LT6558 550MHz, 2200V/µs Gain of 1, Single Supply Triple Video Amplifier with Input Bias Control FEATURES
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DESCRIPTION
The LT®6558 is a high speed triple video amplifier with an internal fixed gain of 1 and a programmable DC input bias voltage. This amplifier features a 400MHz 2VP-P signal bandwidth, 2200V/µs slew rate and a unique ability to drive heavy output loads to 0.8V of the supply rails, making the LT6558 ideal for a single 5V supply, wideband video application. With just one resistor, the inputs of all three amplifiers can be programmed to a common voltage level, simplifying and reducing the need for external circuitry in AC-coupled applications. Without the programming resistor, the input bias circuit becomes inactive, allowing the use of an external clamp circuit or direct coupled input. The LT6558 has separate power supply and ground pins for each amplifier to improve channel separation and to ease power supply bypassing. The LT6558 provides uncompromised performance in many high speed applications where a low voltage, single supply is required. The LT6558 is available in 16-lead SSOP and 5mm × 3mm DFN packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
–3dB Small-Signal Bandwidth: 550MHz –3dB 2VP-P Large-Signal Bandwidth: 400MHz Slew Rate: 2200V/µs Fixed Gain of 1, No External Resistors Required AC Coupling with Programmable DC Input Bias Output Swings to 0.8V of Supply Rails Full Video Swing with 5V Single Supply Differential Gain: 0.02% Differential Phase: 0.02° Enable/Shutdown Pin High Output Current: ±90mA Supply Range: 3V to 7.5V Operating Temperature Range: –40°C to 85°C Available in 16-Lead SSOP and 5mm × 3mm DFN Packages
APPLICATIONS
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LCD Video Projectors RGB HD Video Amplifiers Coaxial Cable Drivers Low Supply ADC Drivers
TYPICAL APPLICATION
AC-Coupled Triple Video Driver
EN 22µF IN R GND IN R LT6558 BCV V+ OUT R 4 V+ R 5V RL* OUTPUT (V) RL* 5V 3 5V 220µF 158Ω
Fast Large-Signal Transient Response
5 VS = 5V VIN = 2VP-P RL = 150Ω
+ –
GND R 22µF IN G IN G
+ –
220µF OUT G
2
GND G 22µF IN B IN B
V+ G
1
+ –
220µF OUT B RL*
0 –10 –8 –6 –4 –2 0 2 TIME (ns)
4
6
8
10
6558 TA01b
GND B
V+ B
5V
6558 TA01a
*50Ω OR GREATER FOR RL
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LT6558 ABSOLUTE MAXIMUM RATINGS
(Note 1)
Total Supply Voltage (VS+ to GND) ...........................7.5V Input Current........................................................±10mA Output Current (Note 2) .......................................±90mA Output Short-Circuit Duration (Note 2) ............ Indefinite Operating Temperature Range (Note 3) ... –40°C to 85°C Specified Temperature Range (Note 4) .... –40°C to 85°C
Junction Temperature SSOP ................................................................ 150°C DFN................................................................... 125°C Storage Temperature Range SSOP ................................................. –65°C to 150°C DFN.................................................... –65°C to 125°C Lead Temperature (Soldering, 10 sec) SSOP ................................................................ 300°C
PACKAGE/ORDER INFORMATION
TOP VIEW TOP VIEW EN GND IN R GND R IN G GND G IN B GND B 1 2 3 4 5 6 7 8 G = +1 G = +1 G = +1 16 BCV 15 V+ EN GND IN R GND R IN G GND G IN B GND B 1 2 3 4 5 6 7 8 G = +1 G = +1 17 G = +1 16 BCV 15 V+ 14 OUT R 13 V+ R 12 OUT G 11 V+ G 10 OUT B 9 V+ B
14 OUT R 13 V+ R 12 OUT G 11 V+ G V+ B
10 OUT B 9
GN PACKAGE 16-LEAD PLASTIC SSOP TJMAX = 150°C, θJA = 110°C/W
DHC PACKAGE 16-LEAD (5mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 40°C/W EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
ORDER PART NUMBER LT6558CGN LT6558IGN
GN PART MARKING 6558 6558I
ORDER PART NUMBER LT6558CDHC LT6558IDHC
DHC PART MARKING* 6558 6558
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 5V, RL = 150Ω to VS/2, VEN = 0.4V, RBCV = open, unless otherwise noted.
SYMBOL VOS IIN RIN CIN PARAMETER Input Offset Voltage Input Current Input Resistance Input Capacitance CONDITIONS VIN = 2.5V VIN = 2.5V VIN = 2V to 3V, BCV (Pin 16) Open f = 1MHz
● ● ●
ELECTRICAL CHARACTERISTICS
MIN
TYP 12 15 35 45
MAX 45 55 70 100
UNITS mV mV µA µA kΩ kΩ pF
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200 150
450 400 1.4
2
LT6558
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 5V, RL = 150Ω to VS/2, VEN = 0.4V, RBCV = open, unless otherwise noted.
SYMBOL AV ERR AV MATCH VIN(DC) PSRR VOL VOH IS PARAMETER Gain Error Gain Match Between Channels Input Voltage Bias Power Supply Rejection Ratio Output Voltage Swing Low
●
ELECTRICAL CHARACTERISTICS
CONDITIONS VIN = 1.5V to 3.5V VIN = 1.5V to 3.5V RBCV = 158Ω VS = 4V to 6V, VIN = 1.25V
● ● ● ●
MIN
TYP ±0.7 ±0.9 ±0.02 ±0.05
MAX ±2.0 ±2.5 ±1.5 ±2.5 3 3.5
UNITS % % % % V V dB dB
2.0 1.5 42 38
2.5 2.8 50 47 0.8 0.9
0.9 1.0
V V V V
Output Voltage Swing High
●
4.1 4.0
4.2 4.1 22.5 25.0 10 10 24 28 450 1000
Supply Current per Amplifier Total Supply Current (Disabled)
VEN = 0.4V, RL = ∞, Includes IS of V+ (Pin 15) VEN = Open, RL = ∞ VEN = 0.4V
● ● ● ●
mA mA µA µA µA µA mA mA V/µs MHz MHz MHz MHz dB dB ns ns ps % Deg dBc dBc
IEN ISC SR –3dB BW 0.1dB BW FPBW XTalk tS tr, tf ΔG ΔΦ HD2 HD3
Enable Pin Current Short-Circuit Current Slew Rate –3dB Bandwidth Gain Flatness ±0.1dB Bandwidth Full Power Bandwidth All Hostile Crosstalk Settling Time Rise Time, Fall Time Differential Gain Differential Phase 2nd Harmonic Distortion 3rd Harmonic Distortion
–250 –300 ±60 ±40 1200
–125 –150 ±90 ±80 2200 400 550 100
VOUT = 1.25V to 3.75V (Note 5) VOUT = 2VP-P VOUT = 0.2VP-P VOUT = 2VP-P VOUT = 2VP-P (Note 6) f = 10MHz, VOUT = 2VP-P f = 100MHz, VOUT = 2VP-P To 1%, VOUT = 1.5V to 3.5V To 0.1% 10% to 90%, VOUT = 1.5V to 3.5V NTSC Signal NTSC Signal f = 10MHz, VOUT = 2VP-P f = 10MHz, VOUT = 2VP-P
190
350 –80 –55 4 7 875 0.02 0.02 –75 –79
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: A heat sink may be required to keep the junction temperature below the Absolute Maximum Rating. Note 3: The LT6558C is guaranteed functional over the temperature range of –40°C and 85°C. Note 4: The LT6558C is guaranteed to meet specified performance from 0°C to 70°C. The LT6558C is designed, characterized and expected to
meet specified performance from –40°C to 85°C but is not tested or QA sampled at these temperatures.The LT6558I is guaranteed to meet specified performance from –40°C to 85°C. Note 5: Slew rate is 100% production tested on the R channel and measured on the rising edge of the output signal. The slew rate of the falling edge and of the G and B channels is guaranteed through design and characterization. Note 6: Large-signal bandwidth is calculated from slew rate: FPBW = SR/(π • VP-P)
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LT6558 TYPICAL PERFORMANCE CHARACTERISTICS
Gain Error Distribution
60 VS = 5V ∆VOUT = 2V 50 RL = 150Ω PERCENT OF UNITS (%) PERCENT OF UNITS (%) 40 30 20 10 0 –1.0 70
Gain Error Matching Distribution
1.03 1.02 1.01 50 40 30 20 10 0 –0.3 GAIN (V) 1.00 0.99 0.98 0.97 0.96 VS = 5V ∆VOUT = 2V 60 R = 150Ω L
Voltage Gain vs Temperature
VS = 5V VOUT = 2VP-P RLOAD = 150Ω
–0.5 –0.9 –0.8 –0.7 –0.6 GAIN ERROR, INDIVIDUAL CHANNEL (%)
6558 G01
–0.2 –0.1 0 0.1 0.2 0.3 GAIN ERROR, BETWEEN CHANNELS (%)
6558 G02
0.95 –50 –25
25 0 50 75 TEMPERATURE (°C)
100
125
6558 G03
Supply Current per Amplifier vs Supply Voltage
40 35 SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) 30 25 20 15 10 5 0 0 1 2 3 4 5 6 SUPPLY VOLTAGE (V) 7
6558 G04
Supply Current per Amplifier vs Temperature
40 40 VS = 5V 35 VOUT = VS/2 VEN = 0V 30 25 20 15 10 5 0 –50 0 –25 0 25 50 75 TEMPERATURE (°C) 100 125 SUPPLY CURRENT (mA) 30
Supply Current per Amplifier vs EN Voltage
VS = 5V VOUT = VS/2 TA = 125°C TA = 25°C 20 TA = – 55°C
VOUT = VS/2
10
0
1
4 2 3 ENABLE PIN VOLTAGE (V)
5
6558 G06
6558 G05
EN Pin Current vs EN Pin Voltage
0 –20 ENABLE PIN CURRENT (µA) OFFSET VOTLAGE (mV) –40 –60 –80 TA = –55°C TA = 125°C TA = 25°C VS = 5V 40 35 30 25 20 15 10 5 0 1 4 2 3 ENABLE PIN VOLTAGE (V) 5
6558 G07
Offset Voltage vs Temperature
400 VS = 5V VIN = 2.5V INPUT BIAS CURRENT (µA) 300 200 100 0 –100 –200 –300 –400 –25 50 0 25 75 TEMPERATURE (°C) 100 125
Input Bias Current vs Input Voltage
VS = 5V
TA = 25°C TA = 125°C TA = –55°C
–100 –120 –140 –160
0 –50
0
1
2 3 INPUT VOLTAGE (V)
4
5
6558 G09
6558 G08
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LT6558 TYPICAL PERFORMANCE CHARACTERISTICS
Output Voltage vs Input Voltage
5 VS = 5V RLOAD = 150Ω TO VS/2 5.0 TA = 125°C OUTPUT VOLTAGE SWING (V) 4.5
Output Voltage Swing vs Load Current (Output High)
VS = 5V VIN = 4.5V OUTPUT VOLTAGE SWING (V) TA = 125°C 2.5
Output Voltage Swing vs Load Current (Output Low)
VS = 5V VIN = 0V
4 OUTPUT VOLTAGE (V) TA = 25°C TA = –55°C
2.0
3
4.0 TA = 25°C 3.5 TA = –55°C
1.5
TA = –55°C TA = 25°C
2
1.0 TA = 125°C 0.5
1
3.0
0 0 1 2 3 INPUT VOLTAGE (V) 4 5
6558 G10
2.5 0 10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA)
6558 G11
0 0 10 20 30 40 50 60 70 80 90 100 LOAD CURRENT (mA)
6558 G12
Input Bias Voltage vs Resistance at BCV Pin
3.5 VS = 5V 5.0 4.5 4.0 INPUT VOLTAGE (V) 3.5 3.0 2.5 2.0 1.5 1.0 0.5 1.0 120 140 160 180 200 220 BVC-RESISTANCE (Ω) 240 260
Input Bias Voltage vs Temperature
80 VS = 5V RBCV = 158Ω BIAS CONTROL VOLTAGE (mV) 70 60 50 40 30
Bias Control Voltage vs Temperature
VS = 5V RBCV = 158Ω
3.0 INPUT VOLTAGE (V)
2.5
2.0
1.5
0 –50 –25
0 50 25 75 TEMPERATURE (°C)
100
125
20 –50 –25
0 50 25 75 TEMPERATURE (°C)
100
125
6558 G13
6558 G14
6558 G15
Frequency Response
5 4 3 2 GAIN (dB) 1 0 –1 –2 –3 –4 –5 1 10 100 FREQUENCY (MHz) 1000
6558 G16
Frequency Response of Three Amplifiers
5 4 VS = 5V VOUT = 2VP-P RL = 150Ω 0.5
Gain Flatness vs Frequency
VS = 5V 0.4 VOUT = 2VP-P RL = 150Ω 0.3 0.2 GAIN (dB) 0.1 0 –0.1 –0.2
VS = 5V RL = 150Ω VOUT = 200mVP-P GAIN (dB)
3 2 1 0 –1 –2 –3 –4 –5 1
VOUT = 2VP-P
IN-R IN-G IN-B 10 100 FREQUENCY (MHz) 1000
6558 G17
–0.3 –0.4 –0.5 1
IN-R IN-G IN-B 10 100 FREQUENCY (MHz) 1000
6558 G18
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5
LT6558 TYPICAL PERFORMANCE CHARACTERISTICS
Frequency Response with Capacitive Loads
5 VS = 5V 4 VOUT = 200mVP-P RL = 150Ω 3 2 GAIN (dB) 1 0 –1 –2 –3 –4 –5 1 10 100 FREQUENCY (MHz) 1000
6558 G19
Large-Signal Group Delay
2.00 1.75 1.50 AMPLITUDE (dB) DELAY (ns) 1.25 1.00 0.75 0.50 0.25 0 1 10 100 FREQUENCY (MHz) 1000
6558 G20
Crosstalk Between Amplifiers vs Frequency
–30 VS = 5V –40 VOUT = 2VP-P RL = 150Ω –50 –60 –70 –80 –90 –100 –110 1 10 100 FREQUENCY (MHz) TYPICAL CHANNEL TO CHANNEL R TO G B TO G 1000
6558 G21
CL = 8.2pF CL = 4.7pF
VS = 5V VOUT = 2VP-P RL = 150Ω
WORST CASE CHANNEL TO CHANNEL
CL = 0pF
RBCV = 158Ω
Output Impedance vs Frequency
1000000 100000 OUTPUT IMPEDANCE (Ω) 10000 1000 100 10 1 0.1 0.01 ENABLE 0.1 1 10 FREQUENCY (MHz) 100 1000
6558 G22
Input Impedance vs Frequency
1000000 RBCV = OPEN INPUT IMPEDANCE (Ω) REJECTION RATIO (dB) VS = 5V 60 50 40 30 20 10 100 0.01
Power Supply Rejection Ratio vs Frequency
VS = 5V
VS = 5V DISABLE
100000
10000
RBCV = 158Ω
1000
0.1
1 10 FREQUENCY (MHz)
100
1000
6558 G23
0 0.001
0.01
0.1 1 FREQUENCY (MHz)
10
100
6558 G24
Distortion vs Frequency
VS = 5V 10 V OUT = 2VP-P 20 RL = 150Ω 30 DISTORTION (dBc) DISTORTION (dBc) 40 50 60 70 80 90 100 110 120 0.01 0.1 1 10 FREQUENCY (MHz) 100
6558 G25
Distortion vs Frequency
VS = 5V 10 V OUT = 1VP-P 20 RL = 150Ω 30 40 50 60 70 80 90 100 110 120 0.01 0.1 1 10 FREQUENCY (MHz) 100
6558 G26
0
0
HD2 HD3
HD2 HD3
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LT6558 TYPICAL PERFORMANCE CHARACTERISTICS
Input Noise Spectral Density
1000 INPUT VOLTAGE NOISE (nV/√Hz) VS = 5V VIN = 2.5V +in 1000 INPUT CURRENT NOISE (pA/√Hz) 6 VEN(DISABLE) 5 4 VOLTAGE (V) 3 VOUT 2 1 0 VEN(ENABLE) 1 0.01 0.1 1 10 FREQUENCY (kHz) 0 100
6558 G27
Enable/Disable Response
100 en 10
100
VS = 5V VOUT = 2VP-P RL = 150Ω
10
–1 0 0.4 0.8 1.6 1.2 TIME (µs) 2.0 2.4 2.6
6558 G28
Large-Signal Transient Response
5 VS = 5V VIN = 2VP-P RL = 150Ω 2.65
Small-Signal Transient Response
VS = 5V VIN = 100mVP-P RL = 150Ω
4
2.60 OUTPUT (V)
OUTPUT (V)
3
2.55
2
2.50 1
0 0 2 4 6 8 10 12 14 16 18 20 TIME (ns)
6558 G29
2.45 0 2 4 6 8 10 12 14 16 18 20 TIME (ns)
6558 G30
PIN FUNCTIONS
⎯E⎯N (Pin 1): Enable Control Pin. The part is enabled when this pin is pulled low. An internal pull-up resistor of 40k will turn the part off if this pin is unconnected. GND (Pin 2): Ground Reference for Enable Pin (Pin 1) and Bias Control Voltage Pin (Pin 16). This pin must be connected externally to ground. IN R (Pin 3): Red Channel Input. This pin has a nominal impedance of 450kΩ with input bias circuit inactive, Pin 16 open. GND R (Pin 4): Ground of Red Channel Amplifier. This pin is not internally connected to other ground pins and must be connected externally to ground. IN G (Pin 5): Green Channel Input. This pin has a nominal impedance of 450kΩ with input bias circuit inactive, Pin 16 open. GND G (Pin 6): Ground of Green Channel Amplifier. This pin is not internally connected to other ground pins and must be connected externally to ground. IN B (Pin 7): Blue Channel Input. This pin has a nominal impedance of 450kΩ with input bias circuit inactive, Pin 16 open. GND B (Pin 8): Ground of Blue Channel Amplifier. This pin is not internally connected to other ground pins and must be connected externally to ground.
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LT6558 PIN FUNCTIONS
V+ B (Pin 9): Positive Supply Voltage of Blue Channel Amplifier. This pin is not internally connected to other supply voltage pins and must be externally connected to the supply voltage bus with proper bypassing. For best performance, see Power Supply Considerations. OUT B (Pin 10): Blue Channel Output. V+ G (Pin 11): Positive Supply Voltage of Green Channel Amplifier. This pin is not internally connected to other supply voltage pins and must be externally connected to the supply voltage bus with proper bypassing. For best performance, see Power Supply Considerations. OUT G (Pin 12): Green Channel Output. V+ R (Pin 13): Positive Supply Voltage of Red Channel Amplifier. This pin is not internally connected to other supply voltage pins and must be externally connected to the supply voltage bus with proper bypassing. For best performance, see Power Supply Considerations. OUT R (Pin 14): Red Channel Output. V+ (Pin 15): Positive Supply Voltage of Control Circuitry. This pin is not internally connected to other supply voltage pins and must be externally connected to supply voltage bus with proper bypassing. For best performance, see Power Supply Considerations. BCV (Pin 16): Bias Control Voltage. A resistor connected between Pin 16 and Pin 2 (GND) will generate a DC voltage bias at the inputs of the three amplifiers for AC coupling application, see Programmable Input Bias. Exposed Pad (Pin 17, DFN Package): Ground. This pad must be soldered to PCB and is internally connected to GND (Pin 2).
APPLICATIONS INFORMATION
Power Supply Considerations The LT6558 is optimized to provide full video signal swing output when operated from a standard 5V single supply. Due to the supply current involved in ultrahigh slew rate amplifiers like the LT6558, selection of the lowest workable supply voltage is recommended to minimize heat generation and simplify thermal management. Temperature rise at the internal devices (TJ) must be kept below 150°C (SSOP package) or 125°C (DFN package), and can be estimated from the ambient temperature (TA) and power dissipation (PD) as follows: TJ = TA + PD • 40°C/W for DFN package or TJ = TA + PD • 110°C/W for SSOP package where PD = (IS + 0.5 • IO) • VS(TOTAL) The latter equation assumes (conservatively) that the output swing is small relative to the supply and RMS load current (IO) is bidirectional (as with AC coupling). The grounds are separately pinned for each amplifier to minimize crosstalk. Operation from split supplies can be accomplished by connecting the LT6558 ground pins to the negative rail. With dual supplies, recommended voltages range from nominal ±2.5V to ±3.3V. The ultrahigh frequency (UHF) operating range of the LT6558 requires that careful printed circuit layout practices be followed to obtain maximum performance. Trace lengths between power pins and bypass capacitors should be minimized (