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MAX14778

Dual ±25V Above- and Below-the-Rails

4:1 Analog Multiplexer

Functional Diagram

19-5929; Rev 1; 6/12

Ordering Information appears at end of data sheet.

For related parts and recommended products to use with this part,

refer to www.maximintegrated.com/MAX14778.related.

EVALUATION KIT AVAILABLE

General Description

The MAX14778 dual 4:1 analog multiplexer supports

analog signals up to Q25V with a single 3.0 to 5.5V

supply. Each multiplexer has separate control inputs to

allow independent switching, making the device ideal for

multiplexing different communications signals with the

same connector pins. Extended ESD protection of Q6kV

(Human Body Model) enable direct interfacing to cables

and connectors.

The MAX14778 features a low 1.5I (max) on-resistance

and 3mI (typ) flatness to maximize signal integrity over

the entire common-mode voltage range. Each multiplex-

er can carry up to 300mA of continuous current through

the multiplexer in either direction.

The MAX14778 supports switching of full-speed USB 1.1

signals (12Mbps) and RS-485 data rates of up to 20Mbps.

The MAX14778 is available in a 20-pin (5mm x 5mm)

TQFN package and is specified over the -40NC to +85NC

extended temperature range.

Applications

RS-485/RS-232/USB 1.1 Multiplexing

POS Peripherals

Handheld Industrial Devices

Communication Systems

Audio/Data Multiplexing

Connector Sharing

Gaming Machines

Features

S ±25V Signal Range

Single 3.0V to 5.5V Supply

Two Independent Multiplexers

1.5I R

(max)

3mI R

Flatness (typ)

300mA Maximum Current Through Multiplexer

78pF Input Capacitance

75MHz Large-Signal Bandwidth

Break-Before-Make Operation

Extended ESD Protection on A_ and B_ Pins



Q6kV Human Body Model (HBM)

CONTROL A

BIAS

GENERATION

SA0ENA

SA1 V

ACOM

CONTROL B

SB0ENB SB1

GND

BCOM

MAX14778

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

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

Summary of content (15 pages)

PAGE 1
EVALUATION KIT AVAILABLE MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer General Description The MAX14778 dual 4:1 analog multiplexer supports analog signals up to Q25V with a single 3.0 to 5.5V supply. Each multiplexer has separate control inputs to allow independent switching, making the device ideal for multiplexing different communications signals with the same connector pins. Extended ESD protection of Q6kV (Human Body Model) enable direct interfacing to cables and connectors.
PAGE 2
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) VDD...........................................................................-0.3V to +6V VP............................ -0.3V to the lesser of +52V and (VN + 70V) VN................. The lesser of (VDD - 40V) and (VP - 70V) to +0.3V VP to VN..................................................................-0.3V to +70V ENA, ENB, SA_, SB_................................. -0.
PAGE 3
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer ELECTRICAL CHARACTERISTICS (continued) (VDD = 3.0V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 5V, TA = +25NC.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS LOGIC INPUTS (ENA, ENB, SA_, SB_) Input Logic-Low Voltage VIL VDD = 5.5V 0.8 VDD = 4.5V 0.8 VDD = 3.6V 0.7 VDD = 3.0V Input Logic-High Voltage VIH V 0.7 VDD = 5.5V 2.1 VDD = 4.5V 2.0 VDD = 3.6V 1.9 VDD = 3.
PAGE 4
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Test Circuits/Timing Diagrams V +5V 1µF VDD MAX14778 A_ B_ VIN ACOM BCOM ICOM GND Figure 1. On-Resistance Measurement +5V +5V 1µF 1µF VDD IA(OFF) IB(OFF) A VIN VDD MAX14778 A_ B_ ACOM BCOM GND IACOM(OFF) IBCOM(OFF) IA(ON) IB(ON) A A VOUT VIN MAX14778 A_ B_ ACOM BCOM GND Figure 2.
PAGE 5
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Test Circuits/Timing Diagrams (continued) MAX14778 VIN LOGIC INPUT A_ B_ ACOM BCOM t R < 20ns t F < 20ns VIH VIL 50% VOUT RL t OFF CL ENA VOUT ENB SWITCH OUTPUT LOGIC INPUT 0.9 x V0UT 0.1 x VOUT 0V t ON CL INCLUDES FIXTURE AND STRAY CAPACITANCE. RL VOUT = VIN R + R L ON ( ) Figure 3.
PAGE 6
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Test Circuits/Timing Diagrams (continued) +5V +5V A_ B_ LOGIC INPUT VDD LOGIC INPUT OFF MAX14778 OFF 0V ACOM BCOM ENA ENB ON VOUT C L = 1nF GND DVOUT VOUT Q = CL x DVOUT Figure 5.
PAGE 7
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Typical Operating Characteristics (VDD = 5.0V, TA = +25°C, unless otherwise noted.) 0.97 VDD = 5V 0.96 1.1 TA = +85°C 1.0 0.9 TA = +25°C 0.8 0.7 0.6 IACOM = 300mA 0.95 -5 5 15 0.5 25 -15 -5 CHARGE INJECTION vs. ANALOG SIGNAL VOLTAGE MAX14778 toc04 -40 1,000 35 60 600 3.0 2.0 VDD = 5V -25 -15 -5 5 15 0 -40 25 -15 10 OFF-ISOLATION vs.
PAGE 8
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Typical Operating Characteristics (continued) (VDD = 5.0V, TA = +25°C, unless otherwise noted.) MAX14778 toc10 A0 TO ACOM RS = 600I RL = 1kI VDD TO ACOM -20 -40 PSRR (dB) THD+N (%) 0.1 PSRR vs. FREQUENCY 0 MAX14778 toc11 THD+N vs. FREQUENCY 1 0.01 -60 -80 -100 0.001 -120 0.0001 -140 0.2 0.02 2 20 100 TURN-OFF TIME vs. ANALOG-SIGNAL VOLTAGE 0.45 0.40 0.35 1.12 0.30 tOFF (ms) 1.14 1.10 1.08 MAX14778 toc13 0.
PAGE 9
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer SB1 VDD SA1 SA0 TOP VIEW SB0 Pin Configuration 15 14 13 12 11 ENB 16 10 ENA B3 17 9 A3 8 A2 7 A1 6 A0 MAX14778 B2 18 B1 19 *EP *CONNECT EXPOSED PAD TO VN. 2 3 4 5 VN ACOM BCOM 1 GND + VP B0 20 TQFN 5mm x 5mm Pin Description PIN NAME 1 BCOM 2 VP 3 GND FUNCTION MUX B Common Terminal Positive Charge-Pump Output. Bypass VP to GND with a 100nF 50V ceramic capacitor.
PAGE 10
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Truth Tables Table 1. MUX A Channel Selection ENA SA1 SA0 ACOM CONNECTED TO Table 2.
PAGE 11
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Non-Powered Condition The MAX14778 can tolerate input voltages on the A_, B_, ACOM, and BCOM pins in the ±25V range when it is not powered. When VDD = 0V, the DC input leakage current into the A_, B_, ACOM or BCOM pins will typically be below 1µA. Some devices can have a larger leakage current up to mA range due to technology spread.
PAGE 12
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Typical Operating Circuits +5V 1µF VDD VP MAX14778 RS-232 TRANSCEIVER TX A0 RX B0 A A1 B B1 D+ A2 D- B2 L A3 R B3 VN 100nF 100nF SHARED CONNECTOR +5V ACOM RS-485 TRANSCEIVER USB 1.
PAGE 13
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Typical Operating Circuits (continued) +5V 1µF VDD VP MAX14778 RS-232 TRANSCEIVER TX A0 RX B0 A A1 B B1 D+ A2 D- B2 CLOCK A3 DATA B3 VN 100nF 100nF SHARED CONNECTOR +5V ACOM RS-485 TRANSCEIVER USB 1.
PAGE 14
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Ordering Information PART TEMP RANGE PIN-PACKAGE MAX14778ETP+ -40NC to +85NC 20 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. Chip Information PROCESS: BiCMOS Maxim Integrated Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only.
PAGE 15
MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Revision History REVISION NUMBER REVISION DATE 0 6/11 Initial release 1 6/12 Added new TOCs 14 and 15, updated Non-Powered Condition section, updated Note 4, Pin Description, ESD Test Conditions, Typical Operating Circuits, updated capacitor values DESCRIPTION PAGES CHANGED — 3, 8, 9, 10, 11, 12, 13 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated