MAX14858 [MAXIM]

Operates From a Single 3.3V Supply;


型号：	MAX14858
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	Operates From a Single 3.3V Supply
文件：	总13页 (文件大小：2150K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

Evaluates: MAX14852/MAX14854/

MAX14856/MAX14858

MAX148X1 Evaluation Kit

Startup Procedure

General Description

The EV kit is fully assembled and tested. Follow the steps

below to verify board operation.

The MAX148X1 evaluation kit (EV kit) is a fully assembled

and tested PCB that demonstrates the functionality of the

MAX14852 isolated RS-485/RS-422 transceiver. The EV

kit operates from a single 3.3V supply and features an on-

board isolated power supply to power the secondary-side

of the circuit.

1) Set the DC power supply to 3.3V and connect the

DC power supply between the EV kits V

GNDA connectors.

and

DDA

2) Ensure that all jumpers are in their default positions

(see Table 1).

3) Turn on the power supply.

The MAX148X1 EV kit may also be used to evaluate the

MAX14854, MAX14856, and the MAX14858.

4) Set the signal/function generator to output a 100kHz

0-to-3V square wave. NOTE: Set the signal/function

generator to operate with a high-impedance load. If

needed, the R1 pad is available to add a 50Ω impedance

to ground.

5) Connect the signal/function generator to the TXD

test point.

6) Using the oscilloscope, verify that the Y and Z outputs

Features

● Operates From a Single 3.3V Supply

● Terminal Block Connectors for Easy RS-485/RS-422

Evaluation

● Up to 5000V

Isolation for 60s

RMS

● Fully Assembled and Tested

switch as the signal toggles.

Quick Start

Required Equipment

● MAX148X1 EV kit

● 3.3V, 1A DC power supply

● Signal/function generator

● Oscilloscope

Ordering Information appears at end of data sheet.

19-8594; Rev 0; 7/16

Evaluates: MAX14852/MAX14854/

MAX14856/MAX14858

MAX148X1 Evaluation Kit

Resistors R2 – R4 Conﬁguration

Detailed Description of Hardware

For end-of-the-line transceivers, close J9 to connect

a 120Ω termination resistor (R6) between the A and B

RS-485 receiver inputs on the MAX14852.

The EV kit is a fully assembled and tested circuit board

for evaluating the MAX14852 isolated RS-485/RS-422

transceiver (U2). The EV kit has been designed to allow

for evaluating the MAX14852 alone or in a standard

RS-485 configuration. The EV kit is powered from a single

3.3V power supply.

Close J6 to connect a 120Ω termination resistor (R3)

between the Y and Z driver outputs.

Pullup and pulldown resistors are generally used on the

receiver inputs to guarantee a known state in the event

that all nodes on the bus are in receive mode, or the

cable becomes disconnected. The exact value for these

resistors will vary with the application. R2 and R4 pads are

provided for pullup and pulldown resistors on the Y and

Z lines. R5 and R7 pads provide for pullup and pulldown

resistors on the A and B lines, if needed. The use of

any of these resistors is purely optional. Note that the

MAX14852 features true fail-safe receiver inputs, which

ensures that RXD is high when the receiver inputs are

shorted, open, or connected to an idle bus.

Powering the Board

The power on the EV kit is derived from a single 3.3V

source. Connect an external supply from GNDA to either

the V

test point or P1 connector to supply the 3.3V to

DDA

the logic-side (A) of the circuit.

An on-board MAX258 transformer driver (U1) and external

transformer (TX1) generate an isolated supply for powering

the (B) isolated side of the board. To disable the MAX258

circuit, connect jumper J1 to 2-3. To disconnect the output

of the transformer circuit from the MAX14852 LDO input,

remove the shunt on J5.

Evaluating the Isolated RS-485 Interface

Driver and Receiver Enable Selection

The EV kit features three jumpers (J2, J3, and J4) to

enable/disable the driver and receiver outputs. Set J2

to 2-3 to enable the receiver. Set J3 to 1-2 to enable the

driver. To actively control both enables, remove J2 and J3

and close J4, which connects DE and RE together.

Loopback Conﬁguration

The MAX14852 features one drive channel and one

receive channel. Driver outputs are Y and Z and receiver

inputs are A and B. To configure the device for loopback

testing, close J7 and J8 to connect B to Z and A to Y,

respectively.

Maxim Integrated

│ 2

www.maximintegrated.com

Evaluates: MAX14852/MAX14854/

MAX14856/MAX14858

MAX148X1 Evaluation Kit

Table 1. Jumper Table (J1-J9)

JUMPER

SHUNT POSITION

DESCRIPTION

1-2

2-3*

MAX258 transformer driver is disabled.

MAX258 transformer driver is enabled.

1-2*

RE is high. The RS-485 receiver is disabled.

RE is low. The RS-485 receiver is enabled.

DE is high. The RS-485 driver outputs are enabled.

DE is low. The RS-485 driver outputs are disabled.

DE and RE are not connected together.

2-3

1-2*

2-3

Open*

Closed

Open

DE and RE are connected together.

The output of the transformer circuit is not connected to VLDO.

The output of the transformer circuit is connected to VLDO and powers the B-side

of the MAX14852.

Closed*

Open*

Y and Z are connected through the on-board 120Ω termination resistor.

Closed

Open*

Closed

Open*

Closed

Open*

Closed

Y and Z are not connected through the on-board termination resistor.

B is not connected to Z.

B is connected to Z.

A is not connected to Y.

A is connected to Y.

A and B are connected through the on-board 120Ω termination resistor.

A and B are not connected through the on-board termination resistor.

*Default position.

Maxim Integrated

│ 3

www.maximintegrated.com

Evaluates: MAX14852/MAX14854/

MAX14856/MAX14858

MAX148X1 Evaluation Kit

Component Information, PCB Layout

and Schematic

Ordering Information

PART

TYPE

See the following links for component information, PCB

layout diagrams, and schematic.

MAX148X1EVKIT#

EV Kit

#Denotes RoHS compliant.

●

MAX148X1 EV BOM

MAX148X1 EV PCB

MAX148X1 EV Schematic

Maxim Integrated

│ 4

www.maximintegrated.com

Evaluates: MAX14852/MAX14854/

MAX14856/MAX14858

MAX148X1 Evaluation Kit

Revision History

REVISION REVISION

PAGES

CHANGED

DESCRIPTION

NUMBER

DATE

7/16

Initial release

—

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses

are implied. Maxim Integrated reserves the right to change the circuitry and speciﬁcations without notice at any time.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.

2016 Maxim Integrated Products, Inc.

│ 5

TITLE: Bill of Materials

DATE: 04/09/2015

DESIGN: max148x1_evkit_a

ITEM

REF_DES

DNI QTY MFG PART #

GRM188R71E105KA12D;

MANUFACTURER

VALUE

DESCRIPTION

CAPACITOR; SMT (0603); CERAMIC CHIP; 1UF; 25V; TOL=10%; MODEL=GRM

SERIES; TG=‐55 DEGC TO +125 DEGC; TC=X7R

1 C1, C3, C6, C8

‐

4 CGA3E1X7R1E105K

C0603C104K4RAC;

MURATA

1UF

GCM188R71C104KA37;

C1608X7R1C104K;

GRM188R71C104K;

2 C0603X7R160‐104KNE

GRM21BR61E106K;

C2012X5R1E106K125AB;

2 C2012X5R1E106K

C0603C104K3RAC;

KEMET/MURATA/T

DK/VENKEL LTD.

CAPACITOR; SMT (0603); CERAMIC CHIP; 0.1UF; 16V; TOL=10%; TG=‐55 DEGC TO

+125 DEGC; TC=X7R;

2 C2, C7

3 C4, C10

4 C5

‐

0.1UF

10UF

0.1UF

CAPACITOR; SMT (0805); CERAMIC CHIP; 10UF; 25V; TOL=10%; MODEL=; TG=‐55

DEGC TO +125 DEGC; TC=X5R

MURATA/TDK

GRM188R71E104KA01;

1 C1608X7R1E104K

KEMET/MURATA/

TDK

CAPACITOR; SMT; 0603; CERAMIC; 0.1uF; 25V; 10%; X7R; ‐55degC to + 125degC;

+/‐15% from ‐55degC to +125degC;

DIODE; SCH; SCHOTTKY RECTIFIER; SMT (SOD‐123); PIV=20V; IF=0.5A; ‐55 DEGC

TO +150 DEGC

CONNECTOR; MALE; THROUGH HOLE; BREAKAWAY; STRAIGHT; 3PINS

CONNECTOR; MALE; THROUGH HOLE; BREAKAWAY; STRAIGHT; 2PINS

CONNECTOR; FEMALE; THROUGH HOLE; GREEN TERMINAL BLOCK; STRAIGHT;

5 D1, D2

6 J1‐J3

7 J4‐J9

‐

2 MBR0520

3 PEC03SAAN

6 PEC02SAAN

GENERIC PART

SULLINS

MBR0520

PEC03SAAN

PEC02SAAN

8 P1

‐

1935161 PHOENIX CONTACT

1935161 2PINS

CONNECTOR; FEMALE; THROUGH HOLE; GREEN TERMINAL BLOCK; STRAIGHT;

1935200 6PINS

9 P2, P3

10 R3, R6

‐

1935200 PHOENIX CONTACT

VISHAY DALE

2 CRCW0603120RJN

120 RESISTOR; 0603; 120 OHM; 5%; 200PPM; 0.10W; THICK FILM

SULLINS

TEST POINT; JUMPER; STR; TOTAL LENGTH=0.256IN; BLACK; INSULATION=PBT

CONTACT=PHOSPHOR BRONZE; COPPER PLATED TIN OVERALL

5010 TESTPOINT WITH 1.80MM HOLE DIA, RED, MULTIPURPOSE

TEST POINT; PIN DIA=0.125IN; TOTAL LENGTH=0.445IN; BOARD HOLE=0.063IN;

5011 BLACK; PHOSPHOR BRONZE WIRE SILVER PLATE FINISH;

11 SU1‐SU4

12 T1, T9, T10

‐

4 STC02SYAN

ELECTRONICS CORP. STC02SYAN

5010 ?

13 T2, T3, T11, T12

‐

5011 ?

5014 ?

TEST POINT; PIN DIA=0.125IN; TOTAL LENGTH=0.445IN; BOARD HOLE=0.063IN;

5014 YELLOW; PHOSPHOR BRONZE WIRE SILVER PLATE FINISH;

14 T4‐T8, T13‐T16

HALO ELECTRONICS,

15 TX1

16 U1

‐

1 TGMS‐1455V6LF

INC

TGMS‐1455V6LF

TRANSFORMER; SMT; 1:1.5; POWER TRANSFORMER; DRAFT DATASHEET ONLY

IC; DRV; 0.5A; PUSH‐PULL TRANSFORMER DRIVER FOR ISOLATED POWER SUPPLY;

TDFN8‐EP 2X3

1 MAX258ATA+

MAXIM

MAX258ATA+

EVKIT PART‐IC; PACKAGE CODE: W16M+10; OUTLINE DRAWING NO.: 21‐0042;

LAND PATTERN DRAWING NO.: 90‐0107; WSOIC16 300MIL

PACKAGE OUTLINE 0603 RESISTOR ‐ EVKIT

17 U2

18 R1, R2, R4, R5, R7

‐

1 MAX14852GWE+

5 N/A

MAXIM

N/A

MAX14852

OPEN

DNP

TOTAL

TOP SILKSCREEN

TOP

INTERNAL 2

INTERNAL 3

BOTTOM

BOTTOM SILKSCREEN

VLDO

VDDB

VLDO

VDDA

VLDO

1UF

TX1

TGMS-1455V6LF

VDDB

T10

MAX258ATA+

VDDA

VDD

C10

10UF

/EN

VDDA

10UF

T13

T14

HICLK

PGND

GNDGND

VDDB

VLDO

VDDB

T15

T16

RXD

MAX14852GWE+

OPEN

1UF

0.1UF

1UF

VDDA

0.1UF

VDDA

VLDO

VDDB

0.1UF

1UF

RXD

/RE

VDDA

RXD

VDDB

TXD

VDDB

RXD

120

/SBA

TXD

SBA

GNDA

GNDB

OPEN

VDDA

TXD

OPEN

120

TXD

GNDA

T11

OPEN

GNDB

T12

SBA

相关型号：