MAX3313ECUB中文资料

General Description

The MAX3311E/MAX3313E are low-power, 5V EIA/TIA-232-compatible transceivers. All transmitter outputs and receiver inputs are protected to ±15kV using the Human Body Model, making these devices ideal for applications where more robust transceivers are required.

Both devices have one transmitter and one receiver.The transmitters have a proprietary low-dropout trans-mitter output stage enabling RS-232-compatible opera-tion from a +5V supply with a single inverting charge pump. These transceivers require only three 0.1μF capacitors and will run at data rates up to 460kbps while maintaining RS-232-compatible output levels.The MAX3311E features a 1μA shutdown mode. In shutdown the device turns off the charge pump, pulls V- to ground, and the transmitter output is disabled.The MAX3313E features an INVALID output that asserts high when an active RS-232 cable signal is connected,signaling to the host that a peripheral is connected to the communication port.

________________________Applications

Digital Cameras PDAs GPS POS

Telecommunications Handy Terminals Set-Top Boxes

Features

o ESD Protection for RS-232-Compatible I/O Pins

±15kV—Human Body Model

o 1μA Low-Power Shutdown (MAX3311E)o INVALID Output (MAX3313E)

o Receiver Active in Shutdown (MAX3311E)o Single Transceiver (1Tx/1Rx) in 10-Pin μMAX Package

MAX3311E/MAX3313E

±15kV ESD-Protected, 460kbps, 1μA,RS-232-Compatible Transceivers in μMAX

________________________________________________________________Maxim Integrated Products

1

Pin Configurations

19-1910; Rev 0; 1/01

Ordering Information

For price, delivery, and to place orders,please contact Maxim Distribution at 1-888-629-4642,

or visit Maxim’s website at https://www.wendangku.net/doc/0014193865.html,.

Typical Operating Circuit

M A X 3311E /M A X 3313E

±15kV ESD-Protected, 460kbps, 1μA,

RS-232-Compatible Transceivers in μMAX 2

_______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

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.

V CC to GND.............................................................-0.3V to +6V V- to GND................................................................+0.3V to -7V V CC + |V-|............................................................................+13V Input Voltages

TIN, SHDN to GND...............................................-0.3V to +6V RIN to GND......................................................................±25V Output Voltages

TOUT to GND................................................................±13.2V ROUT, INVALID to GND.....................…-0.3V to (V CC + 0.3V)Short-Circuit Duration

TOUT to GND.........................................................Continuous

Continuous Power Dissipation

10-Pin μMAX (derate 5.6mW/°C above +70°C)..........444mW Operating Temperature Ranges

MAX331_ECUB.................................................0°C to +70°C MAX331_EEUB..............................................-40°C to +85°C Junction Temperature.....................................................+150°C Storage Temperature Range............................-65°C to +150°C Lead Temperature (soldering, 10s)................................+300°C

MAX3311E/MAX3313E

±15kV ESD-Protected, 460kbps, 1μA,RS-232-Compatible Transceivers in μMAX

_______________________________________________________________________________________3

ELECTRICAL CHARACTERISTICS (continued)

TIMING CHARACTERISTICS

M A X 3311E /M A X 3313E

±15kV ESD-Protected, 460kbps, 1μA,

RS-232-Compatible Transceivers in μMAX 4

_______________________________________________________________________________________

Typical Operating Characteristics

(V CC = +5V, 0.1μF capacitors, transmitter loaded with 3k ?and C L , T A = +25°C, unless otherwise noted.)

04286121014

1000

1500

500

2000

2500

3000SLEW RATE

vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)S L E W R A T E (V /μs )

-5

-4-3-2-10123456050010001500200025003000TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)T R A N S M I T T E R O U T P U T V O L T A G E (V )

010001500500200025003000

SUPPLY CURRENT vs. LOAD CAPACITANCE

LOAD CAPACITANCE (pF)

Detailed Description

Single Charge-Pump Voltage Converter

The MAX3311E/MAX3313E internal power supply has a single inverting charge pump that provides a negative voltage from a single +5V supply. The charge pump operates in a discontinuous mode and requires a flying capacitor (C1) and a reservoir capacitor (C2) to gener-ate the V- supply.

RS-232-Compatible Driver

The transmitter is an inverting level translator that con-verts CMOS-logic levels to EIA/TIA-232 compatible lev-els. It guarantees data rates up to 460kbps with worst-case loads of 3k ?in parallel with 1000pF. When SHDN is driven low, the transmitter is disabled and put into tri-state. The transmitter input does not have an internal pullup resistor.

RS-232 Receiver

The MAX3311E/MAX3313E receiver converts RS-232signals to CMOS-logic output levels. The MAX3311E receiver will remain active during shutdown mode. The MAX3313E INVALID indicates when an RS-232 signal is present at the receiver input, and therefore when the port is in use.

The MAX3313E INVALID output is pulled low when no valid RS-232 signal level is detected on the receiver input.

MAX3311E Shutdown Mode

In shutdown mode, the charge pump is turned off, V- is pulled to ground, and the transmitter output is disabled (Table 1). This reduces supply current typically to 1μA.The time required to exit shutdown is less than 25ms.

Applications Information

Capacitor Selection

The capacitor type used for C1 and C2 is not critical for proper operation; either polarized or nonpolarized capacitors are acceptable. If polarized capacitors are used, connect polarity as shown in the Typical Operating Circuit . The charge pump requires 0.1μF capacitors. Increasing the capacitor values (e.g., by a factor of 2) reduces power consumption. C2 can be

increased without changing C1’s value. However, do not increase C1’s value without also increasing the value of C2 and C BYPASS to maintain the proper ratios (C1 to the other capacitors).

When using the minimum 0.1μF capacitors, make sure the capacitance does not degrade excessively with temperature. If in doubt, use capacitors with a larger nominal value. The capacitor ’s equivalent series resis-tance (ESR) usually rises at low temperatures and influ-ences the amount of ripple on V-.

To reduce the output impedance at V-, use larger capacitors (up to 10μF).

Bypass V CC to ground with at least 0.1μF. In applica-tions sensitive to power-supply noise generated by the charge pump, decouple V CC to ground with a capaci-tor the same size as (or larger than) charge-pump capacitors C1 and C2.

Transmitter Output when Exiting

Shutdown

Figure 1 shows the transmitter output when exiting shutdown mode. The transmitter is loaded with 3k ?in parallel with 1000pF. The transmitter output displays no ringing or undesirable transients as the MAX3311E comes out of shutdown. Note that the transmitter is enabled only when the magnitude of V- exceeds approximately -3V.

High Data Rates

The MAX3311E/MAX3313E maintain RS-232-compati-ble ±3.7V minimum transmitter output voltage even at

MAX3311E/MAX3313E

±15kV ESD-Protected, 460kbps, 1μA,RS-232-Compatible Transceivers in μMAX

5

Figure 1. Transmitter Output when Exiting Shutdown or Powering Up

10μs/div

SHDN

TOUT

5V/div

1.5V/div

TIN = GND

TIN = V CC

M A X 3311E /M A X 3313E

±15kV ESD-Protected, 460kbps, 1μA,

RS-232-Compatible Transceivers in μMAX 6

_______________________________________________________________________________________

high data rates. Figure 2 shows a transmitter loopback test circuit. Figure 3 shows the loopback test result at 120kbps, and Figure 4 shows the same test at 250kbps.

±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 MAX3311E/MAX3313E driver outputs

and receiver inputs have extra protection against static discharge. 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. After an ESD event, Maxim ’s E versions keep working without latchup; whereas, competing products can latch and must be powered down to remove latchup.

ESD protection can be tested in various ways. The transmitter outputs and receiver inputs of the product family are characterized for protection to ±15kV using the Human Body Model.

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

Figure 5 shows the Human Body Model, and Figure 6shows the current waveform it generates when dis-charged into 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 1.5k ?resistor.

Machine Model

The Machine Model for ESD tests all pins using a 200pF storage capacitor and zero discharge resis-tance. Its objective is to emulate the stress caused by contact that occurs with handling and assembly during manufacturing. Of course, all pins require this protec-tion during manufacturing, not just RS-232 inputs and outputs. Therefore, after PC board assembly, the Machine Model is less relevant to I/O ports.

Figure 4. Loopback Test Results at 250kbps

2μs/div

TOUT

TIN

ROUT

Figure 3. Loopback Test Results at 120kbps 5μs/div

TOUT

TIN

ROUT

MAX3311E/MAX3313E

±15kV ESD-Protected, 460kbps, 1μA,RS-232-Compatible Transceivers in μMAX

_______________________________________________________________________________________7

Figure 5. Human Body ESD Test Model

Figure 6. Human Body Current Waveform

Pin Configurations (continued)

Chip Information

TRANSISTOR COUNT: 278

M A X 3311E /M A X 3313E

±15kV ESD-Protected, 460kbps, 1μA,

RS-232-Compatible Transceivers in μMAX Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are 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?2001 Maxim Integrated Products

Printed USA

is a registered trademark of Maxim Integrated Products.

______________________________________________________________Pin Description