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Description
The ISL3331EVAL1Z evaluation board is RoHS compliant,
and provides a quick and easy method for evaluating this
Dual Protocol IC. The evaluation board also accommodates
the ISL3333; see the "ISL3333EVAL1Z User's Manual" for
details.
This board was designed to allow the user to evaluate all the
features available on the ISL3330 and ISL3331 products.
The ISL3331 is the full featured version (see "Key Features"
in next section), where the QFN package's increased pin
count gives the user access to functionality not available on
the pin limited ISL3330. The same die is used in both
products, so other than minor package effects, evaluating
the QFN packaged ISL3331 is a reasonable substitute for
evaluating the ISL3330.
By changing jumper positions the user can quickly set the
board to evaluate any of the ISL3331's many modes and
features, and the input states can also be set via jumpers.
Refer to the ISL3331 data sheet for complete details
regarding the functions and features of this device. These
dual protocol ICs feature many modes, so studying the
device's truth-table along with its operating circuits and
detailed description is the best way to gain an understanding
of how the part works.
Key Features
• QFN Version Demonstrates All Enhanced Features:
- Logic Supply Pin (V
)
L
- Three RS-485 Speed Options -
115kbps/460kbps/20Mbps
- Active Low RS-485 Rx Enable for Simple Direction
Control
• Quick Configuration Using Jumpers
• State of All Inputs Can be Set by Jumper Positions
• No Bus Termination Resistors; Allows RS-232 or RS-485
Evaluation
• Simple Operation Requires Only One, 3.3V, Power Supply
Important Notes
To facilitate locating jumpers on this board, Figure 3 is a
jumper locator and, in this Application Note, the
a jumper mention corresponds to the red jumper number on
the locator. See the "Jumper Definitions" section for a
description of the function of each jumper.
The base board is used to evaluate both the ISL3333
(2-port) and ISL3331 (1-port) products, so the jumper and
connector names reflect the functionality of both products.
Application Note
(#)
following
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
ISL3331EVAL1Z User's Manual
June 4, 2009
Due to space limitations some jumper labels are
abbreviated, but the corresponding BNC connector has the
full label.
In most cases, a name that applies to both products contains
no parenthesis (e.g., "B1"), a name that applies to only the
ISL3333 is followed by "(NC)" (e.g., "B2 (NC)"), and a name
that applies to only the ISL3331 is preceded by "NC" and/or
has the name in parenthesis (e.g., "NC (RXEN)" or
"(RXEN)").
It is important to note that the ISL333x don't follow the
RS-485 convention whereby the inverting I/O is labeled
"B/Z", and the noninverting I/O is "A/Y". Thus, the ISL3330
and ISL3331 A/Y (B/Z) pins connect to the B/Z (A/Y) pins of
generic RS-485/422 ICs.
Input signals that are likely to be driven by a generator
connect to a BNC connector, and there is a 50Ω termination
resistor to GND when the jumper is in the "LOW" position.
Default Configuration
As delivered (see "Functional Diagram (Default
Configuration)" on page 2), the evaluation board is
configured for powered-up (not SHDN) RS-485 mode, driver
enabled, via DEN, and set for high speed (20Mbps)
operation, driver input (DY) low, Rx enabled via the RXEN
line, Rx inputs floating, and V
this configuration, the jumpers are installed as follows
(unlisted jumpers are not installed, and
jumper number on the Figure 3 jumper locator):
A2 (485/232)
(7)
= VH; (DEN)
RXEN1
(10)
= VH; (RXEN)
(11)
DY1(DZ/SLEW)
(13)
= VH; DZ1/DE1(DY)
RXBIAS-V
(15)
= installed; V
CC
V
-VHIGH
(17)
= installed.
L
Note that there are no differential termination resistors on
either the Rx inputs nor the Tx outputs. If these resistors are
desired, they can be added at positions R
respectively.
|
Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2009. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
AN1471.0
shorted to V
. To achieve
L
CC
(#)
indicates the
(8)
= VH; SPB
(9)
= VH;
= VH; (ON)
(12)
= VH;
(14)
= LOW;
-V
(16)
= installed;
CC
L
and R
,
9
7

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Summary of Contents for Intersil ISL3331EVAL1Z

  • Page 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2009. All Rights Reserved All other trademarks mentioned are the property of their respective owners.
  • Page 2 Application Note 1471 Functional Diagram points; the “VCC-VL” (16) jumper shorts this jack to V , so (Default Configuration) remove this jumper if supplying a voltage other than V (16) (17) VHIGH (V +3.3V Getting Started 0.1µF Connect a 3.3V, 500mA minimum, power supply to the V and GND banana jacks.
  • Page 3: Internal Loopback

    Application Note 1471 now sets the Rx differential input voltage, via “A1”, and Return jumpers “(ON)”, “(DEN)”, and “(RXEN)” to the “VH” varying this supply switches the Rx output state. For position. example, with the RXBIAS supply = 0V (V = 0V) the Basic RS-485 AC Evaluation output is high, and increasing RXBIAS to at least +200mV...
  • Page 4 Application Note 1471 DRIVER TESTS “A2 (485/232)” to the “LOW” position. If RS-485 termination resistors (“R ” or “R ”) were added, ensure that There are no driver loads on this board, so if loading is they have been removed. Note that the RS-232 data rate is desired a differential load resistor, and/or differential load fixed at 400kbps, so the “SPB”...
  • Page 5 Application Note 1471 the Rx input voltages, in case the user wants to evaluate the SINGLE TX AND SINGLE TRANSCEIVER MODES Rx switching points. RS-232 mode also offers the options of selecting a single Tx mode, or a single Tx/Rx pair mode. To evaluate the single Tx To disable the Rx outputs via the active high RXEN pin, mode, set the “(ON)”...
  • Page 6 Application Note 1471 which connects an Rx input, including its 5kΩ pull-down, to TABLE 2. V AND V vs V FOR V = 3.3V the driver output. To measure the Tx output enable/disable times to/from a high output state, start with the previous jumper 0.85 0.26 configuration and move the “(DEN)”...
  • Page 7 Application Note 1471 J-DZ1/DE1(DY) (14) - “LOW” sets the Y Tx input low in VL-VHIGH (17) - Connects V to the “VHIGH” jack; if driving RS-232 or RS-485 Modes; “VH” sets the Y Tx input high in VHIGH from a voltage other than V , remove this jumper.
  • Page 8 FIGURE 3. JUMPER LOCATOR DIAGRAM Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding.
  • Page 9 Application Note 1471 VHIGH RXBIAS RXBIAS VHIGH RXBIAS VLOAD RXBIAS RB1(RA) P-GND VLOAD J-B1 VLOAD VLOAD RA1(RB) J-A1 VHIGH TP18 P-VCC J-DZ1/DE1 (DY) VL-VHIGH RXBIAS-VCC VHIGH ON/OFF (NC) J-ON/OFF (NC) VCC-VL TP16 NC NC C1- C1+ C2+ C2- V VLOAD VHIGH VHIGH DY2 (NC)