5305 Spectrum Drive, Frederick, MD 21703-7362 TEL: 301-846-9222, 800-638-2048 Fax: 301-846-9116
web: www.aeroflex.com/weinschel email: weinschel-sales@aeroflex.com
98
Revision Date: 3/4/09
Programmable Attenuators
Model 3250 & 3250T dc to 1.0 GHz
Programmable Attenuators 1 Watt
with optional TTL Interface 75 Ω
T Series for use with Weinschel 8210A Controller
Features
oCost Effective design for Wireless/Cellular
Applications.
oOptional Built-in Interface
oCustom Configurations including bus controlled
attenuator subsystems
Specifications
NOMINAL IMPEDANCE: 75 Ω
FREQUENCY RANGE: dc to 1.0 GHz:
CELL CONFIGURATIONS:
Model NO. Attenuation Cell
Number Cells Range/Steps Increments
(dB) (dB)
3250-63 6 63/1 1, 2, 4, 8, 16, 32
INCREMENTAL ATTENUATION ACCURACY:
Frequency Accuracy
Range (GHz)
dc - 0.5 + 0.3 dB or 2.0%
0.5 - 1.0 + 0.4 dB or 2.0%
MAXIMUM SWR:
Frequency Range (GHz) SWR
dc - 0.5 1.60
0.5 - 1.0 1.40
Frequency Range (GHz) Loss (dB)
dc - 0.5 2.25
0.5 - 1.0 5.00
RATED SWITCH LIFE: 5 million operations per cell (typ)
SWITCHING TIME: 8 msec. maximum @ nominal rated
voltage.
CYCLING RATE: 5 Hz maximum
OPERATING VOLTAGE: +11V to +16V
+12V to +17V (TTL opt -1)
OPERATING CURRENT: 16 mA maximum per cell
TEMPERATURE RANGE (Operating): -40 to +70°C
POWER RATING: 1 watt average, 50 watts peak (5 μsec
pulse width; 1% duty cycle)
CONNECTORS: BNC female connectors per MIL-STD-
348 interface dimensions - mate nondestructively with
MIL-C-39012 connectors.
CONTROL TERMINALS: 0.040 inch. (1 mm) diameter
solderable leads
CONSTRUCTION:
Housing: Aluminum
Connectors: Nickel plated brass body and
beryllium copper contacts.
WEIGHT: 3250 140 g (4.5 oz)
3250T 189 g (4.9 oz)
MAXIMUM CHARACTERISTIC ZERO LOSS (dB):
ACCESSORIES
Programmable Attenuator/Switch Controller: The Model
8210A Programmable Attenuator/Switch Controller provides
a flexible, low cost solution for the operation of programma-
ble step attenuators and other electromechanical devices
under computer control. Designed to interface to Aeroflex /
Weinschel's intelligent programmable attenuators, the
8210A represents a new concept in device control applica-
tions for bench test and subsystem designs. The 8210A
provides a high-level interface from various industry stan-
dard communications interfaces, including IEEE-488 and
RS232/RS422/RS485, to the programmable attenuator's
serial Driver Interface Bus.
99
5305 Spectrum Drive, Frederick, MD 21703-7362 TEL: 301-846-9222, 800-638-2048 Fax: 301-846-9116
web: www.aeroflex.com/weinschel email: weinschel-sales@aeroflex.com Revision Date: 3/4/09
Programmable Attenuators
MODEL NUMBER DESCRIPTION:
Example:
3250* - XX - X
*Add T to Basic Model Number when ordering Digital Control
Circuitry.
Basic
Model
Number
Attenuation
Value (dB)
TTL Option
(Add -1)
Example: 3250-63-1
Figure 1. Built-In Driver Circuitry
CONTROL CONFIGURATION:
Standard Unit: One terminal is connected to case ground
and the remaining terminals are provided for activation of
individual cells. Attenuation is fail-safe to "0" setting in the
absence of a control voltage. Application of a voltage (+) to
a particular cell causes it to switch to the attenuate position.
Units with TTL Option: Units with this options are supplied
with a very low profile connectorized TTL interface board
mounted directly to the control terminals. This TTL interface
option is available with a 10 pin ribbon cable connector and
is supplied with a mating connector. Refer to Physical
Dimensions for mating connector pin/wiring details. Two
wires are specified for supply voltage and ground. The
remaining wires will accept TTL control signals to activate or
de-activate a particular attenuation cell. A TTL high will
energize a cell to the high attenuation state, whereas a TTL
low will maintain a cell in its zero attenuation state.
To order 3250 Series Attenuators with this option add -1 to
basic model number for ribbon cable connector. Example:
Model 3250-63 with a TTL interface would be 3250-63-1.
Note: Control is non-latching and requires a continuous
control signal for the period of time in which attenuation is
required.
TTL DRIVER SPECIFICATIONS:
INTERFACE CONNECTOR: Option -1: 10 pin .025 square
post header on .1 center, mates with Amp connector
746285-1 or equivalent
INPUT VOLTAGE: VIN High= +2.0V minimum
+5.0V typical
Vcc maximum
VIN Low = 0 minimum
0.8 maximum
INPUT CURRENT: IIN (VIN=2.4 V) = 55 μA
IIN (VIN=3.85 V) = 280 μA
SUPPLY CURRENT: ICC=25 mA maximum per cell
SUPPLY VOLTAGE: VCC=+12.0 to +15 V
TEMPERATURE RANGE (Operating): -40 to +70 °C
Units with driver Circuitry (Figure 1): Model 3250T-63
features an internal microcontroller-based driver that pro-
vides a TTL-level digital interface for control of the
attenuator relays.
This card simplifies operation and interfacing requirements,
while at the same time providing for greatly enhanced flexi-
bility over past designs. User-selectable modes of operation
include both parallel and serial bus. The parallel mode pro-
vides a simple, one-bit per relay on/off control with internal
pullups for use primarily in single attenuator applications.
This mode allows the attenuator to be controlled via a vari-
ety of methods, such as a TTL-level digital output port, or
mechanical toggle switches. The built-in driver bus provides
a two-wire serial bus structure and protocol for connecting a
number of devices to a single host control interface, suitable
for use in larger system and sub-system applications. This
programmable attenuator contains non-volatile configura-
tion memory that is used to hold a wide variety of attenuator
Non-Volatile
Configuration
Memory
Single-Chip
Microcontroller
Relay
Drivers
TTL/CMOS
Compatible
Digital Interface
+12 to
+15 V
Input
To
Attenuator
Relays
EMI
Filters
+5 V
Regulator
and driver-dependent parameters, including serial number,
attenuator cell dB values, relay configurations, and switch-
ing requirements, which are all accessible via the digital
interface.
Digital Driver Interface Specifications:
Input Supply Voltage: +12.0 to +15.0V
Control Signals: TTL/CMOS compatible
Interface Modes: parallel/ I2C serial
DC Characteristics (at 25°C):
Digital Interface:
Parameter Specification
VILLow Level input: -0.5 min, 0.8V max
VIH High Level input: 2.0 min, 5.25V max
IPU Pullup Current 50 μA min, 400 μA max
Power Supply:
VIN Supply Voltage: +12.0 to +15.0V
IIN Supply current: 25 mA
ICELL Supply Current: 150 mA (per cell, switching)
TEMPERATURE: -20° to +70°C operating
-55° to +85°C nonoperating
INTERFACE CONNECTOR: 14 pin .025 square post
header on .1 center. Mates with Amp connector 746285-2 or
equivalent (one mating connector included with each unit).
5305 Spectrum Drive, Frederick, MD 21703-7362 TEL: 301-846-9222, 800-638-2048 Fax: 301-846-9116
web: www.aeroflex.com/weinschel email: weinschel-sales@aeroflex.com
100
Revision Date: 3/4/09
Programmable Attenuators
BNC CONNECTORS
BOTH ENDS
Aeroflex / Weinschel
PHYSICAL DIMENSIONS:
Model 3250:
Model 3250 w/TTL Option -1:
TTL Conn 3250-63-1
PIN No. (J3) dB (Cell)
1NC
2NC
332
41
52
64
78
816
9 COM
10 +Vcc
NC = Not Connected
Control Connector J3 Pin Locations:
NOTE: All dimensions are given in mm (inches) and are maximum, unless otherwise specified.
101
5305 Spectrum Drive, Frederick, MD 21703-7362 TEL: 301-846-9222, 800-638-2048 Fax: 301-846-9116
web: www.aeroflex.com/weinschel email: weinschel-sales@aeroflex.com Revision Date: 3/4/09
Programmable Attenuators
PHYSICAL DIMENSIONS:
Model 3250T:
NOTE: All dimensions are given in mm (inches) and are maximum, unless otherwise specified.
