STMICROELECTRONICS TSH344

TSH344
340MHz Single-Supply Triple Video Buffer
■
Bandwidth: 340MHz
■
5V single-supply operation
■
Low output rail guaranteed at 60mV max.
■
Internal gain of 6dB for a matching between 3
channels
■
Very low harmonic distortion
■
Slew rate: 740V/µs
■
Specified for 150Ω and 100Ω loads
■
Tested on 5V power supply
■
Data min. and max. are tested during
production
Pin Connections (top view)
Pin1 identification
Top View
IN1 1
6dB
8 OUT1
IN2 2
6dB
7 OUT2
IN3 3
6dB
6 OUT3
Description
The TSH344 is a triple single-supply video buffer
featuring an internal gain of 6dB and a large
bandwidth of 340MHz.
The main advantage of this buffer is its very low
output rail very close to GND when supplied in
single supply 0/5V. This output rail is guaranteed
by test at 60mV from GND on 150Ω. Chapter 4 of
this datasheet gives technical support when using
the TSH344 as RGB driver for video DAC output
on a video line (see TSH343 for Y-Pb-Pr signals).
The TSH344 is available in the compact SO8
plastic package for optimum space-saving.
5 GND
+Vcc 4
SO8
Applications
■
High-end video systems
■
High Definition TV (HDTV)
■
Broadcast and graphic video
■
Multimedia products
Order Codes
Part Number
Temperature Range
Package
-40°C to +85°C
SO-8
TSH344ID
TSH344IDT
January 2006
Rev. 2
Packing
Marking
Tube
TSH344I
Tape & Reel
TSH344I
1/14
www.st.com
14
Absolute Maximum Ratings
TSH344
1
Absolute Maximum Ratings
Table 1.
Key parameters and their absolute maximum ratings
Symbol
Parameter
(1)
VCC
Supply voltage
Vin
Input Voltage Range (2)
Value
Unit
6
V
0 to +2
V
Toper
Operating Free Air Temperature Range
-40 to +85
°C
Tstd
Storage Temperature
-65 to +150
°C
Maximum Junction Temperature
150
°C
Rthjc
SO8 Thermal Resistance Junction to Case
28
°C/W
Rthja
SO8 Thermal Resistance Junction to Ambient Area
157
°C/W
Pmax.
Maximum Power Dissipation (@Ta=25°C) for Tj=150°C
800
mW
ESD
CDM: Charged Device Model
HBM: Human Body Model
MM: Machine Model
2
1.5
200
kV
kV
V
Value
Unit
3 to 5.5
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 +0.3V.
Table 2.
Operating conditions
Symbol
VCC
Parameter
Power Supply Voltage (1)
1. Tested in full production at 0V/5V single power supply
2/14
Rev. 2
TSH344
Electrical Characteristics
2
Electrical Characteristics
Table 3.
VCC = +5V Single Supply, Tamb = 25°C (unless otherwise specified)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
-35
-8
+35
Unit
DC Performance
VOS
Output Offset Voltage(1)
Input Bias Current
Iib
no Load, Tamb
mV
-40°C < Tamb < +85°C
-8.6
Tamb, input to GND
5.5
-40°C < Tamb < +85°C
6
16
µA
Rin
Input Resistance
Tamb
4
GΩ
Cin
Input Capacitance
Tamb
1
pF
PSR
Power Supply Rejection Ratio
20 log (∆Vcc/∆Vout)
input to GND, F=1MHz,
∆Vcc=200mV
-90
dB
Supply Current per Buffer
no Load, input to GND
10.1
-40°C < Tamb < +85°C
10.3
ICC
DC Voltage Gain
RL = 150Ω, Vin=1V
MG1
Gain Matching between 3 channels
MG0.3
Gain Matching between 3 channels
G
13
mA
1.92
2
2.05
V/V
Input = 1V
0.5
2
%
Input = 0.3V
0.5
2
%
Dynamic Performance and Output Characteristics
-3dB Bandwidth
Small Signal Vout=20mVp
Vicm=0.6V, RL = 150 Ω
Gain Flatness @ 0.1dB
Small Signal Vout=20mVp
Vicm=0.6V, RL = 150 Ω
Full Power Bandwidth
Vicm=0.6V, VOUT = 2Vp-p,
RL = 150Ω
Delay between each channel
0 to 30MHz
SR
Slew Rate (2)
Vicm=0.6V, VOUT = 2Vp-p,
RL = 150Ω
VOH
High Level Output Voltage
RL = 150Ω
VOL
Low Level Output Voltage
RL = 150Ω
Output Current
Vout=2Vp, Tamb
Bw
FPBW
D
IOUT
-40°C < Tamb < +85°C
Output Short Circuit Current (Isource)
190
340
MHz
65
130
200
MHz
0.5
ns
500
740
V/µs
3.7
3.9
V
40
45
mV
93
mA
83
100
Rev. 2
60
mA
3/14
Electrical Characteristics
Table 3.
TSH344
VCC = +5V Single Supply, Tamb = 25°C (unless otherwise specified)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
Noise and Distortion
F = 100kHz, Rin = 50 Ω
Total Input Voltage Noise
eN
2nd Harmonic Distortion
HD2
3rd Harmonic Distortion
HD3
8
nV/√Hz
Rin = 50Ω
Bw=30MHz
Bw=100MHz
55
100
µVrms
VOUT = 2Vp-p, RL = 150 Ω
F= 10MHz
F= 30MHz
-57
-42
dBc
VOUT = 2Vp-p, RL = 150 Ω
F= 10MHz
F= 30MHz
-72
-51
dBc
1. Output Offset Voltage is determined from the following expression: VOUT =G.VIN+VOS
2. Non-tested value. Guaranteed value by design.
4/14
Rev. 2
TSH344
Figure 1.
Electrical Characteristics
Frequency response
Figure 2.
10
6,2
8
6,1
6
6,0
4
5,9
2
Gain (dB)
Gain (dB)
Gain flatness
0
-2
-4
5,8
5,7
5,6
5,5
-6
5,4
Vcc=5V
Load=150Ω
-8
-10
1M
Vcc=5V
Load=150 Ω
5,3
10M
100M
5,2
1M
1G
10M
Figure 3.
Cross-talk vs. frequency (amp1)
Figure 4.
-20
1G
Cross-talk vs. frequency (amp2)
0
0
-10
100M
Frequency (Hz)
Frequency (Hz)
Small Signal
Vcc=5V
Load=150 Ω
Small Signal
Vcc=5V
Load=150 Ω
-20
Gain (dB)
Gain (dB)
-30
-40
-50
1/2
-60
-40
2/1
-60
-70
-80
-80
1/3
2/3
-90
-100
1M
10M
-100
1M
100M
10M
Figure 5.
100M
Frequency (Hz)
Frequency (Hz)
Cross-talk vs. frequency (amp3)
Figure 6.
Input noise vs. frequency
0
Vcc=5V
DC input = 1.5V (Battery)
Input Noise (nV/VHz)
Gain (dB)
-20
Small Signal
Vcc=5V
Load=150 Ω
-40
-60
3/1
-80
-100
1M
3/2
10M
100
10
100M
10
Frequency (Hz)
100
1k
10k
100k
1M
10M
Frequency (Hz)
Rev. 2
5/14
Electrical Characteristics
Figure 7.
TSH344
Distortion on 150Ω load - 10MHz
Figure 8.
-30
-35
-35
Vcc=5V
F=10MHz
input DC component = 1.15V
Load=150Ω
-45
-50
-45
-55
-60
-65
HD2
-70
Vcc=5V
F=10MHz
input DC component = 1.15V
Load=100 Ω
-40
-50
HD2 & HD3 (dBc)
-40
HD2 & HD3 (dBc)
Distortion on 100Ω load - 10MHz
-30
-75
-80
-55
-60
-65
-70
HD2
-75
-80
-85
-85
HD3
-90
HD3
-90
-95
-95
-100
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
-100
0,0
4,0
0,5
1,0
Output Amplitude (Vp-p)
Figure 9.
Distortion on 150Ω load - 30MHz
-15
Vcc=5V
F=30MHz
input DC component = 1.15V
Load=150 Ω
3,0
3,5
4,0
-25
-30
-25
-35
-40
-45
-50
HD2
-55
Vcc=5V
F=30MHz
input DC component = 1.15V
Load=100 Ω
-20
HD2 & HD3 (dBc)
-20
HD2 & HD3 (dBc)
2,5
-10
-15
-60
-65
-30
-35
-40
-45
-50
HD2
-55
-60
-65
HD3
-70
HD3
-70
-75
-75
-80
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
-80
0,0
4,0
0,5
1,0
Output Amplitude (Vp-p)
2,0
2,5
3,0
3,5
4,0
Figure 12. Slew rate
4,0
0
-10
+5V
3,5
VOH
without load
-20
Output Response (V)
-30
Isource
-40
V
-50
0V
-60
-70
-80
-90
SR+
3,0
2,5
2,0
SR-
1,5
1,0
-100
Vcc=5V
Load=150Ω
0,5
-110
-120
0,0
1,5
Output Amplitude (Vp-p)
Figure 11. Output current
Isource (mA)
2,0
Figure 10. Distortion on 100Ω load - 30MHz
-10
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
4,0
4,5
5,0
-2
-1
0
1
2
3
Time (ns)
V (V)
6/14
1,5
Output Amplitude (Vp-p)
Rev. 2
4
5
6
7
8
TSH344
Electrical Characteristics
Figure 13. Reverse isolation vs. frequency
Figure 14. Output swing vs. frequency
5
0
Vcc=5V
Load=150 Ω
-10
4
-20
Vout max. (Vp-p)
Gain (dB)
-30
-40
-50
-60
-70
3
2
1
-80
Vcc=5V
Load=100 Ω or Load=150Ω
-90
-100
1M
10M
0
1M
100M
10M
Figure 15. Quiescent current vs. Supply
Figure 16. Output swing vs. supply
5
30
Vcc=5V
no load
4
Vout peak-peak (Vp-p)
Total Icc (mA)
25
100M
Frequency (Hz)
Frequency (Hz)
20
15
10
3
2
1
5
0
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
4,0
4,5
Vcc=5V
F=30MHz
Load=100 Ω or 150 Ω
0
3,00
5,0
3,25
3,50
3,75
4,00
4,25
4,50
4,75
5,00
Vcc (V)
Vcc (V)
Figure 17. Bandwidth vs. temperature
Figure 18. Voltage gain vs. temperature
500
2,05
450
2,04
2,03
400
Gain (dB)
Bw (MHz)
2,02
350
300
250
2,01
2,00
1,99
1,98
200
1,97
150
100
-40
Vcc=5V
Load=150Ω
-20
1,96
0
20
40
60
80
Temperature (°C)
1,95
-40
Vcc=5V
Load=150Ω
-20
0
20
40
60
80
Temperature (°C)
Rev. 2
7/14
Electrical Characteristics
TSH344
Figure 19. Ibias vs. temperature
Figure 20. Gain matching vs. temperature
1,0
2
3
0,8
4
0,6
GM (%)
IBIAS (µA)
Vcc=5V
Load=150 Ω
5
0,4
0,2
6
7
-40
Gain Matching between 3 channels
Vcc=5V
Load=150Ω
Vin=0.3V and 1V
-20
0
20
40
60
0,0
-40
80
-20
0
20
40
60
80
Temperature (°C)
Temperature (°C)
Figure 21. Supply current vs. temperature
Figure 22. Output current vs. temperature
100
Isource (mA)
ICC (mA)
11
10
9
8
7
-40
Vcc=5V
no Load
-20
90
80
70
60
0
20
40
60
50
-40
80
Vcc=5V
Load=150 Ω
-20
0
20
40
60
80
Temperature (°C)
Temperature (°C)
Figure 23. Output higher rail vs. temperature
Figure 24. Output lower rail vs. temperature
50
4,2
45
4,1
40
VOL (V)
VOH (V)
4,0
3,9
35
3,8
30
3,7
25
3,6
3,5
-40
Vcc=5V
Load=150Ω
Vcc=5V
Load=150Ω
-20
0
20
40
60
80
-20
0
20
40
Temperature (°C)
Temperature (°C)
8/14
20
-40
Rev. 2
60
80
TSH344
Power Supply Considerations and improvement of
the PSRR
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 (C LF) greater than 100uF is
necessary to improve the PSRR in low frequencies. For better quality bypassing, a capacitor
of 470nF (C HF) is added using the same implementation conditions to improve the PSRR in
the higher frequencies.
Figure 25. Circuit for power supply bypassing
+VCC
CLF
+
CHF
4
R
G
B
TSH344
5
The following graph in Figure 26 shows the evolution of the PSRR against the frequency
when the power supply decoupling is achieved carefuly or not.
Figure 26. PSRR improvement
0
-10
Vcc=5V
Load=150Ω
PSRR=20 log ( ∆VCC/∆Vout)
-20
PSRR (dB)
3
Power Supply Considerations and improvement of the PSRR
without
capacitor
-30
-40
CLF=100uF
CHF=470nF
-50
-60
-70
-80
10k
100k
1M
10M
100M
Frequency (Hz)
Rev. 2
9/14
Using the TSH344 to Drive RGB Video Components
4
TSH344
Using the TSH344 to Drive RGB Video Components
Figure 27. Shapes of video signals coming from DACs
DAC Outputs: RGB
100 IRE
White Level
Image Content
30 IRE
Black Level
1Vp-p
300mV
0 IRE
0Volt
Figure 28. Implementation of the video driver on output video DACs
(1) DAC output
(2) Amplifier output
(3) On the line
Amplifier output rail
(3.7V min.)
Content of the
video signal
2.6V
1.4Vp-p
0.7Vp-p
0.7Vp-p
600mV
300mV
0V
Amplifier output rail
(70mV max.)
0V
300mV
0V
+5V
Video
DAC
R
Reconstruction
Filtering
LPF
75Ω
+6dB
75Ω Cable
0.7Vpp
75Ω
0.7Vpp
1.4Vpp
Video
DAC
G
Reconstruction
Filtering
LPF
75Ω
+6dB
75Ω Cable
0.7Vpp
75Ω
0.7Vpp
1.4Vpp
Video
DAC
B
Reconstruction
Filtering
LPF
75Ω
+6dB
0.7Vpp
75Ω
0.7Vpp
TSH344
-5V
10/14
75Ω Cable
Rev. 2
1.4Vpp
TV
TSH344
Using the TSH344 to Drive RGB Video Components
Figure 28 shows a schematic diagram of the use of the TSH344 to drive video output from
DACs.
The TSH344 is used to drive high definition video signals up to 30MHz on 75-ohm video
lines. It is dedicated to driving RGB signals typically between 300mV and 1V, as seen in (1).
With a very low output rail (VOL) guaranteed in test of production at 60mV maximum, it is
possible to drive the signal in single supply without any saturation of the driver against the
lower rail.
Assuming that we lose half of the signal by output impedance-matching in order to properly
drive the video line, the shifted signal is multiplied by a gain of 2 or +6dB (3).
4.1
Delay between channels
Figure 29. Measurement of the delay between each channel
5V
75Ω
+6dB
75Ω Cable
V1
75Ω
Vin
75Ω
+6dB
75Ω Cable
V2
75Ω
75Ω
75Ω
+6dB
75Ω Cable
V3
75Ω
Delay between each video component is an important aspect in high definition video
systems. To drive porperly the three video components without any relative delay, the dice of
the TSH344 is layouted out with a very symetrical geometry. The effect is direct on the
synchronization of each channel, as shown in Figure 30. No delay appears between each
channel when the same Vin signal is applied on the three inputs. Note that the delay from
the inputs the outputs equals 4ns.
Rev. 2
11/14
Using the TSH344 to Drive RGB Video Components
TSH344
3 Output responses
Figure 30. Relative delay between each channel
Input
Vcc=5V
Load=150 Ω
-4ns -2ns
0s
2ns
4ns
6ns
8ns 10ns 12ns 14ns 16ns 18ns 20ns
Time
12/14
Rev. 2
TSH344
5
Package Mechanical Data
Package Mechanical Data
SO-8 MECHANICAL DATA
DIM.
mm.
MIN.
TYP
inch
MAX.
MIN.
TYP.
MAX.
A
1.35
1.75
0.053
0.069
A1
0.10
0.25
0.04
0.010
A2
1.10
1.65
0.043
0.065
B
0.33
0.51
0.013
0.020
C
0.19
0.25
0.007
0.010
D
4.80
5.00
0.189
0.197
E
3.80
4.00
0.150
e
1.27
0.157
0.050
H
5.80
6.20
0.228
0.244
h
0.25
0.50
0.010
0.020
L
0.40
1.27
0.016
0.050
k
ddd
8˚ (max.)
0.1
0.04
0016023/C
Rev. 2
13/14
Revision History
TSH344
6
Revision History
Table 4.
Document revision history
Date
Revision
Description of Changes
Dec. 2005
1
First release of datasheet.
Jan. 2006
2
Capa-load option paragraph deleted in page 11.
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are
subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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14/14
Rev. 2