Datenblatt für MAX14783E von Analog Devices Inc./Maxim Integrated

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General Description

The MAX14783E is a half-duplex RS-485/422 transceiver

that operates at either 3.3V or 5V rails with high ±35kV

ESD performance and up to 42Mbps data rate. The

device is optimized for high speeds over extended cable

runs while maximizing tolerance to noise.

The MAX14783E is available in 8-pin µMAX®, 8-pin SO,

and 8-pin TDFN-EP packages. The device in the TDFN-EP

package operates over the -40°C to +125°C temperature

range. The MAX14783E in the μMAX and SO packages

operates over the -40°C to +85°C and -40°C to +125°C

temperature ranges.

Applications

● Motion Controllers

● Field Bus Networks

● Encoder Interfaces

● Backplane Busses

Benefits and Features

● Integrated Protection Increases Robustness

• High ESD Protection

±35kV HBM ESD per JEDEC JS-001-2012

±20kV Air Gap per IEC 61000-4-2

±12kV Contact ESD per IEC 61000-4-2

• Short-Circuit Protected Outputs

• True Fail-Safe Receiver Prevents False Transition

on Receiver Input Short or Open Events

• Hot-Swap Capability Eliminates False Transitions

During Power-Up or Hot Insertion

● 3V to 5.5V Supply Voltage Range

● High-Speed Data Rates up to 42Mbps

● -40°C to +125°C Operating Temperature

● Allows Up to 32 Transceivers on the Bus

● Low 10µA (max) Shutdown Current for Lower Power

Consumption

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

19-6734; Rev 1; 1/15

Ordering Information appears at end of data sheet.

µMAX is a registered trademark of Maxim Integrated Products, Inc,.

SHUTDOWN

VCC

GND

MAX14783E

Functional Diagram

EVALUATION KIT AVAILABLE

(Voltages referenced to GND.)

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

RO ............................................................ -0.3V to (VCC + 0.3V)

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

A, B (VCC ≥ 3.6V) .............................................-8.0V to +13.0V

A, B (VCC < 3.6V) .............................................-9.0V to +13.0V

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

Operating Temperature Range

MAX14783EE_ ............................................... -40°C to +85°C

MAX14783EA_ ............................................. -40°C to +125°C

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

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

Continuous Power Dissipation (TA = +70°C)

µMAX (derate at 4.8mW/°C above +70°C) .................387mW

SO (derate at 7.6mW/°C above +70°C) ......................606mW

TDFN-EP (derate at 24.4mW/°C above +70°C) ........ 1951mW

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

Soldering Temperature (reflow) ...................................... +260°C

Junction-to-Case Thermal Resistance (θJC)

8-pin µMAX ..................................................................42°C/W

8-pin SO ......................................................................38°C/W

8-pin TDFN-EP ..............................................................8°C/W

Junction-to-Ambient Thermal Resistance (θJA)

8-pin µMAX ................................................................206°C/W

8-pin SO ....................................................................132°C/W

8-pin TDFN-EP ............................................................41°C/W

(Note 1)

(VCC = +3.0V to +5.5V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +5V and TA = +25°C.) (Notes 2, 3)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER SUPPLY

Supply Voltage VCC 3.0 5.5 V

Supply Current ICC DE = VCC, RE = GND, no load 1.9 4 mA

Shutdown Supply Current ISHDN DE = GND, RE = VCC 10 µA

DRIVER

Differential Driver Output VOD

VCC = 4.5V, RL = 54Ω, Figure 1 2.1

VVCC = 3V, RL = 100Ω, Figure 1 2.0

VCC = 3V, RL = 54Ω, Figure 1 1.5

Change in Magnitude of Differential

Output Voltage ΔVOD RL = 54Ω or 100Ω, Figure 1 (Note 4) -0.2 0 +0.2 V

Driver Common-Mode Output

Voltage VOC RL = 54Ω or 100Ω, Figure 1 VCC / 2 3 V

Change in Magnitude of Common-

Mode Voltage ΔVOC RL = 54Ω or 100Ω, Figure 1 (Note 4) -0.2 +0.2 V

Single-Ended Driver Output High VOH A or B output, IA or B = -20mA 2.2 V

Single-Ended Driver Output Low VOL A or B output, IA or B = 20mA 0.8 V

Differential Output Capacitance COD DE = RE = VCC, f = 4MHz 12 pF

Driver Short-Circuit Output Current |IOST|0 ≤ VOUT ≤ +12V, output low 250 mA

-7V ≤ VOUT ≤ VCC, output high 250 mA

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

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.maximintegrated.com/thermal-tutorial.

Absolute Maximum Ratings

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.

Package Thermal Characteristics

Electrical Characteristics

(VCC = +3.0V to +5.5V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +5V and TA = +25°C.) (Notes 2, 3)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

RECEIVER

Input Current IA, B DE = GND, VCC = GND

or +5.5V

VIN = +12V 400 1000 µA

VIN = -7V -800 300

Differential Input Capacitance CA, B Between A and B, DE = GND, f = 4MHz 12 pF

Receiver Differential Threshold

Voltage VTH -7V ≤ VCM ≤ +12V -200 -105 -10 mV

Receiver Input Hysteresis ΔVTH VCM = 0V 10 mV

Receiver Input Resistance RIN -7V ≤ VCM ≤ +12V 12 kΩ

LOGIC INTERFACE (DI, DE, RE, RO)

Input Voltage High VIH DE, DI, RE 2.0 V

Input Voltage Low VIL DE, DI, RE 0.8 V

Input Hysteresis VHYS DE, DI, RE 50 mV

Input Current IIN DE, DI, RE ±1 µA

Input Impedance on First Transition DE, RE 1 10 kΩ

RO Output Voltage High VOHRO

RE = GND, IRO = -2mA,

(VA - VB) > 200mV VCC - 1.5 V

RO Output Voltage Low VOLRO RE = GND, IRO = 2mA,

(VA - VB) < -200mV 0.4 V

Receiver Tri-State Output Current IOZR RE = VCC, 0 ≤ VRO ≤ VCC ±1 µA

Receiver Output Short-Circuit

Current IOSR 0 ≤ VRO ≤ VCC ±110 mA

PROTECTION

Thermal Shutdown Threshold TSHDN Temperature rising +160 °C

Thermal Shutdown Hysteresis 15 °C

ESD Protection on A and B Pins

IEC 61000-4-2 Air Gap Discharge to GND ±20

kVIEC 61000-4-2 Contact Discharge to GND ±12

Human Body Model ±35

ESD Protection, All Other Pins Human Body Model ±2 kV

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Electrical Characteristics (continued)

(VCC = +3V to +5.5V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +5V and TA = +25°C.) (Notes 2, 3, 5)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DRIVER

Driver Propagation Delay tDPLH RL = 54Ω, CL = 50pF,

Figures 2 and 3

20 ns

tDPHL 20

Driver Differential Output Rise or

Fall Time tHL, tLH RL = 54Ω, CL = 50pF,

Figures 2 and 3 7 ns

Differential Driver Output Skew

|tDPLH - tDPHL|tDSKEW RL = 54Ω, CL = 50pF,

Figures 2 and 3 (Note 6) 3 ns

Maximum Data Rate DRMAX

MAX14783EATA 42

Mbps

MAX14783EEUA 30

MAX14783EESA 40

MAX14783EAUA

3.0V ≤ VCC ≤

3.6V 42

3.0V ≤ VCC ≤

5.5V 6

MAX14783EASA

3.0V ≤ VCC ≤

3.6V 42

3.0V ≤ VCC ≤

5.5V 16

Driver Enable to Output High tDZH RL = 110Ω, CL = 50pF,

Figures 4 and 5 (Note 7) 30 ns

Driver Enable to Output Low tDZL RL = 110Ω, CL = 50pF,

Figures 4 and 5 (Note 7) 30 ns

Driver Disable Time from Low tDLZ RL = 110Ω, CL = 50pF,

Figures 4 and 5 30 ns

Driver Disable Time from High tDHZ RL = 110Ω, CL = 50pF,

Figures 4 and 5 30 ns

Driver Enable from Shutdown to

Output High tDLZ(SHDN) RL = 110Ω, CL = 15pF,

Figures 4 and 5 (Note 7) 6µs

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Switching Characteristics MAX14783E

(VCC = +3V to +5.5V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +5V and TA = +25°C.) (Notes 2, 3, 5)

Note 2: All devices 100% production tested at TA = +25°C. Specifications over temperature are guaranteed by design.

Note 3: All currents into the device are positive; all currents out of the device are negative. All voltages are referenced to ground,

unless otherwise noted.

Note 4: ΔVOD and ΔVOC are the changes in VOD and VOC, respectively, when the DI input changes state.

Note 5: Capacitive load includes test probe and fixture capacitance.

Note 6: Guaranteed by design; not production tested.

Note 7: The timing parameter refers to the driver or receiver enable delay, when the device has exited the initial hot-swap protect

state and is in normal operating mode.

Note 8: Shutdown is enabled by driving RE high and DE low. The device is guaranteed to have entered shutdown after tSHDN has

elapsed.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Driver Enable from Shutdown to

Output Low tDHZ(SHDN) RL = 110Ω, CL = 15pF,

Figures 4 and 5 (Note 7) 6µs

Time to Shutdown tSHDN (Note 7) 50 800 ns

RECEIVER

Receiver Propagation Delay tRPLH CL = 15pF, Figures 6 and 7 25 ns

tRPHL 25

Receiver Output Skew tRSKEW CL = 15pF, Figures 6 and 7

(Note 6) 2 ns

Maximum Data Rate DRMAX 42 Mbps

Receiver Enable to Output High tRZH RL = 1kΩ, CL = 15pF,

Figure 8 (Note 7) 30 ns

Receiver Enable to Output Low tRZL RL = 1kΩ, CL = 15pF,

Figure 8 (Note 7) 30 ns

Receiver Disable Time from Low tRLZ RL = 1kΩ, CL = 15pF, Figure 8 30 ns

Receiver Disable Time from High tRHZ RL = 1kΩ, CL = 15pF, Figure 8 30 ns

Receiver Enable from Shutdown to

Output High tRLZ(SHDN) RL = 1kΩ, CL = 15pF,

Figure 8 (Note 7) 6µs

Receiver Enable from Shutdown to

Output Low tRHZ(SHDN) RL = 1kΩ, CL = 15pF,

Figure 8 (Note 7) 6µs

Time to Shutdown tSHDN (Note 7) 50 800 ns

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Switching Characteristics MAX14783E (continued)

Figure 1. Driver DC Test Load Figure 2. Driver Timing Test Circuit

Figure 3. Driver Propagation Delays

VOD

VOC

RLCL

VOD

VCC

1.5V 1.5V

tDPHL

tDPLH

VOD

10%

90%

10%

90%

-VO

VOD

tDSKEW = |tDPLH - tDPHL|

VOD = [VA - VB]

VCC

f = 1MHz, tLH = 3ns, tHL = 3ns

tLH tHL

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Test and Timing Diagrams

Figure 4. Driver Enable and Disable Times (tDZH, tDHZ)

Figure 5. Driver Enable and Disable Times (tDZL, tDLZ)

Figure 6. Receiver Propagation Delay Test Circuit

0.25V

1.5V

tDZH, tDZH(SHDN)

tDHZ

VCC

VOH

1.5V

OUT

RL = 110Ω

50Ω

OUT

GND OR VCC

GENERATOR

50pF

RL = 110Ω

50Ω

OUT

0 OR VCC

VCC

GENERATOR

0.25V

1.5V

tDZL, tDZL(SHDN)

tDLZ

VCC

1.5V

VCC

OUT

VOL

VID

ATE R

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Figure 8. Receiver Enable and Disable Times

Figure 7. Receiver Propagation Delays

GENERATOR 50Ω

1kΩ

15pF

-1.5V

+1.5V

S1 VCC

VID

tRHZ tRLZ

0.25V

1.5V 1.5V

0 0

S1 OPEN

S2 CLOSED

S3 = +1.5V

S1 OPEN

S2 CLOSED

S3 = +1.5V

S1 CLOSED

S2 OPEN

S3 = -1.5V

S1 CLOSED

S2 OPEN

S3 = -1.5V

VOH

VCC

1.5V1.5V

VCC

tRZL, tRZL(SHDN)

VOL

VCC

VOL

tRZH, tRZH(SHDN)

VCC

VOH

VOL

tRPHL

1.5V 1.5V

tRSKEW = |tRPHL - tRPLH|

tRPLH

-1V

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

(VCC = +5V, TA = +25°C, unless otherwise specified.)

NO-LOAD SUPPLY CURRENT

vs. TEMPERATURE

MAX14783E toc01

TEMPERATURE (°C)

SUPPLY CURENT (mA)

1109580655035205-10-25

0.5

1.0

1.5

2.0

2.5

3.0

-40 125

DE = VCC

RE = GND

VCC = 3.3V

VCC = 5V

SHUTDOWN SUPPLY CURRENT

vs. TEMPERATURE

MAX14783E toc02

TEMPERATURE (°C)

SUPPLY CURENT (µA)

1109580655035205-10-25

-40 125

DE = GND

RE = VCC

VCC = 3.3V

VCC = 5V

SUPPLY CURRENT vs. DATA RATE

MAX14783E toc03

DATA RATE (Mbps)

SUPPLY CURENT (mA)

302010

100

120

0 40

DE = VCC VCC = 5V, 54Ω LOAD

VCC = 3.3V, 54Ω LOAD

VCC = 5V, NO LOAD

VCC = 3.3V, NO LOAD

RECEIVER-OUTPUT HIGH VOLTAGE

vs. OUTPUT CURRENT

MAX14783E toc04

OUTPUT CURRENT (mA)

OUTPUT HIGH VOLTAGE (V)

-50-40-30-20-10

0 -60

OUTPUT SOURCING CURRENT

VCC = 3.3V

VCC = 5V

RECEIVER-OUTPUT LOW VOLTAGE

vs. OUTPUT CURRENT

MAX14783E toc05

OUTPUT CURRENT (mA)

OUTPUT LOW VOLTAGE (V)

5040302010

0 60

OUTPUT SINKING CURRENT

VCC = 3.3V

VCC = 5V

DRIVER OUTPUT CURRENT

vs. DIFFERENTIAL OUTPUT VOLTAGE

MAX14783E toc06

DIFFERENTIAL OUTPUT VOLTAGE (V)

DRIVER OUTPUT CURRENT (mA)

4321

120

160

0 5

VCC = 3.3V

VCC = 5V

DIFFERENTIAL DRIVER OUTPUT

VOLTAGE vs. TEMPERATURE

MAX14783E toc07

TEMPERATURE (°C)

DIFFERENTIAL DRIVER OUTPUT VOLTAGE (V)

1109580655035205-10-25

1.5

1.0

0.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

-40 125

RL = 54Ω

CL = 50pF

VCC = 3.3V

VCC = 5V

DRIVER OUTPUT CURRENT

vs. OUTPUT HIGH VOLTAGE

MAX14783E toc08

OUTPUT HIGH VOLTAGE (V)

OUTPUT CURRENT (mA)

431 2-5 -4 -3 -2 -1 0-6

-20

-40

-60

-80

-100

-120

-140

-160

-180

-7 5

VCC = 3.3V

VCC = 5V

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

Maxim Integrated

│

www.maximintegrated.com

Typical Operating Characteristics

HH R AV W1 9W1 , [‘(‘1 ,/—""\ /"_‘”\ *Aﬁ ‘ . 1H,“ NJ” _ \5‘ \__,J;\,J\..Ju 7W 4 ; \,,, f

(VCC = +5V, TA = +25°C, unless otherwise specified.)

DRIVER OUTPUT CURRENT

vs. OUTPUT LOW VOLTAGE

MAX14783E toc09

OUTPUT LOW VOLTAGE (V)

DRIVER OUTPUT CURENT (mA)

108642

100

120

140

160

180

0 12

VCC = 3.3V

VCC = 5V

DRIVER PROPAGATION DELAY

vs. TEMPERATURE

MAX14783E toc10

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

1109580655035205-10-25

-40 125

tDPHL, VCC = 3.3V

tDPHL, VCC = 5V

tDPLH, VCC = 3.3V

tDPLH, VCC = 5V

RL = 54Ω

CL = 50pF

DIFFERENTIAL DRIVER SKEW

vs. TEMPERATURE

MAX14783E toc11

TEMPERATURE (°C)

DIFFERENTIAL DRIVER SKEW (ns)

1109580655035205-10-25

-40 125

VCC = 3.3V

VCC = 5V

RL = 54Ω

CL = 50pF

DRIVER-OUTPUT RISE /FALL TIME

vs. TEMPERATURE

MAX14783E toc12

TEMPERATURE (°C)

DRIVER-OUTPUT RISE/FALL TIME (ns)

1109580655035205-10-25

-40 125

RL = 54Ω

CL = 50pF tHL, VCC = 3.3V

tLH, VCC = 5V

tHL, VCC = 5V

tLH, VCC = 3.3V

DRIVER-OUTPUT TRANSITION SKEW

vs. TEMPERATURE

MAX14783E toc13

TEMPERATURE (°C)

DRIVER-OUTPUT TRANSITION SKEW (ns)

1109580655035205-10-25

0.5

1.0

1.5

2.0

2.5

3.0

-40 125

VCC = 3.3V

VCC = 5V

RL = 54Ω

CL = 50pF

RECEIVER PROPAGATION DELAY

vs. TEMPERATURE

MAX14783E toc14

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

1109580655035205-10-25

-40 125

CL = 15pF

tRPLH, VCC = 3.3V

tRPHL, VCC = 5V

tRPHL, VCC = 3.3V

tRPLH, VCC = 5V

DRIVER/RECEIVER

PROPAGATION DELAY

MAX14783E toc15

10ns/div

VCC = 3.3V

CL = 8pF 5V/div

2V/div

5V/div

A /B

DIFFERENTIAL INPUT CAPACITANCE

vs. FREQUENCY

MAX14783E toc16

FREQUENCY (MHz)

CAPACITANCE (pF)

0 30

DE = GND

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

Maxim Integrated

│

www.maximintegrated.com

Typical Operating Characteristics (continued)

DRIVER PROPAGATION DELAY

vs. TEMPERATURE

MAX14783E toc10

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

1109580655035205-10-25

-40 125

tDPHL, VCC = 3.3V

tDPHL, VCC = 5V

tDPLH, VCC = 3.3V

tDPLH, VCC = 5V

RL = 54Ω

CL = 50pF

*EP

*CONNECT EXPOSED PAD (EP) TO GND

1 3 4

8 6 5

VCC A GND

RO DE DIRE

TDFN-EP

TOP VIEW

VCC

GND

MAX14783E

µMAX/SO

PIN NAME FUNCTION

1 RO Receiver Output. See Function Tables.

2RE Receiver Output Enable. Drive RE low to enable RO. Drive RE high to disable the receiver. RO is high

impedance when RE is high. Drive RE high and pull DE low to enter low-power shutdown mode.

3 DE

Driver Output Enable. Drive DE high to enable the driver. Drive DE low to disable the driver. Driver

outputs are high-impedance when the driver is disabled. Drive RE high and pull DE low to enter low-

power shutdown mode.

4DI Driver Input. With DE high, a low on DI forces the A output low and the B output high. Similarly, a high

on DI forces the A output high and B output low.

5 GND Ground

6ANoninverting RS-485/RS-422 Receiver Input and Driver Output

7B Inverting RS-485/RS-422 Receiver Input and Driver Output

8 VCC Positive Supply Voltage Input. Bypass VCC with a 0.1µF ceramic capacitor to ground.

— EP Exposed Pad (TDFN only). Connect EP to GND.

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Pin Description

Pin Configuration

TRANSMITTING

INPUTS OUTPUTS MODE

RE DE DI B A

X 1 1 0 1 Active

X 1 0 1 0 Active

0 0 X High Impedance Driver Disabled

1 0 X High Impedance Shutdown

RECEIVING

INPUTS OUTPUTS MODE

RE DE A-B RO

0 X ≥ -10mV 1 Active

0 X ≤ -200mV 0 Active

0 X Open/Shorted 1 Active

1 1 X High Impedance Receiver Disabled

1 0 X High Impedance Shutdown

X = Don’t care

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Function Tables

Detailed Description

The MAX14783E is a 3.3V/5V ESD-protected RS-485/

RS-422 transceiver intended for high-speed, half-duplex

communications. Integrated hot-swap functionality elimi-

nates false transitions on the bus during power-up or hot

insertion.

The device features fail-safe receiver inputs guaranteeing

a logic-high receiver output when inputs are shorted or

open. The IC has a 1-unit load receiver input impedance,

allowing up to 32 transceivers on the bus.

True Fail Safe

The MAX14783E guarantees a logic-high receiver output

when the receiver inputs are shorted or open, or when

they are connected to a terminated transmission line with

all drivers disabled. If the differential receiver input voltage

(A–B) is greater than or equal to -10mV, RO is logic-high.

Driver Single-Ended Operation

The A and B outputs can either be used in the standard

differential operating mode, or can be used as single-

ended outputs. Since the A and B driver outputs swing

rail-to-rail, they can individually be used as standard TTL

logic outputs.

Hot-Swap Capability

Hot-Swap Inputs

When circuit boards are inserted in a hot or powered

backplane, disturbances on the enable inputs and dif-

ferential receiver inputs can lead to data errors. Upon

initial circuit board insertion, the processor undergoes its

power-up sequence. During this period, the processor

output drivers are high impedance and are unable to drive

the DE and RE inputs of the MAX14783E to a defined

logic level. Leakage currents up to 10µA from the high-

impedance outputs of a controller could cause DE and RE

to drift to an incorrect logic state. Additionally, parasitic

circuit board capacitance could cause coupling of VCC

or GND to DE and RE. These factors could improperly

enable the driver or receiver. The MAX14783E features

integrated hot-swap inputs that help to avoid these poten-

tial problems.

When VCC rises, an internal pulldown circuit holds DE

low and RE high. After the initial power-up sequence, the

pulldown circuit becomes transparent, resetting the hot-

swap-tolerable inputs.

Hot-Swap Input Circuitry

The DE and RE enable inputs feature hot-swap capabil-

ity. At the input, there are two nMOS devices, M1 and M2

(Figure 9). When VCC ramps from 0V, an internal 10µs

timer turns on M2 and sets the SR latch that also turns

Figure 9. Simplified Structure of the Driver Enable (DE) Pin

VCC

TIMER

5kΩ (typ)

10µs

100µA 500µA

M2M1

DRIVER

ENABLE

(HOT SWAP)

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

on M1. Transistors M2 (a 500µA current sink) and M1 (a

100µA current sink) pull DE to GND through a 5kΩ (typ)

resistor. M2 is designed to pull DE to the disabled state

against an external parasitic capacitance up to 100pF that

can drive DE high. After 10µs, the timer deactivates M2

while M1 remains on, holding DE low against three-state

leakages that can drive DE high. M1 remains on until an

external source overcomes the required input current.

At this time, the SR latch resets and M1 turns off. When

M1 turns off, DE reverts to a standard, high-impedance

CMOS input. Whenever VCC drops below 1V, the hot-

swap input is reset.

A complementary circuit employing two pMOS devices

pulls RE to VCC.

±35kV ESD Protection

ESD protection structures are incorporated on all pins

to protect against electrostatic discharges encountered

during handling and assembly. The driver outputs and

receiver inputs of the MAX14783E have extra protection

against static electricity. The ESD structures withstand

high ESD in all states: normal operation, shutdown, and

powered down. After an ESD event, the MAX14783E

keeps working without latch-up or damage.

ESD protection can be tested in various ways. The trans-

mitter outputs and receiver inputs of the MAX14783E are

characterized for protection to the following limits:

● ±35kV HBM

● ±20kV using the Air-Gap Discharge method specified

in IEC 61000-4-2

● ±12kV using the Contact Discharge method specified

in IEC 61000-4-2

ESD Test Conditions

ESD performance depends on a variety of conditions.

Contact Maxim for a reliability report that documents test

setup, test methodology, and test results.

Human Body Model (HBM)

Figure 10 shows the HBM, and Figure 11 shows the cur-

rent waveform it generates when discharged into a low-

impedance state. This model consists of a 100pF capaci-

tor charged to the ESD voltage of interest, which is then

discharged into the test device through a 1.5kΩ resistor.

IEC 61000-4-2

The IEC 61000-4-2 standard covers ESD testing and per-

formance of finished equipment. However, it does not spe-

cifically refer to integrated circuits. The MAX14783E helps

in designing equipment to meet IEC 61000-4-2 without the

need for additional ESD protection components.

The major difference between tests done using the HBM

and IEC 61000-4-2 is higher peak current in IEC 61000-

4-2 because series resistance is lower in the IEC 61000-

4-2 model. Hence, the ESD withstand voltage measured

to IEC 61000-4-2 is generally lower than that measured

using the HBM.

Figure 10. Human Body ESD Test Model Figure 11. Human Body Current Waveform

CHARGE CURRENT-

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

100pF

1MΩ

1.5kΩ

HIGH-

VOLTAGE

SOURCE

DEVICE

UNDER

TEST

IP 100%

90%

36.8%

tRL TIME

tDL

CURRENT WAVEFORM

PEAK-TO-PEAK RINGING

(NOT DRAWN TO SCALE)

10%

AMPERES

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Figure 12 shows the IEC 61000-4-2 model, and Figure

13 shows the current waveform for IEC 61000-4-2 ESD

Contact Discharge test.

Applications Information

Driver Output Protection

Two mechanisms prevent excessive output current and

power dissipation caused by faults or by bus connec-

tion. The first, a current limit on the output stage provides

immediate protection against short circuits over the whole

common-mode voltage range. The second, a thermal-shut-

down circuit, forces the driver outputs into a high-imped-

ance state if the die temperature exceeds +160°C (typ).

Low-Power Shutdown Mode

Low-power shutdown mode is initiated by bringing RE

high and DE low. In shutdown, the devices draw less than

10µA of supply current.

RE and DE can be connected together and driven simul-

taneously. The MAX14783E is guaranteed not to enter

shutdown if RE is high and DE is low for less than 50ns.

If the inputs are in this state for at least 800ns (max), the

device is guaranteed to enter shutdown.

Typical Applications

The MAX14783E transceiver is designed for bidirectional

data communications on multipoint bus transmission

lines. Figure 14 shows a typical network application cir-

cuit. To minimize reflections, terminate the line at both

ends with its characteristic impedance and keep stub

lengths off the main line as short as possible.

Figure 12. IEC 61000-4-2 ESD Test Model

Figure 14. Typical Half-Duplex RS-485 Network

Figure 13. IEC 61000-4-2 ESD Generator Current Waveform

CHARGE CURRENT-

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

150pF

50MΩ TO 100MΩ

330Ω

HIGH-

VOLTAGE

SOURCE

DEVICE

UNDER

TEST

DI RO DE

D D

B B

AAA

120Ω120Ω

RE RE

MAX14783E

tR = 0.7ns TO 1ns 30ns

60ns

100%

90%

10%

IPEAK

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

+Denotes [ea11(PbHree/RoHsrcompllanI package

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

8 µMAX U8+1 21-0036 90-0092

8 SOIC S8+4 21-0041 90-0096

8 TDFN-EP T833+2 21-0137 90-0059

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

www.maximintegrated.com Maxim Integrated

│

Package Information

For the latest package outline information and land patterns

(footprints), go to www.maximintegrated.com/packages. Note

that a “+”, “#”, or “-” in the package code indicates RoHS status

only. Package drawings may show a different suffix character, but

the drawing pertains to the package regardless of RoHS status.

Chip Information

PROCESS: BiCMOS

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

*EP = Exposed paddle.

PART SUPPLY RANGE DATA RATE (MAX) TEMP RANGE PIN-PACKAGE

MAX14783EEUA+ 3.0V to 5.5V 30Mbps -40°C to +85°C 8 µMAX

MAX14783EESA+ 3.0V to 5.5V 40Mbps -40°C to +85°C 8 SO

MAX14783EATA+ 3.0V to 5.5V 42Mbps -40°C to +125°C 8 TDFN-EP*

MAX14783EASA+ 3.0V to 3.6V 42Mbps -40°C to +125°C 8 SO

3.0V to 5.5V 16Mbps

MAX14783EAUA+ 3.0V to 3.6V 42Mbps -40°C to +125°C 8 µMAX

3.0V to 5.5V 6Mbps

Ordering Information

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

06/13 Initial release —

1 1/15 Updated page 1 content

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. The parametric values (min and max limits)

shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

│

MAX14783E High-Speed 3.3V/5V RS-485/RS-422 Transceiver

with ±35kV HBM ESD Protection

Revision History

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.

Datenblatt für MAX14783E von Analog Devices Inc./Maxim Integrated

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