Datasheet LT5554 (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | Broadband Ultra Low Distortion 7-Bit Digitally Controlled VGA |
| Pages / Page | 32 / 7 — ELECTRICAL CHARACTERISTICS. Note 5:. Note 8. Note 9. Note 6. Note 7. … |
| File Format / Size | PDF / 619 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. Note 5:. Note 8. Note 9. Note 6. Note 7. TYPICAL PERFORMANCE CHARACTERISTICS
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LT5554
ELECTRICAL CHARACTERISTICS Note 5:
RTI (Referred-To-Input) stands for the total input-referred noise
Note 8
: The external loading at OUT+/OUT– pins is RLOAD = 133Ω. voltage source. RTI is close to output noise voltage divided by voltage gain ROUT = RLOAD || RO = 100Ω. (the exact equation is given in Defi nition of Specifi cation section). The
Note 9
: Depending on the actual input matching conditions and frequency equivalent noise source eN is twice the RTI value. of operation, the LT5554 steps involving the input attenuator tap change
Note 6
: The external loading at LT5554 OUT+/OUT– pins is RLOAD = 57Ω. may show less than 0.125dB change. These steps are GMAX –4dB, GMAX ROUT = RLOAD || RO = 50Ω. –8dB, GMAX –12dB, and the code is given in the Programmable Gain Table.
Note 7
: The IN+, IN–, DEC pins are internally biased. The time-constant The LT5554 monotonic operation for 0.125dB step resolution can still be of input coupling capacitor sets the low frequency corner (LF) at input. obtained by skipping any such code with a gain error excedding 0.125dB. The output coupling capacitors or the transformer sets the low frequency corner (LF) at the output. The LT5554 operates internally down to DC.
TYPICAL PERFORMANCE CHARACTERISTICS (ROUT = 50Ω) TA = 25°C. VCC = 5V, VCCO = 5V, ENB = 3V, MODE = 5V, STROBE = 3V, VIH = 2.2V, VIL = 0.6V (Test circuit shown in Figure 16), unless otherwise noted. Gain vs Frequency for Differential Gain Error vs Differential Gain Error vs 0.5dB Steps, Figure 17 Frequency at –40°C Frequency at 85°C
20 0.3 0.3 18 16 0.2 0.2 12dB 14 12dB 12 0.1 0.1 4dB 4dB 10 8dB 8dB GAIN (dB) 8 0 0 GAIN ERROR (dB) GAIN ERROR (dB) 6 4 –0.1 –0.1 2 0 –0.2 –0.2 0 100 200 300 400 500 600 700 800 900 1000 50 75 100 125 150 175 200 50 75 100 125 150 175 200 FREQUENCY (MHz) FREQUENCY (MHz) FREQUENCY (MHz) 5554 G01 5554 G02 5554 G03
Differential Gain Error vs Differential Gain Error vs Differential Gain Error vs Attenuation at 50MHz Attenuation at 100MHz Attenuation at 200MHz
0.3 0.3 0.3 –40°C –40°C –40°C 25°C 25°C 25°C 85°C 85°C 85°C 0.2 0.2 0.2 0.1 0.1 0.1 0 0 0 GAIN ERROR (dB) GAIN ERROR (dB) GAIN ERROR (dB) –0.1 –0.1 –0.1 –0.2 –0.2 –0.2 0 –4 –8 –12 –16 0 –4 –8 –12 –16 0 –4 –8 –12 –16 ATTENUATION (dB) ATTENUATION (dB) ATTENUATION (dB) 5554 G04 5554 G05 5554 G06 5554f 7
ELECTRICAL CHARACTERISTICS Note 5:
RTI (Referred-To-Input) stands for the total input-referred noise
Note 8
: The external loading at OUT+/OUT– pins is RLOAD = 133Ω. voltage source. RTI is close to output noise voltage divided by voltage gain ROUT = RLOAD || RO = 100Ω. (the exact equation is given in Defi nition of Specifi cation section). The
Note 9
: Depending on the actual input matching conditions and frequency equivalent noise source eN is twice the RTI value. of operation, the LT5554 steps involving the input attenuator tap change
Note 6
: The external loading at LT5554 OUT+/OUT– pins is RLOAD = 57Ω. may show less than 0.125dB change. These steps are GMAX –4dB, GMAX ROUT = RLOAD || RO = 50Ω. –8dB, GMAX –12dB, and the code is given in the Programmable Gain Table.
Note 7
: The IN+, IN–, DEC pins are internally biased. The time-constant The LT5554 monotonic operation for 0.125dB step resolution can still be of input coupling capacitor sets the low frequency corner (LF) at input. obtained by skipping any such code with a gain error excedding 0.125dB. The output coupling capacitors or the transformer sets the low frequency corner (LF) at the output. The LT5554 operates internally down to DC.
TYPICAL PERFORMANCE CHARACTERISTICS (ROUT = 50Ω) TA = 25°C. VCC = 5V, VCCO = 5V, ENB = 3V, MODE = 5V, STROBE = 3V, VIH = 2.2V, VIL = 0.6V (Test circuit shown in Figure 16), unless otherwise noted. Gain vs Frequency for Differential Gain Error vs Differential Gain Error vs 0.5dB Steps, Figure 17 Frequency at –40°C Frequency at 85°C
20 0.3 0.3 18 16 0.2 0.2 12dB 14 12dB 12 0.1 0.1 4dB 4dB 10 8dB 8dB GAIN (dB) 8 0 0 GAIN ERROR (dB) GAIN ERROR (dB) 6 4 –0.1 –0.1 2 0 –0.2 –0.2 0 100 200 300 400 500 600 700 800 900 1000 50 75 100 125 150 175 200 50 75 100 125 150 175 200 FREQUENCY (MHz) FREQUENCY (MHz) FREQUENCY (MHz) 5554 G01 5554 G02 5554 G03
Differential Gain Error vs Differential Gain Error vs Differential Gain Error vs Attenuation at 50MHz Attenuation at 100MHz Attenuation at 200MHz
0.3 0.3 0.3 –40°C –40°C –40°C 25°C 25°C 25°C 85°C 85°C 85°C 0.2 0.2 0.2 0.1 0.1 0.1 0 0 0 GAIN ERROR (dB) GAIN ERROR (dB) GAIN ERROR (dB) –0.1 –0.1 –0.1 –0.2 –0.2 –0.2 0 –4 –8 –12 –16 0 –4 –8 –12 –16 0 –4 –8 –12 –16 ATTENUATION (dB) ATTENUATION (dB) ATTENUATION (dB) 5554 G04 5554 G05 5554 G06 5554f 7
