LT1399

Manufacturer Part NumberLT1399
DescriptionLow Cost Dual And Triple 300mhz Current Feedback Amplifiers With Shutdown
ManufacturerLinear Technology Corporation
LT1399 datasheet
 


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FEATURES
300MHz Bandwidth on 5V (A
V
0.1dB Gain Flatness: 150MHz (A
Completely Off in Shutdown, 0 A Supply Current
High Slew Rate: 800V/ s
Wide Supply Range:
2V(4V) to 6V(12V) (LT1398/LT1399)
2V (4V) to 7.5V (15V) (LT1399HV)
80mA Output Current
Low Supply Current: 4.6mA/Amplifier
Fast Turn-On Time: 30ns
Fast Turn-Off Time: 40ns
16-Pin Narrow SO/Narrow SSOP Packages
U
APPLICATIO S
RGB Cable Drivers
LCD Drivers
Spread Spectrum Amplifiers
MUX Amplifiers
Composite Video Cable Drivers
Portable Equipment
U
TYPICAL APPLICATIO
3-Input Video MUX Cable Driver
CHANNEL
A
B C
SELECT
EN A
+
V
IN A
97.6
R
G
1/3 LT1399
200
R
F
324
EN B
+
V
IN B
97.6
R
G
1/3 LT1399
200
R
F
324
EN C
+
V
IN C
97.6
R
G
1/3 LT1399
200
R
F
324
Low Cost Dual and Triple
300MHz Current Feedback
Amplifiers with Shutdown
DESCRIPTIO
= 1, 2 and –1)
®
The LT
1399 and LT1399HV contain three independent
= 1, 2 and –1)
300MHz current feedback amplifiers, each with a shut-
V
down pin. The LT1399HV is a higher voltage version of the
LT1399. The LT1398 is a two amplifier version of the
LT1399.
The LT1398/LT1399 operate on all supplies from a single
4V to 6V. The LT1399HV operates on all supplies from 4V
to 7.5V.
Each amplifier draws 4.6mA when active. When disabled
each amplifier draws zero supply current and its output be-
comes high impedance. The amplifiers turn on in only 30ns
and turn off in 40ns, making them ideal in spread spectrum
and portable equipment applications.
The LT1398/LT1399/LT1399HV are manufactured on Lin-
ear Technology’s proprietary complementary bipolar pro-
cess. The LT1399/LT1399HV are pin-for-pin upgrades to
the LT1260 optimized for use on 5V/ 7.5V supplies.
, LTC and LT are registered trademarks of Linear Technology Corporation.
75
CABLE
V
OUT
OUTPUT
200mV/DIV
75
1399 TA01
LT1398/LT1399/LT1399HV
U
Square Wave Response
1398/99 TA02
R
= 100
TIME (10ns/DIV)
L
R
= R
= 324
F
G
f = 10MHz
sn13989 13989fas
1

LT1399 Summary of contents

  • Page 1

    ... LT1399. The LT1398 is a two amplifier version of the LT1399. The LT1398/LT1399 operate on all supplies from a single 4V to 6V. The LT1399HV operates on all supplies from 4V to 7.5V. Each amplifier draws 4.6mA when active. When disabled each amplifier draws zero supply current and its output be- comes high impedance ...

  • Page 2

    ... LT1398/LT1399/LT1399HV BSOLUTE – Total Supply Voltage ( LT1398/LT1399 ................................................ 12.6V LT1399HV ....................................................... 15.5V Input Current (Note 2) ....................................... 10mA Output Current ................................................. 100mA Differential Input Voltage (Note 2) ........................... 5V U PACKAGE/ORDER I FOR ATIO TOP VIEW – OUT A + *GND 4 GND* *GND ...

  • Page 3

    ... Turn-Off Delay Time (Note 7) OFF Small-Signal Rise and Fall Time Propagation Delay PD os Small-Signal Overshoot t Settling Time S dG Differential Gain (Note 8) dP Differential Phase (Note 8) LT1398/LT1399/LT1399HV (LT1398/LT1399) CONDITIONS 5V 5V 100k 5V 100k 5V, 0V; R ...

  • Page 4

    ... Large-Signal Voltage Gain V – R Transimpedance OUT IN I Maximum Output Current OUT I Supply Current per Amplifier S Disable Supply Current per Amplifier I Enable Pin Current EN 4 (LT1399HV) CONDITIONS f = 1kHz 1k 1kHz 1kHz ...

  • Page 5

    ... Note 4: The LT1398C/LT1399C/LT1399HVC are guaranteed to meet specified performance from and are designed, characterized and expected to meet these extended temperature limits, but are not tested or QA sampled at – and 85 C. The LT1399I is guaranteed to meet specified performance from – Note 5: T ...

  • Page 6

    ... LT1398/LT1399/LT1399HV W U TYPICAL PERFOR A Closed-Loop Gain vs Frequency ( – 2 – 10M 100M FREQUENCY (Hz) S 1398/99 G01 V = –10dBm 365 100 L Large-Signal Transient Response ( 1398/99 G04 TIME (5ns/DIV 2. 365 100 L 2nd and 3rd Harmonic Distortion ...

  • Page 7

    ... S – – 30 – –5V – 50 – 60 – 70 – 80 – 100 – AMBIENT TEMPERATURE ( C) 1398/1399 G17 LT1398/LT1399/LT1399HV Output Impedance (Disabled) vs Frequency 100k 10k 1k 100 100k 1M 10M 100M FREQUENCY (Hz) Supply Current vs Supply Voltage 6 5 – ...

  • Page 8

    ... LT1398/LT1399/LT1399HV W U TYPICAL PERFOR A Input Offset Voltage vs Temperature 3 2.5 2.0 1.5 1.0 0.5 0 – 0.5 –1.0 – 50 – AMBIENT TEMPERATURE ( C) All Hostile Crosstalk 324 F G – 100 – –30 B –40 –50 –60 –70 –80 –90 –100 100k 1M FREQUENCY (Hz) Propagation Delay ...

  • Page 9

    ... A Feedback Resistor Selection The small-signal bandwidth of the LT1398/LT1399/ LT1399HV is set by the external feedback resistors and the internal junction capacitors result, the bandwidth is a function of the supply voltage, the value of the feedback resistor, the closed-loop gain and the load resistor. The LT1398/LT1399 have been optimized for 5V supply operation and have a – ...

  • Page 10

    ... U will remain enabled at all times, then the EN pin should be tied to the V mately 30 A when activated. If using CMOS open-drain logic, an external 1k pull-up resistor is recommended to ensure that the LT1399 remains disabled in spite of any CMOS drain-leakage currents – supply. The enable pin current is approxi- 5 ...

  • Page 11

    ... F G small series resistor at the output, minimizing settling time. As seen in Figures 6 and gain of +3 with a 16.9 output series resistor and a 330pF load, the LT1399HV is capable of settling to 0.1% in 30ns for a 6V step. Similarly, a 12V output step settles in 70ns. on both sides of the OUT Figure 6 ...

  • Page 12

    ... 330pF L Figure 7. LT1399HV Output Voltage Swing Buffered RGB to Color-Difference Matrix Two LT1398s can be used to create buffered color- difference signals from RGB inputs (Figure 8). In this application, the R input arrives via 75 coax routed to the noninverting input of LT1398 amplifier A1 and to a 1082 resistor R8. There is also an 80.6 termination ...

  • Page 13

    ... The LT1399 can be used to create buffered RGB outputs from color-difference signals (Figure 9). The R output is a back-terminated 75 signal created using resistor R5 and LT1399 amplifier A1 configured for a gain of +2 via 324 resistors R3 and R4. The noninverting input of amplifier A1 is connected via 1k resistors R1 and R2 to the Y and R-Y inputs respectively, resulting in cancella- tion of the Y signal at the amplifier input ...

  • Page 14

    ... LT1398/LT1399/LT1399HV PLIFIED SCHE ATIC + each amplifier – OUT – V 1398/99 SS sn13989 13989fas ...

  • Page 15

    ... Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. LT1398/LT1399/LT1399HV U Dimensions in inches (millimeters) unless otherwise noted. ...

  • Page 16

    ... TYPICAL A PPLICATI Single Supply RGB Video Amplifier The LT1399 can be used with a single supply voltage more to drive ground-referenced RGB video. In Figure 10, two 1N4148 diodes D1 and D2 have been placed in series with the output of the LT1399 amplifier A1 but within the feedback loop formed by resistor R8. ...