MAXIM MAX14770E User Manual

19-5017; Rev 2; 1/11

Functional Diagram

High-ESD Profibus RS-485 Transceiver

General Description

The MAX14770E is a half-duplex, Q35kV high ESD­protected transceiver for PROFIBUS-DP and RS-485
applications. In addition, it can be used for RS-422/V.11
communications. The MAX14770E is designed to meet
IEC 61158-2, TIA/EIA-422-B, TIA/EIA-485-A, V.11, and
X.27 standards.

The MAX14770E operates from a +5V supply and has
true fail-safe circuitry that guarantees a logic-high receiv­er output when the receiver inputs are open or shorted.

The MAX14770E features a 1/4 standard-unit load
receiver input impedance, allowing up to 128 1/4 unit
load transceivers on the bus. Drivers are short-circuit
current limited and are protected against excessive
power dissipation by thermal-shutdown circuitry.

The MAX14770E is available in 8-pin SO and tiny TDFN
(3mm x 3mm) packages, and is specified over the extend­ed (-40NC to +85NC) and automotive (-40NC to +125NC)
temperature ranges.

Features

S Meets EIA 61158-2 Type 3 PROFIBUS-DP

S

+4.5V to +5.5V Supply Voltage

S

20Mbps Data Rate

S

Short-Circuit Protected

S

True Fail-Safe Receiver

S

Thermal-Shutdown Protected

S

Hot Swappable

S

High ESD Protection

±35kV Human Body Model (HBM)

±20kV IEC 61000-4-2 Air Gap

±10kV IEC 61000-4-2 Contact

S

-40NC to +125NC Automotive Temperature Range

in Tiny 8-Pin (3mm x 3mm) TDFN

Ordering Information

MAX14770E

Applications

PROFIBUS-DP Networks

Industrial Fieldbuses

Motion Controllers

RS-485 Networks

Machine Encoders

Typical PROFIBUS-DP Operating Circuit appears at end of
data sheet.

PART TEMP RANGE

MAX14770EESA+T
MAX14770EATA+T

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.
*EP = Exposed pad.

RO

RE

DE

DI

-40NC to +85NC

-40NC to +125NC

SHUTDOWN

MAX14770E

PIN­PACKAGE

8 SO —
8 TDFN-EP* BMG

R

A

B

D

TOP

MARK

The PROFI BUS PROCESS FIELD BUS logo is a registered
trademark of PROFIBUS and PROFINET International (PI).

_______________________________________________________________ Maxim Integrated Products 1

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

High-ESD Profibus RS-485 Transceiver

ABSOLUTE MAXIMUM RATINGS

(Voltages referenced to GND.)
V

.......................................................................-0.3V to +6.0V

CC

RE, RO .......................................................-0.3V to (V

DE, DI ...................................................................-0.3V to +6.0V

A, B .....................................................................-8.0V to +13.0V

Short-Circuit Duration (RO, A, B) to GND ................. Continuous

Continuous Power Dissipation (T

SO (derate 7.6mW/NC above +70NC) .........................606mW

TDFN (derate 24.4mW/NC above +70NC) .................1951mW

MAX14770E

PACKAGE THERMAL CHARACTERISTICS (Note 1)

SO
Junction-to-Ambient Thermal Resistance (q
Junction-to-Case Thermal Resistance (q

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-

layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.

= +70NC)

A

JA

)...............38°C/W

JC

+ 0.3V)

CC

) ........132°C/W

ELECTRICAL CHARACTERISTICS

(VCC = +5V Q10%, TA = T

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Power-Supply Range V

Supply Current I

Shutdown Supply
Current

DRIVER

Differential Driver
Output

Differential Driver
Peak-to-Peak Output

Change in Magnitude
of Differential Output
Voltage

Driver Common­Mode Output Voltage

Change in Common­Mode Voltage

Driver Short-Circuit
Output Current
(Note 5)

MIN

to T

I

|V

V

ODPP

DV

V

DV

I

OSD

, unless otherwise noted. Typical values are at VCC = +5V, T

MAX

CC

DE = 1, RE = 0 or

CC

SH

OD

OD

OC

OC

DE = 0, RE = 0 or
DE = 1, RE = 1; no load

DE = 0, RE = 1

|

= 54I, DI = VCC or GND; Figure 1

R

L

Figure 2 (Note 3) 4.0 6.8 V

RL = 54I; Figure 1 (Note 4)

RL = 54I; Figure 1

RL = 54I; Figure 1 (Note 4)

0V P V

-7V P V

P +12V; output low

OUT

P VCC; output high

OUT

Operating Temperature Range

SO .................................................................. -40NC to +85NC

TDFN ............................................................ -40NC to +125NC

Storage Temperature Range ............................ -65NC to +150NC

Junction Temperature Range ........................... -40NC to +150NC

Lead Temperature (soldering, 10s) ................................+300NC

Soldering Temperature (reflow) ......................................+260NC

TDFN
Junction-to-Ambient Thermal Resistance (q
Junction-to-Case Thermal Resistance (q

= +25NC.) (Note 2)

A

4.5 5.5 V

2.5 4 mA

2.1 V

-0.2 0 +0.2 V

1.8 3 V

-0.2 +0.2 V

-250

) ..........41°C/W

JA

).................8°C/W

JC

15

+250

FA

mA

2 ______________________________________________________________________________________

High-ESD Profibus RS-485 Transceiver

ELECTRICAL CHARACTERISTICS (continued)

(VCC = +5V Q10%, TA = T

MIN

to T

, unless otherwise noted. Typical values are at VCC = +5V, T

MAX

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Driver Short-Circuit
Foldback Output
Current (Note 5)

I

OSDF

(VCC - 1V) P V

-7V P V

P +1V; output high

OUT

P +12V; output low

OUT

LOGIC INPUTS

Driver Input High
Voltage

Driver Input Low
Voltage

Driver Input
Hysteresis

Driver Input Current I

Input Impedance in
Hot Swap

V

V

V

R

R

IH

IL

HYS

IN

DE

RE

DE, DI, RE

DE, DI, RE

DE, DI, RE

DE, DI, RE

Figure 11 until the first low-to-high transition of DE
occurs

Figure 11 until the first high-to-low transition of RE
occurs

RECEIVER

V

Input Current (A, B) I

Differential Input
Capacitance

Receiver Differential
Threshold Voltage

Receiver Input
Hysteresis

A, IB

C

V

DV

AB

TH

TH

DE = GND, VCC = V

GND

or

+5.5V

Between A and B, DE = RE = GND at 6MHz

-7V P VCM P 12V

VCM = 0V 15 mV

= 12V +250

IN

V

= -7V -200

IN

LOGIC OUTPUT

I

Output High Voltage V
Output Low Voltage V

Three-State Receiver
Output Current

Receiver Input
Resistance

Receiver Output
Short-Circuit Current

I

OZR

R

I

OSR

OH

OL

IN

= -6mA, VA - VB = V

OUT

I

= 6mA, VA - VB = -V

OUT

0V P V

OUT

P V

CC

-7V P VCM P 12V

0V P VRO P V

CC

TH

TH

PROTECTION SPECIFICATIONS

Thermal-Shutdown
Threshold

Thermal-Shutdown
Hysteresis

ESD Protection, A
and B Pins

V

V

TS

TSH

HBM

IEC 61000-4-2 Contact Discharge to GND

= +25NC.) (Note 2)

A

-15

+15

2.0 V

0.8 V

50 mV

-1 +1

1 5.6 10

8 pF

-200 -125 -50 mV

4 V

0.4 V

-1 +1

48

-110 +110 mA

+160

15

±35
±20
±10

MAX14770E

mA

FA

kW

FA

FA

kI

NC

NC

kVIEC 61000-4-2 Air-Gap Discharge to GND

_______________________________________________________________________________________ 3

High-ESD Profibus RS-485 Transceiver

ELECTRICAL CHARACTERISTICS (continued)

(VCC = +5V Q10%, TA = T

MIN

to T

, unless otherwise noted. Typical values are at VCC = +5V, T

MAX

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

ESD Protection, All
Other Pins

HBM

DRIVER SWITCHING CHARACTERISTICS

Driver Propagation
Delay

Differential Driver

MAX14770E

Output Skew |t

- t

|

DPHL

DPLH

t

DPLH

t

DPHL

t

DSKEW

RL = 54I, CL = 50pF; Figures 3 and 4

RL = 54I, CL = 50pF; Figures 3 and 4

Driver Output
Transition Skew
|t

|, |t

t(MLH)

t(MHL)

|

t

TSKEW

RL = 54I, CL = 50pF; Figures 3 and 5

Driver Differential
Output Rise or Fall

t

LH

, t

RL = 54I, CL = 50pF; Figures 3 and 4

HL

Time

Maximum Data Rate

Driver Enable to
Output High

Driver Enable to
Output Low

Driver Disable Time
from Low

Driver Disable Time
from High

Driver Enable Skew
Time

Driver Disable Skew
Time

Driver Enable High—
Propagation Delay
Difference

|t

ZL

|t

LZ

t

DZH

t

DZL

t

DLZ

t

DHZ

- tZH|

- tHZ|

t

DZH -

t

DPHL

RL = 500I, CL = 50pF; Figure 6

RL = 500I, CL = 50pF; Figure 7

RL = 500I, CL = 50pF; Figure 7

RL = 500I, CL = 50pF, Figure 6

= 500I, CL = 50pF; Figures 6 and 7

R

L

= 500I, CL = 50pF; Figures 6 and 7

R

L

Driver Enable Low—
Propagation Delay

t

DZL - tDPHL

Difference

Driver Enable from
Shutdown to Output

t

DZL(SHDN)

RL = 500I, CL = 50pF; Figure 7 (Note 6)

High

Driver Enable from
Shutdown to Output

t

DZH(SHDN)

RL = 500I, CL = 50pF; Figure 6 (Note 6)

Low

Time to Shutdown t

SHDN

(Note 6) 50 800 ns

= +25NC.) (Note 2)

A

±2

15 28 ns

1.2 ns

2 ns

7 15 ns

20 Mbps

25 48 ns

25 48 ns

20 40 ns

20 40 ns

8 20 ns

10 20 ns

46 100

46 100

kV

8 ns

8 ns

Fs

Fs

4 ______________________________________________________________________________________

High-ESD Profibus RS-485 Transceiver

ELECTRICAL CHARACTERISTICS (continued)

(VCC = +5V Q10%, TA = T

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

RECEIVER SWITCHING CHARACTERISTICS

Receiver Propagation
Delay

Receiver Output
Skew

Maximum Data Rate 20 Mbps

Receiver Enable to
Output High

Receiver Enable to
Output Low

Receiver Disable
Time from Low

Receiver Disable
Time from High

Receiver Enable from
Shutdown to Output
High

Receiver Enable from
Shutdown to Output
Low

Time to Shutdown t

Note 2: Devices are production tested at TA = +25NC. Specifications over temperature limits are guaranteed by design.
Note 3: V
Note 4: DV
Note 5: The short-circuit output current applies to peak current just prior to foldback current limiting; the short-circuit foldback out-

Note 6: Shutdown is enabled by bringing RE high and DE low. If the enable inputs are in this state for less than 50ns, the device

Note 7: Capacitive load includes test probe and fixture capacitance.
Note 8: Guaranteed by characterization; not production tested.

is the difference in VOD, with the DI at high and DI at low.

ODPP

and DVOC are the changes in |VOD| and |VOC|, respectively, with the DI at high and DI at low.

OD

put current applies during current limiting to allow a recovery from bus contention.

is guaranteed not to enter shutdown. If the enable inputs are in this state for at least 800ns, the device is guaranteed to
have entered shutdown.

to T

MIN

t

RPLH

t

RPHL

t

RSKEW

t

RZH

t

RZL

t

RLZ

t

RHZ

t

RZL(SHDN)

t

RZH(SHDN)

SHDN

, unless otherwise noted. Typical values are at VCC = +5V, T

MAX

CL = 15pF; Figures 8 and 9 (Note 7) 28 ns

CL = 15pF; Figures 8 and 9 (Notes 7, 8) 2 ns

S2 closed; RL = 1kI, CL = 15pF; Figure 10

S1 closed; RL = 1kI, CL = 15pF; Figure 10

S1 closed; RL = 1kI, CL = 15pF; Figure 10

S2 closed; RL = 1kI, CL = 15pF; Figure 10

S1 closed; RL = 1kI, CL = 15pF; Figure 10
(Notes 6, 7)

S2 closed; RL = 1kI, CL = 15pF; Figure 10
(Notes 6, 7)

(Note 6) 50 800 ns

= +25NC.) (Note 2)

A

30 ns

30 ns

30 ns

30 ns

100

100

Fs

Fs

MAX14770E

_______________________________________________________________________________________ 5