Philips FI1256 MK2 DATA SHEET

BU TUNERS

DATA SH EET

FI1256 MK2

Desktop video tuner
system CCIR D/K

Preliminary specification
File under BU Tuners, DC03

1996 Jul 26

Philips Components Preliminary specification

Desktop video tuner
system CCIR D/K

FEATURES

• System CCIR D/K

• True 5 V device (low power dissipation)

• Full frequency range from channel 1 (49.75 MHz) to

channel 57 (863.25 MHz)

• PLL controlled tuning

• True-synchronous vision IF demodulator (PLL)

• Demodulated video output, AF sound output, second

sound IF output

• I2C-bus control of tuning, address selection, AFC status
information

• Complies with European regulations on radiation, signal
handling and immunity

‘‘CISPR 13”)

• Small horizontally mounted metal housing.

DESCRIPTION

The FI1200 MK2 family of front ends are designed to meet
a wide range of RF applications in the PC Multi-Media
environment.

The FI1256 MK2 types are available with a single 75 Ω
input for TV reception. The input connector is available in
either standard phono (female socket) or IEC (female
socket).

The tuning and bandswitching are performed through the
built-in digitally controlled I2C-bus. All front ends meet the
input immunity and radiation of CISPR 13.

The FI1256 MK2 consists of a tuner section and an IF
section, which are all designed on a single PCB. The front
end is assembled in a metal housing made of a rectangular
tin plated steel frame with front and rear covers which have
soldered contacts to the frame. A single phono or IEC
aerial socket is mounted on one side of the frame. All other
connections are made via pins at the bottom.

The tuner section is equipped with 3 tuned RF MOSFET
input stages, with a 3-band mixer-oscillator IC, containing
the oscillators, mixers and IF amplifier. Tuning and band
switching in the tuner section are done with a digital
programmable PLL tuning system. This enables tuning
with step-size programmable between 31.25, 50.0 or

62.5 kHz. A DC-DC converter is built around the PLL

synthesizer IC to provide the tuning voltage, thus making
the FI1256 MK2 front end a true 5 V device.

The IF section uses a true-synchronous vision IF
demodulator (PLL) with an intercarrier SAW filter in front of
it. The analog AFC voltage is fed to the 5-level A/D

(“CENELEC 55020, 55013’’

and

FI1256 MK2

converter in the PLL tuning IC, so that the AFC status can
be read via the I

ORDERING INFORMATION

TYPE DESCRIPTION

FI1256MK2/HM/PH standard phono 3139 147 13741
FI1256MK2/HM/IEC IEC 3139 147 13751

MARKING

The following items of information are printed on a sticker
that is on the top cover of the tuner:

• Type number

• Code number

• Origin letter of factory

• Change code

• Year and week code.

INTERMEDIATE FREQUENCIES

SYSTEM D/K

Picture carrier 38.90
Colour 34.47
Sound 1 32.40
Sound 2 (if applicable) 32.16

Note

1. The oscillator frequency is above the input signal
frequency.

CHANNEL COVERAGE

Low band 49.75 to 170.00 MHz
Mid band 170.00 to 450.00 MHz
High band 450.00 to 863.25 MHz

2

C-bus.

CATALOGUE

NUMBERS

FREQUENCY

(MHz)

BAND CHANNELS

(1)

1996 Jul 26 2

Philips Components Preliminary specification

Desktop video tuner
system CCIR D/K

BLOCK DIAGRAM

VCO

PLL DEMODULATOR

IF

V

IF

FILTER TRAP

FI1256 MK2

MLC279 - 1

sound

output

CVBS AF

sound

output

2nd IF

IF

V

(+5 V)

HIGH

MIXER - OSCILLATOR IC

HIGH BAND

OSC.

BAND

MID

OSC.

MID BAND

BAND

LOW

OSC.

BAND

LOW BAND

AGC

+ADC

PLLDC - DC

AS

SDASCLV

Fig.1 Electrical block diagram.

T

S

12 11 13 14 15 24 22 23 25

V

(+5 V)

handbook, full pagewidth

1996 Jul 26 3

Philips Components Preliminary specification

Desktop video tuner
system CCIR D/K

PINNING

SYMBOL PIN DESCRIPTION

V

T

V

S

SCL 13 I
SDA 14 I
AS 15 I
n.c. 21 not connected

nd

IF sound output 22 second IF sound output

2
CVBS 23 Composite Video Baseband Signal output
V

IF

AF sound output 25 AF sound output

− TH1, TH2, TH3 and TH4 mounting tags (ground)

11 tuning voltage (monitor)
12 supply voltage tuner section +5 V

2

C-bus serial clock

2

C-bus serial data

2

C-bus address select

24 supply voltage IF section +5 V

FI1256 MK2

1996 Jul 26 4

Philips Components Preliminary specification

Desktop video tuner

FI1256 MK2

system CCIR D/K

LIMITING VALUES
Limiting values under operational conditions

The tuner can be guaranteed to function properly under the following conditions.

SYMBOL PARAMETER PIN MIN. TYP. MAX. UNIT

V

S

V

S(ripple)

I

S

V

SCL

V

SDA

I

SDA

V

AS

Z

IF

Z

CVBS

t

L

V

IF

V

IF(ripple)

I

IF

Z

AF

supply voltage
peak-to-peak ripple voltage susceptibility

(at5V±5%); note 1

20 Hz to 100 kHz −−20 mV

12

>100 kHz to 500 kHz −−10 mV
supply current −−120 mA
SCL bus input voltage 13 −0.3 − +5.25 V
SDA bus input voltage
SDA bus current (open collector) −1 − +5 mA

14

address select voltage; note 2 15 −−+5.25 V
2nd IF sound output load impedance:

22DC 0.5 −−kΩ

AC 0.5 −−kΩ
Composite Video Baseband Signal load

impedance:

DC − 75 −Ω

23

AC − 75 −Ω
load time constant −−100 ns
IF supply voltage
peak-to-peak ripple voltage susceptibility

(at5V±5%); note 1

20 Hz to 100 kHz −−20 mV

24

>100 kHz to 500 kHz −−10 mV
IF supply current −−100 mA
AF sound output load impedance:

25DC 1.0 −−kΩ

AC 0.6 −−kΩ

4.75 5.00 5.25 V

−0.3 − +5.25 V

4.75 5.0 5.25 V

Notes

1. Sinusoidal ripple voltage superimposed on the 5 V supply voltage in the frequency range of 20 Hz to 500 kHz.
Criteria for TV interference >57 dB.

2. For detailed information about the address decoding, refer to Chapter “Application information”.

1996 Jul 26 5

Philips Components Preliminary specification

Desktop video tuner

FI1256 MK2

system CCIR D/K

Environmental conditions

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

Non-operational conditions

T

amb

RH relative humidity −−100 %
g

B

g

S

Operational conditions

T

amb

RH relative humidity −−95 %

OVERALL PERFORMANCE
Conditional data

Unless otherwise specified, all electrical values for Chapter “Overall performance” apply at the following conditions.

ambient temperature −25 − +85 °C

bump acceleration 25 g −−245 m/s
shock acceleration 50 g −−490 m/s
vibration amplitude 10 to 55 Hz − 0.35 − mm

ambient temperature −10 − +60 °C

2
2

SYMBOL PARAMETER VALUE UNIT

T

amb

ambient temperature 25 ±5 °C
RH relative humidity 60 ±15 %
V
Z
Z
t

pr

Z

S
CVBS
IF

S(AE)

supply voltage (tuner and IF section) 5 ±0.125 V

video output load impedance (DC) >75 Ω

IF sound output load impedance (DC) >500 Ω

pre-heating time (+5 V at pin 24) 10 minute

aerial source impedance (unbalanced) 75 Ω

1996 Jul 26 6