Azoteq IQ Switch - ProxSense Series User manual

IQ Switch®
ProxSense®Series
Copyright © Azoteq (Pty) Ltd 2013.
All Rights Reserved.
Revision 1.14
January 2014
AZD084 User Guide for Isolated
digital communications buffer
A technical guide for using the isolated
communications buffer device (AZP344C02)
1 Introduction
The in-line isolated buffer device was made for isolated I2C communications and 1-
wire streaming between an Azoteq USB device (such as the DS100 or CT210) and
Azoteq products.
The purpose of the device is to provide the designer with extensive visual feedback
whilst having a minimal impact on the sensor environment (no common signal
ground between test device and PC).
Figure 1-1 Isolated Communications PCB block diagram
The isolated streaming PCB plugs directly into the USB device. A standard Azoteq
20-pin male header is provided at the isolated side for connection to the test
system.
It is important to note that the isolated streaming PCB does add larger GND to the
test system. This effect is minimized in the layout. In addition capacitive coupling to
the PC GND is made mostly through the isolation ICs. This amounts to a total of
about 3pF as shown in Figure 1-2.
Direct
Supply
>100mA
(optional)
Solid
State
Relay
(<100mA)
Azoteq
GUI
(PC)
Azoteq
USB device
DS100 / CT210
DUT
SDA (pin7)
SCL (pin9)
RDY (pin10)
RDY (pin8)
SDA_ISO
SCL_ISO
RDY1_ISO
RDY2_ISO
Vdd
Bi-directional
I2C isolators
Isolation
Isolated
Power
Supply
3V3
Regulator
(optional)
USB
PC side Isolated Streaming PCB System to be tested

IQ Switch®
ProxSense®Series
Copyright © Azoteq (Pty) Ltd 2013.
Page 2 of 4
All Rights Reserved.
Revision 1.14
January 2014
Figure 1-2 Isolated communications PCB parasitic capacitance model
Signal connections can be made as show in Table 1. More details on the circuit can
be seen in the next section.
Table 1 Isolated streaming buffer pin connections
Signal
Pin (on connector P4)
VDDHI (3V3 / 5V)
2
SDA
4
SCL
5
RDY1
6
RDY2
3
ISO GND
1
2 Schematic
2.1 Device Connections
Figure 2-1 Module connectors, PC side (left), DUT side (right)
ISO GND
ISO GND
Solid
State
Relay
(<100mA)
Azoteq
USB device
DS100 / CT210
DUT
Bi-directional
I2C isolators
Isolated
Power
Supply
ISO GND
SENSOR
Cext Cparasitic
CGNDREF
3pF ISO GND
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U3
SI8400
SDA_CT
SCL_CT RDY_CT2 RDY_CT1
VDDHI_CT
ISO_GND
VDDHI_ISO
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U4
SI8400
SCL_ISO
SDA_ISO
RDY_ISO2
RDY_ISO1
IN
3
1
OUT 2
GND
U2
AP2138N
C1
1uF
V_EXT
VDDHI_ISO
ISO_GND
ISO_GND
RDY_CT2
RDY_CT1
SDA_CT
SCL_CT
GND
GND
ISO_GND
VDDHI_CT
VDDHI_CT
R6
10K R7 10K
VDDHI_ISO
RDY_ISO2
RDY_ISO1
SCL_ISO
SDA_ISO
R8
4.7K R9 4.7K
ISO_GND
VDDHI_ISO
VDDHI_CT
DS2
WEJT81RC-O1
ISO_GND
C10
DNP
C12
DNP
C11
DNP
C13
DNP
GND
R1
330R
VDDHI_ISO
VDDHI_ISO_EXT
C8
100nF
C4
100nF
C7
100nF
C3
100nF C5 1uF
C9
1uF
GND
GND ISO_GND ISO_GND
ISO_GND ISO_GND
A
1
C
2
4
3
U1
ASSR-1218
R10
0R
LK1
2W-SLink Open
R3
47R
R4
47R
1
2
3
4
5
6
P4
6W-SIL-V
1
3
5
7
9
2
4
6
8
10
P3
BOX HEADER-10W-V
GND
ISO_GND
V_EXT
P1
ELx2.0y2.0_D1.0
P2
ELx2.0y2.0_D1.0
VDDHI_ISO_EXT
VDDHI_ISO
R2
2.2K
SDA_ISO
SCL_ISO
R5
10K R11 10K
RDY_ISO1
RDY_ISO2
R13
4.7K
R12
4.7K
closed: RDY active low
open: Disable pull-up 10k
for RDY active high
Top Silk: "DUT Pwr"
100mA load max
Use Coin cell to
guide distance of
Pads - then delete
coin cell from
schematic
Label: V+
Label: GND
Label:
GND
VDD
SDA
SCL
RD1
RD2
Do not place
Cut P4:pin3 down to the plastic
Cable that goes with kit -
12w IDC socket mod (key):
in top row close P4:pin3
ensure bottom row closed
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U3
SI8400
SDA_CT
SCL_CT RDY_CT2 RDY_CT1
VDDHI_CT
ISO_GND
VDDHI_ISO
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U4
SI8400
SCL_ISO
SDA_ISO
RDY_ISO2
RDY_ISO1
IN
3
1
OUT 2
GND
U2
AP2138N
C1
1uF
V_EXT
VDDHI_ISO
ISO_GND
ISO_GND
RDY_CT2
RDY_CT1
SDA_CT
SCL_CT
GND
GND
ISO_GND
VDDHI_CT
VDDHI_CT
R6
10K R7 10K
VDDHI_ISO
RDY_ISO2
RDY_ISO1
SCL_ISO
SDA_ISO
R8
4.7K R9 4.7K
ISO_GND
VDDHI_ISO
VDDHI_CT
DS2
WEJT81RC-O1
ISO_GND
C10
DNP
C12
DNP
C11
DNP
C13
DNP
GND
R1
330R
VDDHI_ISO
VDDHI_ISO_EXT
C8
100nF
C4
100nF
C7
100nF
C3
100nF C5 1uF
C9
1uF
GND
GND ISO_GND ISO_GND
ISO_GND ISO_GND
A
1
C
2
4
3
U1
ASSR-1218
R10
0R
LK1
2W-SLink Open
R3
47R
R4
47R
1
2
3
4
5
6
P4
6W-SIL-V
1
3
5
7
9
2
4
6
8
10
P3
BOX HEADER-10W-V
GND
ISO_GND
V_EXT
P1
ELx2.0y2.0_D1.0
P2
ELx2.0y2.0_D1.0
VDDHI_ISO_EXT
VDDHI_ISO
R2
2.2K
SDA_ISO
SCL_ISO
R5
10K R11 10K
RDY_ISO1
RDY_ISO2
R13
4.7K
R12
4.7K
closed: RDY active low
open: Disable pull-up 10k
for RDY active high
Top Silk: "DUT Pwr"
100mA load max
Use Coin cell to
guide distance of
Pads - then delete
coin cell from
schematic
Label: V+
Label: GND
Label:
GND
VDD
SDA
SCL
RD1
RD2
Do not place
Cut P4:pin3 down to the plastic
Cable that goes with kit -
12w IDC socket mod (key):
in top row close P4:pin3
ensure bottom row closed

IQ Switch®
ProxSense®Series
Copyright © Azoteq (Pty) Ltd 2013.
Page 3 of 4
All Rights Reserved.
Revision 1.14
January 2014
The device is plugged into an Azoteq USB device at P3 and plugged into the DUT
at P4.
2.2 Signal Connections
Figure 2-2 Bi-directional isolated I2C buffers
The SI8400 device offers bi-directional I2C communications. The SDA and SCL
pins are open drain I/Os and always require pull-up resistors in order to function.
Figure 2-3 Top left: synchronized VDDHI selection (when U1 is placed), Bottom left: DUT
Pull-up selection and Right: Power supply circuitry
The PCB offers the capability of selecting the RDY line to operate in a RDY active
low or RDY active high state. This can be set depending on the DUT.
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U3
SI8400
SDA_CT
SCL_CT RDY_CT2 RDY_CT1
VDDHI_CT
ISO_GND
VDDHI_ISO
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U4
SI8400
SCL_ISO
SDA_ISO
RDY_ISO2
RDY_ISO1
IN
3
1
OUT 2
GND
U2
AP2138N
C1
1uF
V_EXT
VDDHI_ISO
ISO_GND
ISO_GND
RDY_CT2
RDY_CT1
SDA_CT
SCL_CT
GND
GND
ISO_GND
VDDHI_CT
VDDHI_CT
R6
10K R7 10K
VDDHI_ISO
RDY_ISO2
RDY_ISO1
SCL_ISO
SDA_ISO
R8
4.7K R9 4.7K
ISO_GND
VDDHI_ISO
VDDHI_CT
DS2
WEJT81RC-O1
ISO_GND
C10
DNP
C12
DNP
C11
DNP
C13
DNP
GND
R1
330R
VDDHI_ISO
VDDHI_ISO_EXT
C8
100nF
C4
100nF
C7
100nF
C3
100nF C5 1uF
C9
1uF
GND
GND ISO_GND ISO_GND
ISO_GND ISO_GND
A
1
C
2
4
3
U1
ASSR-1218
R10
0R
LK1
2W-SLink Open
R3
47R
R4
47R
1
2
3
4
5
6
P4
6W-SIL-V
1
3
5
7
9
2
4
6
8
10
P3
BOX HEADER-10W-V
GND
ISO_GND
V_EXT
P1
ELx2.0y2.0_D1.0
P2
ELx2.0y2.0_D1.0
VDDHI_ISO_EXT
VDDHI_ISO
R2
2.2K
SDA_ISO
SCL_ISO
R5
10K R11 10K
RDY_ISO1
RDY_ISO2
R13
4.7K
R12
4.7K
closed: RDY active low
open: Disable pull-up 10k
for RDY active high
Top Silk: "DUT Pwr"
100mA load max
Use Coin cell to
guide distance of
Pads - then delete
coin cell from
schematic
Label: V+
Label: GND
Label:
GND
VDD
SDA
SCL
RD1
RD2
Do not place
Cut P4:pin3 down to the plastic
Cable that goes with kit -
12w IDC socket mod (key):
in top row close P4:pin3
ensure bottom row closed
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U3
SI8400
SDA_CT
SCL_CT RDY_CT2 RDY_CT1
VDDHI_CT
ISO_GND
VDDHI_ISO
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U4
SI8400
SCL_ISO
SDA_ISO
RDY_ISO2
RDY_ISO1
IN
3
1
OUT 2
GND
U2
AP2138N
C1
1uF
V_EXT
VDDHI_ISO
ISO_GND
ISO_GND
RDY_CT2
RDY_CT1
SDA_CT
SCL_CT
GND
GND
ISO_GND
VDDHI_CT
VDDHI_CT
R6
10K R7 10K
VDDHI_ISO
RDY_ISO2
RDY_ISO1
SCL_ISO
SDA_ISO
R8
4.7K R9 4.7K
ISO_GND
VDDHI_ISO
VDDHI_CT
DS2
WEJT81RC-O1
ISO_GND
C10
DNP
C12
DNP
C11
DNP
C13
DNP
GND
R1
330R
VDDHI_ISO
VDDHI_ISO_EXT
C8
100nF
C4
100nF
C7
100nF
C3
100nF C5 1uF
C9
1uF
GND
GND ISO_GND ISO_GND
ISO_GND ISO_GND
A
1
C
2
4
3
U1
ASSR-1218
R10
0R
LK1
2W-SLink Open
R3
47R
R4
47R
1
2
3
4
5
6
P4
6W-SIL-V
1
3
5
7
9
2
4
6
8
10
P3
BOX HEADER-10W-V
GND
ISO_GND
V_EXT
P1
ELx2.0y2.0_D1.0
P2
ELx2.0y2.0_D1.0
VDDHI_ISO_EXT
VDDHI_ISO
R2
2.2K
SDA_ISO
SCL_ISO
R5
10K R11 10K
RDY_ISO1
RDY_ISO2
R13
4.7K
R12
4.7K
closed: RDY active low
open: Disable pull-up 10k
for RDY active high
Top Silk: "DUT Pwr"
100mA load max
Use Coin cell to
guide distance of
Pads - then delete
coin cell from
schematic
Label: V+
Label: GND
Label:
GND
VDD
SDA
SCL
RD1
RD2
Do not place
Cut P4:pin3 down to the plastic
Cable that goes with kit -
12w IDC socket mod (key):
in top row close P4:pin3
ensure bottom row closed
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U3
SI8400
SDA_CT
SCL_CT RDY_CT2 RDY_CT1
VDDHI_CT
ISO_GND
VDDHI_ISO
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U4
SI8400
SCL_ISO
SDA_ISO
RDY_ISO2
RDY_ISO1
IN
3
1
OUT 2
GND
U2
AP2138N
C1
1uF
V_EXT
VDDHI_ISO
ISO_GND
ISO_GND
RDY_CT2
RDY_CT1
SDA_CT
SCL_CT
GND
GND
ISO_GND
VDDHI_CT
VDDHI_CT
R6
10K R7 10K
VDDHI_ISO
RDY_ISO2
RDY_ISO1
SCL_ISO
SDA_ISO
R8
4.7K R9 4.7K
ISO_GND
VDDHI_ISO
VDDHI_CT
DS2
WEJT81RC-O1
ISO_GND
C10
DNP
C12
DNP
C11
DNP
C13
DNP
GND
R1
330R
VDDHI_ISO
VDDHI_ISO_EXT
C8
100nF
C4
100nF
C7
100nF
C3
100nF C5 1uF
C9
1uF
GND
GND ISO_GND ISO_GND
ISO_GND ISO_GND
A
1
C
2
4
3
U1
ASSR-1218
R10
0R
LK1
2W-SLink Open
R3
47R
R4
47R
1
2
3
4
5
6
P4
6W-SIL-V
1
3
5
7
9
2
4
6
8
10
P3
BOX HEADER-10W-V
GND
ISO_GND
V_EXT
P1
ELx2.0y2.0_D1.0
P2
ELx2.0y2.0_D1.0
VDDHI_ISO_EXT
VDDHI_ISO
R2
2.2K
SDA_ISO
SCL_ISO
R5
10K R11 10K
RDY_ISO1
RDY_ISO2
R13
4.7K
R12
4.7K
closed: RDY active low
open: Disable pull-up 10k
for RDY active high
Top Silk: "DUT Pwr"
100mA load max
Use Coin cell to
guide distance of
Pads - then delete
coin cell from
schematic
Label: V+
Label: GND
Label:
GND
VDD
SDA
SCL
RD1
RD2
Do not place
Cut P4:pin3 down to the plastic
Cable that goes with kit -
12w IDC socket mod (key):
in top row close P4:pin3
ensure bottom row closed
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U3
SI8400
SDA_CT
SCL_CT RDY_CT2 RDY_CT1
VDDHI_CT
ISO_GND
VDDHI_ISO
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U4
SI8400
SCL_ISO
SDA_ISO
RDY_ISO2
RDY_ISO1
IN
3
1
OUT 2
GND
U2
AP2138N
C1
1uF
V_EXT
VDDHI_ISO
ISO_GND
ISO_GND
RDY_CT2
RDY_CT1
SDA_CT
SCL_CT
GND
GND
ISO_GND
VDDHI_CT
VDDHI_CT
R6
10K R7 10K
VDDHI_ISO
RDY_ISO2
RDY_ISO1
SCL_ISO
SDA_ISO
R8
4.7K R9 4.7K
ISO_GND
VDDHI_ISO
VDDHI_CT
DS2
WEJT81RC-O1
ISO_GND
C10
DNP
C12
DNP
C11
DNP
C13
DNP
GND
R1
330R
VDDHI_ISO
VDDHI_ISO_EXT
C8
100nF
C4
100nF
C7
100nF
C3
100nF C5 1uF
C9
1uF
GND
GND ISO_GND ISO_GND
ISO_GND ISO_GND
A
1
C
2
4
3
U1
ASSR-1218
R10
0R
LK1
2W-SLink Open
R3
47R
R4
47R
1
2
3
4
5
6
P4
6W-SIL-V
1
3
5
7
9
2
4
6
8
10
P3
BOX HEADER-10W-V
GND
ISO_GND
V_EXT
P1
ELx2.0y2.0_D1.0
P2
ELx2.0y2.0_D1.0
VDDHI_ISO_EXT
VDDHI_ISO
R2
2.2K
SDA_ISO
SCL_ISO
R5
10K R11 10K
RDY_ISO1
RDY_ISO2
R13
4.7K
R12
4.7K
closed: RDY active low
open: Disable pull-up 10k
for RDY active high
Top Silk: "DUT Pwr"
100mA load max
Use Coin cell to
guide distance of
Pads - then delete
coin cell from
schematic
Label: V+
Label: GND
Label:
GND
VDD
SDA
SCL
RD1
RD2
Do not place
Cut P4:pin3 down to the plastic
Cable that goes with kit -
12w IDC socket mod (key):
in top row close P4:pin3
ensure bottom row closed
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U3
SI8400
SDA_CT
SCL_CT RDY_CT2 RDY_CT1
VDDHI_CT
ISO_GND
VDDHI_ISO
AVDD
1
ASDA
2
ASCL
3
AGND
4BGND 5
BSCL 6
BSDA 7
BVDD 8
U4
SI8400
SCL_ISO
SDA_ISO
RDY_ISO2
RDY_ISO1
IN
3
1
OUT 2
GND
U2
AP2138N
C1
1uF
V_EXT
VDDHI_ISO
ISO_GND
ISO_GND
RDY_CT2
RDY_CT1
SDA_CT
SCL_CT
GND
GND
ISO_GND
VDDHI_CT
VDDHI_CT
R6
10K R7 10K
VDDHI_ISO
RDY_ISO2
RDY_ISO1
SCL_ISO
SDA_ISO
R8
4.7K R9 4.7K
ISO_GND
VDDHI_ISO
VDDHI_CT
DS2
WEJT81RC-O1
ISO_GND
C10
DNP
C12
DNP
C11
DNP
C13
DNP
GND
R1
330R
VDDHI_ISO
VDDHI_ISO_EXT
C8
100nF
C4
100nF
C7
100nF
C3
100nF C5 1uF
C9
1uF
GND
GND ISO_GND ISO_GND
ISO_GND ISO_GND
A
1
C
2
4
3
U1
ASSR-1218
R10
0R
LK1
2W-SLink Open
R3
47R
R4
47R
1
2
3
4
5
6
P4
6W-SIL-V
1
3
5
7
9
2
4
6
8
10
P3
BOX HEADER-10W-V
GND
ISO_GND
V_EXT
P1
ELx2.0y2.0_D1.0
P2
ELx2.0y2.0_D1.0
VDDHI_ISO_EXT
VDDHI_ISO
R2
2.2K
SDA_ISO
SCL_ISO
R5
10K R11 10K
RDY_ISO1
RDY_ISO2
R13
4.7K
R12
4.7K
closed: RDY active low
open: Disable pull-up 10k
for RDY active high
Top Silk: "DUT Pwr"
100mA load max
Use Coin cell to
guide distance of
Pads - then delete
coin cell from
schematic
Label: V+
Label: GND
Label:
GND
VDD
SDA
SCL
RD1
RD2
Do not place
Cut P4:pin3 down to the plastic
Cable that goes with kit -
12w IDC socket mod (key):
in top row close P4:pin3
ensure bottom row closed

IQ Switch®
ProxSense®Series
Copyright © Azoteq (Pty) Ltd 2013.
Page 4 of 4
All Rights Reserved.
Revision 1.14
January 2014
2.3 Power supply connections
The PCB has an optically isolated solid state relay (default a do-not-place
component) to offer synchronized switching of the device power with low voltage
drop-out and relatively high current drive possibilities. It is recommended to place a
0R resistor at R10 when currents larger than 100mA are expected. The
synchronized supply switching functionality will be lost by placing R10.
There are various ways of powering the PCB:
Wires soldered in at “V+” and “GND” (3.3V to 6.6V)
Through-hole coin cell holder at “V+” and “GND” (3.3V to 6.6V)
Power from DUT side –P4:pin2 (VDDHI_ISO, 3.0V to 5.5V)
The 3V3 regulator may be used to regulate the supply. Depending on the current
consumption, V_EXT should be chosen to comply with this LDO regulator.
Maximum dropout expected is 0.6V.
When powering the PCB, be sure to operate the chosen Azoteq IC within the
recommended limits. Some ICs are designed to operate in the 3.0V to 5.5V range
while others are designed for the 1.8V to 3.3V range.
The following patents relate to the device or usage of the device: US 6,249,089 B1, US 6,621,225 B2, US 6,650,066 B2, US 6,952,084
B2, US 6,984,900 B1, US 7,084,526 B2, US 7,084,531 B2, US 7,119,459 B2, US 7,265,494 B2, US 7,291,940 B2, US 7,329,970 B2,
US 7,336,037 B2, US 7,443,101 B2, US 7,466,040 B2, US 7,498,749 B2, US 7,528,508 B2, US 7,755,219 B2, US7,772,781, US
7,781,980 B2, EP 1 120 018 B1, EP 1 206 168 B1, EP 1 308 913 B1, EP 1 530 178 B1, ZL 99 8 14357.X, AUS 761094
IQ Switch®, ProxSense®, AirButton® and the IQ Logo are trademarks of Azoteq.
WWW.AZOTEQ.COM
ProxSenseSupp[email protected]m