Theory of Operation (2620A/2625A)
Detailed Circuit Description
2
2-19
Table 2-4. Analog Measurement Processor Pin Descriptions
Pin
Name
Description
1
2
3
4
5
VDD
ACBO
AIN
AGND2
ACR4
+5.4V supply
AC buffer output
(not used)
Analog ground
AC buffer range 4 (300V)
6
7
8
9
10
ACR3
ACR2
ACR1
VSSA
REFJ
AC buffer range 3 (30V)
AC buffer range 2 (3V)
AC buffer range 1 (300 mV)
-5.4V supply for AC ranging
Reference junction input
11
12
13
14
15
DCV
LOW
GRD
RRS
V4
V3
A/D converter low input
Driven guard
Reference resistor sense for ohms
Tap #4 on the DCV input divider/ohms reference network
Tap #3 on the DCV input divider/ohms reference network
16
17
18
19
20
V1
GRD
V2F
V2
GRD
Tap #1 on the DCV input divider/ohms reference network
Driven guard
Tap #2 input on the DCV input divider/ohms reference network
Tap #2 on the DCV input divider/ohms reference network
Driven guard
21
22
23
24
25
V0
GRD
OVS
GRD
AGND1
Tap #0 on the DCV input divider/ohms reference network
Driven guard
Ohms and volts sense input
Guard
Analog ground
26
27
28
29
30
-
DGND
FC0
FC1
FC2
(not used)
Analog ground
Function control #0
Function control #1
Function control #2
31
32
33
34
35
FC3
FC4
FC5
FC6
FC7
Function control #3
(not used)
(not used)
Function control #6
Function control #7
36
37
38
39
40
XIN
XOUT
MRST
AS
AR
Crystal oscillator input
Crystal oscillator output
Master reset
Analog send
Analog receive
41
42
43
44
45
SK
CS
BRS
VSS
INT
Serial clock
Chip select
(not used)
-5.4V dc
Integrator output
Summary of Contents for 2620A
Page 4: ......
Page 18: ...HYDRA Service Manual 1 2...
Page 48: ...HYDRA Service Manual 1 32...
Page 140: ...HYDRA Service Manual 3 16...
Page 234: ...HYDRA Service Manual 5A 34...
Page 236: ...HYDRA Service Manual 6 2...
Page 254: ...HYDRA Service Manual 6 20 2620A 1601 s63f eps Figure 6 3 2620A 2625A A1 Main PCA...
Page 258: ...HYDRA Service Manual 6 24 2635A 1601 s64f eps Figure 6 4 2635A A1 Main PCA...
Page 260: ...HYDRA Service Manual 6 26 2620A 4002 CKT 1 CKT 2 s65f eps Figure 6 5 A2 Display PCA...
Page 272: ...HYDRA Service Manual 6 38...
Page 274: ...HYDRA Service Manual 7 2...
Page 282: ...HYDRA Service Manual 7 10...
Page 284: ...HYDRA Service Manual 8 2...
Page 285: ...Schematic Diagrams 8 8 3 Figure 8 1 A1 Main PCA 2620A 2625A 2620A 1601 s88f eps...
Page 288: ...Schematic Diagrams 8 8 6 Figure 8 1 A1 Main PCA 2620A 2625A cont 2620A 1001 3 of 4 s73f eps...
Page 292: ...Schematic Diagrams 8 8 10 2635A 1001 2 of 5 Figure 8 2 A1 Main PCA 2635A cont s76f eps...
Page 293: ...Schematic Diagrams 8 8 11 2635A 1001 3 of 5 Figure 8 2 A1 Main PCA 2635A cont s77f eps...
Page 296: ...Schematic Diagrams 8 8 14 2620A 4002 CKT 1 CKT 2 Figure 8 3 A2 Display PCA s90f eps...
Page 300: ...Schematic Diagrams 8 8 18 2620A 1003 2 of 3 Figure 8 4 A3 A D Converter PCA cont s82c eps...
Page 301: ...Schematic Diagrams 8 8 19 2620A 1003 3 of 3 Figure 8 4 A3 A D Converter PCA cont s83c eps...
Page 302: ...Schematic Diagrams 8 8 20 2620A 1604 Figure 8 5 A4 Analog Input PCA s92f eps...
Page 304: ...Schematic Diagrams 8 8 22 2620A 1605 Figure 8 6 A5 IEEE 488 Interface PCA 2620A Only s93f eps...
Page 306: ...Schematic Diagrams 8 8 24 2625A 1606 Figure 8 7 A6 Memory PCA 2625A s94f eps...
Page 310: ...Schematic Diagrams 8 8 28...
