Datasheet TSH344 Datasheet (ST)

340MHz single-supply triple video buffer

Features

■ 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/ms

■ Specified for 150Ω and 100Ω loads

■ Tested on 5V power supply

■ Min. and max. data tested during production

Pin connections (top view)

Pin1 identification

1

IN1

Top View

6dB

TSH344

8

OUT1

Applications

■ High-end video systems

■ High definition TV (HDTV)

■ Broadcast and graphic video

■ Multimedia products

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.
datasheet gives technical information on using
the TSH344 as an RGB driver for video DAC
output on a video line. See the TSH343 datasheet
for Y-Pb-Pr signals.

The TSH344 is available in the compact SO8
plastic package for optimum space-saving.

This

IN2

IN3

+Vcc

7

6

5

OUT2

OUT3

GND

2

3

4

6dB

6dB

SO8

March 2007 Rev 4 1/17

www.st.com

17

Contents TSH344

Contents

1 Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 3

2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.1 Using the TSH344 to drive R-G-B video components . . . . . . . . . . . . . . . 10

3.2 Power supply considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.3 Delay between channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

4 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

6 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2/17

TSH344 Absolute maximum ratings and operating conditions

1 Absolute maximum ratings and operating conditions

Table 1. Absolute maximum ratings (AMR)

Symbol Parameter Value Unit

V

T

T

R
R
P

CC

V

oper

stg

T

thjc
thja

max

Supply voltage
Input voltage range

in

Operating free air temperature range -40 to +85 °C
Storage temperature -65 to +150 °C
Maximum junction temperature 150 °C

j

SO8 thermal resistance junction to case 28 °C/W
SO8 thermal resistance junction to ambient area 157 °C/W
Maximum power dissipation (@T
CDM: charged device model

ESD

HBM: human body model
MM: machine model

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

(1)

(2)

6V

0 to +2 V

=25°C) for Tj=150°C 800 mW

amb

2

1.5

200

kV
kV

V

Symbol Parameter Value Unit

V

CC

1. Tested in full production at 0V/5V single power supply.

Power supply voltage

(1)

3 to 5.5 V

3/17

Electrical characteristics TSH344

2 Electrical characteristics

Table 3. VCC= +5V single supply, T

= 25°C (unless otherwise specified)

amb

Symbol Parameter Test conditions Min. Typ. Max. Unit

DC performance

V

OS

I

ib

R

in

C

in

PSRR

Output offset voltage

(1)

Input bias current

Input resistance T
Input capacitance T
Power supply rejection ratio

20 log (

ΔV

CC

/ΔV

out

(2)

)

No load, T

-40°C < T
T

, input to GND 5.5 16

amb

-40°C < T

amb
amb

Input to GND, F=1MHz,

ΔV

=200mV

CC

-35 -8 +35

amb

< +85°C -8.6

amb

< +85°C 6

amb

4GΩ
1pF

-90 dB

No load, input to GND 10.1 13

CC Supply current per buffer

I

G DC v oltage gain R

-40°C < T
= 150Ω, Vin=1V 1.92 2 2.05 V/V

L

< +85°C 10.3

amb

MG1 Gain matching between 3 channels Input = 1V 0.5 2 %

MG0.3 Gain matching between 3 channels Input = 0.3V 0.5 2 %

Dynamic performance and output characteristics

mV

μA

mA

-3dB bandwidth

Bw

Gain flatness @ 0.1dB

FPBW Full power bandwidth

Small signal V
V

=0.6V, RL = 150Ω

icm

Small signal V
V

=0.6V, RL = 150Ω

icm

=0.6V, V

V

icm

= 150Ω

R

L

=20mVp

out

=20mVp

out

= 2Vp-p,

out

190 340

65

130 200 MHz

D Delay between each channel 0 to 30MHz 0.5 ns

V

SR Slew rate

V
V

High level output voltage RL = 150Ω 3.7 3.9 V

OH

Low level output voltage RL = 150Ω 40 60 mV

OL

Output current

I

OUT

Output short circuit current

)

(I

source

(3)

=0.6V, V

icm

= 150Ω

R

L

= 2Vp, T

V

out

-40°C < T

= 2Vp-p,

out

amb

< +85°C 83

amb

500 740 V/μs

45 93

100 mA

MHz

mA

4/17

TSH344 Electrical characteristics

Table 3. VCC= +5V single supply, T

= 25°C (unless otherwise specified)

amb

Symbol Parameter Test conditions Min. Typ. Max. Unit

Noise and distortion

F = 100kHz, R
R

= 50Ω

eN Total input voltage noise

in

Bw=30MHz
Bw=100MHz

= 2Vp-p, RL = 150Ω

V

out

HD2 2nd harmonic distortion

F= 10MHz
F= 30MHz

V

= 2Vp-p, RL = 150Ω

HD3 3rd harmonic distortion

out

F= 10MHz
F= 30MHz

1. Output offset voltage is determined by the following expression: V

2. See Figure28 and Figure 29.

3. Non-tested value, guaranteed by design and evaluation. See Figure12.

= 50Ω 8nV/√Hz

in

55

100

-57

-42

-72

-51

=G.VIN+VOS.

OUT

μVrms

dBc

dBc

5/17

Electrical characteristics TSH344

Figure 1. Frequency response Figure 2. Gain flatness

10

8

6

4

2

0

-2

Gain (dB)

-4

-6

Vcc=5V

-8

Load=150

-10
1M 10M 100M 1G

Ω

Frequency (Hz)

6,2

6,1

6,0

5,9

5,8

5,7

5,6

Gain (dB)

5,5

5,4

Vcc=5V

5,3

Load=150

5,2

1M 10M 100M 1G

Ω

Frequency (Hz)

Figure 3. Cross-talk vs. frequency (amp1) Figure 4. Cross-talk vs. frequency (amp2)

0

Small Signal

-10

Vcc=5V
Load=150

-20

-30

-40

-50

-60

Gain (dB)

-70

-80

-90

-100
1M 10M 100M

Ω

1/2

1/3

Frequency (Hz)

0

Small Signal
Vcc=5V
Load=150

-20

-40

-60

Gain (dB)

-80

Ω

2/1

2/3

-100
1M 10M 100M

Frequency (Hz)

Figure 5. Cross-talk vs. frequency (amp3) Figure 6. Input noise vs. frequency

0

Small Signal
Vcc=5V
Load=150

-20

-40

-60

Gain (dB)

-80

-100
1M 10M 100M

Ω

3/1

3/2

Frequency (Hz)

6/17

100

Input Noise (nV/VHz)

10

10 100 1k 10k 100k 1M 10M

Frequency (Hz)

Vcc=5V
DC input = 1.5V (Battery)

TSH344 Electrical characteristics

Figure 7. Distortion on 150Ω load - 10MHz Figure 8. Distortion on 100Ω load - 10MHz

-30

-35

-40

-45

-50

-55

-60

-65

-70

-75

-80

HD2 & HD3 (dBc)

-85

-90

-95

-100
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0

Figure 9. Distortion on 150Ω load - 30MHz Figure 10. Distortion on 100Ω load - 30MHz

-10

-15

-20

-25

-30

-35

-40

-45

-50

-55

-60

HD2 & HD3 (dBc)

-65

-70

-75

-80

0,00,51,01,52,02,53,03,54,0

Vcc=5V
F=10MHz
input DC component = 1.15V
Load=150

Ω

HD2

HD3

Output Amplitude (Vp-p)

Vcc=5V
F=30MHz
input DC component = 1.15V
Load=150

Ω

HD2

HD3

Output Amplitude (Vp-p)

-30

-35

Vcc=5V
F=10MHz

-40

input DC component = 1.15V

-45

Load=100

-50

-55

-60

-65

-70

-75

-80

HD2 & HD3 (dBc)

-85

-90

-95

-100
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0

Ω

HD2

HD3

Output Amplitude (Vp-p)

-10

-15

Vcc=5V

-20

F=30MHz
input DC component = 1.15V

-25

Load=100

-30

-35

-40

-45

-50

HD2

-55

-60

HD2 & HD3 (dBc)

-65

-70

-75

-80

0,00,51,01,52,02,53,03,54,0

Ω

HD3

Output Amplitude (Vp-p)

Figure 11. Output current Figure 12. Slew rate

0

-10

-20

-30

-40

-50

-60

-70

Isource (mA)

-80

-90

-100

-110

-120
0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0

+5V

VOH

without load

Isource

0V

V

V (V)

4,0

3,5

3,0

2,5

2,0

1,5

1,0

Output Response (V)

Vcc=5V

0,5

Load=150

0,0

-2-1012345678

Ω

7/17

SR+

SR-

Time (ns)

Electrical characteristics TSH344

Figure 13. Reverse isolation vs. frequency Figure 14. Output swing vs. frequency

0

Vcc=5V

-10

Load=150

-20

-30

-40

-50

-60

Gain (dB)

-70

-80

-90

-100
1M 10M 100M

Ω

Frequency (Hz)

Figure 15. Quiescent current vs. supply Figure 16. Output swing vs. supply

30

Vcc=5V
no load

25

20

15

10

Total Icc (mA)

5

0

0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0

Vcc (V)

5

4

3

2

Vout max. (Vp-p)

1

Vcc=5V
Load=100

0

1M 10M 100M

Ω or Load=150Ω

Frequency (Hz)

5

4

3

2

Vout peak-peak (Vp-p)

1

Vcc=5V
F=30MHz
Load=100

0

3,00 3,25 3,50 3,75 4,00 4,25 4,50 4,75 5,00

Ω or 150Ω

Vcc (V)

Figure 17. Bandwidth vs. temperature Figure 18. Voltage gain vs. temperature

500

450

400

350

300

Bw (MHz)

250

200

150

Vcc=5V
Load=150

100

-40-200 20406080

Ω

Temperature (°C)

8/17

2,05

2,04

2,03

2,02

2,01

2,00

1,99

Gain (dB)

1,98

1,97

Vcc=5V

1,96

Load=150

1,95

-40-200 20406080

Ω

Temperature (°C)

TSH344 Electrical characteristics

Figure 19. I

2

3

Vcc=5V
Load=150

vs. temperature Figure 20. Gain matching vs. temperature

bias

1,0

Ω

Gain Matching between 3 channels

Vcc=5V

0,8

Load=150

Ω

Vin=0.3V and 1V

4

0,6

(μA)

BIAS

5

I

6

7

-40 -20 0 20 40 60 80

Temperature (°C)

GM (%)

0,4

0,2

0,0

-40-200 20406080

Temperature (°C)

Figure 21. Supply current vs. temperature Figure 22. Output current vs. temperature

12

11

10

(mA)

CC

I

9

110

100

90

80

70

Isource (mA)

8

Vcc=5V
no Load

7

-40 -20 0 20 40 60 80

Temperature (°C)

60

Vcc=5V
Load=150

50

-40-200 20406080

Ω

Temperature (°C)

Figure 23. Output higher rail vs. temperature Figure 24. Output lower rail vs. temperature

4,2

4,1

4,0

3,9

(V)

OH

V

3,8

3,7

3,6

Vcc=5V
Load=150

3,5

-40 -20 0 20 40 60 80

Ω

Temperature (°C)

50

45

40

35

(V)

OL

V

30

25

Vcc=5V
Load=150

20

-40 -20 0 20 40 60 80

Ω

Temperature (°C)

9/17

Application information TSH344

3 Application information

3.1 Using the TSH344 to drive R-G-B video components

Figure 25. Shapes of video signals coming from DACs

GND

300mV

10mV

54ns

(4t)

27ns

(2t)

590ns

590ns

(44t)

Synchronization tip

27ns

(2t)

(44t)

Amplitude

1Vp-p

300mV

700mV

14.8µs (1100t): 1920*1080i

24.3µs (1800t): 1280*720i

White (100 IRE)

•Fclock=74.25MHz

•t=1/Fclock=13.5ns

Black (30 IRE)

(0 IRE)

1.030V

0.330V

0.030V

time

Figure 26. TSH344 in single supply for HD

video
outputs

DAC

DAC

DAC

video
outputs

DAC

DAC

DAC

R
G
B

Y,G(+synchro)
Pb,B
Pr,R

+5V

TSH344

SO8

+5V

TSH343

SO8

75Ω

LPF

75Ω

LPF

75Ω

LPF

Digital synchro

75Ω

LPF

75Ω

LPF

75Ω

LPF

30MHz

Frequency

Cable

Cable

Cable

HDTV

Cable

Cable

Cable

Note: Se e the TSH343 datasheet on st.com for more information (the TSH343 is used to drive a

video signal including a synchronization tip).

10/17

TSH344 Application information

Figure 27. Details on one channel of the TSH344

DAC

External resistor.
Load required by
the DAC output
specification

300mV

1V

5Volt

0Volt

1/3 TSH344
(gain=2)

+5V

600mV

0V

2V

10nF

5Volt

0Volt

+

100µF

75Ω

Low output Rail :
60mV max. tested
(see datasheet p.3: Vol)

68pF

470nH

STB

video line

68pF

TV

75Ω

1V

300mV

0Volt

Because of the shape of the signal described in Figure 25, we use a very low output rail
triple high-speed buffer. The TSH344 supplied in 5V single power supply features a low
output rail of 60mV (guaranteed by test) on 150Ω load. It is dedicated for driving RGB
signals without synchronisation (in the case where the synchronization is provided digitally
on the digital bus).

The gain of the TSH344 (gain=2) is internal which make s it possib le to remo v e tw o resist ors
on the BOM. To avoid any perturbation on matching from the DACs output impedance along
a large band of 30MHz in HD, a discrete reconstruction filtering is implemented after the
driver. This filter is matched on 75Ω. Note that the TSH344 uses a single supply architecture
and it is not AC o utput coupled (it ca nnot sink an output curre nt, theref ore it is not possible to
implement an output series capacitor).

11/17

Application information TSH344

3.2 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 (C
necessary to improve the PSRR in low frequencies. F or better quality bypassing, a capacitor
of 470nF (C

) is also added as close as possible to the IC pin to improve the PSRR in the

HF

higher frequencies.

Figure 28. Circuit for power supply bypassing

+VCC

C

LF

+

C

HF

4

R
G

TSH344

B

5

) greater than 100μF is

LF

Figure 29 shows how the power supply noise rejection evolves versus frequen cy depending

on how carefully the power supply decoupling is achi eved.

Figure 29. Improvement of power supply nois e rejection

0

Vcc=5V

-10

Load=150

PSRR=20 log (ΔVCC/ΔVout)

-20

-30

-40

-50

PSRR (dB)

-60

-70

-80
10k 100k 1M 10M 100M

Ω

without
capacitor

CLF=100uF
C

=470nF

HF

Frequency (Hz)

12/17

TSH344 Application information

3.3 Delay between channels

Figure 30. Measurement of the delay between each channel

5V

Vin

75Ω

+6dB

75Ω

75Ω

+6dB

75Ω

+6dB

75Ω Cable

75Ω Cable

75Ω Cable

V1

75Ω

V2

75Ω

V3

75Ω

The delay between each video component is an important aspect in high definition video
systems. To properly drive the three video components without any relative de la y, the layout
of the TSH344 dice has a very symmetrical geometry. this has a direct effect on the
synchronization of each channel, as shown in Figure 31. There is no delay detected
between channels when the same V

signal is applied on the three inputs. Note that the

in

delay between the inputs and the outputs is equal to 4ns.

Figure 31. Relative delay between each channel

Vcc=5V
Load=150

Input 3 Output responses

-4ns -2ns 0s 2ns 4ns 6ns 8ns 10ns 12ns 14ns 16ns 18ns 20ns

Time

13/17

Ω

Package information TSH344

4 Package information

In order to meet environmental requirements, STMicroelectronics offers these devices in
ECOPACK
category of second level interconnect is marke d on the pa ckage and on the inner box label,
in compliance with JEDEC Standard JESD97. The maximum ratings related t o soldering
conditions are also marked on the inner box label. ECOPACK is an STMicroelectronics
trademark. ECOPACK specifications are available at: www.st.com

®

packages. These packages have a lead-free second level interconnect. The

.

14/17

TSH344 Package information

Figure 32. SO-8 package mechanical data

Dimensions

Ref.

Min. Typ. Max. Min. Typ. Max.

A1.750.069
A1 0.10 0.25 0.004 0.010
A2 1.25 0.049

b 0.28 0.48 0.011 0.019

c 0.17 0.23 0.007 0.010
D 4.804.905.000.1890.1930.197
E 5.806.006.200.2280.2360.244

E1 3.80 3.90 4.00 0.150 0.154 0.157

e 1.27 0.050

h 0.25 0.50 0.010 0.020

L 0.40 1.27 0.016 0.050

k1°8°1°8°

ccc 0.10 0.004

Millimeters Inches

15/17

Ordering information TSH344

5 Ordering information

Table 4. Order codes

Part number Temperature range Package Packing Marking

TSH344ID

-40°C to +85°C SO-8

TSH344IDT Tape & reel TSH344I

6 Revision history

Date Revision Changes

Dec-2005 1 First release of datasheet.

Jan-2006 2 Capa-load option paragraph deleted on page 11.

Jul-2006 3 Application information.

14-Mar-2007 4 Updated

Tube TSH344I

Section 3.2: Power supply considerations on page 12 .

16/17

TSH344

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