1999 Jan 13
2
Philips Semiconductors
Product specification
5 V mixer/oscillator-PLL synthesizers
for hyperband tuners
TDA6404; TDA6405;
TDA6405A
FEATURES
Single chip 5 V mixer/oscillator-PLL synthesizer for
hyperband tuners
I
2
C-bus protocol
3 PNP band switch buffers (25 mA)
33 V tuning voltage output
In-lock detector
5-level Analog-to-Digital Converter (ADC)
15-bit programmable divider
Programmable reference divider ratio
(512, 640 or 1024)
Programmable charge pump current
Balanced mixer with a common emitter input for VHF
(single input)
Balanced mixer with a common base input for UHF
(double input)
4-pin common emitter oscillator for VHF
4-pin common emitter oscillator for UHF
IF amplifier with a low output impedance to drive a SAW
filter directly (
2 k
load)
Low power, low radiation, small size
APPLICATIONS
Hyperband tuners for Europe using a 2-band
mixer/oscillator in a switched concept.
GENERAL DESCRIPTION
The TDA6404, TDA6405 and TDA6405A are
programmable 2-band mixer/oscillator-PLL synthesizers
intended for VHF/UHF and hyperband tuners (see Fig.1).
The devices include two double balanced mixers and two
oscillators for the VHF and UHF band, an IF amplifier and
a PLL synthesizer. With proper oscillator application and
by using a switchable inductor to split the VHF band into
two sub-bands (the full VHF/UHF and hyperband) the TV
bands can be covered.
Two pins are available between the mixer output and the
IF amplifier input to enable IF filtering for improved signal
handling. Three PNP ports are provided for band
switching. Band selection is made according to the band
switch bits VHFL, VHFH and UHF.
The PLL synthesizer consists of a divide-by-eight
prescaler, a 15-bit programmable divider, a 4 MHz crystal
oscillator and its programmable reference divider and a
phase comparator combined with a charge pump which
drives the tuning amplifier, including 33 V output.
Depending on the reference divider ratio (512, 640
or 1024), the phase comparator operates at 7.8125 kHz,
6.25 kHz or 3.90625 kHz.
The devices are controlled according to the I
2
C-bus
format. The in-lock detector bit FL is set to logic 1 when the
loop is locked and is read on the SDA line (status byte)
during a read operation. The ADC input is available for
digital Automatic Frequency Control (AFC). The ADC code
is read during a read operation on the I
2
C-bus
(see Table 9). In test mode, pin ADC is used as a test
output for f
REF
and
1
/
2
f
DIV
.
When the charge pump current switch mode is activated
and the loop is phase-locked the charge pump current
value is automatically switched to LOW. This is to improve
carrier-to-noise ratio. The status of this feature can be read
in the ACPS flag during a read operation on the I
2
C-bus
(see Table 7).
Five serial bytes (including address byte) are required for
the I
2
C-bus format to address the devices, select the VCO
frequency, program the three PNP ports, set the charge
pump current and to set the reference divider ratio.
The devices have four independent I
2
C-bus addresses
which can be selected by applying a specific voltage on the
AS input (see Table 4).
1999 Jan 13
5
Philips Semiconductors
Product specification
5 V mixer/oscillator-PLL synthesizers for
hyperband tuners
TDA6404; TDA6405;
TDA6405A
PINNING
SYMBOL
PIN
DESCRIPTION
TDA6404
TDA6405;
TDA6405A
UHFIN1
1
28
UHF input 1
UHFIN2
2
27
UHF input 2
VHFIN
3
26
VHF input
RFGND
4
25
RF ground
IFFIL1
5
24
IF filter output 1
IFFIL2
6
23
IF filter output 2
PVHFL
7
22
PNP port output for VHF low band
PVHFH
8
21
PNP port output for VHF high band
PUHF
9
20
PNP port output for UHF band
AS
10
19
address selection input
SDA
11
18
serial data input/output (I
2
C-bus)
SCL
12
17
serial clock input (I
2
C-bus)
ADC
13
16
Analog-to-Digital Converter input/output
CP
14
15
charge pump output
VT
15
14
tuning output
XTAL
16
13
crystal oscillator input
V
CC
17
12
supply voltage
IFOUT1
18
11
IF amplifier output 1
IFOUT2
19
10
IF amplifier output 2
GND
20
9
ground
UHFOSCIB1
21
8
UHF oscillator base input 1
UHFOSCOC1
22
7
UHF oscillator collector output 1
UHFOSCOC2
23
6
UHF oscillator collector output 2
UHFOSCIB2
24
5
UHF oscillator base input 2
VHFOSCIB1
25
4
VHF oscillator base input 1
VHFOSCOC1
26
3
VHF oscillator collector output 1
VHFOSCOC2
27
2
VHF oscillator collector output 2
VHFOSCIB2
28
1
VHF oscillator base input 2
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