Datasheet

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General Description

The MAX13234E–MAX13237E are +3V to +5.5V pow-

ered EIA/TIA-232 and V.28/V.24 communications inter-

faces with high data-rate capabilities (up to 3Mbps), a

flexible logic voltage interface, and enhanced electro-

static discharge (ESD) protection. All receiver inputs

and transmitter outputs are protected to ±15kV IEC

61000–4-2 Air Gap Discharge, ±8kV IEC 61000-4-2

Contact Discharge, and ±15kV Human Body Model.

The MAX13234E/MAX13235E have two receivers and

two transmitters, while the MAX13236E/MAX13237E

have a single receiver and transmitter. The transmitters

have a low-dropout transmitter output stage, delivering

true RS-232 performance from a +3V to +5.5V supply

based on a dual charge pump. The charge pump

requires only four small 0.1µF capacitors for operation

from a +3.3V supply.

All devices achieve a 1µA supply current using Maxim’s

AutoShutdown Plus™ feature. These devices automati-

cally enter a low-power shutdown mode when the

RS-232 cable is disconnected or the devices driving

the transmitter and receiver inputs are inactive for more

than 30s.

The MAX13234E–MAX13237E are available in space-

saving TQFN and TSSOP packages and operate over

the -40°C to +85°C extended temperature range.

Applications

Features

♦ Data Rate Up to 3Mbps

♦ Low-Voltage Logic Interface

♦ +3V to +5.5V Supply Voltage

♦ AutoShutdown Plus

♦ 1µA Shutdown Current

MAX13234E–MAX13237E

3Mbps RS-232 Transceivers with

Low-Voltage Interface

________________________________________________________________

Maxim Integrated Products

Ordering Information/Selector Guide

19-4343; Rev 0; 10/08

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.

EVALUATION KIT

AVAILABLE

PART

DRIVERS/

RECEIVERS

MAXIMUM

DATA RATE

TEMP RANGE PIN-PACKAGE

MAX13234EEUP+ 2 x 2 250kbps -40°C to +85°C 20 TSSOP

MAX13234EETP+ 2 x 2 250kbps -40°C to +85°C 20 TQFN-EP*

MAX13235EEUP+ 2 x 2 3Mbps -40°C to +85°C 20 TSSOP

MAX13235EETP+ 2 x 2 3Mbps -40°C to +85°C 20 TQFN-EP*

MAX13236EETE+ 1 x 1 250kbps -40°C to +85°C 16 TQFN-EP*

MAX13237EETE+ 1 x 1 3Mbps -40°C to +85°C 16 TQFN-EP*

Telematics

GPS Systems

Industrial Systems

Portable Devices

Wireless Modules

POS Systems

Communication Systems

Data Cables

AutoShutdown Plus is a registered trademark of Maxim

Integrated Products, Inc.

Functional Diagrams continued at end of data sheet.

Denotes a lead-free/RoHS-compliant package.

EP = Exposed pad.

Functional Diagrams

LOGIC-LEVEL TRANSLA

TION

T2IN

T1IN

R1OUT

R2OUT

FORCEOFF

FORCEON

READY

C1+

C1-

C2+

C2-

1.62V to V

3.0V to 5.5V

V+

V-

BYPASS2

GND

RS-232

OUTPUTS

RS-232

INPUTS

TTL/CMOS

OUTPUTS

TTL/CMOS

INPUTS

T1OUT

T2OUT

R1IN

R2IN

MAX13234E

MAX13235E

5kΩ

BYPASS1

Summary of content (16 pages)

PAGE 1
9-4343; Rev 0; 10/08 KIT ATION EVALU E L B A AVAIL 3Mbps RS-232 Transceivers with Low-Voltage Interface ♦ Data Rate Up to 3Mbps ♦ Low-Voltage Logic Interface ♦ +3V to +5.5V Supply Voltage ♦ AutoShutdown Plus ♦ 1µA Shutdown Current Functional Diagrams 1.
PAGE 2
MAX13234E–MAX13237E 3Mbps RS-232 Transceivers with Low-Voltage Interface ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) VCC ...................................................................... -0.3V to +6.0V VL ......................................................................... -0.3V to +6.0V V+ ........................................................................ -0.3V to +7.0V V- ......................................................................... +0.3V to -7.
PAGE 3
Mbps RS-232 Transceivers with Low-Voltage Interface (VCC = +3V to +5.5V, VL = +1.62V to VCC, TA = -40°C to +85°C, C1–C4 = 0.1µF, VCC = VL, tested at 3.3V ±10%. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS +25 V RECEIVER INPUTS Input-Voltage Range -25 Input Threshold Low VIL TA = +25°C Input Threshold High VIH TA = +25°C VCC = +3.3V 0.6 1.2 VCC = +5V 0.8 1.5 V VCC = +3.3V 1.5 2.4 VCC = +5V 1.8 2.4 Input Hysteresis 0.
PAGE 4
MAX13234E–MAX13237E 3Mbps RS-232 Transceivers with Low-Voltage Interface ELECTRICAL CHARACTERISTICS (continued) (VCC = +3V to +5.5V, VL = +1.62V to VCC, TA = -40°C to +85°C, C1–C4 = 0.1µF, VCC = VL, tested at 3.3V ±10%. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL Transition-Region Slew Rate CONDITIONS MIN VCC = +3.
PAGE 5
3Mbps RS-232 Transceivers with Low-Voltage Interface RECEIVER INPUTS TRANSMITTER INPUTS TRANSMITTER OUTPUTS tAUTOSHDN VCC READY tWU tAUTOSHDN tWU 0 V+ V+ VCC 0 VV- Figure 1. AutoShutdown Plus, and READY Timing Diagram T_IN T_OUT R_IN R_OUT CL Figure 2.
PAGE 6
MAX13234E–MAX13237E 3Mbps RS-232 Transceivers with Low-Voltage Interface Test Circuits/Timing Diagram (continued) R_IN tR, tF ≤ 10ns 1.3V tRPHL 1.7V tRPLH VOH R_OUT VOL VL/2 VL/2 Figure 3. Receiver Propagation Delay T_IN T_OUT VO RL CL Figure 4. Transmitter Test Circuit VL tR, tF ≤ 10ns VL/2 T_IN 0 VL/2 tTPHL tTPLH VO 3V 3V 0 0 T_OUT -3V -3V -VO tF SRF = 6/tF SRR = 6/tR tR Figure 5.
PAGE 7
3Mbps RS-232 Transceivers with Low-Voltage Interface TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE 0 MAX13234E/MAX13236E RL = 3kΩ T1 AT 250kbps -2 MAX13234E toc02 2 0 MAX13235E/MAX13237E RL = 3kΩ T1 AT 3Mbps -2 12 MAX13234E/MAX13236E RL = 3kΩ 11 10 SLEW RATE (V/µs) OUTPUT VOLTAGE (V) 2 V+ 4 OUTPUT VOLTAGE (V) V+ 4 SLEW RATE vs. LOAD CAPACITANCE 6 MAX13234E toc01 6 9 MAX13234E toc03 TRANSMITTER OUTPUT VOLTAGE vs.
PAGE 8
Typical Operating Characteristics (continued) (VCC = VL = 3.3V, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. DATA RATE 1.4 1.2 1.0 0.8 0.6 25 MAX13235E 1 TRANSMITTER OPERATING RL = 3kΩ, CL = 150pF 20 15 10 0.4 0 2.1 -15 10 35 60 1.7 1.5 1.1 0.9 0.5 0.01 TEMPERATURE (°C) 0.1 1 3.5 VL (V) V+ 4 MAX13235E/MAX13237E RL = 3kΩ, CL = 150pF 1 TRANSMITTER OPERATING AT 1Mbps -4 8 6 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 6 -2 2.5 1.5 TRANSMITTER OUTPUT VOLTAGE vs.
PAGE 9
3Mbps RS-232 Transceivers with Low-Voltage Interface PIN MAX13234E/ MAX13235E MAX13236E/ MAX13237E NAME FUNCTION TSSOP TQFN-EP TQFN-EP 1 19 14 READY 2 1 16 C1+ 3 20 15 V+ +5.
PAGE 10
MAX13234E–MAX13237E 3Mbps RS-232 Transceivers with Low-Voltage Interface Detailed Description VL Logic Supply Input The MAX13234E–MAX13237E feature a separate logic supply input (VL) that sets the receiver’s output level (VOH), and sets the transmitter’s input thresholds (VIL, V IH ). This feature allows flexibility in interfacing to UARTs or communication controllers that have different logic levels. Connect this input to the host logic supply (1.62V ≤ VL ≤ VCC).
PAGE 11
3Mbps RS-232 Transceivers with Low-Voltage Interface R_IN EDGE DETECT EDGE DETECT FORCEOFF FORCEOFF S 30s TIMER AUTOSHDN POWERDOWN* FORCEON R * POWERDOWN IS ONLY AN INTERNAL SIGNAL. IT CONTROLS THE OPERATIONAL STATUS OF THE TRANSMITTERS AND THE POWER SUPPLIES. FORCEON Figure 6. AutoShutdown Plus and Shutdown Logic Table 1.
PAGE 12
±15kV 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 MAX13234E–MAX13237E have extra protection against static electricity. Maxim’s engineers have developed state-of-the-art structures to protect these pins against ESD of ±15kV without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down.
PAGE 13
3Mbps RS-232 Transceivers with Low-Voltage Interface Human Body Model Figure 8a shows the Human Body Model and Figure 8b shows the current waveform it generates when discharged into a low impedance. This model consists of a 100pF capacitor 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 performance of finished equipment; it does not specifically refer to integrated circuits.
PAGE 14
MAX13234E–MAX13237E 3Mbps RS-232 Transceivers with Low-Voltage Interface High Data Rates The MAX13234E–MAX13237E maintain the RS-232 ±5V minimum transmitter output voltage even at high data rates. Figure 11 shows a transmitter loopback test circuit. Figure 12 shows a loopback test result at 120kbps, and Figure 13 shows the same test at 3Mbps. 1.62V to VCC In Figure 12, all transmitters were driven simultaneously at 120kbps into RS-232 loads in parallel with 1000pF.
PAGE 15
3Mbps RS-232 Transceivers with Low-Voltage Interface TOP VIEW 13 12 11 GND R1IN C2- 6 15 R1OUT V- 7 14 FORCEON T2OUT 8 13 T1IN R2IN 9 12 T2IN R2OUT 10 11 VL VCC 17 FORCEOFF 18 READY 19 V+ 20 MAX13234E MAX13235E *EP + 1 2 TSSOP 3 4 5 V- T1OUT 16 C2- 17 C2+ MAX13234E MAX13235E C1- 5 C1+ 4 16 10 T2IN 9 VL 8 R2OUT 7 R2IN 6 12 11 10 9 FORCEOFF 13 8 TIN READY 14 7 VL V+ 15 6 ROUT C1+ 16 5 RIN T2OUT TQFN MAX13236E MAX13237E *EP + 1
PAGE 16
MAX13234E–MAX13237E 3Mbps RS-232 Transceivers with Low-Voltage Interface Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 20 TSSOP U20-2 21-0066 20 TQFN-EP* T2055-5 21-0140 16 TQFN-EP* T1655-2 21-0140 *EP = Exposed Pad. Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.