MAXIM MAX4885 User Manual

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General Description

The MAX4885 integrates high-bandwidth analog
switches and level-translating buffers to implement a
complete 1:2 or 2:1 multiplexer for VGA signals. The
device provides switching for RGB, display data chan­nel (DDC), and horizontal and vertical synchronization
(HSYNC, VSYNC) signals. A low-noise charge pump
with internal capacitors provides a boosted gate-drive
voltage to improve performance of the RGB switches.

In the 1:2 multiplexer mode, HSYNC/VSYNC inputs fea­ture level-shifting buffers to support low-voltage CMOS
or standard TTL-compatible graphics controllers. In the
2:1 multiplexer mode, the output buffers for the
HSYNC/VSYNC inputs are disabled, allowing bidirec­tional signaling. In both modes, DDC signals are volt­age-clamped to an external voltage to provide level
translation and protection. The MAX4885 features a
5µA shutdown mode and is ESD protected to ±8kV
Human Body Model (HBM) on externally routed pins.

The MAX4885 is specified over the extended (-40°C to
+85°C) temperature range, and is available in the 32­pin, 5mm x 5mm TQFN package.

Applications

Notebook Computers

Digital Projectors

Computer Monitors

Servers

KVM Switches

Features

♦ +5V Single-Supply Operation

♦ Programmable Voltage Clamp for Open-Drain

DDC Signals

♦ Low 5Ω (typ) On-Resistance (R, G, B Signals)

♦ Low 13pF (typ) On-Capacitance (R, G, B Signals)

♦ Break-Before-Make Switching Protects Against

Circuit Shorts

♦ ±8kV HBM ESD Protection on Externally Routed

Pins

♦ Low 300µA Supply Current (Lower than 1µA with

Charge Pump Disabled)

♦ Space-Saving, Lead-Free, 32-Pin (5mm x 5mm)

TQFN Package

MAX4885

Complete VGA 1:2 or 2:1 Multiplexer

________________________________________________________________ Maxim Integrated Products 1

19-0554; Rev 0; 5/06

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.

MAX4885

TQFN

TOP VIEW

29

30

28

27

12

11

13

R0

B0

H0

V0

DDCA0

14

QP

H1

V+

GNDB1V2

H2

12

DDCA1

4567

2324 22 20 19 18

GND

V+

DDCB2

DDCA2

GND

V+

G0

V1

3

21

31

10

M

V

CL

32

9

SEL

EN

DDCB1

26

15

R2

R1

25

16

G2

DDCB0

B2

8

17

G1

*EXPOSED PADDLE CONNECTED TO GND

*EP

Pin Configuration

Ordering Information

GRAPHICS

CONTROLLER

V

CL

V+

GND

+3.3V

+5V

EN

SEL

R0, B0, G0

H0, V0

DDCA0, DDCB0

0.1µF

0.1µF

VGA

PORT 1

VGA

PORT 2

R2, G2, B2

H2, V2

DDCA2, DDCB2

2

3

2

2

3

2

R1, G1, B1

H1, V1

DDCA1, DDCB1

2

3

2

DOCKING
STATI ON

M

MAX4885

Typical Operating Circuit

PART

TEMP RANGE

PIN-PACKAGE

PKG

CODE

MAX4885ETJ+

32 TQFN-EP*

T3255-4

*EP = Exposed pad.
+Denotes lead-free package.

-40°C to +85°C

MAX4885

Complete VGA 1:2 or 2:1 Multiplexer

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

(All voltages referenced to GND.)
V

+

, VCL.....................................................................-0.3V to +6V

R_, G_, B_, DDCA_, DDCB_, SEL, M,

EN, QP (Note 1) ...........................................-0.3V to V+ + 0.3V

H_, V_ .......................................................................-0.3V to +6V

Continuous Current Through RGB Switches ....................±70mA

Continuous Current Through HV, DDC Switches…..........±50mA

Peak Current Through RGB Switches

(pulsed at 1ms, 10% duty cycle).................................±140mA

Peak Current Through HV, DDC Switches (pulsed at 1ms,

10% duty cycle)..............................................................±100mA

Continuous Power Dissipation (T

A

= +70°C)

32-Pin TQFN (derate 21.3mW/°C above +70°C) ........1702mW

Operating Temperature Range ...........................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

Junction Temperature......................................................+150°C

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

ELECTRICAL CHARACTERISTICS

(V+ = +5.0V ±10%, VCL= +3.3V ±10%, TA= T

MIN

to T

MAX

, QP = GND, unless otherwise noted. Typical values are at V+ = +5.0V,

V

CL

= +3.3V and TA= +25°C.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Supply Voltage Range V+ 4.5 5.5 V

Clamp Voltage Range V

CL

2.7 V+ V

QP = GND 0.3 0.5 mA

V+ Quiescent Supply Current I

+

V+ = +5.5V

QP = V+ 1 µA

VCL Quiescent Supply Current I

CL

VCL = V+ = +5.5V 1 µA

V+ Shutdown Current I

+SHDN

5µA

VCL Shutdown Current

VCL = V+ = +5.5V, all digital inputs to V+ or
GND

1µA

RGB ANALOG SWITCHES

QP = GND 5 7.5

On-Resistance R

ON

IIN = -40mA

QP = V+ 6 10

Ω

On-Resistance Matching ∆R

ON

0V < VIN < +2.5V, IIN = -40mA 0.5 1.5 Ω

On-Resistance Flatness

)

0V < VIN < +2.5V, IIN = -40mA

Ω

Off-Leakage Current I

L(OFF)

R_, G_, B_ = 0V or +5.5V, EN = GND -1 +1 µA

On-Leakage Current I

L(ON)

R_, G_, B_ = 0V or +5.5V, EN = V+ -1 +1 µA

QP = GND 10

Charge Injection Q

CL = 1000pF

QP = V+ 8

pC

HV MULTIPLEXER

Input-Voltage Low V

ILHV

M = GND 0.8 V

Input-Voltage High V

IHHV

M = GND 2.0 V

High-Output Drive Current I

OHHV

V

OUT

= V+ - 0.5V, M = GND -16 mA

Low-Output Drive Current I

OLHV

V

OUT

= +0.5V, M = GND

mA

On-Resistance R

ONHV

H_ = V_ = +2.5V, IIN = -40mA, M = V+ 15 Ω

Charge Injection Q H_, V_ = 0V, M = V+, CL = 1000pF 21 pC

Note 1: Signals exceeding V+ or GND are clamped by internal diodes. Limit forward-diode current to maximum current rating.

V+ = +5.5V, all digital inputs to V+ or GND

I

CLSHDN

R

FLAT(ON

0V < VIN < +2.5V,

R_, G_, B_ = 0V,

0.02 0.75

+16

MAX4885

Complete VGA 1:2 or 2:1 Multiplexer

_______________________________________________________________________________________ 3

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

DDC MULTIPLEXER

On-Resistance

)

VIN < +0.4V, VCL = +3.0V, IIN = -20mA 20 Ω

DDC Leakage I

L(DDC)

V

CL

- 0.4V < V

OUT

< VCL, VIN = V+ -1 +1 µA

Charge Injection Q DDCA_, DDCB_ = 0V, CL = 1000pF 10 pC

SWITCH LOGIC (SEL, M, EN, QP)

Input-Low Voltage V

IL

V+ = +5.5V 0.8 V

Input-High Voltage V

IH

V+ = +4.5V 2.0 V

Input Leakage Current I

LEAK

VIN = V+ -1 +1 µA

ESD PROTECTION

Human Body Model, all pins ±2 kV

ESD Protection

Human Body Model, R_, G_, B_, H_, V_,
DDCA_, DDCB_

±8 kV

ELECTRICAL CHARACTERISTICS (continued)

(V+ = +5.0V ±10%, VCL= +3.3V ±10%, TA= T

MIN

to T

MAX

, QP = GND, unless otherwise noted. Typical values are at V+ = +5.0V,

V

CL

= +3.3V and TA= +25°C.)

PARAMETER

CONDITIONS

UNITS

QP = GND

Bandwidth f

MAX

RS = RL = 50Ω

QP = V+

MHz

QP = GND

1.2

Insertion Loss I

LOS

1MHz < f < 50MHz,
R

S

= RL = 50Ω

QP = V+ 1 1.6

dB

Crosstalk V

CT

1MHz < f < 50MHz, VIN = 0.7V

P-P

,

R

S

= RL = 50Ω

-40 dB

Off-Capacitance C

OFF

f = 1MHz,
QP = GND or V+

5pF

QP = GND 13

On-Capacitance C

ON

f = 1 MHz

QP = V+ 17

pF

Charge-Pump Noise V

NQP

VIN = +1.0V, RS = RL = 50Ω 50

µV

AC ELECTRICAL CHARACTERISTICS

(V+ = +5.0V ±10%, VCL= +3.3V ±10%, TA= T

MIN

to T

MAX

, QP = GND. Typical values are at V+ = +5.0V, VCL= +3.3V and TA=

+25°C, unless otherwise noted.) (Note 2)

R

ON(DDC

SYMBOL

MIN TYP MAX

350

350

0.85

200

MAX4885

Complete VGA 1:2 or 2:1 Multiplexer

4 _______________________________________________________________________________________

PARAMETER

CONDITIONS

UNITS

Charge-Pump Startup Time t

QPON

µs

RGB ANALOG SWITCHES

Turn-On Time t

ON

VIN = +1.0V, RL = 100Ω, Figure 1 7 µs

Turn-Off Time t

OFF

VIN = +1.0V, RL = 100Ω, Figure 1 0.1 µs

Propagation Delay t

PD

CL = 10pF, Figure 2, RL = RS = 50Ω 0.1 ns

Output Skew Between Ports t

SKEW

CL = 10pF, Skew between any two ports: R,
G, B. Figure 2, R

S

= RL = 50Ω

30 ps

HV MULTIPLEXER

Turn-On Time t

ON

M = 0, Figure 1 5 µs

Turn-Off Time t

OFF

M = 0, Figure 1 0.1 µs

M = GND 6 16

Propagation Delay t

PD

CL = 10pF

M = V+ 0.1

ns

DDC MULTIPLEXER

Turn-On Time t

ON

VIN = +1.0V, RL = 100Ω, Figure 1 5 µs

Turn-Off Time t

OFF

VIN = +1.0V, RL = 100Ω, Figure 1 0.1 µs

Propagation Delay t

PD

CL = 10pF, Figure 2

ns

TIMING CHARACTERISTICS

(V+ = +5.0V ±10%, VCL= +3.3V ±10%, TA= T

MIN

to T

MAX

, QP = GND. Typical values are at V+ = +5.0V, VCL= +3.3V and TA=

+25°C, unless otherwise noted.) (Note 2)

Note 2: Timing parameters are guaranteed by design and correlation over the full operating temperature range.

RON vs. VR0*

(RGB SWITCHES)

MAX4885 toc01

V

R0

(V)

R

ON

(Ω)

4321

1

2

3

4

5

6

7

8

9

10

0

05

TA = +85°C

TA = +25°C

TA = -40°C

QP = 0 OR 1

*R0, G0, B0 ARE INTERCHANGEABLE.

RON vs. VR0*

(RGB SWITCHES)

MAX4885 toc02

R

ON

(Ω)

321

5

10

15

20

25

30

35

0

04

TA = +85°C

TA = +25°C

TA = -40°C

QP = 1

V

R0

(V)

*R0, G0, B0 ARE INTERCHANGEABLE.

RON vs. VR0*

(HV SWITCHES)

MAX4885 toc03

R

ON

(Ω)

4321

2

4

6

8

10

12

0

05

TA = +85°C

TA = +25°C

TA = -40°C

V

R0

(V)

*R0, G0, B0 ARE INTERCHANGEABLE.

Typical Operating Characteristics

(V+ = +5.0V, VCL= +3.3V and TA= +25°C, unless otherwise noted.)

SYMBOL

MIN TYP MAX

150

0.25