Datasheet

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General Description

The MAX3316–MAX3319 transceivers have a proprietary

low-dropout transmitter output stage enabling RS-232-

compatible performance from +2.25V to +3.0V with a

dual-charge pump. These devices require only four

0.1µF capacitors, and are guaranteed to operate at data

rates up to 460kbps.

The MAX3318/MAX3319 achieve a 1µA supply current

using Maxim’s revolutionary AutoShutdown Plus™ fea-

ture. These devices automatically enter a low-power

shutdown mode when the RS-232 cable is disconnected

or the transmitters of the connected peripherals are inac-

tive for more than 30 seconds. They turn on again when

they sense a valid transition at any transmitter or receiver

input. AutoShutdown Plus saves power without changes

to the existing BIOS or operating system. The MAX3318

is a 2-Tx/2-Rx device while the MAX3319 is a 1-Tx/1-Rx

device. These devices also feature a logic-level output

(READY) that asserts when the charge pump is regulat-

ing and the device is ready to begin transmitting.

The MAX3316/MAX3317 are 2-Tx/2-Rx transceivers. The

MAX3317 features a 1µA shutdown mode that can be

entered by driving SHDN low. The MAX3317’s receivers

remain active while in shutdown mode, allowing external

devices such as modems to be monitored using only

1µA supply current.

These devices are available in space-saving packages:

MAX3316 (16-pin SSOP and 20-pin TSSOP), MAX3317/

MAX3318 (20-pin SSOP and 20-pin TSSOP), and

MAX3319 (16-pin SSOP).

________________________Applications

Palmtop Computers

Hand-Held Instruments

Pagers

Cellular Phones

GPS

Handy Terminals

Hand-Held Electronic Books

Features

♦ AutoShutdown Plus (MAX3318/MAX3319)

♦ 300µA Operating Supply Current

♦ 1µA Low-Power Shutdown with Receivers Active

♦ Guaranteed 460kbps Data Rate

♦ Guaranteed 4V/µs Slew Rate

♦ RS-232 Compatible Down to 2.25V

MAX3316–MAX3319

2.5V, 1µA, 460kbps,

RS-232-Compatible Transceivers

________________________________________________________________ Maxim Integrated Products 1

MAX3319

FORCEON

READY

AutoShutdown

Plus

R1OUT9

FORCEOFF

INVALID 10

GND

T1IN

C2-

C2+

C1-

C1+

R1IN 8

T1OUT 13

V-

V+

0.1µF

BYPASS

+2.5V

TO POWER-

MANAGEMENT

UNIT

CMOS

INPUT

RS-232-

COMPATIBLE

OUTPUT

RS-232-

COMPATIBLE

INPUT

CMOS

OUTPUT

Typical Application Circuits

19-1751; Rev 0; 6/00

Ordering Information

AutoShutdown Plus is a trademark of Maxim Integrated Products.

Pin Configurations appear at end of data sheet.

Typical Application Circuits continued at end of data sheet.

PIN-PACKAGETEMP. RANGEPART

MAX3316CUP

0°C to +70°C 20 TSSOP

16 SSOP0°C to +70°CMAX3316CAE

MAX3316EUP -40°C to +85°C 20 TSSOP

16 SSOP-40°C to +85°CMAX3316EAE

PART

NO. OF DRIVERS/

RECEIVERS

GUARANTEED

DATA RATE (kbps)

READY OUTPUT SHUTDOWN

——460

460 —

✓

—

✓

460

2/2

1/1

MAX3316

MAX3317

MAX3318

MAX3319

AutoShutdown

Plus

—

✓

Selector Guide

Ordering Information continued at end of data sheet.

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Summary of content (15 pages)

PAGE 1
9-1751; Rev 0; 6/00 2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers Features ♦ AutoShutdown Plus (MAX3318/MAX3319) ♦ 300µA Operating Supply Current ♦ 1µA Low-Power Shutdown with Receivers Active ♦ Guaranteed 460kbps Data Rate ♦ Guaranteed 4V/µs Slew Rate ♦ RS-232 Compatible Down to 2.
PAGE 2
MAX3316–MAX3319 2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers ABSOLUTE MAXIMUM RATINGS VCC to GND ..............................................................-0.3V to +6V V+ to GND (Note 1) ..................................................-0.3V to +7V V- to GND (Note 1) ...................................................-7V to +0.3V V+ + |V-| (Note 1) .................................................................+13V Input Voltages T_IN, EN, SHDN, FORCEON, FORCEOFF to GND .......................
PAGE 3
2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers (V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V, TA = +25°C.) PARAMETER SYMBOL Output Resistance CONDITIONS VCC = 0, transmitter output = ±2V MIN TYP 300 10M ±25 Output Short-Circuit Current VCC = 0 or 2.25V to 3.
PAGE 4
TIMING CHARACTERISTICS (continued) (V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V, TA = +25°C.) PARAMETER SYMBOL Transition-Region Slew Rate CONDITIONS MIN VCC = 2.
PAGE 5
2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers 15 20kbps 230kbps 9 20kbps 6 T1 TRANSMITTING AT SPECIFIED DATA RATE T2 TRANSMITTING AT 20kbps CL = 1000pF 3 5 0 0 0 1000 2000 LOAD CAPACITANCE (pF) 3000 2.25 MAX3318/MAX3319 TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE 4 T_OUT+ 3 T1 TRANSMITTING AT 460kbps T2 TRANSMITTING AT 20kbps 1 0 -1 2.85 3.05 3.25 -5 1000 2000 LOAD CAPACITANCE (pF) 3000 MAX3316 TOC07 -2 T_OUT- -4 2.25 2.45 2.65 2.85 3.05 3.25 3.
PAGE 6
Typical Operating Characteristics (continued) (VCC = +2.5V, C1–C4 = 0.1µF, 460kbps data rate, all transmitters loaded with 3kΩ, TA = +25°C, unless otherwise noted.) MAX3318/MAX3319 READY TURN-ON TIME vs. TEMPERATURE 300 MAX3316/MAX3317 200 MAX3318/MAX3319 100 25 20 15 10 0 0 500 1000 1500 2000 2500 120 80 0 -40 3000 160 40 5 0 200 MAX3316E TOC13 30 READY TURN-OFF TIME (ns) 400 MAX3318/MAX3319 READY TURN-OFF TIME vs.
PAGE 7
2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers PIN NAME FUNCTION — SHDN Shutdown Control, Active Low SSOP TSSOP — — MAX3317 SSOP/ TSSOP 20 — — — 1 1 READY Ready to Transmit Output, Active High. READY is enabled high when V- goes below -2.75V and the device is ready to transmit. — — — 11 10 INVALID Valid Signal Detector Output, Active Low. A logic high indicates that a valid RS-232 level is present on a receiver input. — — — 14 12 FORCEON Force-On Input, Active High.
PAGE 8
MAX3316–MAX3319 2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers Table 1.
PAGE 9
2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers MAX3316–MAX3319 +2.5V CBYPASS 0.1µF VCC C1+ C1 0.1µF C3 0.1µF C1C2+ C2 0.1µF V+ C2- MAX3316 MAX3317 MAX3318 MAX3319 V- +5V C4 0.1µF T_ OUT T_ IN RX CL 1000pF R_ IN R_ OUT TX RS-232COMPLIANT TRANSCEIVER GND Figure 1a.
PAGE 10
When shut down, the device’s charge pumps turn off, V+ is pulled to VCC, V- is pulled to ground, the transmitter outputs are high impedance, and READY is driven low. The time required to exit shutdown is typically 30µs (Figure 2). By connecting FORCEON to INVALID, the MAX3318/ MAX3319 shut down when no valid receiver level is detected and wake up when a valid receiver level is detected. A system with AutoShutdown Plus may need time to wake up.
PAGE 11
2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers MAX3316–MAX3319 RECEIVER INPUTS INVALID } REGION TRANSMITTER INPUTS TRANSMITTER OUTPUTS INVALID OUTPUT VCC tINVL tINVH 0 tAUTOSHDN tAUTOSHDN tWU tWU READY *VCC OUTPUT 0 V+ VCC 0 V*MAX3318/MAX3319 Figure 4b. AutoShutdown Plus, INVALID, and READY Timing Diagram C2, C3, C4, and CBYPASS to maintain proper ratios (C1 to other capacitors). POWERMANAGEMENT UNIT MASTER SHDN LINE 0.
PAGE 12
MAX3316–MAX3319 2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers allel with 2500pF. The transmitter outputs display no ringing or undesirable transients as they come out of shutdown. Note that the transmitters are enabled only when the magnitude of V- exceeds approximately -3V. 2V/div T1 IN High Data Rates The MAX3316–MAX3319 maintain RS-232-compatible ±3.7V minimum transmitter output voltage even at high data rates. Figure 6 shows a transmitter loopback test circuit.
PAGE 13
2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers TOP VIEW READY 1 C1+ 1 20 FORCEOFF C1+ 2 19 VCC V+ 3 18 GND C1- 3 17 T1OUT C2+ 4 C1- 4 C2+ 5 MAX3318 V+ 2 14 FORCEON T2OUT 8 13 T1IN R2IN 9 12 T2IN R2OUT 10 20 N.C. 15 GND C1+ 2 19 VCC V+ 3 18 GND 13 R1IN C1- 4 17 T1OUT MAX3316 12 R1OUT C2+ 5 V- 6 11 T1IN C2- 6 T2OUT 7 10 T2IN V- 7 14 T1IN T2OUT 8 13 T2IN 15 R1OUT V- 7 N.C.
PAGE 14
2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers MAX3316–MAX3319 Typical Application Circuits (continued) +2.5V +2.5V 19 0.1µF C1 0.1µF 2 C1+ 4 5 C2 0.1µF 6 V+ 3 C3* 0.1µF C1- MAX3317 C2+ V- 0.1µF T1OUT 17 T2OUT 8 12 T2IN CMOS OUTPUTS 5k 10 R2OUT R2IN 9 3 5 VCC V+ C2+ MAX3316 GND 18 SHDN V- 6 CMOS INPUTS T2OUT 7 10 T2IN RS-232COMPATIBLE OUTPUTS R1IN 13 CMOS OUTPUTS 5k 9 R2OUT R2IN 8 5k 20 *C3 CAN BE RETURNED TO EITHER VCC OR GROUND. C4 0.1µF T1OUT 14 5k EN C3* 0.
PAGE 15
2.5V, 1µA, 460kbps, RS-232-Compatible Transceivers +2.5V CBYPASS C1 0.1µF 2 C1+ 4 5 C2 0.1µF CMOS INPUTS 19 0.1µF 6 C1- VCC 3 V+ MAX3318 C2+ V- C3 0.1µF 7 C2- 13 T1IN T1OUT 17 12 T2IN T2OUT 8 C4 0.