General Description
The MAX3161E evaluation kit (EV kit) circuit demon-
strates the RS-232/RS-485/RS-422 multiprotocol trans-
ceivers using the MAX3161E IC. The circuit can be
configured to operate as a dual transceiver in RS-232
mode or as a single transceiver in RS-485/RS-422
mode. The MAX3161E RS-232 data rates can reach
1Mbps, while RS-485/RS-422 data rates can reach
10Mbps. The configurable slew-rate limiting feature
reduces data rates for either protocol to achieve
reduced EMI.
In RS-485/RS-422 mode, the EV kit demonstrates full-
duplex or half-duplex communication. The MAX3161E
drivers feature short-circuit and thermal protection as
well as fail-safe circuitry for open, shorted, or uncon-
nected RS-485/RS-422 receiver inputs. The MAX3161E
EV kit operates from a single 3V to 5.5VDC supply
capable of providing 100mA.
Features
3V to 5.5V Single-Supply Operation
Configurable Multiprotocol Operation:
2Tx/2Rx RS-232 Transceivers
Single RS-485/RS-422 Transceiver
10Mbps RS-485/RS-422 Data Rates and 1Mbps
RS-232 Data Rates
Configurable RS-232/RS-485 Transmitter Slew
Rates
Configurable Full-Duplex/Half-Duplex RS-485/
RS-422 Operation
Fully Assembled and Tested
Evaluates: MAX3161E
MAX3161E Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-0803; Rev 0; 4/07
Component List
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Ordering Information
Component Supplier
PART TEMP RANGE IC PACKAGE
MAX3161EEVKIT+ 0°C to +70°C* 24 SSOP
SUPPLIER PHONE WEBSITE
Murata Mfg. Co., Ltd. 770-436-1300 www.murata.com
DESIGNATION QTY PART DESCRIPTION
C1, C2, C3, C5 4
0.47µF ±10%, 10V X5R ceramic
capacitors (0603)
Murata GRM188R61A474K
C4 1
0.1µF ±10%, 10V X5R ceramic
capacitor (0402)
Murata GRM155R61A104K
C6 1
10µF ±10%, 10V X5R ceramic
capacitor (0805)
Murata GRM21BR61A106K
J1 1 DB9 male right-angle connector
J2 1 5-position terminal block (5mm)
JU1–JU4, JU9,
JU10 6 2-pin headers
JU5–JU8 4 3-pin headers
R1–R4 4 100kΩ ±5% resistors (0603)
R5, R6 2 120Ω ±1% resistors (1206)
U1 1 MAX3161EEAG+ (24-pin SSOP)
— 10 Shunts (JU1–JU10)
— 1 PCB: MAX3161E Evaluation Kit+
+
Denotes a lead-free and RoHS-compliant EV kit.
*
This limited temperature range applies to the EV kit PCB only.
The MAX3161E IC temperature range is -40°C to +85°C.
Note: Indicate that you are using the MAX3161E when contacting
this component supplier.
Evaluates: MAX3161E
MAX3161E Evaluation Kit
2 _______________________________________________________________________________________
Quick Start
Recommended Equipment
• 3.3V, 0.5A DC power supply
• Logic function generator
• Oscilloscope
Procedure
The MAX3161E EV kit is fully assembled and tested.
Follow the steps below to verify board operation.
Caution: Do not turn on the power supply until all
connections are completed.
1) Verify that shunts are installed across pins 1-2 of
jumpers JU5–JU8 (data communications equipment
(DCE) mode).
2) Verify that a shunt is installed on jumpers JU3
(RS-232 mode) and JU4 (full-duplex mode).
3) Verify that shunts are not installed on jumpers JU1
(MAX3161E enabled), JU2 (fast mode), and JU9 and
JU10 (RS-485/RS-422 differential I/O not terminated).
4) Set the DC power-supply output to 3.3V and disable
the output.
5) Set the logic function generator to a 3.3VP-P,
500kHz, 1.65VDC offset square wave and disable
the output. Terminate the function generator as
needed.
6) Connect the DC power-supply positive output to the
VCC pad on the EV kit.
7) Connect the supply ground to the GND pad next to
VCC on the EV kit.
8) Connect the logic function generator output to the
DI/T1IN PCB pad and connect ground to the GND
PCB pad.
9) Enable the power-supply output and then the func-
tion generator output.
10) Use the oscilloscope to measure the transmitter out-
put T1OUT at pin 3 of jumper JU5. Verify that the
waveform is a 500kHz square wave and is approxi-
mately ±5VP-P.
Detailed Description
The MAX3161E EV kit demonstrates the MAX3161E
RS-232/RS-485/RS-422 multiprotocol transceiver IC.
The EV kit operates from a 3V to 5.5VDC source capa-
ble of supplying 100mA.
The EV kit features jumpers to configure the communi-
cation protocol to RS-232 operation or RS-485/RS-422
operation. In RS-232 mode operation, the MAX3161E
communicates at data rates up to 1Mbps. In RS-485/
RS-422 mode operation, the differential driver and
receiver operate in full-duplex or half-duplex mode and
communicate at data rates up to 10Mbps. The
MAX3161E receiver represents a 1/8 unit load on the
RS-485/RS-422 bus. Resistors R5 and R6 provide a
configurable termination for the RS-485/RS-422 bus.
Terminal block J2 eases connection to the RS-485/RS-
422 bus. The DB9 connector J1 is available for interfac-
ing with an RS-232 serial line. See Table 5 and Figures
1, 2, and 3 for the respective signal pins or pads.
Jumper Selection
The MAX3161E EV kit utilizes several jumpers to reconfig-
ure circuit features and functionality: IC enable, slew-rate
selection, communication-protocol selection, full-duplex/
half-duplex communication, DTE/DCE connections, and
RS-485/RS-422 differential I/O termination.
Enable
The MAX3161E EV kit features jumper JU1 to enable the
MAX3161E or place the IC in shutdown mode, thus
reducing quiescent current. A SHDN PCB pad is also pro-
vided for the shutdown signal to interface with an external
controller. See Table 1 for configuring jumper JU1.
Slew-Rate Selection
Jumper JU2 on the EV kit configures the MAX3161E
communication slew-rate mode. Slew-rate limited-mode
operation minimizes EMI radiation, while fast-mode
operation optimizes maximum data rates for either pro-
tocol. See Table 2 for configuring jumper JU2 and refer
to the MAX3161E IC data sheet for more information on
slew-rate configuration.
Table 2. Slew Rate (Jumper JU2)
SHUNT
POSITION FAST PIN EV KIT FUNCTION
Installed Connected to
GND
Slew-rate limited mode.
RS-232/RS-485/RS-422
250kbps maximum data
rate
Not installed
Connected to
VCC through
resistor R2
Fast mode. RS-232 1Mbps
maximum data rate;
RS-485/RS-422 10Mbps
maximum data rate
Table 1. MAX3161E Enable (Jumper JU1)
SHUNT
POSITION SHDN PIN EV KIT FUNCTION
Installed Connected to GND MAX3161E shutdown
Not installed Connected to VCC
through resistor R1 MAX3161E enabled
RS-232/RS-485/RS-422 Protocol Selection
EV kit jumper JU3 sets the communication protocol to
either RS-232 or RS-485/RS-422. See Table 3 for
configuring jumper JU3. For additional protocol-config-
uration information, refer to the
Functional Diagrams
section of the MAX3161E IC data sheet.
RS-485/RS-422 Communication Mode
EV kit jumper JU4 configures the MAX3161E IC’s RS-485/
RS-422 communication mode to full duplex or half
duplex. To receive RS-485 data, disable the RS-485
outputs by driving the DE485/T2IN PCB pad low. See
Table 4 to configure jumper JU4 for the desired mode
of communication.
Header J2 is labeled for full-duplex RS-485/RS-422
communication; however, the driver outputs (Y and Z)
are multiplexed with the receiver inputs (A and B) dur-
ing half-duplex communication. Refer to the
Half-
Duplex RS-485/RS-422 Operation
and
MAX3161E
Functional Diagram
sections of the MAX3161E IC data
sheet for further details.
DTE/DCE Connections
The EV kit features jumpers JU5, JU6, JU7, and JU8 to
configure the RS-232 connector J1 as a data terminal
equipment (DTE) or as a data communications equip-
ment (DCE) connector. See Table 5 for configuring the
respective jumpers for DTE or DCE connection mode.
RS-485/RS-422 Termination
EV kit jumpers JU9 and JU10 configure the RS-485/RS-
422 termination. JU9 sets the input termination with
resistor R6. JU10 sets the output termination with resistor
R5. See Table 6 for the RS-485/RS-422 termination
options.
EV Kit I/O Connections
The MAX3161E EV kit features PCB pads for interfacing
with logic signals and DB9 connector J1 to interface
with an RS-232 serial line. Terminal block J2 eases con-
nection to an RS-485/RS-422 bus. See Figures 1 or 2 for
RS-232 or RS-485/RS-422 transceiver functional modes.
The RS-232/RS-485/RS-422 input range is ±25V and
the output range is ±5V.
Evaluates: MAX3161E
MAX3161E Evaluation Kit
_______________________________________________________________________________________ 3
Table 3. RS-232/RS-485/RS-422 Protocol
(Jumper JU3)
SHUNT POSITION RS-485/RS-232
PIN EV KIT FUNCTION
Installed Connected to GND RS-232 mode
Not installed Connected to VCC
through resistor R3
RS-485/RS-422
mode
Table 4. Communication Mode
(Jumper JU4)
SHUNT POSITION HDPLX PIN RS-485/RS-422
MODE
Installed Connected to GND Full-duplex mode
Not installed Connected to VCC
through resistor R4 Half-duplex mode
Table 5. DTE/DCE Modes (Jumpers JU5–JU8)
JU5 JU6 JU7 JU8
SHUNT POSITION J1 PIN 2
CONNECTED TO
J1 PIN 3
CONNECTED TO
J1 PIN 7
CONNECTED TO
J1 PIN 8
CONNECTED TO
J1 CONNECTION
MODE
1-2 R1IN T1OUT T2OUT R2IN DCE
2-3 T1OUT R1IN R2IN T2OUT DTE
Table 6. RS-485/RS-422 Termination (Jumpers JU9 and JU10)
JU9 JU10
SHUNT POSITION RS-485 INPUT RS-485 OUTPUT TERMINATION VALUE
Installed A connected to B through
resistor R6
Y connected to Z through
resistor R5 120Ω termination
Not installed Not connected Not connected —
Evaluates: MAX3161E
MAX3161E Evaluation Kit
4 _______________________________________________________________________________________
T1OUT
T2OUT
R1IN
R2IN
T1
T2
R1
R2
T1OUT
T2OUT
R1IN
R2IN
RO/R2OUT
R1OUT
DE485/T2IN
DI/T1IN
LOGIC LEVEL I/O MAX3161EEVKIT+
*SEE TABLE 5 FOR J1 PINOUT
R2OUT
R1OUT
T2IN
T1IN
RS-232 LEVEL I/O
J1*
U1
Figure 1. MAX3161E EV Kit I/O Function in RS-232 Mode
Y
Z
B
A
D
R
Y
Z
B
A
RO/R2OUT
DI/T1IN
DE485/T2IN
LOGIC LEVEL I/O MAX3161EEVKIT+
RO
DI
DE485
RS-485/RS-422
LEVEL I/O
U1
J2
Y(A)
Z(B)
B
A
Figure 2. MAX3161E EV Kit I/O Function in RS-485/RS-422 Mode (Full Duplex)
Evaluates: MAX3161E
MAX3161E Evaluation Kit
_______________________________________________________________________________________ 5
Figure 3. MAX3161E EV Kit Schematic
T1OUT
12
3
R1OUT
R0/R2OUT
LOGIC LEVEL
DE485/T2IN
GND
DI/T1IN
R1OUT
R0/R2OUT
DE485/T2IN
DI/T1IN
GND
VCC
GND
VCC
C1
0.47µF
C4
0.1µF
J2
RS-485
J2-1
J2-2
JU10
J2-3
J2-4
J2-5
R5
120Ω
1%
JU9
JU1
JU2
JU5
1
1
2
2
3
3
JU7
JU8
R6
120Ω
1%
C2
0.47µF
C3
0.47µF
J1
RS-232
JU5–JU8
DCE: 1-2
DTE: 2-3
C5
0.47µF
6
1
24
23
22
21
7
6
16
15
5
8
18
17
11 12 13 14
V+
VCC
C1+
C1-
GND
2
1
3
4
20
19
9
10
C2+
C2-
V-
Y(A)
Z(B)
B
A
T1OUT
T2OUT
R1IN
R2IN
SHDN
FAST
RS-485/RS-232
HDPLX
2
3
4
5
7
8
9
R1
100kΩ
VCC
GND
A
B
Z
Y
R1IN
R2IN
R1IN
1
2
3
JU6 T1OUT
R21N
1011
U1
MAX3161E
C6
10µF
R2
100kΩ
VCC
SHDN
JU3
R3
100kΩ
VCC
JU4
R4
100kΩ
VCC
Figure 4. MAX3161E EV Kit Component Placement Guide—
Component Side
Figure 5. MAX3161E EV Kit PCB Layout—Component Side
Evaluates: MAX3161E
MAX3161E Evaluation Kit
6 _______________________________________________________________________________________
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________
7
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Evaluates: MAX3161E
MAX3161E Evaluation Kit
CARDENAS
Figure 6. MAX3161E EV Kit PCB Layout—Solder Side
