Rainbow Electronics MAX9671 User Manual

General Description

The MAX9670/MAX9671 dual SCART matrices route audio and video signals between a set-top box decoder chip and two external SCART connectors under I

C control. Operating from a 3.3V supply and a 12V supply, the MAX9670/MAX9671 consume 70mW during quiescent operation and 471mW during average operation when driving typical signals into typical loads. Video input detection, video load detection, and a 2.5mW standby mode facilitate the design of intelligent, low-power set-top boxes.

The MAX9670/MAX9671 audio section contains a buffered crosspoint to route audio inputs to audio outputs and programmable volume control from -62dB to 0dB in 2dB steps. The DirectDrive

output amplifiers

create a 2V

RMS

full-scale audio signal biased around ground, eliminating the need for bulky output capacitors and reducing click-and-pop noise. The zero-cross detection circuitry also further reduces clicks and pops by enabling audio sources to switch only during a zerocrossing. The MAX9671 offers TV left and right audio inputs.

The MAX9670/MAX9671 video section contains a buffered crosspoint to route video inputs to video outputs. The standard-definition video signals from the settop box decoder chip are lowpass filtered to remove out-of-band artifacts.

The MAX9670/MAX9671 also support slow-switching and fast-switching signals. An interrupt signal from the MAX9670/MAX9671 informs the microcontroller when the system status has changed.

Applications

Set-Top Boxes

TVs

DVD Players

Features

o 70mW Quiescent Power Consumption

o 2.5mW Standby Mode Consumption

o Programmable Audio Gain Control of -62dB to

0dB (TV Audio Outputs)

o Clickless, Popless, DirectDrive Audio

o Video Input and Video Load Detection

o Video Reconstruction Filter with 10MHz Passband

and 52dB Attenuation at 27MHz

o 3.3V and 12V Supply Voltages

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio

Volume Control for Dual SCART Connectors

________________________________________________________________

Maxim Integrated Products

19-4653; Rev 0; 7/09

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.

EVALUATION KIT

AVAILABLE

Ordering Information

Denotes a lead(Pb)-free/RoHS-compliant package.

EP = Exposed pad.

DirectDrive is a registered trademark of Maxim Integrated Products, Inc.

Typical Application Circuit appears at end of data sheet.

System Block Diagram

PART TEMP RANGE

PINPACKAGE

MAX9670CTL+ 0°C to +70°C 40 TQFN-EP* No

MAX9671CTH+ 0°C to +70°C 44 TQFN-EP* Yes

TV R+L

AUDIO

INPUTS

STB CHIP

µC

VIDEO

ENCODER

I2C

INTERRUPT

OUTPUT

RGB, Y/C, CVBS

12V 3.3V3.3V

MAX9670/MAX9671

I2C INTERFACE

REGISTERS AND

ACTIVITY MONITOR

VIDEO FILTERS AND

CROSSPOINT

AUD

VID

RGB, Y/C, CVBS

CVBS

L/R AUDIO

(MAX9671 ONLY)

L/R AUDIO

(MAX9670 ONLY)

SLOW SWITCHING

FAST SWITCHING

SCART

Y/C, CVBS

RGB, Y/C, CVBS

L/R AUDIO

SLOW SWITCHING

FAST SWITCHING

VCR

SCART

STEREO

AUDIO

DAC

SINGLE-ENDED R/L

STEREO AUDIO

AUDIO CROSSPOINT

WITH DIRECTDRIVE OUTPUTS, VOLUME

CONTROL

SLOW SWITCHING

FAST SWITCHING

CHARGE PUMP

EP GNDVID

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio Volume Control for Dual SCART Connectors

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V12= 12V, V

VID

= V

AUD

= 3.3V, V

GNDVID

= VEP= 0V, no load, TA= 0°C to +70°C, unless otherwise noted. Typical values are at

= +25°C.) (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.

VID

to GNDVID........................................................-0.3V to +4V

to EP.................................................................-0.3V to +14V

AUD

to EP ...............................................................-0.3V to +4V

EP to GNDVID .......................................................-0.1V to +0.1V

All Video Inputs, VCRIN_FS to GNDVID...................-0.3V to +4V

All Audio Inputs to EP .........................................-1V to (EP + 1V)

SDA, SCL, DEV_ADDR, INT to GNDVID ..................-0.3V to +4V

TV_SS, VCR_SS to EP .................................-0.3V to (V

+ 0.3V)

Current

All Video/Audio Inputs ...................................................±20mA

C1P, C1N, CPVSS .........................................................±50mA

Output Short-Circuit Current Duration

Video and Fast-Switching Outputs to V

VID

GNDVID.................................................................Continuous

Audio Outputs to V

AUD

, EP .....................................Continuous

TV_SS, VCR_SS to V

, EP......................................Continuous

Continuous Power Dissipation (T

= +70°C) 40-Pin TQFN-EP (derate 26.3mW/°C above +70°C) ...2105.3mW 44-Pin TQFN-EP (derate 26.3mW/°C above +70°C)...2222.2mW

Operating Temperature Range...............................0°C to +70°C

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

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

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

Video Supply Voltage Range V

Audio Supply Voltage Range V

V12 Supply Voltage Range V

Quiescent Supply Current I

VID

Quiescent Supply Current I

AUD

V12 Quiescent Supply Current I

VIDEO CHARACTERISTICS

DC-COUPLED INPUT

Input Current I

Input Resistance R

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

VID_Q

AUD_Q

VID

AUD

12_Q

Inferred from video PSRR test at 3V and

3.6V

Inferred from audio PSRR test at 3V and

3.6V

Inferred from slow-switching levels 11.4 12 12.6 V

Normal operation; all video output amplifiers are enabled and muted (Note 2)

Standby mode, slow switch inputs low 1500

Shutdown 35

Normal operation (Note 2) 3.2 6 mA

Shutdown 35 µA

Slow-switching output

Normal operation (Note 2)

Shutdown, TA = +25°C 10 µA

RL = 75Ω to GNDVID or 150Ω to V

/2; inferred

VID

from gain test

VIN = 0.3V, TA = +25°C 1 2 µA

set to low-level

Slow-switching output set to medium-level

= 3V 1.15

VID

= 3.135V 1.15Input Voltage Range V

VID

= 3.3V 1.3

VID

3 3.3 3.6 V

16 30 mA

0.3 100

475

300 kΩ

µA

P-P

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio

Volume Control for Dual SCART Connectors

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(V12= 12V, V

VID

= V

AUD

= 3.3V, V

GNDVID

= VEP= 0V, no load, TA= 0°C to +70°C, unless otherwise noted. Typical values are at

= +25°C.) (Note 1)

AC-COUPLED INPUT

Sync-Tip Clamp Level V

Sync Crush

Input Clamping Current Sync-tip clamp, VIN = 0.3V, TA = +25°C 1 2 µA

Maximum Input Source Resistance

Input Voltage

Input Resistance

DC CHARACTERISTICS

DC Voltage Gain Av Guaranteed by output voltage swing 1.95 2 2.05 V/V

DC Gain Mismatch Among R, G, and B Outputs

Output Level

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CLP

Sync-tip clamp -13 -4 +6 mV

S ync- ti p cl am p ; p er centag e r ed ucti on i n sync p ul se ( 0.3V cl am p i ng cur r ent m easur em ent, T

) ; g uar anteed b y i np ut

P - P

= + 25° C

Input sync-tip circuit must be stable even if the source resistance is as high as 300Ω

300 Ω

Bias circuit 0.57 0.6 0.63

High-impedance input circuit

0.3 x V

VID

0.36 x V

VID

Bias circuit 10

High-impedance input circuit 222

Guaranteed by output voltage swing of TV_R/C_OUT, TV_G_OUT, and TV_B_OUT; first input signal set is VCR_R/C_IN, VCR_G_IN, and VCR_B_IN; second signal

-2 +2 %

set is ENC_R/C_IN, ENC_G_IN, and ENC_B_IN

Sync-tip clamp (VIN = V

) 0.1 0.30 0.51

CLP

Bias circuit 1.3 1.5 1.78

Sync-tip clamp, measured at output, V

= 3V, VIN = V

VID

= 150Ω to V

to (V

CLP

/2, RL = 75Ω to GNDVID

VID

CLP

+1.15V),

2.3

kΩ

Output Voltage Swing

Measured at output, V

to (V

CLP

/2, RL = 75Ω to GNDVID

VID

+ 1.15V), RL = 150Ω to

CLP

Bias circuit, measured at output, V V

= (V

= 150Ω to V

- 0.575V) to (V

BIAS

VID

Measured at output, V

= (V

= 150Ω to V

- 0.575V) to (V

BIAS

VID

= 3.135V, VIN =

VID

= 3V,

VID

+ 0.575V),

BIAS

/2, RL = 75Ω to GNDVID

= 3.135V,

VID

+ 0.575V),

BIAS

/2, RL = 75Ω to GNDVID

2.243 2.3 2.358

2.3

2.243 2.3 2.358

P-P

Output Short-Circuit Current 100 mA

Output Resistance R

OUT

0.5 Ω

Output Leakage Current Output disabled (load detection not active) 170 µA

Power-Supply Rejection Ratio 3V ≤ V

≤ 3.6V 35 dB

VID

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio Volume Control for Dual SCART Connectors

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(V12= 12V, V

VID

= V

AUD

= 3.3V, V

GNDVID

= VEP= 0V, no load, TA= 0°C to +70°C, unless otherwise noted. Typical values are at

= +25°C.) (Note 1)

AC CHARACTERISTICS

Filter Passband Flatness V

Filter Attenuation

Slew Rate V

Settling Time V

Differential Gain DG 5-step modulated staircase, f = 4.43MHz 0.15 %

Differential Phase DP 5-step modulated staircase, f = 4.43MHz 0.5 Degrees

2T Pulse-to-Bar K Rating

2T Pulse Response 2T = 200ns 0.2 K%

2T Bar Response

Nonlinearity 5-step staircase 0.1 % Group Delay Distortion 100kHz ≤ f ≤ 5MHz, outputs are 2V

Glitch Impulse Caused by Charge-Pump Switching

Peak Signal to RMS Noise 100kHz ≤ f ≤ 5MHz 70 dB

Power-Supply Rejection Ratio f = 100kHz, 100mV

Output Impedance f = 5MHz 2 Ω

Video Crosstalk f = 4.43MHz -80 dB

Reverse Isolation

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

= 2V

OUT

= 2V

OUT

attenuation is referred to 100kHz

= 2V

OUT

= 2V

OUT

2T = 200ns, bar time is 18µs, the beginning

2.5% and the ending 2.5% of the bar time is ignored

2T = 200ns, bar time is 18µs, the beginning

2.5% and the ending 2.5% of the bar time is ignored

Measured at outputs 100 pV-s

VCR SCART inputs to encoder inputs, full-power mode with VCR being looped through to TV, f = 4.43MHz

, f = 100kHz to 5.5MHz -1 dB

P-P

, no filter in video path 60 V/µs

P-P

, settle to 0.1% (Note 3) 400 ns

P-P

f = 9.5MHz 3

f = 27MHz 40

f = 54MHz 55

P-P

0.3 K%

0.2 K%

11 ns

47 dB

92 dB

Pulldown Resistance

AUDIO CHARACTERISTICS

Voltage Gain VIN = -0.707V to +0.707V 3.95 4 4.05 V/V

Gain Mismatch VIN = -0.707V to +0.707V -1.5 +1.5 %

Flatness f = 20Hz to 20kHz, 0.25V

Frequency Bandwidth

Capacitive Drive

Enable VCR_R/C_OUT pulldown through

C interface

input 0.006 dB

RMS

0.25V

-3dB referenced to 1kHz

No sustained oscillations; 75Ω series resistor on output

input, frequency where output is

RMS

4.4 7.5 Ω

230 kHz

300 pF

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio

Volume Control for Dual SCART Connectors

_______________________________________________________________________________________ 5

ELECTRICAL CHARACTERISTICS (continued)

(V12= 12V, V

VID

= V

AUD

= 3.3V, V

GNDVID

= VEP= 0V, no load, TA= 0°C to +70°C, unless otherwise noted. Typical values are at

= +25°C.) (Note 1)

Input Resistance VIN = -0.707V to +0.707V 10 MΩ

Input Bias Current VIN = 0, TA = +25°C 500 nA

Input Signal Amplitude f = 1kHz, THD < 1% 0.5 V

Output DC Level No input signal, VIN grounded -4 +4 mV

Power-Supply Rejection Ratio

Signal-to-Noise Ratio f = 1kHz, 0.25V

Total Harmonic Distortion Plus Noise

Output Impedance f = 1kHz 0.4 Ω

Volume Control Attenuation Step

Volume Control Minimum Attenuation

Volume Control Maximum Attenuation

Mute Suppression f = 1kHz, 0.25V

Audio Crosstalk f = 1kHz, 0.25V

VIDEO-TO-AUDIO INTERACTION

Crosstalk

CHARGE PUMP

Switching Frequency 570 kHz

FAST SWITCHING

Input Low 0.4 V

Input High Level 1V

Input Current TA = +25°C 10 µA

Output Low Voltage I

Output High Voltage I

Output Resistance 7 Ω

Rise Time 143Ω to GNDVID 12 ns

Fall Time 143Ω to GNDVID 10 ns

SLOW SWITCHING

Input Low Voltage 2V

Input Medium Voltage 4.5 7 V

Input High Voltage 9.5 V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

RMS

DC 75 100

f = 1kHz 90

input, 20Hz to 20kHz 96 dB

RMS

RL = 3.33kΩ, f = 1kHz, 0.25V

= 3.33kΩ, f = 1kHz, 0.5V

Programmable gain to TV SCART volume control from -62dB to 0

input 110 dB

RMS

input 100 dB

RMS

Video input: f = 15kHz, 1V Audio input: f = 15kHz, 0.5V

= 0.5mA 0.1 V

= 0.5mA

input 0.002

RMS

input 0.001

RMS

signal

P-P

signal

RMS

VID

0.1

2dB

0dB

62 dB

92 dB

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio Volume Control for Dual SCART Connectors

6 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(V12= 12V, V

VID

= V

AUD

= 3.3V, V

GNDVID

= VEP= 0V, no load, TA= 0°C to +70°C, unless otherwise noted. Typical values are at

= +25°C.) (Note 1)

Input Current 70 100 µA

Output Low Voltage 10kΩ to EP, 11.4V ≤ V

Output Medium Voltage 10kΩ to EP, 11.4V ≤ V12 ≤ 12.6V 5 6.5 V

Output High Voltage 10kΩ to EP, 11.4V ≤ V

DIGITAL INTERFACE

Input High Voltage V

Input Low Voltage V

Input Hysteresis V

Input Leakage Current IIH, I

Input Capacitance 6pF

Input Current

Output Low Voltage SDA V

Serial-Clock Frequency f

Bus Free Time Between a STOP and a START Condition

Hold Time, (Repeated) START Condition

Low Period of the SCL Clock t

High Period of the SCL Clock t

Setup Time for a Repeated START Condition

Data Hold Time t

Data Setup Time t

Fall Time of SDA Transmitting t

Setup Time for STOP Condition t

Pulse Width of Spike Suppressed t

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

≤ 12.6V 1.5 V

≤ 12.6V 10 V

HYS

0.7 x V

VID

0.06 x V

VID

TA = +25°C -1 +1 µA

< SDA < 3.3V,

0.1V

VID

0.1V

< SCL < 3.3V

VID

I/O pins of fast-mode devices must not

-10 +10 µA

0.3 x V

VID

obstruct the SDA and SCL lines if V+ is

= +25°C

and tF measured between

VID

0 400 kHz

1.3 µs

0.6 µs

1.3 µs

0.6 µs

100 ns

0.6 µs

050ns

SCL

BUF

HD, STA

LOW

HIGH

SU, STA

HD, DAT

SU, STO

switched off, T

= 6mA 0.4 V

SINK

(Note 4) 0 0.9 µs

≤ 6mA, CB = total capacitance of one

SINK

bus line in pF, t

and 0.7V

0.3V

VID

Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio

Volume Control for Dual SCART Connectors

_______________________________________________________________________________________ 7

ELECTRICAL CHARACTERISTICS (continued)

(V12= 12V, V

VID

= V

AUD

= 3.3V, V

GNDVID

= VEP= 0V, no load, TA= 0°C to +70°C, unless otherwise noted. Typical values are at

= +25°C.) (Note 1)

Note 1: All devices are 100% production tested at TA= +25°C. Specifications over temperature limits are guaranteed by design. Note 2: Normal operation mode is full power with input video and load detection active. Note 3: The settling time is measured from the 50% of the input swing to the 0.1% of the final value of the output. Note 4: A master device must provide a hold time of at least 300ns for the SDA signal (referred to V

of the SCL signal) to bridge

the undefined region of SCL’s falling edge.

Typical Operating Characteristics

VID

= V

AUD

= 3.3V, V12= 12V, V

GNDVID

= VEP= 0V, video load is 150Ω to GNDVID, audio load is 10kΩ to EP, TA= +25°C, unless

otherwise noted.)

OTHER DIGITAL I/O

DEV_ADDR Low Level

DEV_ADDR High Level

DEV_ADDR Input Current TA = +25°C -1 +1 µA

Interrupt Output Low Voltage I Interrupt Output Leakage Current INT high impedance, TA = +25°C 10 µA

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

0.3 x V

VID

0.7 x V

VID

= 0.5mA 0.1 V

SMALL-SIGNAL GAIN

vs. FREQUENCY

-10

-20

GAIN (dB)

-30

-40

-50

-60 100k 1G

FREQUENCY (Hz)

FILTER

OUT

= 100mV

100M10M1M

P-P

NO FILTER

MAX9670 toc01

SMALL-SIGNAL GAIN FLATNESS

vs. FREQUENCY

-1

-2

-3

GAIN (dB)

-4

-5

-6

-7

-8 1M 100M

FILTER

FREQUENCY (Hz)

10M

OUT

= 100mV

P-P

NO FILTER

MAX9670 toc02

LARGE-SIGNAL GAIN

vs. FREQUENCY

-10

-20

GAIN (dB)

-30

-40

-50

-60 100k 1G

FILTER

100M10M1M

FREQUENCY (Hz)

= 2V

OUT

NO FILTER

P-P

MAX9670 toc03

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio Volume Control for Dual SCART Connectors

8 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

VID

= V

AUD

= 3.3V, V12= 12V, V

GNDVID

= VEP= 0V, video load is 150Ω to GNDVID, audio load is 10kΩ to EP, TA= +25°C, unless

otherwise noted.)

LARGE-SIGNAL GAIN FLATNESS

vs. FREQUENCY

MAX9670 toc04

FREQUENCY (Hz)

GAIN (dB)

10M

-7

-6

-5

-4

-3

-2

-1

-8 1M 100M

NO FILTER

FILTER

GROUP DELAY

vs. FREQUENCY

FILTER

NO FILTER

-20

-40

-60

DELAY (ns)

-80

-100

VIDEO CROSSTALK

vs. FREQUENCY

OUT

ALL HOSTILE

= 100mV

MAX9670 toc05

140

120

100

DELAY (ns)

P-P

= 2V

OUT

P-P

MAX9670 toc06

VIDEO POWER-SUPPLY REJECTION RATIO

-5

-10

-15

-20

-25

PSRR (dB)

-30

-35

-40

-45

-50 100k

DIFFERENTIAL GAIN AND PHASE

0.3

0.2

0.1 0

-0.1

-0.2

-0.3

DIFFERENTIAL GAIN (%)

0.6

0.4

0.2 0

-0.2

-0.4

-0.6

DIFFERENTIAL PHASE (deg)

102345

vs. FREQUENCY

FILTER

NO FILTER

10M1M

FREQUENCY (Hz)

100M

-120 100k

2.04

2.03

MAX9670 toc07

2.02

2.01

2.00

1.99

OUTPUT VOLTAGE (V)

1.98

1.97

1.96

0.3

0.2

0.1

MAX9670 toc10

-0.1

-0.2

-0.3

DIFFERENTIAL GAIN (%)

0.6

0.4

0.2 0

-0.2

-0.4

-0.6

DIFFERENTIAL PHASE (deg)

10M1M

FREQUENCY (Hz)

VIDEO VOLTAGE GAIN

vs. TEMPERATURE

INPUT VOLTAGE (V)

5025

DIFFERENTIAL GAIN AND PHASE

102345

1023

100M

100k

FREQUENCY (Hz)

10M1M

100M

VIDEO OUTPUT VOLTAGE

vs. INPUT VOLTAGE

3.5

3.0

MAX9670 toc08

2.5

2.0

1.5

OUTPUT VOLTAGE (V)

1.0

0.5

MAX9670 toc11

INPUT VOLTAGE (V)

2T WITH FILTER

80ns/div

1.20.80.4

MAX9670 toc12

MAX9670 toc09

1.6

VIDEO INPUT 200mV/div

VIDEO OUTPUT 500mV/div

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio

Volume Control for Dual SCART Connectors

_______________________________________________________________________________________ 9

Typical Operating Characteristics (continued)

VID

= V

AUD

= 3.3V, V12= 12V, V

GNDVID

= VEP= 0V, video load is 150Ω to GNDVID, audio load is 10kΩ to EP, TA= +25°C, unless

otherwise noted.)

2T NO FILTER

80ns/div

12.5T NO FILTER

MAX9670 toc13

MAX9670 toc15

VIDEO INPUT 200mV/div

VIDEO OUTPUT 500mV/div

VIDEO INPUT 200mV/div

12.5T WITH FILTER

1µs/div

NTC7 WITH FILTER

MAX9670 toc14

MAX9670 toc16

VIDEO INPUT 200mV/div

VIDEO OUTPUT 500mV/div

VIDEO INPUT 500mV/div

1µs/div

NTC7 NO FILTER

10µs/div

MAX9670 toc17

VIDEO OUTPUT 500mV/div

VIDEO INPUT 500mV/div

VIDEO OUTPUT 1V/div

10µs/div

FIELD SQUARE WAVE

2ms/div

MAX9670 toc18

VIDEO OUTPUT 1V/div

VIDEO INPUT 500mV/div

VIDEO OUTPUT 1V/div

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio Volume Control for Dual SCART Connectors

10 ______________________________________________________________________________________

Typical Operating Characteristics (continued)

VID

= V

AUD

= 3.3V, V12= 12V, V

GNDVID

= VEP= 0V, video load is 150Ω to GNDVID, audio load is 10kΩ to EP, TA= +25°C, unless

otherwise noted.)

VIDEO INPUT SYNC-TIP CLAMP VOLTAGE

-1

-2

-3

-4

INPUT CLAMP VOLTAGE (mV)

-5

-6 0

VIDEO INPUT SYNC-TIP CLAMP CURRENT

1.4

1.3

1.2

1.1

1.0

0.9

0.8

INPUT CLAMP CURRENT (mA)

0.7

0.6 0

vs. TEMPERATURE

5025

TEMPERATURE (°C)

vs. TEMPERATURE

5025

TEMPERATURE (°C)

MAX9670 toc19

MAX9670 toc21

VIDEO INPUT BIAS VOLTAGE

vs. TEMPERATURE

620

615

610

605

600

595

INPUT BIAS VOLTAGE (mV)

590

585

580

TEMPERATURE (°C)

5025

VIDEO INPUT SYNC-TIP CLAMP CURRENT

vs. INPUT VOLTAGE

INPUT CLAMP CURRENT (µA)

0 1.00.5 1.5 2.0 2.5 3.0 3.5

INPUT VOLTAGE (V)

MAX9670 toc20

MAX9670 toc22

VIDEO OUTPUT BIAS VOLTAGE

vs. TEMPERATURE

1.50

1.49

1.48

1.47

1.46

1.45

OUTPUT BIAS VOLTAGE (V)

1.44

1.43

1.42 0

TEMPERATURE (°C)

MAX9670 toc23

-5

GAIN (dB)

-10

-15

5025

-20

AUDIO LARGE-SIGNAL GAIN

vs. FREQUENCY

100k10k1k100

FREQUENCY (Hz)

MAX9670 toc24

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio

Volume Control for Dual SCART Connectors

______________________________________________________________________________________

Typical Operating Characteristics (continued)

VID

= V

AUD

= 3.3V, V12= 12V, V

GNDVID

= VEP= 0V, video load is 150Ω to GNDVID, audio load is 10kΩ to EP, TA= +25°C, unless

otherwise noted.)

AUDIO CROSSTALK

vs. FREQUENCY

-20

-40

-60

CROSSTALK (dB)

-80

-100

-120 10

FREQUENCY (Hz)

POWER-SUPPLY REJECTION RATIO

AUD

(INPUT REFERRED) vs. FREQUENCY

-20

-40

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

= 3.3V + 100mV

AUD

0.1

MAX9670 toc25

0.01 TVIN TO

TVOUT

THD+N (%)

0.001

10k1k100

100k

0.0001 10 100k

FREQUENCY (Hz)

QUIESCENT SUPPLY CURRENT

VID

vs. TEMPERATURE

P-P

MAX9670 toc27

VIN = 0.25V

TVIN TO VCROUT

10k1k100

RMS

MAX9670 toc26

MAX9670 toc28

-60

PSRR (dB)

-80

-100

-120 10 100k

FREQUENCY (Hz)

QUIESCENT SUPPLY CURRENT

AUD

vs. TEMPERATURE

CURRENT (mA)

0255075

TEMPERATURE (°C)

CURRENT (mA)

10k1k100

0255075

TEMPERATURE (°C)

V12 QUIESCENT SUPPLY CURRENT

vs. TEMPERATURE

800

MAX9670 toc29

700

600

500

400

CURRENT (nA)

300

200

100

TEMPERATURE (°C)

MAX9670 toc30

5025

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio Volume Control for Dual SCART Connectors

12 ______________________________________________________________________________________

Pin Description

MAX9670 MAX9671

1 1 SDA Bidirectional I2C Data I/O. Output is open drain and tolerates up to 3.6V.

2 2 SCL I2C Clock Input

3 3 DEV_ADDR Device Address Set Input. Connect to GNDVID, V

44 INT

NAME FUNCTION

Interrupt Output. This is an open-drain output that pulls down to GNDVID to indicate a change in the VCR slow switching or fast switching input, the activity status of the composite video inputs, or the load status of the composite video outputs.

, SDA or SCL. See Table 3.

VID

55 V

6 6 C1P

7 7 C1N

8 8 CPVSS C har g e- P um p N eg ati ve P ow er S up p l y. Byp ass w i th a 1µF cer am i c cap aci tor to E P .

9 9 ENC_INL Encoder Left-Channel Audio Input

10 10 ENC_INR Encoder Right-Channel Audio Input

— 11 TV_INL TV SCART Left-Channel Audio Input

— 12 TV_INR TV SCART Right-Channel Audio Input

11 13 VCR_INL VCR SCART Left-Channel Audio Input

12 14 VCR_INR VCR SCART Right-Channel Audio Input

13 15 TV_OUTL TV SCART Left-Channel Audio Output

14 16 VCR_OUTL VCR SCART Left-Channel Audio Output

15 17 VCR_OUTR VCR SCART Right-Channel Audio Output

16 18 TV_OUTR TV SCART Right-Channel Audio Output

17 19 TV_SS TV SCART Bidirectional Slow-Switch Signal

18 20 V

19 21 VCR_SS VCR SCART Bidirectional Slow-Switch Signal

20 22 TVOUT_FS TV SCART Fast-Switching Logic Output

— 23, 44 N.C. No Connection. Leave unconnected.

21 24 VCRIN_FS VCR SCART Fast-Switching Logic Input

22 25 ENC_B_IN Encoder Blue Video Input

23 26 ENC_G_IN Encoder Green Video Input

24 27 VCR_B_IN VCR SCART Blue Video Input

25 28 VCR_G_IN VCR SCART Green Video Input

26 29 TV_B_OUT TV SCART Blue Video Output

27 30 TV_G_OUT TV SCART Green Video Output

AUD

Audio Supply. Connect to a 3.3V supply. Bypass with a 10µF aluminum electrolytic capacitor and a 0.47µF ceramic capacitor to EP.

Charge-Pump Flying Capacitor Positive Terminal. Connect a 0.47µF capacitor from C1P to C1N.

Charge-Pump Flying Capacitor Negative Terminal. Connect a 0.47µF capacitor from C1P to C1N.

+12V Supply for the Slow Switching Circuit. Bypass with a 10µF + 0.47µF ceramic capacitor to EP.

MAX9670/MAX9671

Low-Power Audio/Video Switch with Audio

Volume Control for Dual SCART Connectors

______________________________________________________________________________________ 13

Detailed Description

The MAX9670/MAX9671 represents Maxim’s third generation of SCART audio/video (A/V) switches. Under I2C control, these devices route audio, video, and control information between the set-top box decoder chip and two SCART connectors. The audio signals are left audio and right audio. The video signals are composite video with blanking and sync (CVBS) and component video (red, green, blue). S-video (Y/C) can be transported across the SCART interface if CVBS is reassigned to luma (Y) and red is reassigned to chroma (C). Support for S-video is optional. The slow-switch signal and the fast-switch signal carry control information. The slowswitch signal is a 12V, three-level signal that indicates whether the picture aspect ratio is 4:3 or 16:9 or causes the television to use an internal A/V source such as an antenna. The fast-switch signal indicates whether the television should display CVBS or RGB signals.

CVBS, left audio, and right audio are full duplex. All the other signals are half duplex. Therefore, one device on the link must be designated as the transmitter, and the other device must be designated as the receiver.

The low power consumption and the advanced monitoring functions of the MAX9670/MAX9671 enable the cre-

ation of lower power set-top boxes, televisions, and DVD players. Unlike competing SCART ICs, the audio and video circuits of the MAX9670/MAX9671 operate entirely from 3.3V rather than from 5V and 12V. Only the slow-switch circuit of the MAX9670/MAX9671 requires a 12V supply. The MAX9670/MAX9671 also have circuits that detect activity on the CVBS inputs, loads on the CVBS outputs, and the level of the slow-switch signals. The INT signal informs the microcontroller if there are any changes so that the microcontroller can intelligently decide whether to power up or power down the equipment.

In addition, the MAX9670/MAX9671 have DirectDrive audio circuitry to eliminate click-and-pop noise. With DirectDrive, the DC bias of the audio line outputs is always at ground, no matter whether the MAX9670/ MAX9671 are being powered up or powered down. Conventional audio line output drivers that operate from a single supply require series AC-coupling capacitors. During power-up, the DC bias on the AC-coupling capacitor moves from ground to a positive voltage, and during power-down, the opposite occurs. The changing DC bias usually causes an audible transient.

Pin Description (continued)

MAX9670 MAX9671

28 31 GNDVID Video Ground

29 32 VCR_R/C_IN VCR SCART Red/Chroma Video Input

30 33 V

31 34 ENC_C_IN Encoder Chroma Video Input

32 35 ENC_R/C_IN Encoder Red/Chroma Video Input

33 36 TV_R/C_OUT TV SCART Red/Chroma Video Output

34 37 VCR_R/C_OUT VCR SCART Red/Chroma Video Output

35 38 VCR_Y/CVBS_OUT VCR SCART Luma/Composite Video Output

36 39 TV_Y/CVBS_OUT TV SCART Luma/Composite Video Output

37 40 VCR_Y/CVBS_IN VCR SCART Luma/Composite Video Input

38 41 TV_Y/CVBS_IN TV SCART Luma/Composite Video Input

39 42 ENC_Y_IN Encoder Luma Video Input

40 43 ENC_Y/CVBS_IN Encoder SCART Luma/Composite Video Input

—— EP

NAME FUNCTION

Video and Digital Supply. Connect to a 3.3V supply. Bypass with parallel 1µF and

VID

0.1µF ceramic capacitors to GNDVID. V

C interface.

Exposed Pad. The exposed pad is the internal ground for the audio amplifiers and charge pump. A low-impedance connection between ground and EP is required for proper isolation.

also serves as a digital supply for the

VID

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