MAXIM MAX3845 User Manual

General Description

The MAX3845 is a TMDS®2-to-4 fanout switch and cable driver for multimonitor distribution of DVI™ or HDMI™ signaling up to 1.65Gbps. Both inputs and outputs are standard TMDS signaling as per DVI and HDMI standards. Because TMDS links are “point-to-point,” buffering is required for fanout applications.

Four DVI/HDMI TMDS outputs are provided for fanout distribution. Each TMDS output can be independently sourced from either input or can be turned off. Each TMDS input or output is composed of four differential channels that can be arbitrarily assigned to the three data signals and the 1/10th-rate clock. The data rate depends on resolution, but it can vary from 250Mbps (VGA) to 1.65Gbps (UXGA or 1080p/60).

Typical applications include multiroom display of the same video source or industrial/commercial signage applications such as airport monitors or trading room floor displays. The MAX3845 includes selectable output preemphasis that extends output cable reach up to an additional 7m.

For DDC switching, use the companion MAX4814E 2:4 low-resistance CMOS crosspoint switch. DDC switching is not required for applications that connect DDC to one reference monitor only.

The MAX3845 can be configured to create a 2 x 8 or 4 x 4 switch (see the

Typical Operating Circuit

diagrams).

The MAX3845 is available in a 14mm × 14mm, 100-pin TQFP-EP package and operates over the -10°C to +85°C temperature range.

Applications

Digital Signage and Industrial Display

PC Monitor Distribution

Home A/V Receivers

DVI/HDMI Distribution Amplifiers

DVI/HDMI Crosspoint Switches

Features

o Two DVI/HDMI TMDS-Compatible Inputs and Four

DVI/HDMI TMDS-Compatible Outputs

o Save Power by Turning Off Unused Outputs

o Each Output Independently Selects Input 1 or

Input 2

o Three Preemphasis Settings Extend Cable Reach

Up to 7m

o Operation Up to 1.65Gbps

o 14mm x 14mm, 100-Pin TQFP Package with

Exposed Paddle for Heat Sinking

o 3.3V Power Supply

o TMDS Data (x3) and Clock (x1) Can Be Arbitrarily

Assigned to the Four Identical Switched Paths (A, B, C, and D)

MAX3845

DVI/HDMI 2:4 TMDS Fanout Switch and

Cable Driver

________________________________________________________________

Maxim Integrated Products

Ordering Information

19-0798; Rev 0; 4/07

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.

Denotes a lead-free package.

EP = Exposed pad.

Typical Operating Circuits continued at end of data sheet.

TMDS is a registered trademark of Silicon Image, Inc.

DVI is a trademark of Digital Display Working Group.

HDMI is a trademark of HDMI Licensing, LLC.

EVALUATION KIT

AVAILABLE

Pin Configuration appears at end of data sheet.

Typical Operating Circuit

PART TEMP RANGE PIN-PACKAGE

MAX3845UCQ+ -10°C to +85°C 100 TQFP-EP C100E-3

PKG

CODE

CONTROL

SIGNALS

VIDEO SOURCE 1

VIDEO SOURCE 2

2:4 FANOUT/SWITCH APPLICATION

IN_SEL[1:4]

PREEMPH[1:4]

MAX3845

2:4 DVI/HDMI TMDS

FANOUT SWITCH AND

CABLE DRIVER

2:4 CMOS

SWITCH x5

HOTPLUG[1:4]

BUFFER

DDC DATA, DDC CLK, HOTPLUG, 5V, GND, (CEC)

OUTPUT TO DISPLAY 1

OUTPUT TO DISPLAY 2

OUTPUT TO DISPLAY 3

OUTPUT TO DISPLAY 4

MAX3845

DVI/HDMI 2:4 TMDS Fanout Switch and Cable Driver

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= 3.0V to +3.6V, TA= -10°C to +85°C. Typical values are at VCC= +3.3V, external terminations = 50Ω ±1%, TMDS rate = 250Mbps to 1.65Gbps, T

= +25°C, unless otherwise noted.) (Note 1)

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.

Supply Voltage Range (VCC) ................................-0.3V to +5.5V

Voltage Range at HOTPLUGx Pins ......................-0.3V to +6.0V

Voltage Range at LVTTL, LVCMOS, I/O Pins .......-0.3V to +5.5V

Voltage Range at CML Output Pins ......................-0.3V to +5.5V

Voltage Range at CML Input Pins

(CML short to GND duration < 1s)....................-0.3V to +4.0V

Voltage Between Any Input CML I/O

Complementary Pair ......................................................±3.3V

Voltage Range at LOSMUTE_EN ..........................-0.3V to +5.5V

Voltage Between Any Output CML I/O

Complementary Pair.......................................................±3.6V

Continuous Power Dissipation (TA= +70°C)

100-Pin TQFP-EP (derate 45.5mW/°C

above +70°C) ............................................................3636mW

Operating Junction Temperature .....................-55°C to +150°C

Storage Temperature Range ............................-55°C to +150°C

Die Attach Temperature ..................................................+400°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Power-Supply C urrent I

Supply-Noise Tolerance DC to 500kHz 50 mV

SKIN-EFFECT EQUALIZER PEAKING

Fixed Rx Equalizer Compensation

Settable Tx Preemphasis

JITTER PERFORMANCE

Residual Deterministic Jitter (Measured at end of cable hav ing ideal skin-effect lo ss and connectors, e.g., Gore Twin Coax, Amphenol Skewclear Twinax, with SMA connectors) (Note 2)

Residua l Random Jitter (Note 3) Measured with source Tr/Tf = 250ps 1.5 2 ps

CML INPUTS (SOURCE SIDE)

Differentia l-Input Voltage Swing V

Common-Mode Input Voltage VCM VCC - 1000 V

Input Voltage When Disconnected VCC - 10 VCC + 10

PREEMPH[1:4] = h igh, OUT_LEVEL = high,

current into V

Gain at 825MHz 1

PREEMPHx pin = low 0

PREEMPHx pin = open 3

PREEMPHx pin = high 6

200 back termination

No back termination

At cable input 400 2000 mV

pins, 1200mV

0dB cable loss, no preemphasis

3dB cable loss, +3dB preemphasis

6dB cable loss, +6dB preemphasis

0dB cable loss, no preemphasis

3dB cable loss, +3dB preemphasis

6dB cable loss, +6dB preemphasis

P-P

= V

454 626 mA

0.04 0.12

0.05 0.12

0.07 0.12

0.07 0.2

0.08 0.2

0.10 0.2

P-P

RMS

P-P

MAX3845

DVI/HDMI 2:4 TMDS Fanout Switch and

Cable Driver

_______________________________________________________________________________________ 3

Note 1: AC specifications are guaranteed by design and characterization. Note 2: Test pattern is a 2

- 1 PRBS + 20 ones + 210- 1 PRBS (inverted) + 20 zeros.

Note 3: Test pattern is a 1111 0000 pattern at 1.65Gbps.

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 3.0V to +3.6V, TA= -10°C to +85°C. Typical values are at VCC= +3.3V, external terminations = 50Ω ±1%, TMDS rate = 250Mbps to 1.65Gbps, T

= +25°C, unless otherwise noted.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Input Resistance R

Input LOS/Mute Threshold Differential peak-peak 150 mV

Input LOS/Mute Response Time

Input Return Loss Differential,  1.6GHz 19 dB

CML OUTPUTS (CABLE SIDE)

Differentia l-Output Voltage Swing V

Output-Voltage High VOH Single-ended, no back termination VCC - 10 VCC + 10

Output Voltage During PowerDown

Rise/Fall Time 20% to 80% (TA = 0°C to +85°C) 75 90 140

Intrapair Skew 12 40

Interpair Skew

CONTROL INTERFACE

LVTTL Input High Voltage V

LVTTL Input Low Voltage V

LVTTL Input High Current V

LVTTL Input Low Current V

HOTPLUGx Input High Voltage Typical input 30k to GND VCC - 0.2 5.5

HOTPLUGx Input Low Voltage 1.5

Single-ended 45 50 55 

Deas sert mute 1.2

Assert mute 0.6

No preemphasis, no back termination, OUT_LEVEL = low

No preemphasis, 200 back termination, OUT_LEVEL = h igh

Single-ended, PWRDWN_x = low or

OFF

= 0V

Worst case among A, B, C, and D of an output

2.0

All except IN_SELx pins 1.0

IN_SELx pins 0.8

< VIN < V

IH(MIN)

< VIN < V

IL(MIN)

IH(MAX)

IL(MAX)

900 1050 1200

825 925 1050

- 10 VCC + 10

35 60

100

All except OUT_LEVEL pin

OUT_LEVEL pin 500

150

μs

μA

P-P

MAX3845

DVI/HDMI 2:4 TMDS Fanout Switch and Cable Driver

4 _______________________________________________________________________________________

Typical Operating Characteristics

(Typical values are at VCC= +3.3V, TA= +25°C, data pattern = 210- 1 PRBS + 20 ones + 210- 1 PRBS (inverted) + 20 zeros, unless otherwise noted.)

SUPPLY CURRENT

vs. AMBIENT TEMPERATURE

MAX3845 toc01

AMBIENT TEMPERATURE (°C)

(mA)

80655 20 35 50

360

380

400

420

440

460

480

500

340

-10

OUT_LEVEL = LOW, ALL INPUTS/OUTPUTS ACTIVE, PREEMPHASIS SAME ON ALL OUTPUT CHANNELS

0dB PREEMPHASIS

3dB PREEMPHASIS

6dB PREEMPHASIS

SUPPLY CURRENT

vs. AMBIENT TEMPERATURE

MAX3845 toc02

AMBIENT TEMPERATURE (°C)

(mA)

80655 20 35 50

360

380

400

420

440

460

480

500

340

-10

OUT_LEVEL = HIGH, ALL INPUTS/OUTPUTS ACTIVE, PREEMPHASIS SAME ON ALL OUTPUT CHANNELS

0dB PREEMPHASIS

3dB PREEMPHASIS

6dB PREEMPHASIS

OUTPUT EYE DIAGRAM AT 1.65Gbps

SHORT LOW-LOSS SMA CABLE

MAX3845 toc03

100ps/div

150mV/div

0dB PREEMPHASIS 200Ω BACK TERMINATION

OUTPUT EYE DIAGRAM AT 2.25Gbps

SHORT LOW-LOSS SMA CABLE

MAX3845 toc04

80ps/div

150mV/div

0dB PREEMPHASIS 200Ω BACK TERMINATION

OUTPUT EYE DIAGRAM AT 1.65Gbps

6dB LOSS, 24AWG, 25ft TWIN-AX CABLE

MAX3845 toc05

100ps/div

150mV/div

6dB PREEMPHASIS 200Ω BACK TERMINATION

OUTPUT EYE DIAGRAM AT 2.25Gbps

6dB LOSS, 24AWG, 25ft TWIN-AX CABLE

MAX3845 toc06

80ps/div

150mV/div

6dB PREEMPHASIS 200Ω BACK TERMINATION

OUTPUT EYE DIAGRAM AT 1.65Gbps

THROUGH 2m DVI TO HDMI CABLE

MAX3845 toc07

100ps/div

150mV/div

6dB PREEMPHASIS 200Ω BACK TERMINATION

JITTER vs. INPUT-SIDE CABLE LOSS

AT 825 MHz

MAX3845 toc08

CABLE LOSS (dB)

JITTER (ps

P-P

)

642

100

120

140

160

DATA RATE = 1.65Gbps 200Ω BACK TERMINATION

JITTER vs. OUTPUT-SIDE CABLE LOSS

AT 825 MHz

MAX3845 toc09

CABLE LOSS (dB)

JITTER (ps

P-P

)

642

100

120

0dB PREEMPHASIS

3dB PREEMPHASIS

6dB PREEMPHASIS

DATA RATE = 1.65Gbps 200Ω BACK TERMINATION

MAX3845

DVI/HDMI 2:4 TMDS Fanout Switch and

Cable Driver

_______________________________________________________________________________________

Typical Operating Characteristics (continued)

(Typical values are at VCC= +3.3V, TA= +25°C, data pattern = 210- 1 PRBS + 20 ones + 210- 1 PRBS (inverted) + 20 zeros, unless otherwise noted.)

Pin Description

DIFFERENTIAL-INPUT RETURN LOSS

vs. FREQUENCY

-5

-10

-15

-20

GAIN (dB)

-25

-30

-35

-40 0 3000

FREQUENCY (MHz)

1.6

1.5

MAX3845 toc10

1.4

1.3

1.2

TEMP (V)

1.1

1.0

0.9

0.8

25002000500 1000 1500

-10 150

TEMP VOLTAGE

vs. JUNCTION TEMPERATURE

JUNCTION TEMPERATURE (°C)

PIN NAME FUNCTION

1, 4, 7, 10,

97, 100

Positive Power-Supply Connection. Powers input channel 1 and output channels 1 and 2.

CC1

3000

2500

MAX3845 toc11

2000

1500

1000

POWER DISSIPATION (mW)

500

13011010 30 50 70 90

-10

POWER DISSIPATION

vs. AMBIENT TEMPERATURE

ALL INPUTS/OUTPUTS ACTIVE, PREEMPHASIS SAME ON ALL OUTPUT CHANNELS

6dB PREEMPHASIS OUT_LEVEL = HIGH

0dB PREEMPHASIS OUT_LEVEL = LOW

AMBIENT TEMPERATURE (°C)

80655035205

MAX3845 toc12

IN1_B+,

2, 5, 8, 98

IN1_C+, IN1_D+,

IN1_A+

IN1_B-,

3, 6, 9, 99

IN1_C-, IN1_D-,

IN1_A-

11 PWRDWN_1

12 V

Positive Power-Supply Connection. Powers the temp-sense circuitry.

CC3

13 LOSMUTE_EN

14 TEMP

15 PWRDWN_2

16, 19, 22,

25, 26, 29

Positive Power-Supply Connection. Powers input channel 2 and output channels 3 and 4.

CC2

Noninverting TMDS CML Input, Channel 1

Inverting TMDS CML Input, Channel 1

Power-Down, LVTTL/LVCMOS Input. Force high or leave open to power down input channel 1. Force low to enable input channel 1. The MAX3845 powers down if both PWRDWN_1 and PWRDWN_2 are forced high or left open.

LOS MUTE Enable Input. Connect to V

for typical operation. Connect to GND to disable the LOS

MUTE function.

Junction Temperature Sensor. Attach a ground-referenced vo ltage DMM to this pin to measure the die’s junction temperature (see the V

pin description). Leave open if not used.

CC3

Power-Down, LVTTL/LVCMOS Input. Force high or leave open to power down input channel 2. Force low to enable input channel 2. The MAX3845 powers down if both PWRDWN_1 and PWRDWN_2 are forced high or left open.

MAX3845

DVI/HDMI 2:4 TMDS Fanout Switch and Cable Driver

6 _______________________________________________________________________________________

Pin Description (continued)

PIN NAME FUNCTION

IN2_A+,

17, 20, 23,

18, 21, 24,

30, 61, 65,

31, 62, 64,

IN2_B+, IN2_C+,

IN2_D+

IN2_A-, IN2_B-, IN2_C-,

IN2_D-

IN_SEL4, IN_SEL3, IN_SEL2,

IN_SEL1

PREEMPH4, PREEMPH3, PREEMPH2,

PREEMPH1

Noninverting TMDS, CML Input, Channel 2

Inverting TMDS, CML Input, Channel 2

Input Select, LVTTL Input. Force high to select input channel 1. Force low to select input channel 2. Leave open to di sable the output channel.

Preemphasis Select, LVTTL/LVCMOS Input. Force h igh for 6dB of output preemphasis. Leave open for 3dB of output preemphas is. Force low for 0dB of output preemphasis (normal).

32, 46, 80,

33, 36, 39, 42, 45, 47, 50, 51, 54,

57, 60

34, 37, 40,

35, 38, 41,

48, 52, 55,

49, 53, 56,

HOTPLUG4, HOTPLUG3, HOTPLUG2,

HOTPLUG1

GND2 Supply Ground. Ground connection for input channel 2 and output channels 3 and 4.

OUT4_D-, OUT4_C-, OUT4_B-,

OUT4_A-

OUT4_D+, OUT4_C+, OUT4_B+,

OUT4_A+

OUT3_D-, OUT3_C-, OUT3_B-, OUT3_A-,

OUT3_D+, OUT3_C+, OUT3_B+, OUT3_A+,

Hotplug Sense Input. Connect this pin to the di spla y’s HOTPLUGx signal (buffered) to allow automatic power-down of the associated output when the display is disconnected. A low-cost quad 5V, noninverting CMOS gate (74ACT32 series) is recommended to buffer the MAX3845 from the HOTPLUGx pin to match HOTPLUG level specifications. If this feature is not used, connect to V

Inverting TMDS, CML Output, Channel 4

Noninverting TMDS, CML Output, Channel 4

Inverting TMDS, CML Output, Channel 3

Noninverting TMDS, CML Output, Channel 3

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