Rainbow Electronics MAX9656 User Manual

General Description

The MAX9655/MAX9656 dual SCART switches route
video signals between a set-top box decoder chip and
two external SCART connectors. Under the control of the
TV_SEL logic input, the MAX9655 selects whether the
CVBS and RGB signals from the encoder or the VCR
SCART are routed to the TV SCART. The CVBS signal
from the encoder is always routed to the VCR SCART.

The MAX9656 is similar to the MAX9655 except that
under the control of the VCR_SEL logic input, the
MAX9656 selects whether the CVBS signal from the
encoder or the TV SCART is routed to the VCR SCART.
The MAX9656 also features a low-power shutdown
mode, in which quiescent current falls to 35µA.

The incoming video signals must be AC-coupled to the
inputs, which have sync-tip clamps to set the internal
DC level. After the input stages, multiplexers select
which video signals are routed to the reconstruction fil­ters and output amplifiers. The reconstruction filters are
optimized for standard-definition signals and typically
have ±1dB passband flatness out to 9.5MHz and 47dB
attenuation at 27MHz.

The amplifiers have 2V/V gain, and the outputs can be
DC-coupled to a 75Ω load, which is the equivalent of
two video loads, or AC-coupled to a 150Ω load.

Applications

SCART Set-Top Boxes

Features

♦ Dual SCART Support for Video Signals

♦ Supports CVBS Input from TV SCART (MAX9656)

♦ Reconstruction Filters with 9.5MHz Passband and

47dB Attenuation at 27MHz

♦ Fixed Gain of 2V/V

♦ Input Sync-Tip Clamps

♦ 2.7V to 3.6V Single-Supply Operation

MAX9655/MAX9656

Low-Power Video Switches

for Dual SCART Connectors

________________________________________________________________

Maxim Integrated Products

1

19-4238; Rev 0; 8/08

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.

UNKNOWN

BIAS

ENC_CVBS_IN

300mV

ENC_R_IN

TV_G_OUT

ENC_G_IN

ENC_B_IN

TV_B_OUT

TV_CVBS_OUT

TV_R_OUT

VCR_CVBS_OUT

VCR_CVBS_IN

VCR_R_IN

VCR_G_IN

VCR_B_IN

TV_SEL

TV_SEL

0

1

0

1

0

1

0

1

0

V

DD

GND

MAX9655

LPF

BUFFER

CLAMPREF

LPF

BUFFER

CLAMPREF

LPF

BUFFER

CLAMPREF

LPF

BUFFER

CLAMPREF

2V/V

2V/V

2V/V

2V/V

2V/V

LPF

BUFFER

CLAMPREF

Functional Diagram

Ordering Information

Note: All devices are specified over the -40°C to +125°C oper­ating temperature range.

+

Denotes a lead-free/RoHS-compliant package.

*

Future product—contact factory for availability.

Pin Configurations and Typical Application Circuits appear
at end of data sheet.

PART PIN-PACKAGE

MAX9655AEE+ 16 QSOP No

MAX9656AEP+* 20 QSOP Yes

TV SCART CVBS

RETURN SUPPORT

MAX9655/MAX9656

Low-Power Video Switches
for Dual SCART Connectors

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= 3.3V, V

GND

= 0, V

SHDN

= VDD, VCR_SEL = VDD, TV_SEL = VDD, RL= 150Ω to GND, TA= T

MIN

to T

MAX

, unless otherwise

noted. Typical values are at T

A

= +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.

Supply Voltage

V

DD

to GND...........................................................-0.3V to +4V

All Video and Logic Input Pins..................(GND - 0.3V) to +4V

Duration of Output Short Circuit to V

DD

or GND ........Continuous

Continuous Input Current

All Video and Logic Input Pins .....................................±20mA

Continuous Power Dissipation (T

A

= +70°C)

16-Pin QSOP (derate 8.3mW/°C above +70°C)............667mW

20-Pin QSOP (derate 9.1mW/°C above +70°C)............727mW

Operating Temperature Range .........................-40°C to +125°C

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

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

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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range V

Quiescent Supply Current I

Shutdown Supply Current I

Input Voltage Unselected input VDD/3 V

Input Resistance

Sync-Tip Clamp Level V

Input Voltage Range

Sync Crush

Input Clamping Current 12µA

Maximum Input Source
Resistance

DC Voltage Gain A

DC Gain Mismatch Guaranteed by output-voltage swing -2 +2 %

Output Level Measured at output, C

Output-Voltage Swing

DD

DD

SHDN

Guaranteed by power-supply rejection test 2.7 3.3 3.6 V

No load 21 45 mA

V

= 0 (MAX9656 only) 35 µA

SHDN

Unselected input 222 kΩ

CLP

Guaranteed by output­voltage swing

Sync-tip clamp; percentage reduction in
sync pulse (0.3V
clamping current measurement

RL = 150Ω to GND

V

(Note 2) V

Measured at output, VDD = 2.7V, V

to (V

V

CLP

CLP

Measured at output, VDD = 2.7V, V

to (V

V

CLP

CLP

Measured at output, VDD = 3.0V, VIN =

to (V

V

CLP

CLP

Measured at output, VDD = 3.0V, V

to (V

V

CLP

CLP

Measured at output, V

to (V

V

CLP

CLP

0.23 0.3 0.39 V

2.7V ≤ VDD ≤ 3.6V 1.05

3.0V ≤ V

); guaranteed by input

P-P

≤ 3.6V 1.2

DD

2%

300 Ω

VDD = 2.7V, 0V ≤ V
≤ 1.05V

= 3.0V, 0V ≤ V

DD

≤ 1.2V

= 0.1µF to GND 0.218 0.3 0.39 V

IN_

+1.05V), RL = 150Ω to -0.2V

+1.05V), RL = 150Ω to VDD/2

+1.2V), RL = 150Ω to -0.2V

+1.2V), RL = 150Ω to VDD/2

= 3.135V, V

DD

+1.05V), RL = 75Ω to -0.2V

IN

IN

IN

=

=

=

IN

IN

1.96 2 2.04

IN

1.96 2 2.04

2.1

2.1

2.4

2.4

=

2.1

V

V/V

V

P-P

P-P

MAX9655/MAX9656

Low-Power Video Switches

for Dual SCART Connectors

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 3.3V, V

GND

= 0, V

SHDN

= VDD, VCR_SEL = VDD, TV_SEL = VDD, RL= 150Ω to GND, TA= T

MIN

to T

MAX

, unless otherwise

noted. Typical values are at T

A

= +25°C.) (Note 1)

Note 1: All devices are 100% production tested at T

A

= +25°C. Specifications over temperature limits are guaranteed by design.

Note 2: Voltage gain (A

V

) is a two-point measurement in which the output-voltage swing is divided by the input-voltage swing.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Output Short-Circuit Current

Output Resistance R

Power-Supply Rejection Ratio

Standard-Definition
Reconstruction Filter

Differential Gain DG

Differential Phase DP

Group-Delay Distortion 100kHz ≤ f ≤ 5MHz, outputs are 2V

Peak Signal to RMS Noise 100kHz ≤ f ≤ 5MHz 71 dB

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

2T Bar Response

Short to GND (sourcing) 140

(sinking) 70

DD

= 1.5V, -10mA ≤ I

P-P

= 2V

= 2V

, reference frequency is

P-P

, reference

P-P

≤ +10mA 0.2 Ω

LOAD

f = 5.5MHz 0.1

f = 9.5MHz -1

f = 10MHz -3

f = 27MHz -47

P-P

OUT

Short to V

V

OUT

2.7V ≤ VDD ≤ 3.6V 48 64

f = 1MHz, 100mV

V

OUT

100kHz, ±1dB passband flatness

V

OUT

frequency is 100kHz

5-step modulated staircase of 129mV step
size and 286mV peak-to-peak subcarrier
amplitude, f = 4.43MHz

5-step modulated staircase of 129mV step
size and 286mV peak-to-peak subcarrier
amplitude, f = 4.43MHz

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

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

20

9.5 MHz

0.4 %

0.45 deg

9ns

0.2 K%

mA

dB

dB

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

2T Pulse-to-Bar K Rating

Nonlinearity 5-step staircase 0.1 %

Output Impedance f = 5.5MHz 8.07 Ω

All-Hostile Crosstalk

Output-to-Input Crosstalk f = 30MHz -68 dB

LOGIC SIGNALS (MAX9655: TV_SEL, MAX9656: TV_SEL, VCR_SEL, SHDN)

Logic-Low Threshold V

Logic-High Threshold V

Logic Input Current I

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

f = 15kHz -82

f = 4.43MHz -78

TA = +25°C

IL

TA = +25°C

IH

TA = +25°C10µA

IN

0.7 x
V

DD

0.3 K%

0.3 x
V

DD

dB

V

V

MAX9655/MAX9656

Low-Power Video Switches
for Dual SCART Connectors

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VDD= 3.3V, V

GND

= 0, V

SHDN

= VDD, RL= 150Ω to GND, TA= +25°C.)

SMALL-SIGNAL GAIN

vs. FREQUENCY

MAX9655 toc01

FREQUENCY (Hz)

GAIN (dB)

10M1M

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

5

10

-50
100k 100M

VIN 50mV

P-P

NOTE: GAIN IS NORMALIZED TO 0dB

SMALL-SIGNAL GAIN FLATNESS

vs. FREQUENCY

MAX9655 toc02

FREQUENCY (Hz)

GAIN (dB)

10M1M

-6

-5

-4

-3

-2

-1

0

1

2

3

-7
100k 100M

VIN 50mV

P-P

NOTE: GAIN IS NORMALIZED TO 0dB

LARGE-SIGNAL GAIN

vs. FREQUENCY

MAX9655 toc03

FREQUENCY (Hz)

GAIN (dB)

10M1M

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

5

10

-50
100k 100M

VIN 1V

P-P

NOTE: GAIN IS NORMALIZED TO 0dB

LARGE-SIGNAL GAIN FLATNESS

vs. FREQUENCY

MAX9655 toc04

FREQUENCY (Hz)

GAIN (dB)

10M1M

-6

-5

-4

-3

-2

-1

0

1

2

3

-7
100k 100M

VIN 1V

P-P

NOTE: GAIN IS NORMALIZED TO 0dB

VIDEO CROSSTALK

vs. FREQUENCY

MAX9655 toc05

FREQUENCY (Hz)

GAIN (dB)

10M1M

-100

-80

-60

-40

-20

0

-120
100k 100M

ALL-HOSTILE

1 ADJACENT CHANNEL

2 ADJACENT CHANNELS

VIN 1V

P-P

NOTE: GAIN IS NORMALIZED TO 0dB

VIDEO GROUP DELAY DISTORTION

vs. FREQUENCY

MAX9655 toc06

FREQUENCY (Hz)

GROUP DELAY (ns)

10M1M

10

20

30

40

50

60

70

80

90

100

110

120

0

100k 100M

VIN 1V

P-P

NOTE: GAIN IS NORMALIZED TO 0dB

MAX9655/MAX9656

Low-Power Video Switches

for Dual SCART Connectors

_______________________________________________________________________________________

5

Typical Operating Characteristics (continued)

(VDD= 3.3V, V

GND

= 0, V

SHDN

= VDD, RL= 150Ω to GND, TA= +25°C.)

VIDEO PSRR

vs. FREQUENCY

0

VDD = 3.3V + 100mV

-10

-20

-30

-40

PSRR (dB)

-50

-60

-70

-80
100k 100M

P-P

FREQUENCY (Hz)

DIFFERENTIAL GAIN

0.1
0

-0.1

-0.2

-0.3

-0.4

-0.5

DIFFERENTIAL GAIN (%)

103245

DIFFERENTIAL PHASE

0.8

0.6

0.4

0.2
0

-0.2

-0.4

DIFFERENTIAL PHASE (deg)

103245

VOLTAGE GAIN

vs. TEMPERATURE

2.10

10M1M

f = 3.58MHz

f = 3.58MHz

MAX9655 toc07

MAX9655 toc09

2.08

2.06

2.04

2.02

2.00

1.98

VOLTAGE GAIN (V/V)

1.96

1.94

1.92

1.90

-50 -25 0 25 50 75 100 125
TEMPERATURE (°C)

DIFFERENTIAL GAIN

0.1
0

-0.1

-0.2

-0.3

-0.4

-0.5

DIFFERENTIAL GAIN (%)

103245

DIFFERENTIAL PHASE

0.8

0.6

0.4

0.2
0

-0.2

-0.4

DIFFERENTIAL PHASE (deg)

103245

f = 4.43MHz

f = 4.43MHz

MAX9655 toc08

MAX9655 toc10

2T RESPONSE

100ns/div

MAX9655 toc11

IN
200mV/div

OUT
400mV/div

12.5T RESPONSE

400ns/div

MAX9655 toc12

IN
200mV/div

OUT
400mV/div