INTEGRATED CIRCUITS
DATA SHEET
SAA7158
Back END IC
Preliminary specification
File under Integrated Circuits, IC02
July 1994
Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
FEATURES
• Line Flicker Reduction (LFR) by means of MEDIAN filtering
• Vertical zoom
• Digital colour transient improvement
• Digital luminance peaking
• Movie phase detection
• 4:4:4 YUV data throughput selectable, standard is 4:1:1 Y/U/V
• D/A conversion
• UART interface.
GENERAL DESCRIPTION
Application Environment
The Back END IC (abbreviated as BENDIC) is designed to cooperate with an 8051 type of microprocessor, the ECO3
(SAA4951) memory controller and Texas Instruments TMS4C2970 memories, but other configurations may be
applicable. Fig.1 shows the block diagram of the feature box. The nominal clock frequency of the IC is 27 MHz or 32 MHz,
with a maximum of 36 MHz.
The system supports the digital Y/U/V bus for selection of different video signal sources. The Y/U/V bus and the BENDIC
data input are fully synchronous with respect to the clock signal. A line reference signal BLN for timing control purposes
has to be provided by external elements which always controls the system timing, independent of active signal sources
or desired functions.
Analog Characteristics
The BENDIC contains 3 independent, high speed digital to analog converters for luminance and colour difference signal
processing and conversion. The resolution of the two DA converters for the colour difference signals is 8 bit. The
luminance peaking up to 6 dB at high frequencies widens the resolution of the luminance channel. To avoid aliasing
effects due to time discrete amplitude limiting the resolution of 9-bit is offered for the luminance conversion. All output
stages provide high performance output stages for driving lines with low impedance line termination.
QUICK REFERENCE DATA
SYMBOL
VDD
Tamb
PARAMETER
MIN.
MAX.
5.5
digital supply voltage
4.5
analog supply voltage
4.75
5.25
V
operating ambient temperature
0
+70
°C
ORDERING INFORMATION
PACKAGE
EXTENDED
TYPE NUMBER
PINS
PIN POSITION
MATERIAL
CODE
SAA7158WP
68
PLCC
plastic
SOT188(1)
Note
1. SOT188-2; 1996 November 26.
July 1994
UNIT
2
V
Philips Semiconductors
Preliminary specification
SAA7158
Fig.1 Block diagram of the feature box.
Back END IC
July 1994
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Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
PINNING
SYMBOL
PIN
TYPE
DESCRIPTION
TEST1/AP
1
input
action pin for testing; to be connected to VSS
Y0-0
2
3-state output
feedback_data to second memory, Y bit 0
Y0-1
3
3-state output
feedback_data to second memory, Y bit 1
Y0-2
4
3-state output
feedback_data to second memory, Y bit 2
Y0-3
5
3-state output
feedback_data to second memory, Y bit 3
Y0-4
6
3-state output
feedback_data to second memory, Y bit 4
Y0-5
7
3-state output
feedback_data to second memory, Y bit 5
VDD1
8
supply
positive digital supply voltage (+5 V)
VSS1
9
ground
digital ground
Y0-6
10
3-state output
feedback_data to second memory, Y bit 6
Y0-7
11
3-state output
feedback_data to second memory, Y bit 7
UV0-0
12
3-state output
feedback_data to second memory, UV bit 0
UV0-1
13
3-state output
feedback_data to second memory, UV bit 1
UV0-2
14
3-state output
feedback_data to second memory, UV bit 2
UV0-3
15
3-state output
feedback_data to second memory, UV bit 3
TEST2/SP
16
input
shift pin for testing; to be connected to VSS
RE2_OUT
17
output
redirected read enable to memory 2
RE1_OUT
18
output
redirected read enable to memory 1
RSTR
19
input
memory read, µP interface and movie detection reset
RE2_IN
20
input
input for read enable to memory 2
RE1_IN
21
input
input for read enable to memory 1
BLN
22
input
blanking signal
µPCL
23
input
clock for interface with 8051 UART, mode 0
µPDA
24
in/output
data for interface with 8051 UART, mode 0
VSS2
25
ground
digital ground
CLK
26
input
master clock, nominal 27 (32) MHz
VDD2
27
supply
positive digital supply voltage (+5 V)
V1-0/Y2-0
28
input
V data, bit 0 in 4:4:4; Y data second memory, bit 0
V1-1/Y2-1
29
input
V data, bit 1 in 4:4:4; Y data second memory, bit 1
V1-2/Y2-2
30
input
V data, bit 2 in 4:4:4; Y data second memory, bit 2
V1-3/Y2-3
31
input
V data, bit 3 in 4:4:4; Y data second memory, bit 3
V1-4/Y2-4
32
input
V data, bit 4 in 4:4:4; Y data second memory, bit 4
V1-5/Y2-5
33
input
V data, bit 5 in 4:4:4; Y data second memory, bit 5
V1-6/Y2-6
34
input
V data, bit 6 in 4:4:4; Y data second memory, bit 6
V1-7/Y2-7
35
input
V data, bit 7 in 4:4:4; Y data second memory, bit 7
U1-0/UV2-0
36
input
U data, bit 0 in 4:4:4; UV data second memory, bit 0
U1-1/UV2-1
37
input
U data, bit 1 in 4:4:4; UV data second memory, bit 1
U1-2/UV2-2
38
input
U data, bit 2 in 4:4:4; UV data second memory, bit 2
U1-3/UV2-3
39
input
U data, bit 3 in 4:4:4; UV data second memory, bit 3
VSS3
40
ground
digital ground
July 1994
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Philips Semiconductors
Preliminary specification
Back END IC
SYMBOL
SAA7158
PIN
TYPE
DESCRIPTION
U1-4/UV1-0
41
input
U data, bit 4 in 4:4:4; UV data first memory, bit 0
U1-5/UV1-1
42
input
U data, bit 5 in 4:4:4; UV data first memory, bit 1
U1-6/UV1-2
43
input
U data, bit 6 in 4:4:4; UV data first memory, bit 2
U1-7/UV1-3
44
input
U data, bit 7 in 4:4:4; UV data first memory, bit 3
Y1-0
45
input
Y data first memory, bit 0
Y1-1
46
input
Y data first memory, bit 1
Y1-2
47
input
Y data first memory, bit 2
Y1-3
48
input
Y data first memory, bit 3
Y1-4
49
input
Y data first memory, bit 4
Y1-5
50
input
Y data first memory, bit 5
Y1-6
51
input
Y data first memory, bit 6
Y1-7
52
input
Y data first memory, bit 7
VSUB
53
analog ground
substrate pin; connect to analog ground (VSSA)
RFHY
54
analog input
connect C = 100 nF to analog ground (VSSA)
RFLY
55
analog input
connect to analog ground (VSSA)
RFLC
56
analog input
connect to analog ground (VSSA)
RFHC
57
analog input
connect C = 100 nF to analog ground (VSSA)
VDDA4
58
analog supply
analog supply voltage for reference ladders of the three DA
converters and for current sources of the output buffers
CUR
59
analog input
current input for analog output buffers (0.4 mA from VDDA4 = 5 V);
connect with R = 15 kΩ
VDDA3
60
analog supply
analog supply voltage for output buffer AY
AY
61
analog output
analog luminance Y output
VSSA3
62
analog ground
analog ground for output buffer AY
VDDA2
63
analog supply
analog supply voltage for output buffer AU
AU
64
analog output
analog (B-Y) or −(B-Y) output
VSSA2
65
analog ground
analog ground for output buffer AU
VSSA1
66
analog ground
analog ground for output buffer AV
AV
67
analog output
analog (R-Y) or −(R-Y) output
VDDA1
68
supply
analog supply voltage for output buffer AV
July 1994
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Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
Fig.2 Pin configuration.
July 1994
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Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
FUNCTIONAL DESCRIPTION
Block Diagram
The BENDIC will be produced in a CMOS double metal process. It is possible to feed the BENDIC with 8-bit wide
luminance and chrominance signals Y/U/V in 4:1:1 mode from the digital Y/U/V bus and to run it in a bypass mode with
Y/U/V in 4:4:4 mode without any bandwidth reduction.
The BENDIC contains the processing functions as depicted in Fig.3.
Following functions are available:
Datapath:
• 1H - 4:1:1 line memory, 852 words by 8-bits luminance + 4-bits multiplexed chrominance
• REFORMATTER to get 8-bit wide UV from the Y/U/V bus format
• MIX UV and MIX Y to interpolate between actual and 1H-delayed input signals, programmable for realization of vertical
zoom
• MEDIAN filter in luminance processing path for line flicker reduction
• MOVIE PHASE DETECT for supporting line flicker reduction control
• PEAKING for luminance channel
• UPSAMPLING and DCTI for chrominance transient improvement
• HOLD/GREY/BLANK blocks for blanking and grey level insertion
• RE PROCESSING controls read enable for first and second memory, outputs are programmable for different
applications
• Data switches for field select, mix/median select, 4:1:1/4:4:4 select
• DAC blocks for digital to analog conversion of Y, U, V video signals
• REGISTER with 3-state control for direct output of Y/U/V 1 input to memories.
Control:
• µP INTERFACE for the control of BENDIC functions, including zoom control
• TIMING CONTROL and TEST as support blocks.
All video data signal processing inside the BENDIC is phaselinear and nonrecursive (except line delay in recirculation
mode).
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Philips Semiconductors
Preliminary specification
SAA7158
Fig.3 Block diagram.
Back END IC
July 1994
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Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
• UPSAMPLING and DCTI for chrominance transient
improvement
Data Path Signal processing
• 1H - 4:1:1 line memory, 852 words by 8-bits luminance
+ 4-bits multiplexed chrominance
After upsampling of U and V, in the DCTI block the U and
V signals are processed with a
look-backwards/look-forwards device. The chrominance
signal values are stored in a 26 tap pixel delay line.
Controlled by a multiplexer select signal K the values are
read from the pixel delay line into the output registers of
DCTI. The calculation of the K signal is done within this
block. To determine the number of steps to look back and
˙˙
dV
d dUforwards the following relation is used: ----- ------+ ------- .
dt
dt dt
The Y/U/V line memory is organized as 852 x 12 bits. It
works as a shift register with recirculation mode if desired.
The line start is synchronized to RE, and if there are more
than 852 words to be stored it will stop and hold.
• REFORMATTER to get 8-bit wide UV from the Y/U/V
bus format
The reformatter changes the 4:1:1 format of UV signals
into a sequential 8-bit U and V data stream with a sampling
rate of half the master clock.
U and V are processed serially with the same circuitry. The
final upsampling towards the master clock for D/A
conversion is part of the algorithm and done by linear
interpolation between two adjacent taps of choice. It is
controlled by the K signal too.
• MIX UV and MIX Y to interpolate between actual and
1H-delayed input signals, programmable for realization
of vertical zoom
The function of the MIX-blocks is to interpolate between
two input sources A and B (original signal and 1H-delayed
signal). Possible interpolation coefficients
• HOLD/GREY/BLANK blocks for blanking and grey level
insertion
3
1
1
are { 1 or --- or ----- or ----- or 0 } × ( A – B ) + B.
4
2
4
The function of these blocks is to insert desired levels for
Y, U and V, where no active video is present. BLANKing is
performed during line and field blanking period indicated
by BLN. GREY is performed where RE indicates that the
memory is not read out, and pixel repetition is switched off
by the µP interface; the grey value comes via the µP
interface. HOLD is performed if pixel repetition is selected
by the µP interface; the last value of Y, U and V is kept until
RE is active again.
• MEDIAN filter in luminance processing path for line
flicker reduction
The median filter consists of two different median filters
working in parallel with full clock rate. Filters for up and
downsampling are implemented with an 8-bit output.
• MOVIE PHASE DETECT for supporting line flicker
reduction control
• RE PROCESSING controls read enable for first and
second memory
A pixel by pixel luminance level comparison is made on the
active video of two consecutive fields from the memory.
The absolute difference of the 4 most significant bits of
each pixel from the two fields is added to the accumulated
value of the current field in a register. The highest
significant two bytes thereof are transferred during field
blanking period with rising edge of RSTR signal into a
register that can be read via the µP interface. After reading
the register will be cleared.
Here the output signals RE1 and RE2 are shifted by
adding a programmable delay of 5, 6, 7 or 8 clock pulses
with respect to the input signals. In addition RE1 will be
influenced in case of zoom.
• data switches for field select, mix/median select,
4:1:1/4:4:4 select
The switches shown in the block diagram Fig.3 are
controlled via the µP interface and allow control of the data
streams inside the BENDIC.
• PEAKING for luminance channel
The H-peaking of the luminance channel compensates the
bandwidth reduction caused by various components of the
TV signal processing chain. Because of the possibility to
convert over and undershoots it is even possible to
precompensate the si-amplitude attenuation of the D/A
converter by 6 dB. The absolutely phaselinear filters can
be programmed: frequency response, amplitude of the
high frequency signals and degree of coring is controlled
via the µP interface. Frequency responses c. f. separate
application sheet.
July 1994
• DAC blocks for digital to analog conversion of Y, U, V
video signals
The D/A conversion is performed in the DAC blocks. The
converters consist of the resistor strings to be connected
externally and three buffers with a 25 Ω serial resistor at
the output built in. To get 75 Ω impedance externally three
50 Ω resistors have to be used near the pins. The
capacitive load at the outputs should not exceed 30 pF.
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Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
• REGISTER with 3-state control for direct output of Y/U/V
1 input to memories
µPCL
Microprocessor interface clock signal
This signal is transferred (asynchronous with CLK) by a
microprocessor (8051, UART mode 0) as communication
clock signal at 1 MHz.
The 3-state switch with internal register is supplied for the
feedback data to the second memory. The feedback bus is
a copy of the field 1 bus, but with 4 clockpulses delay.
3-state control is done via µP interface.
µPDA
Microprocessor interface data signal
This signal is transferred or received (asynchronous with
CLK) by a microprocessor (8051, UART mode 0) as
communication data signal at 1 MBaud, related to µPCL.
Data is valid the rising edge of µPCL.
The control signals
CLK
Line locked clock of maximal 36 MHz.
This is the system clock. Within the BENDIC the CLK
signal is distributed to the different blocks.
The external control
BLN
Blanking NOT signal.
This signal marks the horizontal and vertical blanking and
defines with its rising edge the start phase of the UV 4:1:1
format. A programmable delay of 0, 1, 2 or 3 clock pulses
shifts the internal pulse with respect to the input.
The µP interface has the following functions:
• Receive settings from the µP
• Transmit movie phase detect data to the µP
The interface is based on a two wire interface, one for
clock, the other for bidirectional data form. It is compatible
with the 8051 family UART mode 0 interface. The µP is the
master of the communication, it generates the clock
(nominal 12 MHz/12 = 1 MHz), only active when transfer is
done.
RE1_in
Read enable memory 1 signal.
This signal is generated by the memory controller and its
HIGH state determines the read enable on the first
memory bank, after it is processed by BENDIC for the
ZOOM mode and fine shift of the edges.
The protocol for the communication is:
8 addressbits are sent by the µP (LSB first), if the address
is a write address then 8 databits (LSB first) are sent by the
µP, else (if the address is a read address) 8 databits are
sent by BENDIC.
RE2_in
Read enable memory 2 signal.
This signal is generated by the memory controller and its
HIGH state determines the read enable on the second
memory bank, including a fine shift of the edges.
note:
RE1_in and RE2_in are processed in the BENDIC to:
RSTR is used to reset the phase of the address/data
transfer. The negative going edge of RSTR clears the
address register. After reset the first transmitted bit is to be
taken as the first (LSB) bit of an address.
• external signals: RE1_out and RE2_out
For field1/field2 selection and for mix/median selection, 4
addresses are used to select each of the four
combinations. A databyte is not obligatory after each of
these four addresses, but a dummy databyte is needed if
the transmission is to be followed by a further one.
• RE with correct internal delay to match datapath delays,
is used to define the edges between video and side
panels (grey insertion or pixel repetition).
RSTR
Reset signal
This signal is transferred (asynchronous with CLK) by e. g.
a microprocessor to reset the communication between the
microprocessor and the BENDIC. CLK has to be present
in this case. In a typical application, RSTR is an active
HIGH pulse, issued only in the vertical blanking period.
During RSTR HIGH-state, the ‘feedback_data’ lines are
switched to 3-state, temporarily overruling the mode that
has been set by the microprocessor. By this provision,
RSTR can be used to prevent data collision on the 3-state
databus, e. g. during a power on sequence. Also, this
signal is used to transfer the ‘movie phase detect’ data to
a register that can be read by the microprocessor.
July 1994
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Philips Semiconductors
Preliminary specification
Back END IC
Table 1
SAA7158
Write address table.
ADDRESS (HEX)
1
FUNCTION
dataformat setting
BIT
bit2: invUV
bit3: UV8bit
bit4: UVbin
bit5: Yclip
bit6: 4:4:4
bit7: feedback
2
grey value setting
bit4: grey(0)
bit5: grey(1)
bit6: grey(2)
bit7: grey(3)
3
read enable setting
bit0: re1_d(0)
bit1: re1_d(1)
bit2: inv_re1
bit3: re2_d(0)
bit4: re2_d(1)
bit5: inv_re2
bit6: bln_d(0)
bit 7: bln_d(1)
4
zoom setting
bit0: lps
bit1: pixrep
bit2: black16
bit3: zoom(0)
bit4: zoom(1)
bit5: zoom(2)
bit6: zoom(3)
bit7: zoom(4)
5
CTI setting
bit4: range(0)
bit5: range(1)
bit6: gain(0)
bit7: gain(1)
6
peaking setting,
average UV select
bit0: av_w_med
bit1: WG(0)
bit2: WG(1)
bit3: BFB
bit4: BP(0)
bit5: BP(1)
bit6: coring(0)
bit7: coring(1)
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Philips Semiconductors
Preliminary specification
Back END IC
ADDRESS (HEX)
SAA7158
FUNCTION
BIT
7C
multiplexer setting
SET select field1 OFF; select median OFF (all databits are dummy)
7D
multiplexer setting
SET select field1 ON; select median OFF (all databits are dummy)
7E
multiplexer setting
SET select field1 OFF; select median ON (all databits are dummy)
7F
multiplexer setting
SET select field1 ON; select median ON (all databits are dummy)
The function of the bits in the control datawords are explained below:
feedback
HI: feedback output is 3-state enabled = outputs active
4:4:4
HI: YUV-4:4:4 mode selected instead of 4:1:1 mode
Yclip
HI: Y signal after peaking is clipped and converted to 9-bit range
UVbin
HI: UV signals are taken from input as binary signals instead 2’s complement
UV8bit
HI: UV signals are taken from input as 8-bit values instead of 7-bit
invUV
HI: UV signals are inverted before the DACs (outputs = −U and −V)
grey(3:0)
determines highest 4 bits in shade of grey in side panels
bln_d(1:0)
shifts the internal BLN signal from 0 to 3 clock pulses with respect to input
re2_d(1:0)
shifts 5 to 8 clock pulses the RE2 output signal versus input
re1_d(1:0)
shifts 5 to 8 clock pulses the RE1 output signal versus input, additionally influenced by zoom
inv_re2
HI: RE2 output is polarity reversed in relation to RE2 input
inv_re1
HI: RE1 output is polarity reversed in relation to RE1 input
zoom(4:0)
determines vertical zoom factor, which is (32/zoom(4:0)); zoom(4:0) = 0 is equivalent to no zoom
black16
HI: the Y signal value during the blanking period is 16 instead of 0
pixrep
HI: side panels have the same Y, U and V as on the edge of the last video information
Ips
HI: functional test mode for line on line median on/off
range(1:0)
determines maximum in CTI range of looking back/looking forward
gain(1:0)
determines gain of CTI function
coring(1:0)
determines coring level in Y peaking
av_w_med
enable average UV while median in Y (UV := 1/2 × direct + 1/2 × delayed)
BP(1:0)
determines frequency response in Y peaking
WG(1:0)
determines weighted addition in Y peaking with 1 or 1/2 or 1/4 or 0
BFB
HI: determines bypass for BF1 in Y peaking
The BENDIC provides the correlation of two subsequent fields with its ‘Movie phase detector’ via the µP interface. The
MSB or LSB values of this correlation factor is read from the BENDIC by sending an addressbyte and subsequently
receiving a databyte from it, according to Table 2.
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Philips Semiconductors
Preliminary specification
Back END IC
Table 2
Read address table.
ADDRESS
(HEX)
80
SAA7158
ADDRESS
(HEX)
BIT
bit0: corr(0)
81
bit0: corr(8)
bit1: corr(1)
bit1: corr(9)
bit2: corr(2)
bit2: corr(10)
bit3: corr(3)
bit3: corr(11)
bit4: corr(4)
bit4: corr(12)
bit5: corr(5)
bit5: corr(13)
bit6: corr(6)
bit6: corr(14)
bit7: corr(7)
bit7: corr(15)
corr(15:0) is the measured Y correlation factor between two successive fields.
July 1994
BIT
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Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
CHARACTERISTICS
Specification of input/output and clock levels and timing
The following table shows the specifications of input/output/clock levels and timing for
Tamb = 0 to +70 °C; VDD = 4.5 to 5.5 V; VDDA = 4.75 to 5.25 V unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
Supply
VDD1-2
digital supply voltages
4.5
−
5.5
V
VDDA1-4
analog supply voltages
4.75
−
5.25
V
IDD1-2
supply current digital
−
−
250
mA
IDDA1-4
supply current analog
−
−
18
mA
note 1
Digital inputs
VIL
LOW level input voltage
−0.5
−
+0.8
V
VIH
HIGH level input voltage
2.0
−
VDD + 0.5
V
ILI
input leakage current
−
−
10
µA
CIC
input capacitance (clocks)
−
−
10
pF
CID
input capacitance (data)
−
−
10
pF
CIZ
input capacitance (I/O in high Z)
−
−
10
pF
−
−
0.4
mA
Reference and current inputs
ICUR
input current
Digital outputs
VOH
HIGH level output voltage
note 2
2.4
−
VDD1-2
V
VOL
LOW level output voltage
note 2
0
−
0.6
V
Timing
tCLK
CLK cycle time
27
−
41
ns
kCLK
CLK duty cycle tCLK-HIGH/tCLK
40
−
60
%
tr
CLK rise time
−
−
5
ns
tf
CLK fall time
−
−
6
ns
tSU
input data setup time
−
−
5
ns
tHD
input data hold time
−
−
6
ns
tOH
output data hold time
note 2
6
−
−
ns
tOD
output data delay time
note 2
−
−
25
ns
10
−
35
pF
Data output loads (3-state outputs)
Cld
output load capacitance
Characteristics of the DA converters
RSLY
resolution of the Y DAC
−
9
−
bit
RSLC
resolution of the U and V DAC
−
8
−
bit
B
analog signal bandwidth (−3 dB)
20
−
−
MHz
CT
crosstalk between channels
−
−
−42
dB
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Philips Semiconductors
Preliminary specification
Back END IC
SYMBOL
SAA7158
PARAMETER
CONDITIONS
MIN.
TYP.
MAX.
UNIT
DNL
differential nonlinearity
referred to 8 MSB’s
−
−
±0.5
LSB
INL
integral nonlinearity
referred to 8 MSB’s
−
−
±1
LSB
Vout
output voltage (without load)
−
2 Vp-p
−
V
Notes
1. fCLK = 36 MHz, fdata = 18 MHz (rectangular full scale); without output load.
2. Timings and levels have to be measured with load circuits 1.2 kΩ connected to 3.0 V (TTL load), and CL = 25 pF.
APPLICATION NOTE FOR THE ANALOG PART OF BENDIC
The digital to analog conversion is done in parallel for the three channels. The DA converters (8-bit for U and V; 9-bit
for Y) are based on resistor strings with low impedance output buffers. They are designed for 2 Vp-p unloaded output
swing. To avoid integral nonlinearity errors, the minimum output voltage is 200 mV; so the DC range for unloaded output
is between 0.2 and 2.2 V.
A serial resistor of 25 Ω is integrated at the outputs of the buffers. With 50 Ω in series - close to the output pins - the
nominal output voltage for 75 Ω line termination is 1 Vp-p with a DC range of 0.1 to 1.1 V. Amplitude matching to external
requirements has to be done with external dividers. Capacitance load should not exceed 30 pF.
The DAC’s require three separate analog supply voltages VDDA1−3 and analog ground lines VSSA1−3 for the output buffers.
The accuracy of an external voltage reference input VDDA4 directly influences the output amplitude of the video signals.
The current input CUR supplies the output buffers with a current of about 0.3 mA at VDDA = 5 V, if a resistor of 15 kΩ is
connected to this pin.
A larger current improves the output bandwidth but makes the integral nonlinearity worse.
July 1994
15
Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
Fig.4 Timing diagram.
July 1994
16
Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
PACKAGE OUTLINE
PLCC68: plastic leaded chip carrier; 68 leads
SOT188-2
eD
eE
y
X
60
A
44
43 Z E
61
bp
b1
w M
68
1
HE
E
pin 1 index
A
e
A4 A1
(A 3)
β
9
k1
27
Lp
k
detail X
10
26
e
v M A
ZD
D
B
HD
v M B
0
5
10 mm
scale
DIMENSIONS (millimetre dimensions are derived from the original inch dimensions)
UNIT
A
A1
min.
A3
A4
max.
bp
b1
mm
4.57
4.19
0.51
0.25
3.30
0.53
0.33
0.81
0.66
0.180
inches
0.020 0.01
0.165
D (1)
E (1)
e
eD
eE
HD
HE
k
24.33 24.33
23.62 23.62 25.27 25.27 1.22
1.27
24.13 24.13
22.61 22.61 25.02 25.02 1.07
k1
max.
Lp
v
w
y
0.51
1.44
1.02
0.18
0.18
0.10
Z D(1) Z E (1)
max. max.
2.16
β
2.16
45 o
0.930 0.930 0.995 0.995 0.048
0.057
0.021 0.032 0.958 0.958
0.020
0.05
0.007 0.007 0.004 0.085 0.085
0.13
0.890 0.890 0.985 0.985 0.042
0.040
0.013 0.026 0.950 0.950
Note
1. Plastic or metal protrusions of 0.01 inches maximum per side are not included.
REFERENCES
OUTLINE
VERSION
IEC
JEDEC
SOT188-2
112E10
MO-047AC
July 1994
EIAJ
EUROPEAN
PROJECTION
ISSUE DATE
92-11-17
95-03-11
17
Philips Semiconductors
Preliminary specification
Back END IC
SAA7158
applied to the substrate by screen printing, stencilling or
pressure-syringe dispensing before device placement.
SOLDERING
Plastic leaded chip carriers
Several techniques exist for reflowing; for example,
thermal conduction by heated belt, infrared, and
vapour-phase reflow. Dwell times vary between 50 and
300 s according to method. Typical reflow temperatures
range from 215 to 250 °C.
BY WAVE
During placement and before soldering, the component
must be fixed with a droplet of adhesive. After curing the
adhesive, the component can be soldered. The adhesive
can be applied by screen printing, pin transfer or syringe
dispensing.
Preheating is necessary to dry the paste and evaporate
the binding agent. Preheating duration: 45 min at 45 °C.
Maximum permissible solder temperature is 260 °C and
maximum duration of package immersion in solder bath is
10 s, if allowed to cool to less than 150 °C within 6 s.
Typical dwell time is 4 s at 250 °C.
REPAIRING SOLDERED JOINTS (BY HAND-HELD SOLDERING
IRON OR PULSE-HEATED SOLDER TOOL)
Fix the component by first soldering two, diagonally
opposite, end pins. Apply the heating tool to the flat part of
the pin only. Contact time must be limited to 10 s at up to
300 °C. When using proper tools, all other pins can be
soldered in one operation within 2 to 5 s at between 270
and 320 °C. (Pulse-heated soldering is not recommended
for SO packages).
A modified wave soldering technique is recommended
using two solder waves (dual-wave) in which a turbulent
wave with high upward pressure is followed by a smooth
laminar wave. Using a mildly-activated flux eliminates the
need for removal of corrosive residues in most
applications.
For pulse-heated solder tool (resistance) soldering of VSO
packages, solder is applied to the substrate by dipping or
by an extra thick tin/lead plating before package
placement.
BY SOLDER PASTE REFLOW
Reflow soldering requires the solder paste (a suspension
of fine solder particles, flux and binding agent) to be
DEFINITIONS
Data sheet status
Objective specification
This data sheet contains target or goal specifications for product development.
Preliminary specification
This data sheet contains preliminary data; supplementary data may be published later.
Product specification
This data sheet contains final product specifications.
Limiting values
Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or
more of the limiting values may cause permanent damage to the device. These are stress ratings only and
operation of the device at these or at any other conditions above those given in the Characteristics sections of this
specification is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information
Where application information is given, it is advisory and does not form part of the specification.
LIFE SUPPORT APPLICATIONS
These products are not designed for use in life support appliances, devices, or systems where malfunction of these
products can reasonably be expected to result in personal injury. Philips customers using or selling these products for
use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such
improper use or sale.
July 1994
18