 V
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34950A 64 bit I/O
Digital input/output characteristics
Number of channels
Eight 8 bits. Input or output, non-isolated
V
in
0 V – 5 V
1
V
out
1.65 V – 5 V
1,2
I
out
(max) 24 mA
2
Frequency (max)
10 MHz
3
I
load
(max)
400 mA
t
rise
+ t
fall
(typ)
6 ns
5
Handshake lines
V
in
0 V – 5 V
V
out
1.65 V – 5 V
2,4
I
out
(max)
24 mA
2
Frequency (max)
10 MHz
Counter function characteristics
Max frequency
10 MHz (max) 50% duty cycle
V
in
0 V to 5 V
Min rise/fall time
5 µsec
Totalizer function characteristics
Maximum count
2
32
-1 (4,294,967,296)
Maximum input frequency
10 MHz (max), rising or falling edge, programmable
V
in
0 V – 5 V
Gate input
0 V – 5 V
Maximum input frequency
5 µsec
System clock generator characteristics
Frequency
20 MHz – 10 Hz, configurable divide by-n 24-bits, programmable on/off
V
out
1.65 V – 5 V
2
I
out
(max)
24 mA
2
Accuracy
100 ppm
Note:
1. Configurable by 8-bit channel
2. Lower current drive at lower voltages
3. From memory with handshaking
4. Configurable by bank
5. 5V, 50 pF load