19-3204; Rev 1; 11/08
MAX13487E Evaluation Kit
vluates:7/MAX1348E
General Description
Features
The MAX13487E evaluation kit (EV kit) is a fully assem-
bled and tested PCB that contains a half-duplex RS-
485/RS-422 AutoDirection-controlled transceiver with
ESD protection. The EV kit circuit features a differential
driver and receiver. The circuit’s receiver is a 1/4-unit
load for the RS-485 bus and can communicate up to
500kbps. The MAX13487E AutoDirection and reduced-
driver slew-rate features are demonstrated on the EV kit
circuit. The EV kit can also be used to evaluate the
MAX13488E IC, which can communicate up to 16Mbps.
o Demonstrates MAX13487E AutoDirection Feature
o Designed for 2500VRMS Isolation
o 1/4 RS-485 Unit Loading
o 500kbps Half-Duplex RS-485/RS-422
Communication
o +5V DC Input Range
o Isolated +5V Output
o Center-Tapped Full-Wave Rectifier Output
o 420kHz Switching Frequency
Power for the transceiver circuit is provided by a MAX256
H-bridge DC/DC converter, which powers the isolated
section of the MAX13487E RS-485/RS-422 circuit. Input-
ripple current and radiated noise are minimized by using
an H-bridge design. The isolated H-bridge DC-DC con-
verter operates at 420kHz. Input power to the EV kit
circuit can be supplied by a +5V DC source.
o Output Current Limit and Thermal Shutdown
o Low-Cost Integrated-FET H-Bridge Design
o Also Evaluates MAX13488E (After IC
Replacement)
The DC-DC converter circuit uses a surface-mount
transformer to provide galvanic isolation and a full-wave
rectifier, and provides a regulated +5V to the
MAX13487E. A MAX1659 linear low dropout (LDO) reg-
ulator provides the regulated output and up to 300mA
of current. The output current limit and thermal shut-
down provide for a robust isolated RS-485/RS-422
transceiver circuit and power supply. The transceiver
and power circuits and PCB are designed for
o Fully Assembled and Tested
Ordering Information
PART
TYPE
MAX13487EEVKIT#
#Denotes RoHS compliant.
EV Kit
2500V
isolation.
RMS
Component List
DESIGNATION QTY
DESCRIPTION
DESIGNATION QTY
DESCRIPTION
10µF 10ꢀ, 10V X7R ceramic
capacitor (1206)
Murata GRM31CR71A106K
JU1, JU3, JU4,
5
2-pin headers
3-pin header
C1
C2
1
1
4
JU5, JU6
JU2
1
1
2
2
2
1
0.47µF 10ꢀ, 16V X7R ceramic
capacitor (0805)
Murata GRM219R71C474K
R1
39.2kΩ 1ꢀ resistor (0603)
100kΩ 5ꢀ resistors (0603)
270Ω 5ꢀ resistors (0805)
220Ω 5ꢀ resistors (0805)
120Ω 5ꢀ resistor (0805)
R2, R9
R4, R5
R6, R8
R7
0.1µF 10ꢀ, 16V X7R ceramic
capacitors (0603)
Murata GRM188R71C104K
C3, C5, C6, C7
500µH, 1.5W, 3:8-turn, 400kHz
transformer (6-pin Gull Wing)
HALO Electronics TGM-380NARL
1µF 10ꢀ, 16V X7R ceramic
capacitor (0805)
Murata GRM21BR71C105K
T1
1
1
C4
D1, D2
D3
1
2
1
Half-duplex, high-speed transceiver
(8 SO)
Maxim MAX13487EESA+
30V, 1A Schottky diodes (SOD123)
Diodes Inc. B130LAW
U1
15V, 350mW 5ꢀ zener diode
(SOT-23)
Central Semiconductor CMPZ5245B+
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.