api technologies corp. 4205A Series Specification sheet

MANUAL IM672
Operation and Installation Manual Revision A
Operation and Installation Manual
Model 4205A Series
Digital Attenuator
This documentation may not be reproduced in any form, for
any purpose unless authorized in writing by Weinschel, a part
of API Technologies Corp.

MANUAL IM672
Table of Contents Page 2
Table of Contents
Table of Contents .......................................................................................................................................2
1. Safety Summary ....................................................................................................................................4
1.1 Definitions......................................................................................................................................4
1.2 Detailed Precautions .......................................................................................................................4
1.3 Electrostatic Discharge Sensitive (ESDS) ..........................................................................................4
2. General Information ...............................................................................................................................5
2.1 Purpose .........................................................................................................................................5
2.2 Equipment Overview.......................................................................................................................5
3. Specifications.........................................................................................................................................5
3.1 Electrical Specifications ...................................................................................................................5
3.2 Timing Specifications ......................................................................................................................5
3.3 DC Power Input..............................................................................................................................6
4. Installation and Operation ......................................................................................................................7
4.1 Mounting .......................................................................................................................................7
4.2 RF Connectors & Cable Installation ..................................................................................................7
4.3 Control Connectors .........................................................................................................................7
4.3.1 J1 –AUX mode digital IO (10-pin 0.1” Header) .........................................................................7
4.3.2 J2 –USB Mini-B ......................................................................................................................8
4.4 USB/AUX Mode Interface Selection ..................................................................................................8
4.5 AUX Interface Modes ......................................................................................................................8
4.5.1 AUX Modes .............................................................................................................................8
4.5.2 PIO Mode ...............................................................................................................................9
4.5.3 SPI Mode................................................................................................................................9
4.5.4 I2C Mode ...............................................................................................................................9
4.5.5 SPI and I2C Attenuation Data Format.....................................................................................10
4.5.6 UART Mode .......................................................................................................................... 12
4.6 AUX Application Modes .................................................................................................................12
4.6.1 PIOSW Mode ........................................................................................................................12
4.6.2 PULSE Mode ......................................................................................................................... 13
4.6.3 FADE Mode...........................................................................................................................13
4.6.4 USB Mode AUX pin usage ......................................................................................................14
4.6.5 USB......................................................................................................................................14
5. Command Operation ............................................................................................................................15
5.1 Command Reference .................................................................................................................... 16
5.2 Application Specific Commands .....................................................................................................17
ATTN...........................................................................................................................................17
ATTN? .........................................................................................................................................17
STEPSIZE.....................................................................................................................................17
STEPSIZE? ................................................................................................................................... 17
INCR ...........................................................................................................................................18
DECR...........................................................................................................................................18
FADE ...........................................................................................................................................18
FADE?.......................................................................................................................................... 18
5.3 488.2 Common Commands ...........................................................................................................19
*CLS............................................................................................................................................ 19

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*IDN?..........................................................................................................................................19
*OPC? .........................................................................................................................................19
*ESR?..........................................................................................................................................19
*RST ...........................................................................................................................................19
*TST?.......................................................................................................................................... 20
ERR? ...........................................................................................................................................20
5.4 Setup and Configuration Commands ..............................................................................................21
SET AUX ...................................................................................................................................... 21
SET USB ......................................................................................................................................21
SET ALIAS ...................................................................................................................................21
SET BAUDRATE ............................................................................................................................ 22
SET ATTN .................................................................................................................................... 22
SET I2CADDR............................................................................................................................... 22
SET I2CTRIG................................................................................................................................22
SET WPU ..................................................................................................................................... 22
SET PULSE...................................................................................................................................23
SET FADE .................................................................................................................................... 23
RUN AUX ..................................................................................................................................... 23
SHOW SET................................................................................................................................... 24
SHOW VERSION........................................................................................................................... 24
FACTORY PRESET ........................................................................................................................ 25
5.5 Misc. Commands .......................................................................................................................... 26
ALIAS?......................................................................................................................................... 26
ATTNIO .......................................................................................................................................26
CONSOLE.....................................................................................................................................26
CONSOLE? ................................................................................................................................... 26
DELAY .........................................................................................................................................27
REPEAT ....................................................................................................................................... 27
RFCONFIG?..................................................................................................................................27
RUN LOADER ............................................................................................................................... 27
5.6 USB Driver Installation..................................................................................................................29
5.7 awusbcdc.inf Installation File.........................................................................................................32
6. Factory Service and Repairs.................................................................................................................. 33
7. Contacting Weinschel ...........................................................................................................................34
8. Manufacturer Warranty ........................................................................................................................35
9. Revision History ................................................................................................................................... 36
10. Appendix .......................................................................................................................................37

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Specifications Page 4
1. Safety Summary
1.1 Definitions
The following definitions apply to WARNINGS, CAUTIONS, and NOTICES may found throughout this manual.
WARNING: An operating or maintenance procedure, practice, statement, condition, etc., which, if not strictly
observed, could result in injury and/or death of personnel. Do not proceed beyond a WARNING symbol until all
the indicated conditions have been fully understood and/or met.
CAUTION: An operating or maintenance procedure, practice, statement, condition, etc., which, if not strictly
observed, could result in damage or destruction of the equipment or long-term health hazards to personnel. Do
not proceed beyond a CAUTION symbol until all the indicated conditions have been fully understood and/or met.
NOTICE: An essential operating or maintenance procedure, condition, or statement that must be highlighted.
1.2 Detailed Precautions
The following WARNINGS, CAUTIONS and NOTES appear throughout the text of this manual and are repeated
here for emphasis.
All procedures and/or steps identified as must be followed exactly as written and according to
industry accepted ESDS device handling procedures. Failure to comply may result in ESD
damage.
1.3 Electrostatic Discharge Sensitive (ESDS)
The equipment documented in this manual contains certain Electrostatic Discharge Sensitive (ESDS) components
or parts. Therefore, certain procedures/steps are identified by the use of the symbol . This symbol is used in
two ways:
When the ESDS symbol is placed between a paragraph and title, that paragraph, including all
subparagraphs, is considered ESDS device handling procedure.
When the ESDS symbol is placed between a procedure/step number and the text, all of that procedure is
considered an ESDS device handling procedure.
All procedures and/or steps identified as ESDS must be followed exactly as written and according to accepted
ESDS device handling procedures. Failure to comply may result in ESDS damage

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Specifications Page 5
2. General Information
2.1 Purpose
This manual contains setup and operation information for the Weinschel Model 4205A Series, MMIC Digital
Attenuators. This manual is to be used in conjunction with the operation and installation of the Model 4205A
Series. The manual also provides a description of the assembly and general maintenance procedures.
2.2 Equipment Overview
The 4205A series digital attenuators provide for control either via USB or a variety of digital interfaces via the
AUX mode connector, including parallel input (PIO), I2C, SPI, or a logic-level UART interface. AUX mode selection
is done via USB command and can be changed via the user.
3. Specifications
3.1 Electrical Specifications
Parameter
Min
Typ
Max
Comments
DC Power (AUX pin 9)
VDC Supply Voltage
3.3V
5V
16V
Supply voltage 3.5V MIN for full spec
compliance
IDC Supply Current (VDC=5V)
15mA
25mA
AUX IO
Note: All AUX IO have weak pullups enabled by default
VIH Input High Voltage
VDC= 3.3V to 4.5V
VDC= 4.5V to 16V
2.0V
VDC+0.3
2.0V
5.0V
VIL Input Low Voltage
VDC= 3.3V to 4.5V
VDC= 4.5V to 16V
-0.3V
0.15VDC
-0.3V
0.8V
VOH Output High Voltage
2.6V
ILOAD = 3mA
VOL Output Low Voltage
0.6V
ILOAD = 3mA
IPU Pullup Current
25uA
130uA
300uA
User selectable
USB
USB Supply Voltage (VBUS)
4.4V
5.25V
D+/D- Input Voltage
3.6V
3.2 Timing Specifications
Parameter
Min
Typ
Max
Comments
General
RF switching speed
400ns
Powerup time
50ms
DC power to first command
Attenuation update rate
200KHz
Command processing time
2ms
USB mode
PIO mode
PIO input change to RF change
3us
5us
PIOSW input change to RF
1us
Single line input
SPI mode
SCLK clock frequency
10MHz
SSN setup/hold time
100ns
SSN falling/rising edge to SCLK
SDI data setup time
25ns
SDI to SCLK rising edge

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Specifications Page 6
Parameter
Min
Typ
Max
Comments
I2C mode
SCL clock frequency
400KHz
RESETN width
10us
RESETN low pulse width (optional)
TRIG
1us
TRIG input, rising/falling edge (optional)
UART mode
Baudrate
9600
115K
3.3 DC Power Input
The 4205A can be powered from either the USB VBUS (5V) or the AUX VDC input. While USB operates at a
nominal 4.75V-5.25V range, the AUX VDC supply input can accept a wider range of voltage, from 3.3V-16VDC. If
both AUX power and USB VBUS are present then the 4205A will be powered from whichever provides the higher
voltage. For AUX VDC voltages < 5V the input logic signals are limited to the VDC supply voltage. Otherwise,
input logic signals are limited to a max voltage of 5V.

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Installation and Operation Page 7
4. Installation and Operation
4.1 Mounting
Each Digital Attenuator is supplied with 12 mounting holes (4-40 UNC-2B x 4.1 [0.16 Deep]) located on the front,
back, top and bottom end of the attenuator. Refer to the appropriate Weinschel Specification/ICD drawing for the
mounting hole locations.
Figure 1. Connector Locations
4.2 RF Connectors & Cable Installation
The Model 4205A series contains two SMA female connectors labeled J1 and J2 that mate nondestructively with
SMA male connectors per MIL-STD-39012. Weinschel recommends a torque value of 7 to 8 inch pounds when
connecting any cable to the attenuator's RF connectors.
4.3 Control Connectors
4.3.1 J1 –AUX mode digital IO (10-pin 0.1” Header)
A variety of control interfaces can be used with the AUX Connector. Options include Parallel IO, I2C, SPI, UART,
and USB. The SET AUX command allows the user to select the control interface for the AUX Connector. The table
below describes the pinouts for the various control modes.
When applying a signal to the RF connectors, DO NOT exceed the maximum allowable power
level specifications of the unit.
Do not over torque the SMA connectors more than 10 inch pounds. Damage may occur.

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AUX Application Modes Page 8
PIN
SIGNAL
PIO
I2C
SPI
UART
USB
4205A-31.5
4205A-63.5
4205A-95.5*
4205A-127*
1
D0
0.25dB
0.25dB
0.5dB
0.5dB
A0
2
D1
0.5dB
0.5dB
1dB
1dB
A1
3
D2
1dB
1dB
2dB
2dB
A2
RXD
4
D3
2dB
2dB
4dB
4dB
A3
TXD
5
D4
4dB
4dB
8dB
8dB
TRIG
SSN
6
D5
8dB
8dB
16dB
16dB
RESETN
SCLK
7
D6
16dB
16dB
32dB
32dB
SCL
SDI
8
D7
--
32dB
32dB
64dB
SDA
BOOTN
9
VDC
VDC
VDC
VDC
VDC
VDC
VDC
VDC
10
GND
GND
GND
GND
GND
GND
GND
GND
GND
*0.25dB accessible in serial or USB modes
4.3.2 J2 –USB Mini-B
The table below describes the pinout of the USB connector.
PIN
SIGNAL
DESCRIPTION
1
VBUS
+5V
2
D-
Data-
3
D+
Data+
4
ID
unused
5
GND
Ground
4.4 USB/AUX Mode Interface Selection
The main operating mode of the 4205A is determined from the DC Power input. At power on the USB connector
VBUS pin is examined, and if detected then the unit will operate in USB mode. Otherwise the 4205A will operate
in one of the digital AUX modes powered via the AUX VDC power input. It is allowable to have both cables
connected at the same time.
If an AUX mode is currently active the unit will detect a USB connect event and switch over to USB mode
automatically.
Typically you would return to AUX mode by disconnecting the USB cable (or removing USB power). The USB
command RUN AUX also allows switching from USB mode to an AUX mode via command, and does not require
the AUX connector VDC power to be present. This is usefully in certain AUX application modes (see PULSE and
FADE modes).
4.5 AUX Interface Modes
4.5.1 AUX Modes
There are four user-selectable digital interface AUX modes: PIO, I2C, SPI, and UART. In addition there are three
AUX application modes (PIOSW, PULSE, and FADE) that allow the generation of RF patterns when operating
stand-alone. The AUX mode selection is done via USB command (see SET AUX) and is stored in non-volatile
memory (NVM) so that changes to the mode will be automatically applied at startup. The AUX digital interface
pins vary in function depending on the selected mode. Each pin can have a software programmable weak pullup
assigned, which is enabled by default for all pins (see SET WPU). The weak pullup will provide a logic high to the
pin if left unconnected.

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AUX Application Modes Page 9
4.5.2 PIO Mode
In PIO mode there are up to eight parallel digital input signals, D0-D7. Each input represents a dB value setting,
with a logic low input = 0dB setting and a logic high = dB value for each control input as shown in the PIO
column of the J1 AUX mode table.
4.5.3 SPI Mode
SPI mode is a serial interface that operates as a 16-bit serial-in shift register and latch comprised of three signals:
SSN low-active chip select, SCLK serial shift clock, and SDI serial data in. Data present on the SDI input is clocked
into the shift register on the rising edge of SCLK. Data is comprised of either a single 8-bit value for the 31.5dB
and 63.5dB models, or 16-bits for the 95.5dB and 127dB models which provides access to the 9th 0.25dB bit.
Serial data is clocked in MSB first to LSB and must be in multiples of 8-bits. SSN must be asserted low before
sending data to the attenuator, allowing multiple attenuators to be controlled via the same SCLK and SDI signals.
Attenuation changes are updated on the rising edge of SSN after all data bits have been clocked in.
Note that all models will accept 16-bits of programming data. The data should be left-justified in the 16-bit word
so that the MSB is the first bit sent and any unused bits should be set to 0. The first byte represents the D7-D0
values shown in the PIO mode table. The first bit of the second byte ('D-1') represents the 0.25dB value for the
4205A-95.5 and 4205A-127. Refer to the Attenuation Data Format section for examples on formatting 16-bit data.
D7 D6 D5 D4 D3 D2 D1 D0
SSN
SCLK
SDI D-1 D-2 0 0 0 0 0 0
MSB LSB OPTIONAL 2ND BYTE
(0.25dB FOR 4205A-95.5)
4.5.4 I2C Mode
I2C mode is a serial interface that uses two lines: SCL serial clock and SDA serial data, along with the optional
controls RESETN, TRIG, and address bits A3-A0. Both the SCL and SDA connections are bidirectional open-drain
lines, each requiring pull-up resistors to the logic supply voltage (5V max).
I2C messages consist of a device address byte, register select byte, and one or more data bytes depending on
the register. The Register address will automatically increment after each byte transferred. Messages are framed
using the standard I2C START, STOP, and ACK conditions. The I2C master should support clock stretching as the
4205A will hold the SCL clock low during the byte ACK phase until the data is accepted by the 4205A.
START
DEV ADDR
REG ADDR
DATA
<DATA>
STOP
The 4205A is a slave I2C device that supports 7-bit slave addressing. The slave address can be set via hardware
address pins A3-A0 on the AUX connector or via USB command (see SET I2CADDR). Using the hardware address
pins allows for up to 16 attenuators to share the same bus. In this mode the three upper bits of the address byte
are fixed at 0b010. The I2C R/W bit is the LSB of the address byte, providing for device addresses 0b0100000x –
0b0101111x (0x40-0x5E).
I2C Device Address
7
6
5
4
3
2
1
0
0
1
0
A3
A2
A1
A0
R/W
010 : fixed bits
A3-A0 : addr bits
R/W bit : WR=0, RD=1

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AUX Application Modes Page 10
A device address can also be assigned using the USB SET I2CADDR command which allows the use of all 7 D7-D1
address bits, with the exception of the reserved address 0. A software assigned address overrides the hardware
A3-A0 pins and connections to these pins are ignored. When specifying a software address always use the full 8-
bit byte value, with bit 0 set to 0 (it will be ignored as this is the I2C R/W bit). Setting the I2CADDR to 0 will
remove any software assigned address and revert back to hardware addressing mode.
I2C mode provides two optional control inputs: RESETN and TRIG. RESETN is a low-active signal that will reset
and reinitialize the attenuator. The TRIG signal allows attenuation changes to be performed on the TRIG input
becoming asserted instead of changing immediately when the I2C command is sent, and can be programmed to
be active-high or active-low (see I2CTRIG command). This can be used to synchronize multiple attenuators.
Register 1 –Echo Test Register
This is a general scratchpad register. Any 8-bit value written to this register can be read back and used to check
communications.
Register 2 –ATTN_LB Low Byte Register
The ATTN_LB register is the lower byte of attenuation data used for attenuators with more than 8-bits of
programming data (4205A-95.5 and 4205A-127). This register should be written to prior to writing the ATTN_HB
register.
Register 3 –ATTN_HB High Byte Register
The ATTN_HB register is used to set the upper byte of attenuation data for units with > 8-bits, or the single 8-bit
programming data for units that require only a single byte. The attenuator setting will be changed when this
register is written unless external triggering has been enabled.
4.5.5 SPI and I2C Attenuation Data Format
The data programming format is the same for both I2C and SPI modes; either a single 8-bit value or a 16-bit
word value. Either method may be used as long as the data properly formatted. 16-bit word data must be left-
justified and sent as two 8-bit bytes. In SPI mode 16-bit data should be written high-byte then low-byte, and the
value will be loaded on the rising edge of the SSN signal. In I2C mode the ATTN_LB low-byte register should be
written prior to setting the ATTN_HB register since in this mode accessing the high-byte register loads the value
into the attenuator.
The 4205A-31.5 and 4205A-63.5 models use a single byte to represent the D0-D7 programming bits. For these
units a single byte write to the ATTN_HB register is all that is required. The 4205A-95.5 and 4205A-127 models
require 9-bits of data to access the 0.25dB bit, so two bytes must be written if control of the 0.25dB bit is
desired.
Example 1: 4205A-31.5 using hardware addr pins A3-A0 set to 0100
Desired attenuation: 10.25dB
Compute the device address by combining the fixed upper portion, the addr pin setting, and the R/W bit=0
(write):
DEV ADDR = (0b010 << 5) + (0b0100 << 1) + 0 = 0b01001000 = 72 = 0x48
Compute the programming value. Each bit represents 0.25dB, so setting = INT((dB * 100)/25), or simply multiply
the dB value by 4 and use the integer result:
VAL = 10.25dB * 4 = 41 = 0x29 = 0b00101001