Weinschel
C O R P O R A T I O N
Model 150T
Model 151T
Model 152T
Model 155T
SmartStep
TM
Programmable Attenuators
Greatly Simplifies OEM & System Design!
dc to 18.0
dc to 4.0
dc to 26.5
dc to 8.0
GHz
GHz
GHz
GHz
cells and a internal TTL interface. The attenuator elements
located in the attenuator cell are created by a thin-film
process which provides exceptional long-term stability, low
power and temperature coefficients. This series of step
attenuators uses a reed switching structure that provides
rapid switching together with low insertion loss.
BUILT-IN SMARTSTEP DRIVER CIRCUITRY:
These
SmartStep attenuators feature an internal microcontroller-
based driver that provides a TTL-level digital interface for
control of the attenuator relays. This card simplifies opera-
tion and interfacing requirements, while at the same time
providing for greatly enhanced flexibility over past designs.
User-selectable modes of operation include both parallel
and serial I
2
C bus. The parallel mode provides 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 variety of methods,
such as a TTL-level digital output port, or mechanical toggle
switches. The I
2
C mode 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 sys-
tem and sub-system applications. The SmartStep contains
non-volatile configuration memory that is used to hold a
wide variety of attenuator and driver-dependant parame-
ters, including serial number, attenuator cell dB values,
relay configurations, and switching requirements, which are
all accessable via the I
2
C interface. This frees the system
designer from such low-level details, allowing faster inte-
gration. In either operational mode, the microcontroller
enters an idle condition during periods of inactivity, turning
off all on-board clocks, reducing EMI concerns, and lower-
ing power consumption. On-board regulation for the digital
circuitry allows the SmartStep to operate from a single input
supply voltage.
Other features include:
To
Attenuator
Relays
Description
Weinschel Corporation introduces a new generation of intel-
ligent programmable step attenuators with a built-in TTL
interface (Figure 1). These models are designed to simplify
the control and integration of these devices into subsystem
and bench applications. These intelligent attenuators offer
the same long reliable operation with exceptional accuracy
and repeatability as with our other 150 Series
Programmable Attenuators. They provide programmable
adjustments of RF signal levels in precise steps of 1 dB, 5
dB, 10 dB, or with custom steps available. Each attenuator
consists of a cascaded assembly of switched attenuator
Non-Volatile
Configuration
Memory
TTL/CMOS
Compatible
Digital Interface
Single-Chip
Microcontroller
Relay
Drivers
+5 V
Regulator
+12 to
+15 V
Input
EMI
Filters
DC-DC
Converter
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Wide Variety of Frequency & Attenuation Ranges
Broadband Frequency Coverage
High Accuracy and Repeatability
Long Life, 5 Million Cycles Per Cell
Common 14 pin Interface Connector
Custom Attenuation Ranges
Figure 1. SmartStep Driver Circuitry
For additional information on the 150 Series, visit our website @ www.weinschel.com/programmable.htm
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2/14/00
5305 Spectrum Drive, Frederick, MD 21703-7362
!
TEL: 301-846-9222, 800-638-2048
!
Fax: 301-846-9116
web: www.weinschel.com
!
email: sales@weinschel.com
APITECH [ API Technologies Corp ]
