Datasheet LT1204 (Analog Devices) - 9
| Manufacturer | Analog Devices |
| Description | 4-Input Video Multiplexer with 75MHz Current Feedback Amplifier |
| Pages / Page | 20 / 9 — TYPICAL PERFOR A CE CH. ARA TERISTICS. Settling Time to 1mV. Enabled … |
| File Format / Size | PDF / 272 Kb |
| Document Language | English |
TYPICAL PERFOR A CE CH. ARA TERISTICS. Settling Time to 1mV. Enabled Supply Current. Disabled and Shutdown Supply. vs Output Step
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Text Version of Document
LT1204
W U TYPICAL PERFOR A CE CH C ARA TERISTICS Settling Time to 1mV Enabled Supply Current Disabled and Shutdown Supply vs Output Step vs Supply Voltage Current vs Supply Voltage
10 22 22 V 8 S = ±15V 21 21 RF = RG = 1k 6 20 20 –55°C 125°C 4 19 19 2 18 18 25°C 25°C 0 17 17 –55°C –2 16 16 OUTPUT STEP (V) –4 15 15 SUPPLY CURRENT (mA) 125°C SUPPLY CURRENT (mA) –6 14 2 –55°C, 25°C, 125°C ISHDN –8 13 1 –10 12 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 0 2 4 6 8 10 12 14 16 18 SETTLING TIME (µs) SUPPLY VOLTAGE (±V) SUPPLY VOLTAGE (±V) 1205 G25 1204 G26 1204 G27
O U U W U APPLICATI S I FOR ATIO Logic Inputs
specified over a very wide range of conditions. An advan- tage of the current feedback topology used in the LT1204 The logic inputs of the LT1204 are compatible with all 5V is well-controlled frequency response. In all cases of the logic. All pins have ESD protection (> 2kV), and shorting performance table, the peaking is 0.1dB or less. If more them to 12V or 15V will cause excessive currents to flow. peaking can be tolerated, larger bandwidths can be Limit the current to less than 50mA when driving the logic obtained by lowering the feedback resistor. For gains of above 6V. 2 or less, the 0.1dB bandwidth is greater than 30MHz for all loads and supply voltages.
Power Supplies
At high gains (low values of R The LT1204 will operate from G) the disabled output ±5V (10V total) to ±15V resistance drops slightly due to loading of the internal (30V total) and is specified over this range. It is not buffer amplifier as discussed in Multiplexer Expansion. necessary to use equal value supplies, however, the offset voltage and inverting input bias current will change. The offset voltage changes about 600µV per volt of supply
Small-Signal Rise Time, AV = 2
mismatch. The inverting bias current changes about 2.5µA per volt of supply mismatch. The power supplies should be bypassed with quality tantalum capacitors.
Feedback Resistor Selection
The small-signal bandwidth of the LT1204 is set by the external feedback resistors and internal junction capaci- tors. As a result the bandwidth is a function of the supply voltage, the value of the feedback resistor, the closed- loop gain and the load resistor. These effects are outlined in the resistor selection guide of the Typical AC Perfor- 1204 AI01 VS = ±15V RF = 1k mance table. Bandwidths range as high as 95MHz and are RL = 150Ω RG = 1k 9
W U TYPICAL PERFOR A CE CH C ARA TERISTICS Settling Time to 1mV Enabled Supply Current Disabled and Shutdown Supply vs Output Step vs Supply Voltage Current vs Supply Voltage
10 22 22 V 8 S = ±15V 21 21 RF = RG = 1k 6 20 20 –55°C 125°C 4 19 19 2 18 18 25°C 25°C 0 17 17 –55°C –2 16 16 OUTPUT STEP (V) –4 15 15 SUPPLY CURRENT (mA) 125°C SUPPLY CURRENT (mA) –6 14 2 –55°C, 25°C, 125°C ISHDN –8 13 1 –10 12 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 0 2 4 6 8 10 12 14 16 18 SETTLING TIME (µs) SUPPLY VOLTAGE (±V) SUPPLY VOLTAGE (±V) 1205 G25 1204 G26 1204 G27
O U U W U APPLICATI S I FOR ATIO Logic Inputs
specified over a very wide range of conditions. An advan- tage of the current feedback topology used in the LT1204 The logic inputs of the LT1204 are compatible with all 5V is well-controlled frequency response. In all cases of the logic. All pins have ESD protection (> 2kV), and shorting performance table, the peaking is 0.1dB or less. If more them to 12V or 15V will cause excessive currents to flow. peaking can be tolerated, larger bandwidths can be Limit the current to less than 50mA when driving the logic obtained by lowering the feedback resistor. For gains of above 6V. 2 or less, the 0.1dB bandwidth is greater than 30MHz for all loads and supply voltages.
Power Supplies
At high gains (low values of R The LT1204 will operate from G) the disabled output ±5V (10V total) to ±15V resistance drops slightly due to loading of the internal (30V total) and is specified over this range. It is not buffer amplifier as discussed in Multiplexer Expansion. necessary to use equal value supplies, however, the offset voltage and inverting input bias current will change. The offset voltage changes about 600µV per volt of supply
Small-Signal Rise Time, AV = 2
mismatch. The inverting bias current changes about 2.5µA per volt of supply mismatch. The power supplies should be bypassed with quality tantalum capacitors.
Feedback Resistor Selection
The small-signal bandwidth of the LT1204 is set by the external feedback resistors and internal junction capaci- tors. As a result the bandwidth is a function of the supply voltage, the value of the feedback resistor, the closed- loop gain and the load resistor. These effects are outlined in the resistor selection guide of the Typical AC Perfor- 1204 AI01 VS = ±15V RF = 1k mance table. Bandwidths range as high as 95MHz and are RL = 150Ω RG = 1k 9
