Datasheet SL1710 Datasheet (MITEL)

SL1710

Quadrature Downconverter

Preliminary Information

Supersedes October 1996 version in Media IC Handbook HB4599-1.0 DS3842 - 4.1 March 1997

The SL1710 is a quadrature downconverter, intended for
use with both Professional and Consumer Digital Satellite
Applications.

The device contains high linearity, low noise amplifiers,
quadrature mixers, plus an on-chip oscillator, operating
between 350MHz and 500MHz, which may be synthesised via
the differential prescaler outputs.

An AGC with 18dB gain control is provided to cope with a
wide range of input signal levels.

I and Q outputs are via low impedance single ended
amplifiers. These may be connected to a dual channel analog
to digital converter such as the PCA916, VP216, VP215 or
VP213, via a suitable anti-alias filter.

AGC
IOUT

VEEA

IFINB

IFIN
VCCA
QOUT

VEEC

1

16

SL1710

VCCB
VCODIS

VCO B
VCO A

VEEB
PSCAL
PSCALB
VCCC

MP16

FEATURES

■ Wide input frequency range (350-500MHz)

■ On chip oscillator with varactor tuning or SAW

resonator operation capability

■ Nominal 40dB conversion gain from IF input to I
and Q outputs

■ AGC amplifier with 18dB gain control range

■ I to Q phase match 90°C to ± 2°, gain match

better than 1dB

■ Low impedance I and Q single ended outputs,
with 15MHz ± 1dB BW

■ Divide by 32 prescaler outputs

■ Suitable for QPSK and up to 64QAM systems

AGC

IFIN
IFINB

Fig. 1 Pin allocation top view

ORDERING INFORMATION

SL1710/KG/MPAS
SL1710/KG/MPAD (Tape and Reel)

ABSOLUTE MAXIMUM RATINGS

Storage temperature -55°C to +150°C
Junction temperature -29°C to +150°C
Supply voltage -0.3 to 7.0V
Voltage at any other pin -0.3 to +7.0V

APPLICATIONS

■ Consumer digital satellite decoders

■ Professional digital satellite decoders

■ Communication systems

AGC

I OUT

VCODIS

VCOA
VCOB

LO

0 deg 90 deg

Quadrature
generator

Fig.2. SL1710 block diagram

AGC

÷32

Q OUT

PSCAL
PSCALB

SL1710

ELECTRICAL CHARACTERISTICS

T

= 0oC to +80oC, Vee= 0V, Vcc = 4.75 to 5.25 V, Fif = 479.5 MHz, IF bandwidth ± 15 MHz, output amplitude -11dBV

amb

These characteristics are guaranteed by either production test or design. They apply within the specified ambient temperature

and supply voltage unless otherwise stated.

Value

Characteristic Pin Min Typ Max Units Conditions

Supply voltage 6,9,16 4.75 5.25 V
Supply current 6,9,16 94 110 mA

RF Input

RF freq range 4, 5 350 500 MHz
Impedance 4, 5 75 ohm @ 480MHz. Fig. 4
VSWR 4, 5 1.7 @ 480MHz. Fig. 4
Noise Figure 4, 5 19 dB AGC at maximum gain
Noise Figure variation with 4, 5 0.5 1 dB/dB
gain

VCO

VCO freq (fo) control range 13, 14 350 500 MHz External tank circuit with varicap
Phase noise 13, 14 -85 dBc/Hz @ 10kHz from fo. but measured in

I or Q output. Note

Fo sensitivity to V

CC

13, 14 2 MHz/Volt Fixed external components and no

control loop
Fo sensitivity to temperature 13, 14 40 KHz/°C Uncompensation
Prescaler output, VOH 10, 11 V

VOL 10, 11 V

-0.96 Volt At 25°C

CC

-1.65 Volt

CC

Prescaler output duty cycle 10, 11 40 60 %Under maximum load conditions

Fig. 5

AGC

Gain, Vagc = +2.5V 40 dB
Temp stability of gain 1 ±2 dB For any gain setting 0V to 5V
Gain, Vagc = +0.5V 1 44 dB See Fig.6
Gain, Vagc = + V

-0.5V 1 32 dB See Fig.6

CC

AGC range 18 dB
I Q outputs 480MHz local oscillator, 481 to

495MHz RF input @ -51dBV

Gain set to give -11dBV,

1-15MHz baseband output into

maximum load. Fig. 7
Output impedance 2, 7 8 ohm Fig. 8
Output clipping level 2, 7 1.5 V p-p
I phase lag with respect to Q 2, 7 88 90 92 degs 1 -15MHz
IQ crosstalk 20 dB
Output amplitude match 2, 7 1 dB I releative to Q, 1 -15MHz
Baseband flatness 2, 7 ±1 dB 1-15MHz, 1kΩ 15pF load
Two tone 3rd order intercept 2, 7 +3 dBV Referred to output. @ 1MHz
point Output load 1kohm, 15pF, all

AGC settings, 0.7V pk-pk output
Im3 2, 7 28 dBc
LO, and Sputii in IQ outputs 2, 7 -30 dBV 1-100MHz

(1, 2)

2

SL1710

ELECTRICAL CHARACTERISTICS (continued)

T

= 0oC to 80oC, Vee= 0V, Vcc = 4.75 to 5.25 V, These characteristics are guaranteed by either production test or design.

amb

They apply within the specified ambient temperature and supply voltage unless otherwise stated.

Value

Characteristic Pin Min Typ Max Units Conditions

Prescaler sidebands 2, 7 -50 -47 dBV Measured in IQ outputs
Power supply rejection 2, 7 25 30 dB Attenuation VCC to IQ outputs,

over 0-500kHz

Notes:

1. The choice of L will have an effect on phase noise of the VCO

2. Target value at fo=500MHz, L (tank)=10nH, Q (tank, unloaded)=50, SSB

DESCRIPTION

The SL1710 is a quadrature downconverter, intended for
high linearity, low noise digital satellite applications. It contains
all the elements necessary, with the exception of the VCO
tuning components, to extract baseband I and Q signals from
a QPSK or QAM IF input signal.

A block diagram for the SL1710 is shown in Fig. 2.

In normal consumer digital satellite applications, the device
is fed via a SAW filter, centred at the standard IF of 479.5MHz.
A filtered single channel is therefore presented to the device,
at a typical level of -51dBV. An AGC is included with 18dB of
gain control, which is guaranteed to provide an overall conver­sion gain between 30 and 45dB from the RF input to the I and
Q outputs.

The quadrature mixers are fed from an on-chip oscillator
which is centred on the incoming IF. The oscillator external
tuning network should be fully symmetric, to ensure optimum
gain and phase match.

Single ended I and Q amplifiers are provided, which output
a 760mV (p/p) signal, assuming a nominal -51dBV input signal
and 40dB gain, suitable for driving a dual channel ADC such as
the PCA 869, PCA 913 and PCA 916 via an anti-alias filter (see
application notes). The ADC is normally AC coupled via two
capacitors (typically 4.7µF).

The SL1710 also includes divide by 32 prescaler output.
These may be fed to an external PLL circuit which can be used
to drive the on-chip oscillator, thus forming a complete control
loop.

The VCO can be disabled by applying 0V to pin 15.

3

SL1710

CH PUMP

1

XTAL1

2

XTAL2

3

SDA

4

SCL

5

P76P67P5

8

P4

9

P310NC11Vcc12RF I/P13RF I/P14Vee

15

DRV

16

IC2 SP5611

AGC

1

IOUT

2

VEEA

3

IFINB

4

IFIN

5

VCCA

6

QOUT

7

VEEC

8

VCCC

9

PSCALB

10

PSCAL

11

VEEB

12

VCOA

13

VCOB

14

VCODIS

15

VCCB

16

/32

Oscillator

I Mixer

Q Mixer

IC1 SL1710

L1

12nH

C12

3p9

D1

BB811

C13

3p3

1

42

3

LK2

T2

BCW31

5V

R4

110R

SK4

Q CH O/P

C11

220nF

SW1

VCO DISABLE

R2

4K7

5V

SK1

RF IN

C1

100nF

C2

100nF

R1

75R

L5

4u7

L6

4u7

C3

100nF

C4

100pF

C5

100nF

C6

100pF

C7

100nF

C8

100pF

+

C9

47uF

5V

5V

5V 5V

VR1

1K

R5

680R

R6

4K7

R7

680R

T1

BCW31

1

42

3

LK1

R3

110R

SK3

I CH O/P

C10

220nF

C14

10nF

C15

10nF

C19

220nF

C20

47nF

R8

22K

R9

22K

R10

4K7

T3

BCW31

R11

10K

C21

10nF

30V

C18

18pF

X1

4 MHz

C16

10nF

C17

100pF

1

2

3

CN1

DC POWER

30V

5V

SDA5

3

5V04GND5SCL5

6

SK4

I2C

5V

Fig. 3 Demonstration board circuit diagram

4

+j1

SL1710

+j0.5

+j0.2

0.50.2 10

–j0.2

–j0.5

START 350 MHz STOP 650 MHz

Fig.4 Typical RF input impedance

APPLICATION NOTES

These application notes should be read in conjunction with
the circuit diagram Fig 3. and the PCB layout illustrated in Figs
9 and 10. An alternative oscillator configuration using a SAW
Resonator is shown in the circuit diagram Fig. 11 and the PCB
layout illustrated in Figs 12 and 13. These boards have been
designed to permit the initial evaluation of the SL1710
performance.

VARACTOR TUNED

The application detailed in Fig.3 uses a synthesised VCO.
The tuning range of the oscillator is;

Varactor line Voltage. Oscillator Frequency

5 Volts 458MHz
30 Volts 504MHz

This configuration gives a VCO sensitivity of 1.84MHz/
Volt. The inductor L1 is a 12nF surface mount component.
Different VCO centre frequencies and sensitivities can be
achieved by changing the values of L1, C12 and C13.

The VCO frequency is controlled by the SP5611
synthesiser which is programmed via an I2C bus. The RF

input to the synthesiser is from the SL1710 prescaler outputs
via RF inductors L3 and L4.

+j2

+j5

2 5

–j5

–j2

–j1

Marker
Zreal
Zimag

1 480MHz

= 75.7
= –36.4

SAW RESONATOR OSCILLATOR

The application detailed in Fig. 11 shows an SL1710 with
a SAW Resonator controlled oscillator. In this instance the
frequency accuracy and stability of the oscillator are
determined by the Saw Resonator. The PCB detailed in Figs.
12 and 13 is designed to accommodate the following SAWR;

Manufacturer Part No

MURATA SAR479.45MB10X200

PRESCALER OUTPUTS

The VCO frequency/32 is available at the differential
prescaler outputs pins 10 and 11. This enables the on board
VCO to be synthesised via a PLL.

VCO DISABLE

The on-chip oscillator can be disabled by connecting the
VCO Disable (pin 15) to ground and enabled by connecting the
pin to VCC via a 4K7 pull up resistor.

AGC

The DC voltage measured at TP1 should be adjusted using
VR1 to read 2.5 volts with respect to VEE. this voltage equates

to the nominal centre of the AGC control curve. The control
voltage applied to pin 1 can be varied between 0.5 Volts
(maximum gain) and V

-0.5 Volts minimum gain)

CC

5

SL1710

I & Q OUTPUTS

The I and Q output stages of the SL1710 are sensitive to the
loads connected to them. To avoid degrading the output
signals resistive loads connected to these pins should always
be 1KΩ or greater with a parallel capacitance of 15pF or less

For evaluation purposes this makes the output unsuitable
for connection to test equipment via normal coaxial cables. To
alleviate this problem the application board is fitted with
emitter follower buffer amplifiers which allow the connection of
loads as low as 50Ω via coaxial cables without loading the
output stages of the SL1710. These buffer amplifiers can be
either connected in circuit, or bypassed by changing the
position of Links 1 and 2.

This technique may be used in a real application where the
SL1710 is used to drive and ADC via an anti-alias filter. Great
care must be taken to ensure that the loading conditions
stated above are not exceeded when designing the anti-alias
filter section. Use of an emitter follower buffer is the easiest
way to alleviate this constraint.

With the AGC voltage adjusted to 2.5 Volts apply an input
signal to the IF IN (pin 5) and monitor the Base Band output
level at the I and Q outputs. Adjust the RF input level until an
output level of 760mV pk-pk is achieved. For best
performance this level should not exceeded.

Vcc 2

2K

PRESCALER
OUTPUT

15pF

Fig.5 Maximum prescaler output load

6

50.00

45.00

40.00

33.00

GAIN (dB)

30.00

25.00

IQ OUTPUT

012345

V

agc (V)

Fig. 6 AGC operation

SL1710

Marker

Freq

1 500KHz 3.5
2 15MHz 4.5
3 30MHz 56

Zreal Zimag

Ω 0.5
Ω 32

Ω 92

ART .010 MHz

ST

15pF

1KΩ

Fig. 7 Maximum IQ output load

+j1

Ω

Ω

Ω

+j0.2

–j0.2

+j0.5

1

–j0.5

2

0.50.2 10

2 5

–j1

+j2

+j5

3

–j5

–j2

30.MHz

STOP

Fig. 8 Output impedance

7

SL1710

Fig. 9 Demonstration PCB top view

Fig. 10 Demonstration PCB bottomview

8

T1

+

C7

C9

C8

C12

1nF

BCW31

LK1

47uF

100nF

100pF

SL1710

4

1nF

T2

C13

BCW31

LK2

SW1

R4

110R

423

1

SK3

Q CH OUT

C11

220nF

R2

4K7

5V

3

R3

110R

SAW1

C10

SK2

220nF

4

3

2

1

SL1710

IC1

I CH OUT

100pF

C14

2

13

IOUT

VCOA

SAW

RESONATOR

1

14

VCOB

Osc

7

2

C15

QOUT

5V

100pF

15

VCODIS

CN1

5V

POWER

5V

C6

100nF

5V

C5

100pF

C4

100nF

C3

100pF

1K

VR1

R5

680R

3

2

1

5V

5V

R6

4K7

R7

680R

I Mixer

9

VCCC

16

VCCB

6

VCCA

TP1

AGC VOLTS

C1

SK1

1

AGC

100nF

IF IN

/32

IFINB

IFIN

5

PSCALB

PSCAL

4

11

10

C2

100nF

R1

75R

Q Mixer

VEEC

VEEB

VEEA

VCO DISABLE

8

12

3

Fig. 11 SL1710 I & Q downconverter with saw resonator

9

SL1710

Fig. 12

10

Fig. 13

http://www.mitelsemi.com

World Headquarters - Canada

Tel: [phone]

Fax: [phone]

North America Asia/Pacific Europe, Middle East,

Tel: [phone] Tel: [phone] and Africa (EMEA)

Fax: [phone] Fax: [phone] Tel: [phone]

Fax: [phone]

Information relating to products and services furnished herein by Mitel Corporation or its subsidiaries (collectively “Mitel”) is believed to be reliable. However, Mitel assumes no
liability for errors that may appear in this publication, or for liability otherwise arising from the application or use of any such information, product or service or for any infringement of
patents or other intellectual property rights owned by third parties which may result from such application or use. Neither the supply of such information or purchase of product or
service conveys any license, either express or implied, under patents or other intellectual property rights owned by Mitel or licensed from third parties by Mitel, whatsoever.
Purchasers of products are also hereby notified that the use of product in certain ways or in combination with Mitel, or non-Mitel furnished goods or services may infringe patents or
other intellectual property rights owned by Mitel.

This publication is issued to provide information only and (unless agreed by Mitel in writing) may not be used, applied or reproduced for any purpose nor form par t of any order or
contract nor to be regarded as a representation relating to the products or services concerned. The products, their specifications, services and other information appearing in this
publication are subject to change by Mitel without notice. No warranty or guarantee express or implied is made regarding the capability, performance or suitability of any product or
service. Information concerning possible methods of use is provided as a guide only and does not constitute any guarantee that such methods of use will be satisfactory in a specific
piece of equipment. It is the user’s responsibility to fully determine the performance and suitability of any equipment using such information and to ensure that any publication or
data used is up to date and has not been superseded. Manufacturing does not necessarily include testing of all functions or parameters. These products are not suitable for use in
any medical products whose failure to perform may result in significant injury or death to the user. All products and materials are sold and services provided subject to Mitel’s
conditions of sale which are available on request.

M Mitel (design) and ST-BUS are registered trademarks of MITEL Corporation
Mitel Semiconductor is an ISO 9001 Registered Company
Copyright 1999 MITEL Corporation
All Rights Reserved
Printed in CANADA

TECHNICAL DOCUMENTATION - NOT FOR RESALE