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MAX1488ECPD

_______________General Description

The MAX1488E quad, low-power line driver is designed for EIA/TIA-232, EIA/TIA-562, and CCITT V.28 commu-nications in harsh environments. Each transmitter out-put is protected against ±15kV electrostatic discharge (ESD) shocks. The inputs are TTL and CMOS compati-ble with minimal loading. The outputs feature internally controlled slew-rate limiting and current limiting. This device has a guaranteed 120kbps data rate. Power-supply current is less than 180μA over a ±4.5V to ±13.2V supply voltage range.

The MAX1488E is pin compatible with the MC1488,MC14C88, SN75188, SN75C188, DS1488, and DS14C88. It is available in 14-pin plastic DIP and SO packages.

________________________Applications

PC Motherboards Modems

Interface Data Terminal Equipment (DTE) with Data Circuit-Terminating Equipment (DCE)Equipment Meeting IEC1000-4-2

(formerly IEC801-2) or ±15kV ESD Protection

____________________________Features

o ESD Protection:

±15kV—Human Body Model

±6kV—IEC801-2, Contact Discharge ±15kV—IEC801-2, Air-Gap Discharge o Latchup Free, Even During an ESD Event o Low 85μA Supply Current from I EE or I CC o Guaranteed 120kbps Data Rate

o No External Capacitors Required for Slew-Rate Limiting o Pin Compatible with MC1488, MC14C88, SN75188,SN75C188, DS1488, and DS14C88

MAX1488E

±15kV ESD-Protected, Quad, Low-Power

RS-232 Line Driver

________________________________________________________________Maxim Integrated Products 1

__________________Pin Configuration

__________Typical Operating Circuit

Call toll free 1-800-998-8800 for free samples or literature.

19-2403; Rev 0; 8/95

M A X 1488E

±15kV ESD-Protected, Quad, Low-Power RS-232 Line Driver

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V CC = 4.5V to 13.2V, V EE = -4.5V to -13.2V, T A = 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.

Positive Supply Voltage (V CC ).............................................+14V Negative Supply Voltage (V EE ).............................................-14V Input Voltage (V IN ).................................................-0.3V to +15V Driver Output Voltage..........................................................±15V Continuous Power Dissipation (T A = +70°C)

Plastic DIP (derate 10.00mW/°C above +70°C)..........800mW SO (derate 8.7mW/°C above +70°C)...........................695mW

Operating Temperature Ranges

MAX1488EC_D...................................................0°C to +70°C MAX1488EE_D ................................................-40°C to +85°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10sec).............................+300°C

MAX1488E

±15kV ESD-Protected, Quad, Low-Power

RS-232 Line Driver

_______________________________________________________________________________________3

Note 1:The I OS value is for one output at a time. If more than one output is shorted simultaneously, damage may occur.

ELECTRICAL CHARACTERISTICS (continued)

(V CC = 4.5V to 13.2V, V EE = -4.5V to -13.2V, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)

__________________________________________Typical Operating Characteristics

(V CC = 12V, V EE = -12V, T A = +25°C, unless otherwise noted.)

10-15

OUTPUT VOLTAGE vs. SUPPLY VOLTAGE

5V CC AND -V EE SUPPLIES (V)

O U T P U T V O L T A G E (V )

10-5

-106

140125

117

9139811103

SLEW RATE vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)

S L E W R A T E (V /μs )

1500

54500

1000625002000

3000

10-15

-40OUTPUT VOLTAGE vs. TEMPERATURE

5TEMPERATURE (°C)

O U T P U T V O L T A G E (V )

-5-10-20

100

M A X 1488E

_______________Detailed Description

The MAX1488E provides ±15kV of ESD protection when operating or when powered down. After an ESD event,the MAX1488E will not latch up. Internal slew-rate-limit-ing circuitry eliminates the need for external capacitors.The MAX1488E has a guaranteed 120kbps data rate.

Outputs

Tables 1 and 2 describe the output states. The output voltage level is affected by both the load current and supply voltage, and is stable over temperature. Refer to the Typical Operating Characteristics to see how the output voltage varies with supply voltage, load capaci-tance, and temperature.

Table 1. Driver A Functions

Table 2. Driver B–D Functions

Inputs

The driver inputs determine the driver output states (Tables 1 and 2). Driver inputs B, C, and D have two inputs. Connect unused inputs to ground or V CC .

±15kV ESD Protection

As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electro-static discharges encountered during handling and assembly. The MAX1488E driver outputs have extra protection against static electricity found in normal

operation. Maxim’s engineers developed state-of-the-art structures to protect these pins against ESD of ±15kV, without damage. After an ESD event, the MAX1488E keeps working without latchup.

ESD protection can be tested in various ways; the transmitter outputs are characterized for protection to the following:

1)±15kV using the Human Body Model

2)±6kV using the Contact-Discharge Method specified in IEC1000-4-2 (formerly IEC801-2)

3)±15kV using the Air-Gap Method specified in IEC1000-4-2 (formerly IEC801-2).

ESD Test Conditions

ESD performance depends on a number of conditions.Contact Maxim for a reliability report that documents test setup, methodology, and results.

Human Body Model

Figure 2a shows the Human Body Model, and Figure 2b shows the current waveform it generates when dis-charged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of inter-est, which is then discharged into the test device through a 1.5k ?resistor.

±15kV ESD-Protected, Quad, Low-Power

RS-232 Line Driver 4

_______________________________________________________________________________________

_____________________Pin Description

NAME FUNCTION

1V EE -4.5V to -13.2V Supply Voltage Input 2, 4, 5, 9,10, 12, 13INPUT_Driver Inputs PIN 3, 6, 8, 11

OUTPUT_Driver Outputs 7GND Ground

V CC

+4.5V to +13.2V Supply Voltage Input

Figure 1.Slew-Rate Test Circuit and Timing Diagram

IEC1000-4-2

The IEC1000-4-2 standard covers ESD testing and per-formance of finished equipment; it does not specifically refer to integrated circuits. The MAX1488E helps you design equipment that meets Level 4 (the highest level)of IEC1000-4-2, without additional ESD-protection com-ponents.

The major difference between tests done using the Human Body Model and IEC1000-4-2 is higher peak current in IEC1000-4-2. Because series resistance is lower in the IEC1000-4-2 ESD test model (Figure 3a),the ESD withstand voltage measured to this standard is generally lower than that measured using the Human Body Model. Figure 3b shows the current waveform for the ±6kV IEC1000-4-2 Level 4 ESD Contact-Discharge test.

The Air-Gap test involves approaching the device with a charged probe. The Contact-Discharge method con-nects the probe to the device before the probe is ener-gized.

Machine Model

The Machine Model for ESD testing uses a 200pF stor-age capacitor and zero-discharge resistance. Its objec-tive is to mimic the stress caused by contact that occurs with handling and assembly during manufactur-ing. Of course, all pins (not just RS-232 inputs and out-puts) require this protection during manufacturing.Therefore, the Machine Model is less relevant to the I/O ports than the Human Body Model and IEC1000-4-2.

__________Applications Information

Use proper layout to ensure other devices on your board are not damaged in an ESD strike. Currents as high as 60A can instantaneously pass into the ground,so it is important to minimize the ground-lead return path to the power supply. A separate return path to the power supply is recommended. Trace widths should be greater than 40 mils. V CC and V EE must be bypassed with 0.1μF capacitors as close to the part as possible to ensure maximum ESD protection.

MAX1488E

±15kV ESD-Protected, Quad, Low-Power

RS-232 Line Driver

_______________________________________________________________________________________5

Figure 2a.Human Body ESD Test Model Figure 2b.Human Body Model Current Waveform Figure 3a.IEC1000-4-2 ESD Test Model

Figure 3b.IEC1000-4-2 ESD Generator Current Waveform

M A X 1488E

___________________Chip Topography

TRANSISTOR COUNT: 95

SUBSTRATE CONNECTED TO GND

±15kV ESD-Protected, Quad, Low-Power RS-232 Line Driver 6_______________________________________________________________________________________

INPUT D1

INPUT B1INPUT B2

OUTPUT B 0.134" (3.40mm)

0.070" (1.78mm)

GND INPUT D2

OUTPUT D INPUT C1INPUT C2

OUTPUT C

V SS

V DD

OUTPUT A

INPUT A

MAX1488E

±15kV ESD-Protected, Quad, Low-Power

RS-232 Line Driver

_______________________________________________________________________________________7

________________________________________________________Package Information

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

M A X 1488E

±15kV ESD-Protected, Quad, Low-Power RS-232 Line Driver implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

8___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600?1995 Maxim Integrated Products

Printed USA

is a registered trademark of Maxim Integrated Products.

___________________________________________Package Information (continued)