STMICROELECTRONICS TSH345ID

TSH345
Triple video buffer with selectable filter
for HD and SD video applications
Preliminary Data
Features
Selectable 6th order filtering of 36 MHz,
18 MHz and 9 MHz
■
5 V single-supply operation
■
Internal input DC level shifter
■
No input capacitor required
■
3 matched 6 dB amplifiers
■
AC or DC output-coupled
■
Very low harmonic distortion
■
Specified for 150 Ω loads
TSSOP14
R1 in 1
R2 in 2
Data min. and max. are tested during
production
G1 in 3
MUX
■
SO14
MUX
■
Applications
High-end video systems
■
High definition TV (HDTV)
■
Broadcast and graphic video
■
Multimedia products
B1 in 5
MUX
■
G2 in 4
B2 in 6
36MHz
18MHz
9MHz
LPF
36MHz
18MHz
9MHz
LPF
36MHz
18MHz
9MHz
LPF
14 Fs0
+
6dB
13 Fs1
12 R out
+
6dB
11 G out
10 B out
+
6dB
9 Mux
DC Shifter
+VCC 7
8 GND
Description
The TSH345 is a triple single-supply video buffer
featuring an internal gain of 6 dB and selectable
filtering for HD and SD video outputs on 75 Ω
video lines. The TSH345 is ideal to drive either
Y-C, CVBS, Y-U-V, Y-Pb-Pr or R-G-B signals from
video DAC outputs.
The TSH345 is available in the SO14 plastic
package for optimum space-saving.
The main advantage of this circuit is its input DC
level shifter. It allows you to drive video signals on
75 Ω video lines without damage to the
synchronization tip, and without either input or
output capacitor while using a single 5 V power
supply. The DC level shifter is internally fixed and
optimized to keep the output video signals
between low and high output rails in the best
position for the greatest linearity.
May 2007
Rev 1
This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to
change without notice.
1/14
www.st.com
14
Absolute maximum ratings and operating conditions
TSH345
1
Absolute maximum ratings and operating conditions
Table 1.
Absolute maximum ratings (AMR)
Symbol
VCC
Vin
Parameter
Supply voltage (1)
Input voltage range
(2)
Value
Unit
6
V
TBD
V
Toper
Operating free air temperature range
-40 to +85
°C
Tstg
Storage temperature
-65 to +150
°C
Maximum junction temperature
150
°C
Rthjc
Thermal resistance junction to case
SO14
TSSOP14
22
32
°C/W
Rthja
Thermal resistance junction to ambient area
SO14
TSSOP14
125
110
°C/W
Pmax
Maximum power dissipation (@Tamb = 25°C) for Tj = 150° C
SO14
TSSOP14
1
1.1
W
ESD
CDM: charged device model
HBM: human body model
MM: machine model
200
2
200
V
kV
V
Tj
1. All voltage values, except differential voltage, are with respect to network terminal.
2. The magnitude of input and output voltage must never exceed VCC +0.3 V.
Table 2.
Operating conditions
Symbol
VCC
Parameter
Power supply voltage
1. Tested in full production with +5 V single power supply.
2/14
Value
Unit
4.5 to 5.5(1)
V
TSH345
2
Electrical characteristics
Electrical characteristics
Table 3.
Electrical characteristics at VCC = +5 V single supply, Tamb = 25°C
(unless otherwise specified)
Symbol
Test conditions
Min.
Typ.
Max.
Unit
DC performance
VDC
Output DC shift
RL = 150 Ω, Tamb
-40° C < Tamb < +85° C
197
329
405
389
mV
Iib
Input bias current
Tamb , input to GND
-40° C < Tamb < +85° C
0.85
1.5
2.38
2.9
µA
Rin
Input resistance, Tamb
12.6
GΩ
Cin
Input capacitance, Tamb
0.1
pF
ICC
Total supply current
No load, input to GND
-40°C < Tamb < +85°C
50.7
TBD
PSRR
G
Power supply rejection ratio 20 log (ΔVout/ΔVCC)
Input to GND, RL = 150 Ω ΔVCC :
100 mVp/F = 1 MHz, CLF = 470 nF, CHF = 100 µF
DC voltage gain
RL = 150Ω, Vin = 0.5V
-40°C < Tamb < +85°C
65
-70
1.94
mA
dB
1.99
2
2.02
V/V
DG
Variation of the DC voltage gain between inputs of
0.3 V and 1 V
Input step from 0.3 V to 1 V
0.2
0.5
%
MG1
Gain matching between 3 channels, input = 1 V
0.5
1
%
Gain matching between 3 channels, input = 0.3 V
0.5
1
%
MG0.3
Output characteristics
VOH
High level output voltage
RL = 150 Ω
-40° C < Tamb < +85° C
VOL
Low level output voltage(1)
RL = 150 Ω
-40° C < Tamb < +85° C
Iout
3.84
3.87
TBD
33
TBD
V
40
mV
91
Isource
Tamb
-40° C < Tamb < +85° C
46
Isink
-40° C < Tamb < +85° C
TBD
mA
79
145
102
mA
3/14
Electrical characteristics
Table 3.
Symbol
TSH345
Electrical characteristics at VCC = +5 V single supply, Tamb = 25°C
(unless otherwise specified) (continued)
Test conditions
Min.
Typ.
5.12
9.3
7.3
Max.
Unit
Filtering
Bandwidth
F1 selected, small signal, VICM= 0.5 V, RL = 150 Ω
3 dB bandwidth
1 dB bandwidth
Standard
definition
Flatness
F1selected/F= 6 MHz, small signal, VICM = 0.5 V,
RL = 150 Ω
Attenuation
F1 selected/F=27 MHz, small signal, VICM = 0.5 V,
RL = 150 Ω
Bandwidth
F2 selected, small signal, VICM = 0.5 V, RL = 150 Ω
3 dB bandwidth
1 dB bandwidth
Standard
definition
Flatness
with
progressive F2 selected/F=12 MHz small signal, VICM = 0.5 V,
scanning RL = 150 Ω
Attenuation
F2 selected/F=54 MHz, small signal, VICM = 0.5 V,
RL = 150 Ω
Bandwidth
F3 selected, small signal, VICM = 0.5 V, RL = 150 Ω
3 dB bandwidth
1 dB bandwidth
High
definition
4/14
0.5
dB
30
47
dB
10.4
21.5
18.2
MHz
0.36
dB
34
42.7
dB
22
35.6
30.8
Flatness
F3 selected/F=30 MHz, small signal, VICM = 0.5 V,
RL = 150 Ω
Attenuation
F3 selected/F=74.25 MHz, small signal,
VICM = 0.5 V, RL = 150 Ω
MHz
TBD
MHz
0.46
dB
36
dB
D
Delay between each channel
0.5
ns
gd
Group delay variation
F1 selected/F=0 to 6 MHz
10.3
ns
Δg
Differential gain
F1 selected/F=6 MHz, RL = 150 Ω
0.5
%
ΔΦ
Differential phase
F1 selected/F=6 MHz, RL = 150 Ω
0.5
°
TSH345
Electrical characteristics
Table 3.
Electrical characteristics at VCC = +5 V single supply, Tamb = 25°C
(unless otherwise specified) (continued)
Symbol
Test conditions
Min.
Typ.
Max.
Unit
Noise and distortion
Total input voltage noise in Standard Definition
F = 100 kHz, RIN = 50 Ω
70
Total input voltage noise in High Definition
F = 100 kHz, RIN = 50 Ω
93
HD2
2nd harmonic distortion
F1 selected/F=1 MHz, Vout = 2 Vp-p, RL = 150 Ω
-44
dBc
HD3
3rd harmonic distortion
F1 selected/F=1 MHz, Vout = 2 Vp-p, RL = 150 Ω
-63
dBc
eN
nV/√Hz
Standby mode
Total current consumption in standby mode
Fs1=1, Fs0=1
ISTBY
TBD
570
µA
Ton
Time from standby to active mode
5
µs
Toff
Time from active to standby mode
5
µs
Fs1, Fs0 and Mux features
Vhigh
High level
Vlow
Low level
0.9
V
0.3
V
1. Simulated data.
Table 4.
Filter and standby settings, VCC = +5 V single supply, Tamb = 25°C
Fs1
Fs0
Settings
0
0
F3
Filtering for high definition (HD), 36 MHz
0
1
F2
Filtering for progressive video (PV), 18 MHz
1
0
F1
Filtering for standard definition (SD), 9 MHz
1
1
Standby
TSH345 in standby mode
Fs1 and Fs0 floating: forbidden
(for proper behavior of the TSH345, the Fs1 and Fs0 pins must never be left floating)
Table 5.
Mux settings, VCC = +5 V single supply, Tamb = 25°C
Mux
Settings
0
R1 G1 B1
Video1 selected
1
R2 G2 B2
Video2 selected
Floating
R1 G1 B1
Video1 selected
MUX floating: forbidden
(for proper behavior of the TSH345, the MUX pin must never be left floating)
5/14
Power supply considerations
3
TSH345
Power supply considerations
Correct power supply bypassing is very important for optimizing performance in low and
high-frequency ranges. Bypass capacitors should be placed as close as possible to the IC
pin (pin 4) to improve high-frequency bypassing. A capacitor (CLF) greater than 100 µF is
necessary to improve the PSRR in low frequencies. For better quality bypassing, you can
add a capacitor of 470 nF (CHF), also placed as close as possible to the IC pin, to improve
the PSRR in the higher frequencies.
Figure 1.
Circuit for power supply bypassing
+VCC
CLF
+
CHF
4
R in
G in
B in
TSH345
5
6/14
R out
G out
B out
TSH345
4
Using the TSH345 to drive Y-C, CVBS, Y-U-V, Y-Pb-Pr and R-G-B video components
Using the TSH345 to drive Y-C, CVBS, Y-U-V, Y-Pb-Pr
and R-G-B video components
Figure 2.
Implementation of the video driver on output video DACs
+5V
Video
DAC
Reconstruction
Filtering
Y
+6dB
+
LPF
75Ω
75Ω Cable
1Vpp
TV
75Ω
1Vpp
2Vpp
Video
DAC
Pb
Reconstruction
Filtering
+6dB
+
LPF
75Ω
75Ω Cable
0.7Vpp
75Ω
0.7Vpp
1.4Vpp
Video
DAC
Reconstruction
Filtering
Pr
+6dB
+
LPF
75Ω Cable
0.7Vpp
75Ω
0.7Vpp
TSH345
1.4Vpp
GND
-5V
Figure 3.
75Ω
Shapes of video signals coming from DACs (example for a black picture)
54ns
(4t)
27ns
(2t)
590ns
(44t)
HD
300mV
27ns
(2t)
•Fclock=74.25MHz
•t=1/Fclock=13.5ns
300mV
Black (30IRE)
14.8us (1100t): 1920/1080i
24.3us (1800t): 1280/720i
590ns
(44t)
GND
sync.tip
160ns
150ns
SD
Black (30IRE)
64us
300mV
4.6us
GND
sync.tip
7/14
Using the TSH345 to drive Y-C, CVBS, Y-U-V, Y-Pb-Pr and R-G-B video components
Figure 4.
TSH345
Flexibility of the TSH345 for SD and HD signals
HD/PV/SD
Y,G
DAC
+5V
TV
75Ω
Cable
75Ω
Cable
75Ω
Cable
150Ω
DAC
75Ω
150Ω
Pb,B
150Ω
DAC
TSH345
150Ω
Pr,R
TSSOP14
SO14
150Ω
75Ω
75Ω
150Ω
DAC
DAC
DAC
Y,G
Mux
Filter select
Standby
Pb,B,C
Pr,R,CVBS
HD/PV/SD
Y,G
DAC
+5V
TV
75Ω
150Ω
DAC
DAC
NC
75Ω
Pb,B,C
75Ω
150Ω
NC
Pr,R,CVBS
150Ω
Cable
NC
TSH345
TSSOP14
SO14
Cable
75Ω
75Ω
Cable
75Ω
Mux (NC)
Filter select
Standby
The TSH345 is used to drive either high definition video signals up to 30 MHz, or progessive
and interlaced standard definition video signals on 75-ohm video lines. It can drive a large
panel of signals like Y-C and CVBS, Y-U-V, Y-Pb-Pr and R-G-B where the bottom of the signal
(the synchronization tip in the case of Y and CVBS signals) is close to zero volts. An internal
input DC value is added to the video signal in order to shift the bottom from GND.
The shift is not based on the average of the signal, but is an analog summation of a DC
component to the video signal. Therefore, no input capacitors are required, which provides a
real advantage in terms of cost and board space.
Under these conditions, it is possible to drive the signal in single supply without any
saturation of the driver against the lower rail.
Because half of the signal is lost through output impedance matching, in order to properly
drive the video line, the shifted signal is multiplied by a gain of 2 or +6 dB.
8/14
TSH345
4.1
Using the TSH345 to drive Y-C, CVBS, Y-U-V, Y-Pb-Pr and R-G-B video components
Output capacitor
The output can be either DC-coupled or AC-coupled. The output can be connected to the
line via a 75-ohm resistor directly (see Figure 5). Or, an output capacitor can be used to
remove any DC components in the load. Assuming the load is 150-ohm, a coupling
capacitor of 220 µF can be used to provide a very low cut-off frequency close to 5 Hz (see
Figure 6).
Figure 5.
DC output coupling (1 of 3 channels)
+5V
75Ω
Video
DAC
75Ω Cable
TSH345
75Ω
150Ω
Figure 6.
AC output coupling (1 of 3 channels)
+5V
75
Video
DAC
TSH345
C=220µF
75
+
Cable
75
150
CS
1. CS is a 100nF used to decrease the parasitic components of C in high frequencies.
2. The 75-ohm resistor must be as close as possible to the output of the driver to minimize the effect of
parasitic capacitance.
9/14
Package information
5
TSH345
Package information
In order to meet environmental requirements, STMicroelectronics offers these devices in
ECOPACK® packages. These packages have a lead-free second level interconnect. The
category of second level interconnect is marked on the package and on the inner box label,
in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering
conditions are also marked on the inner box label. ECOPACK is an STMicroelectronics
trademark. ECOPACK specifications are available at: www.st.com.
10/14
TSH345
5.1
Package information
SO-14 package
Dimensions
Ref.
Millimeters
Min.
Typ.
A
a1
Inches
Max.
Min.
Typ.
1.75
0.1
0.2
a2
Max.
0.068
0.003
0.007
1.65
0.064
b
0.35
0.46
0.013
0.018
b1
0.19
0.25
0.007
0.010
C
0.5
0.019
c1
45° (typ.)
D
8.55
8.75
0.336
0.344
E
5.8
6.2
0.228
0.244
e
1.27
0.050
e3
7.62
0.300
F
3.8
4.0
0.149
0.157
G
4.6
5.3
0.181
0.208
L
0.5
1.27
0.019
0.050
M
S
0.68
0.026
8° (max.)
11/14
Package information
5.2
TSH345
TSSOP14 package
Dimensions
Ref.
Millimeters
Min.
Typ.
A
Inches
Max.
Min.
Max.
1.2
A1
0.05
A2
0.8
b
0.047
0.15
0.002
0.004
0.006
1.05
0.031
0.039
0.041
0.19
0.30
0.007
0.012
c
0.09
0.20
0.004
0.0089
D
4.9
5
5.1
0.193
0.197
0.201
E
6.2
6.4
6.6
0.244
0.252
0.260
E1
4.3
4.4
4.48
0.169
0.173
0.176
1
e
0.65 BSC
K
0°
L1
0.45
A
0.0256 BSC
8°
0°
0.60
0.75
0.018
e
c
8°
0.024
0.030
A2
A1
b
K
E1
PIN 1 IDENTIFICATION
1
L
E
D
12/14
Typ.
TSH345
6
Ordering infomation
Ordering infomation
Table 6.
Order codes
Temperature
range
Part number
TSH345ID
TSH345IDT
-40°C to +85°C
TSH345IPT
7
Package
SO14
TSSOP14
Packing
Marking
Tube
TSH345I
Tape & reel
TSH345I
Tape & reel
TSH345I
Revision history
Date
Revision
29-May-07
1
Changes
Preliminary data, initial release.
13/14
TSH345
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