Maxim MAX3385EEAP, MAX3385ECWN, MAX3385ECAP Datasheet

________________General Description

The MAX3385E is a 3V-powered EIA/TIA-232 and
V.28/V.24 communications interface with low power
requirements, high data-rate capabilities, and en­hanced electrostatic discharge (ESD) protection. All
transmitter outputs and receiver inputs are protected to
±15kV using IEC 1000-4-2 Air-Gap Discharge, ±8kV
using IEC 1000-4-2 Contact Discharge, and ±15kV
using the Human Body Model.

The transceiver has a proprietary low-dropout transmit­ter output stage, delivering true RS-232 performance
from a +3.0V to +5.5V supply with a dual charge pump.
The charge pump requires only four small 0.1µF capac­itors for operation from a +3.3V supply. Each device is
guaranteed to run at data rates of 250kbps while main­taining RS-232 output levels.

The MAX3385E has two receivers and two drivers. It
features a 1µA shutdown mode that reduces power con­sumption and extends battery life in portable systems.
Its receivers can remain active in shutdown mode,
allowing external devices such as modems to be moni­tored using only 1µA supply current.

The MAX3385E is available in a space-saving SSOP
package in either the commercial (0°C to +70°C) or
extended-industrial (-40°C to +85°C) temperature range.

________________________Applications

Hand-Held Equipment Battery-Powered
Peripherals

Equipment

Printers

____________________________Features

♦ ESD Protection for RS-232 I/O Pins

±15kV—Human Body Model
±8kV—IEC 1000-4-2, Contact Discharge
±15kV—IEC 1000-4-2, Air-Gap Discharge

♦ Latchup Free

♦ 300µA Supply Current

♦ 1µA Low-Power Shutdown with Receivers Active

♦ 250kbps Guaranteed Data Rate
♦ 250µs Time to Exit Shutdown with 3kΩ Load on V+

♦ 6V/µs Guaranteed Slew Rate

♦ Meets EIA/TIA-232 Specifications Down to 3.0V

MAX3385E

†

±15kV ESD-Protected, 3.0V to 5.5V, Low-Power,

up to 250kbps, True RS-232 Transceiver

________________________________________________________________ Maxim Integrated Products 1

Pin Configurations

19-1437; Rev 1; 10/99

†

Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; and other patents pending.

Typical Operating Circuit

Ordering Information

PART

MAX3385ECAP

MAX3385EEAP -40°C to +85°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

20 SSOP

20 SSOP

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone].

MAX3385ECWN 0°C to +70°C 18 SO

Pin Configurations continued at end of data sheet.

TOP VIEW

N.C.

C1+

C1-

C2+

C2-

T2OUT

R2IN

N.C.

1

2

V+

3

4

MAX3385E

5

6

V-

7

8

9

10

SHDN

20

V

19

CC

GND

18

T1OUT

17

R1IN

16

R1OUT

15

T1IN

14

T2IN

13

R2OUT

12

N.C.

11

+3.3V

C

BYPASS

C1

0.1µF

C2

0.1µF

TTL/CMOS

INPUTS

TTL/CMOS

OUTPUTS

V

C1+

C1-

C2+

C2-

T1IN

T2IN

R1OUT

R2OUT

CC

MAX3385E

GND

T1OUT

T2OUT

R1IN

5k

R2IN

5k

SHDN

V+

V-

C3*

0.1µF

C4

0.1µF

RS-232
OUTPUTS

RS-232
INPUTS

SSOP

* C3 CAN BE RETURNED TO EITHER V

NOTE: SEE TABLE 2 FOR CAPACITOR SELECTION

OR GROUND.

CC

MAX3385E

±15kV ESD-Protected, 3.0V to 5.5V, Low-Power,
up to 250kbps, True RS-232 Transceiver

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= T

MIN

to T

MAX

,

unless otherwise noted. Typical values are at T

A

= +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.

VCCto GND..............................................................-0.3V to +6V

V+ to GND (Note 1) ..................................................-0.3V to +7V

V- to GND (Note 1) ...................................................+0.3V to -7V

V+ + |V-| (Note 1) .................................................................+13V

Input Voltages

T_IN, SHDN to GND ..............................................-0.3V to +6V

R_IN to GND .....................................................................±25V

Output Voltages

T_OUT to GND...............................................................±13.2V

R_OUT.....................................................-0.3V to (V

CC

+ 0.3V)

Short-Circuit Duration, T_OUT to GND.......................Continuous

Continuous Power Dissipation (T

A

= +70°C)

20-Pin SSOP (derate 8.00mW/°C above +70°C) ..........640mW

18-Pin SO (derate 9.52mW/°C above +70°C)...............762mW

Operating Temperature Ranges

MAX3385ECAP ....................................................0°C to +70°C

MAX3385ECWN...................................................0°C to +70°C

MAX3385EEAP .................................................-40°C to +85°C

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

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

TA = +25°C

SHDN = VCC, no load

TA = +25°C

TA = +25°C

I

OUT

= 1.6mA

R_OUT, receivers disabled

T_IN, SHDN

T_IN, SHDN

I

OUT

= -1.0mA

CONDITIONS

kΩ357Input Resistance

V0.5Input Hysteresis

V

1.8 2.4

Input Threshold High

1.5 2.4

V

0.8 1.5

Input Threshold Low

0.6 1.2

V-25 +25Input Voltage Range

V

VCC-VCC-

0.6 0.1

Output Voltage High

mA0.3 1Supply Current

V0.4Output Voltage Low

µA±0.05 ±10Output Leakage Current

V0.5Transmitter Input Hysteresis

V0.8Input Logic Threshold Low

2.0
V

2.4

Input Logic Threshold High

UNITSMIN TYP MAXPARAMETER

Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.

VCC= 5.0V

VCC= 3.3V

VCC= 3.3V

VCC= 5.0V

VCC= 3.3V

VCC= 5.0V

T_IN, SHDN

µA±0.01 ±1Input Leakage Current

SHDN = GND

µA110Shutdown Supply Current

DC CHARACTERISTICS (VCC= +3.3V or +5V, TA= +25°C)

LOGIC INPUTS

RECEIVER OUTPUTS

RECEIVER INPUTS

MAX3385E

±15kV ESD-Protected, 3.0V to 5.5V, Low-Power,

up to 250kbps, True RS-232 Transceiver

_______________________________________________________________________________________ 3

Note 2: Transmitter skew is measured at the transmitter zero cross points.

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= T

MIN

to T

MAX

,

unless otherwise noted. Typical values are at T

A

= +25°C.)

Receiver input to receiver output,
C

L

= 150pF

RL= 3kΩ, CL= 1000pF,
one transmitter switching

VCC= 3.3V,
T

A

= +25°C,
RL= 3kΩ to 7kΩ,
measured from +3V
to -3V or -3V to +3V

V

OUT

≥ +3.7V, R

LOAD

at V+ = 3kΩ

(Note 2)

CONDITIONS

µs

0.15t

PLH

Receiver Propagation Delay

0.15t

PHL

kbps250Maximum Data Rate

630

µs250Time to Exit Shutdown

ns100

t

PHL

- t

PLH



Transmitter Skew

ns50

t

PHL

- t

PLH



Receiver Skew

UNITSMIN TYP MAXSYMBOLPARAMETER

VCC= V+ = V- = 0, transmitter output = ±2V

All transmitter outputs loaded with 3kΩ to ground

IEC1000-4-2 Contact Discharge

IEC1000-4-2 Air Discharge

Human Body Model

VCC= 0 or 3V to 5.5V, V

OUT

= ±12V, transmitters disabled

CONDITIONS

Ω300 10MOutput Resistance

V±5 ±5.4Output Voltage Swing

±8

R_IN, T_OUT

±15

kV

±15

mA±60Output Short-Circuit Current

µA±25Output Leakage Current

UNITSMIN TYP MAXPARAMETER

TIMING CHARACTERISTICS

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= T

MIN

to T

MAX

,

unless otherwise noted. Typical values are at T

A

= +25°C.)

CL= 150pF to
1000pF

CL= 150pF to
2500pF

V/µs

430

Transition-Region Slew Rate

TRANSMITTER OUTPUTS

ESD PROTECTION

PIN

MAX3385E

±15kV ESD-Protected, 3.0V to 5.5V, Low-Power,
up to 250kbps, True RS-232 Transceiver

4 _______________________________________________________________________________________

__________________________________________Typical Operating Characteristics

(VCC= +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ and CL, TA = +25°C, unless otherwise noted.)

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

0 1000 2000 3000 4000 5000

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3385E-01

LOAD CAPACITANCE (pF)

TRANSMITTER OUTPUT VOLTAGE (V)

T1 TRANSMITTING AT 250kbps
T2 TRANSMITTING AT 15.6kbps

V

OUT+

V

OUT-

0

6

2

4

10

8

14

12

16

0 1000 2000 3000 4000 5000

SLEW RATE vs. LOAD CAPACITANCE

MAX3885E-02

LOAD CAPACITANCE (pF)

SLEW RATE (V/µs)

+SLEW

FOR DATA RATES UP TO 250kbps

-SLEW

0

25

20

15

5

10

35

30

40

45

0 20001000 3000 4000 5000

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3885E-03

LOAD CAPACITANCE (pF)

SUPPLY CURRENT (mA)

250kbps

120kbps

20kbps

T1 TRANSMITTING AT 250kbps
T2 TRANSMITTING AT 15.6kbps

1 No Connection. Not internally connected.N.C.

3 +5.5V generated by the charge pump.V+

4 Negative terminal of the voltage-doubler charge-pump capacitor.C1-

5 Positive terminal of inverting charge-pump capacitor.C2+

6 Negative terminal of inverting charge-pump capacitor.C2-

7 -5.5V generated by the charge pump.V-

8, 15 RS-232 Transmitter OutputsT_OUT

9, 14 RS-232 Receiver InputsR_IN

10, 13 TTL/CMOS Receiver OutputsR_OUT

11, 12 TTL/CMOS Transmitter InputsT_IN

16 GroundGND

17 +3.0V to +5.5V Supply VoltageV

CC

18 Active-Low Shutdown-Control Input. Drive low to shut down transmitters and charge

SHDN

FUNCTIONNAME

______________________________________________________________ Pin Description

2 Positive terminal of the voltage-doubler charge-pump capacitor.C1+

PIN

2

1, 10, 11

3

4

5

6

7

8, 17

9, 16

12, 15

13, 14

18

19

20

SO SSOP