MAXIM MAX3535E, MXL1535E User Manual

General Description

The MAX3535E/MXL1535E isolated RS-485/RS-422 full­duplex transceivers provide 2500V

RMS

of galvanic isola­tion between the RS-485/RS-422 side and the processor
or control logic side. These devices allow fast,
1000kbps communication across an isolation barrier
when the common-mode voltages (i.e., the ground
potentials) on either side of the barrier are subject to
large differences. Isolation is achieved through integrat­ed high-voltage capacitors. The MAX3535E/MXL1535E
also feature a 420kHz transformer driver that allows
power transfer to the RS-485 side using an external
transformer.

The MAX3535E/MXL1535E include one differential driver,
one receiver, and internal circuitry to send the RS-485
signals and control signals across the isolation barrier
(including the isolation capacitors). The MAX3535E/
MXL1535E RS-485 receivers are 1/8 unit load, allowing
up to 256 devices on the same bus.

The MAX3535E/MXL1535E feature true fail-safe circuitry.
The driver outputs and the receiver inputs are protected
from ±15kV electrostatic discharge (ESD) on the inter­face side, as specified in the Human Body Model (HBM).

The MAX3535E/MXL1535E feature driver slew-rate
select that minimizes electromagnetic interference (EMI)
and reduces reflections. The driver outputs are short-cir­cuit and overvoltage protected. Other features are hot­swap capability and isolation-barrier fault detection.

The MAX3535E operates with a single +3V to +5.5V
power supply. The improved secondary supply range of
the MAX3535E allows the use of step-down transformers
for +5V operation, resulting in considerable power sav­ings. The MXL1535E operates with a single +4.5V to
+5.5V power supply. The MXL1535E is a function-/pin­compatible improvement of the LTC1535. The
MAX3535E/MXL1535E are available over the commer­cial 0°C to +70°C and extended -40°C to +85°C temper­ature ranges.

Applications

Isolated RS-485 Systems

Systems with Large Common-Mode Voltages

Industrial-Control Local Area Networks

Telecommunications Systems

Features

♦ 2500V

RMS

RS-485 Bus Isolation Using On-Chip

High-Voltage Capacitors

♦ 1000kbps Full-Duplex RS-485/RS-422

Communication

♦ +3V to +5.5V Power-Supply Voltage Range

(MAX3535E)

♦ +4.5V to +5.5V Power-Supply Voltage Range

(MXL1535E)

♦ 1/8 Unit Receiver Load, Allowing 256 Devices on

Bus

♦ ±15kV ESD Protection Using HBM
♦ Pin-Selectable Slew-Rate Limiting Controls EMI
♦ Hot-Swap-Protected Driver-Enable Input
♦ Undervoltage Lockout
♦ Isolation-Barrier Fault Detection
♦ Short-Circuit Protected
♦ Thermal Shutdown
♦ Open-Line and Shorted-Line Fail-Safe Receiver

Inputs

MAX3535E/MXL1535E

+3V to +5V, 2500V

RMS

Isolated RS-485/RS-422

Transceivers with ±15kV ESD Protection

________________________________________________________________

Maxim Integrated Products

1

Pin Configuration

Ordering Information

19-3270; Rev 0; 4/04

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.

Typical Application Circuit appears at end of data sheet.

EVALUATION KIT

AVAILABLE

PART TEMP RANGE

MAX3535ECWI 0°C to +70°C 28 Wi d e S O

MAX3535EEWI -40°C to +85°C 28 Wi d e S O

MXL1535ECWI 0°C to +70°C 28 Wi d e S O

MXL1535EEWI -40°C to +85°C 28 Wi d e S O+ 4.5 to + 5.5

TOP VIEW

PIN-

PACKAGE

1

V

CC1

2

ST1

3

ST2

4

GND1

MAX3535E
MXL1535E

11

GND2

12

Z

13

Y

V

14

CC2

PINS 5–10 and 19–24 ARE REMOVED FROM THE PACKAGE

WIDE SO

RO1

28

RE

27

DE

26

DI

25

SLO

18

RO2

17

A

16

B

15

POWER­SUPPLY

RANGE

(V)

+ 3.0 to + 5.5

+ 3.0 to + 5.5

+ 4.5 to + 5.5

MAX3535E/MXL1535E

+3V to +5V, 2500V

RMS

Isolated RS-485/RS-422

Transceivers with ±15kV ESD Protection

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS TABLE (MAX3535E)

(V

CC1

= +3.0V to +5.5V, V

CC2

= +3.13V to +7.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at V

CC1

= +3.3V,

V

CC2

= +5V, TA= +25°C.)

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.

Logic Side—All Voltages Referenced to GND1.
V

CC1

.........................................................................-0.3V to +6V

RE, DE, DI.................................................................-0.3V to +6V

RO1, ST1, ST2 ..........................................-0.3V to (V

CC1

+ 0.3V)
Isolated Side—All Voltages Referenced to GND2.
V

CC2

.........................................................................-0.3V to +8V

SLO...........................................................-0.3V to (V

CC2

+ 0.3V)

A, B ......................................................................................±14V

RO2 .....................-0.3V to the lower of (V

CC2

+ 0.3V) and +3.4V

Y, Z ............................................................................-8V to +13V

Digital Outputs Maximum Current

RO1, RO2 .....................................................................±20mA

Y, Z Maximum Current .............................Short-Circuit Protected

ST1, ST2 Maximum Current............................................±300mA

Continuous Power Dissipation (T

A

= +70°C)
28-Pin Wide SO

(derate 9.5mW/°C above +70°C).................................750mW

Operating Temperature Range

MXL1535ECWI, MAX3535ECWI .........................0°C to +70°C

MXL1535EEWI, MAX3535EEWI.......................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

LOGIC-SIDE SUPPLY (V

Logic-Side Supply Voltage V

Logic-Side Supply Current I

V

CC1

Falling Trip

V

CC1

Rising Trip

LOGIC INPUTS (DI, DE, RE)

Input High Voltage, DE, DI, RE V
Input Low Voltage, DE, DI, RE V

Logic-Side Input Current, DE, DI I

LOGIC OUTPUTS (RO1, RE)

Receiver-Output High Voltage
(RO1)

Receiver-Output Low Voltage
(RO1)

Receiver-Output (RO1) Leakage
Current

RE Low Output Current for Fault
Detect

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Undervoltage-Lockout

Undervoltage-Lockout

, GND1)

CC1

CC1

Transformer not driven, ST1 and ST2

CC1

V

UVL1

V

UVH1

V

RO1H

V

RO1L

I

OZR

I

INC

OL

unconnected, RE = low, DE = high,

= 0, RO1 = no load

f

DATA

VIH is measured with respect to GND1 2.0 V

IH

VIL is measured with respect to GND1 0.8 V

IL

I

I

I

I

RE = high, V
0 ≤ V

RE = +0.4V, fault not asserted 40 60 80 µA

SOURCE

SOURCE

= 4mA, V

SINK

= 4mA, V

SINK

RO1

= 4mA, V

= 4mA, V

≤ V

= +4.5V 3.7

CC1

= +3V 2.4

CC1

= +4.5V 0.4

CC1

= +3V 0.4

CC1

= +5.5V,

CC1

CC1

3.0 5.5 V

5.9 13 mA

2.53 2.69 2.85 V

2.63 2.80 2.97 V

±2µA

±1 µA

V

V

+3V to +5V, 2500V

RMS

Isolated RS-485/RS-422

Transceivers with ±15kV ESD Protection

_______________________________________________________________________________________ 3

MAX3535E/MXL1535E

DC ELECTRICAL CHARACTERISTICS TABLE (MAX3535E) (continued)

(V

CC1

= +3.0V to +5.5V, V

CC2

= +3.13V to +7.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at V

CC1

= +3.3V,

V

CC2

= +5V, TA= +25°C.)

RE High Output Current for Fault
Detect

TRANSFORMER DRIVER (ST1, ST2)

DC-Converter Switching
Frequency (ST1, ST2)

DC-Converter Total Impedance
R

OH

ST1, ST2 Duty Cycle ST1, ST2, not loaded 44 50 56 %

ISOLATED-SIDE SUPPLY (V

Isolated-Side Supply Voltage V

Isolated-Side Supply Current I

V

CC2

Falling Trip

V

CC2

Rising Trip

DRIVER OUTPUTS (Y, Z)

Driver-Output High Voltage V

Differential Driver Output V

Driver Common-Mode Output
Voltage

Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

+ ROL (ST1, ST2)

Undervoltage-Lockout

Undervoltage-Lockout

CC2

R

, GND2)

V

V

V

ΔV

I

OH

f

SW

OHL

CC2

CC2

UVL2

UVH2

DOH

OD

OC

RE = V

ST1, ST2, not loaded 290 460 590 kHz

V

CC1

V

CC1

f

DATA

RO2 = no load,
A, B floating, Figure 1

No load, V
GND2

RL = 50Ω (RS-422), V
Figure 1

RL = 27Ω (RS-485), V
Figure 1

RL = 27Ω or 50Ω, VOC is measured with
respect to GND2, Figure 1

RL = 27Ω or 50Ω, Figure 1 ±0.2 V

OD

- 0.5V, fault asserted -140 -100 -60 µA

CC1

= +4.5V, Figure 13 1.6 2.6

= +3V, Figure 13 1.8 2.9

3.13 7.50 V

= 0, SLO floating,

is measured with respect to

DOH

RL = 27Ω 56 70

R

= ∞ 10 16

L

2.68 2.85 3.02 V

2.77 2.95 3.13 V

= +3.13V,

CC2

= +3.13V,

CC2

2.0 2.35

1.5 1.95

1.0 3.0 V

4V

Ω

mA

V

Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States

Driver Short-Circuit Output
Current

ΔV

I

OC

OSD

RL = 27Ω or 50Ω, Figure 1 ±0.2 V

Driver enabled (DE =1 )
DI = high, V
DI = low, V

Driver enabled (DE =1 )
DI = high, V
DI = low, V

> -7V

Y

> -7V

Z

< +12V

Z

< +12V

Y

-250

mA

+250

MAX3535E/MXL1535E

+3V to +5V, 2500V

RMS

Isolated RS-485/RS-422

Transceivers with ±15kV ESD Protection

4 _______________________________________________________________________________________

DC ELECTRICAL CHARACTERISTICS TABLE (MAX3535E) (continued)

(V

CC1

= +3.0V to +5.5V, V

CC2

= +3.13V to +7.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C,

V

CC1

= +3.3V, V

CC2

= +5V).

Driver Short-Circuit Foldback
Output Current

SLEW-RATE SELECT (SLO)

Input High Voltage SLO V
Input Low Voltage SLO V
SLO Pullup Resistor R

RECEIVER INPUTS (A, B)

Receiver Input Current I

Receiver Differential Threshold
Voltage

Receiver-Input Hysteresis ΔV

Receiver-Input Resistance R

Receiver-Input Open Circuit
Voltage

RECEIVER OUTPUT (RO2)

Receiver-Output (RO2) High
Voltage

Receiver-Output (RO2) Low
Voltage

ISOLATION

Isolation Voltage (Notes 2, 3) V

Isolation Resistance R

Isolation Capacitance C

ESD Protection Human Body Model (A, B, Y, Z) ±15 kV

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DI = high

Driver

I

OSFD

IHS

ILS

SLO

AB

V

V

OAB

V

RO2HISOURCE

V

RO2LISINK

ISO

ISO

ISO

enabled
(DE =1)

V

IHS

V

ILS

V

SLO

VA or VB = +12V +125

VA or VB = -7V -100

-7V ≤ VCM ≤ +12V -200 -90 -10 mV

TH

-7V ≤ V

TH

-7v ≤ V

-7V ≤ VCM ≤ +12V (Note 1) 96 200 kΩ

IN

60s 2500

1s 3000

TA = +25°C, V

TA = +25°C2pF

-7V < V

DI = low

-7V < V

DI = high
+1V < V

DI = low
+1V < V

is measured with respect to GND2 3.0 V

is measured with respect to GND2 1.0 V

= +3V 100 kΩ

≤ +12V, TA = 0°C to +70°C103070

CM

≤ +12V, TA = -40°C to +85°C 5 30 70

CM

= 4mA, V

= 4mA, V

< min[(V

Y

< min[(V

Z

< +12V

Z

< +12V

Y

= +3.13V 2.4 V

CC2

= +3.13V 0.4 V

CC2

= 50V (Note 3) 100 10,000 MΩ

ISO

- 1V) +2V]

CC2

- 1V) +2V]

CC2

+25

2.6 V

-25

V

µA

µA

mV

RMS

+3V to +5V, 2500V

RMS

Isolated RS-485/RS-422

Transceivers with ±15kV ESD Protection

_______________________________________________________________________________________ 5

MAX3535E/MXL1535E

SWITCHING ELECTRICAL CHARACTERISTICS (MAX3535E)

(V

CC1

= +3.0V to +5.5V, V

CC2

= +3.13V to +7.5V, RL= 27Ω, CL= 50pF, TA= -40°C to +85°C, unless otherwise noted. Typical values

are at V

CC1

= +3.3V, V

CC2

= +5V, TA= +25°C.)

Data Sample Jitter t

Maximum Data Rate f

Self-Oscillating Frequency f

Driver-Differential Output Delay
Time

Driver-Differential Output
Transition Time

Driver-Output Enable Time t

Driver-Output Disable Time t

Receiver-Propagation Delay Time
to RO1

Receiver-Propagation Delay Time
to RO2

RO1, RO2 Rise or Fall Time tR, t

Receiver-Output Enable Time
RO1

Receiver-Output Disable Time
RO1

Initial Startup Time (from Internal
Communication Fault)

Internal Communication Timeout
Fault Time

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Figure 6 220 285 ns

J

DATA

SOS

t

t

PZL

PHZ

t

PLH1

t

PHL1

t

PLH2

t

PHL2

t

ZL,tZH

t

LZ,tHZ

DD

TD

, t

tJ = 25% of data cell, receiver and driver,

SLO = high (Note 4)
SLO = high, Figure 5 250 450

SLO = low, Figure 5 200 375
SLO = high, Figures 2, 6 490 855
SLO = low, Figures 2, 6 850 1560
SLO = high, Figures 2, 6 30 100
SLO = low, Figures 2, 6 120 220 1000

SLO = high, DI = high or low,

PZH

Figures 3, 7

SLO = high, DI = high or low,

, t

PLZ

Figures 3, 7

,

Figures 4, 8 440 855 ns

,

Figures 4, 8 40 ns

Figures 4, 8 40 ns

F

Figures 4, 9 30 ns

Figures 4, 9 30 ns

(Note 5) 1200 ns

(Note 5) 1200 ns

877 1136 kbps

kHz

ns

ns

730 1400 ns

720 1300 ns

MAX3535E/MXL1535E

+3V to +5V, 2500V

RMS

Isolated RS-485/RS-422

Transceivers with ±15kV ESD Protection

6 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (MXL1535E)

(V

CC1

= +4.5V to +5.5V, V

CC2

= +4.5V to +7.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at V

CC1

= +5V,

V

CC2

= +5V, TA= +25°C.)

Logic-Side Supply Voltage V

Isolated-Side Supply Voltage V

Logic-Side Supply Current I

Isolated-Side Supply Current I

Differential Driver Output V

Driver Output High Voltage V

Driver Common-Mode Output
Voltage

Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

4.5 5.5 V

4.5 7.5 V

1.0 3.0 V

ΔV

CC1

CC2

CC1

CC2

OD

DOH

V

OC

Transformer not driven, ST1 and ST2
unconnected, RE = low, DE = high,

= 0, RO1 = no load

f

DATA

f

= 0, SLO floating,

DATA

RO2 = no load, A, B
floating, Figure 1

RL = 50Ω (RS-422), V

RL = 27Ω (RS-485), V

No load, V
GND2

RL = 27Ω or 50Ω, VOC is measured with
respect to GND2, Figure 1

RL = 27Ω or 50Ω, Figure 1 ±0.2 V

OD

is measured with respect to

DOH

RL = 27Ω 56 70

R

= ∞ 10 16

L

= +4.5V, Figure 1 2.0 3.0

CC2

= +4.5V, Figure 1 1.5 2.5

CC2

5.9 13 mA

mA

V

5.0 V

Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States

Driver Short-Circuit Output
Current

Driver Short-Circuit Foldback
Output Current

ΔV

I

OSD

I

OSFD

RL = 27Ω or 50Ω, Figure 1 ±0.2 V

OC

Driver enabled (DE =1)
DI = high, V
DI = low, V

Driver enabled (DE =1)
DI = high, V
DI = low, V

Driver enabled (DE =1)
DI = high

-7V < V
DI = low

-7V < V

Driver enabled (DE =1)
DI = high
+1V < V
DI = low
+1V < V

> -7V

Y

> -7V

Z

< +12V

Z

< + 12V

Y

< min[(V

Y

< min[(V

Z

< +12V

Z

< +12V

Y

- 1V) +2V]

CC2

- 1V) +2V]

CC2

-250

+25

mA

+250

-25

mA

+3V to +5V, 2500V

RMS

Isolated RS-485/RS-422

Transceivers with ±15kV ESD Protection

_______________________________________________________________________________________ 7

MAX3535E/MXL1535E

ELECTRICAL CHARACTERISTICS (MXL1535E) (continued)

(V

CC1

= +4.5V to +5.5V, V

CC2

= +4.5V to +7.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at V

CC1

= +5V,

V

CC2

= +5V, TA= +25°C.)

Input High Voltage, DE, DI, RE V

Input High Voltage, SLO V

Input Low Voltage, DE, DI, RE V

Input Low Voltage, SLO V

Logic-Side Input Current, DE, DI I

Receiver Input Current I

Receiver Differential Threshold
Voltage

Receiver-Input Hysteresis ΔV

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

VIH is measured with respect to GND1 2.0 1.45 V

IH

V

is measured with respect to GND2 4.0 2.1 V

IHS

VIL is measured with respect to GND1 1.45 0.8 V

V

is measured with respect to GND2 2.1 1.0 V

ILS

VA or VB = +12V +0.25

VA or VB = -7V -0.20

-7V ≤ VCM ≤ +12V -200 -90 -10 mV

-7V ≤ VCM ≤ +12V, TA = 0°C to +70°C 10 30 70

-7V ≤ VCM ≤ +12V, TA = -40°C to +85°C 5 30 70

V

IHS

IL

ILS

INC

AB

TH

TH

±2µA

mA

mV

Receiver-Input Resistance R

Receiver-Input Open-Circuit
Voltage

Receiver-Output High Voltage
(RO1)

Receiver-Output Low Voltage
(RO1)

Driver-Output Leakage Current I

Driver-Output Leakage Current I

Receiver-Output (RO2) High
Voltage

Receiver-Output (RO2) Low
Voltage

DC-Converter Switching
Frequency (ST1, ST2)

V

V

V

V

V

-7V ≤ VCM ≤ +12V (Note 1) 96 140 200 kΩ

IN

OAB

RO1HISOURCE

RO1LISINK

OZ

OZ

RO2H

RO2LISINK

f

SW

= 4mA, V

DE = low

-7V < V

DE = low

-7V < V

I

SOURCE

= 4mA, V

ST1, ST2 not loaded 290 460 590 kHz

= 4mA, V

< +12V, -7V < VZ < +12V

Y

< +12V, -7V < VZ < +12V

Y

= 4mA, V

= +4.5V 3.7 4.3 V

CC1

= +4.5V 0.4 0.8 V

CC1

= +4.5V 2.8 3.4 V

CC2

= +4.5V 0.4 0.8 V

CC2

2.6 V

±30 µA

±30 ±100 µA

MAX3535E/MXL1535E

+3V to +5V, 2500V

RMS

Isolated RS-485/RS-422

Transceivers with ±15kV ESD Protection

8 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (MXL1535E) (continued)

(V

CC1

= +4.5V to +5.5V, V

CC2

= +4.5V to +7.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at V

CC1

= +5V,

V

CC2

= +5V, TA= +25°C.)

DC-Converter Impedance High
ST1, ST2

DC-Converter Impedance Low
ST1, ST2

RE Low Output Current for Fault
Detect

RE High Output Current for Fault
Detect

V

CC2

Falling Trip

V

CC2

Rising Trip

V

CC1

Falling Trip

V

CC1

Rising Trip

Isolation Voltage (Note 2) V

SLO Pullup Resistor R

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Undervoltage-Lockout

Undervoltage-Lockout

Undervoltage-Lockout

Undervoltage-Lockout

R

R

I

I

V

UVL2

V

UVH2

V

UVL1

V

UVH1

OH

OL

OH

ISO

SLO

Figure 13 4 6 Ω

Figure 13 2.5 5 Ω

OL

RE = sink current,
RE = +0.4V, fault not asserted

RE = source current,
RE = +V

60s 2500

1s 3000

V

SLO

- 0.5V, fault asserted

CC1

= +3V 100 kΩ

-40 -50 -80 µA

60 100 140 µA

2.68 2.85 3.02 V

2.77 2.95 3.13 V

2.53 2.69 2.85 V

2.63 2.80 2.97 V

V

RMS