Datasheet

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VCA8500
SBOS390A – JANUARY 2008 – REVISED MARCH 2008
ELECTRICAL CHARACTERISTICS (continued)
All specifications at T
A
= +25 ° C, AVDD2 = 5.0V, AVDD1 = DVDD = 3.3V; single-ended, ac-coupled (1 µ F) input configuration to the preamp
(LNA), f
IN
= 5MHz, V
CNTL
= 1.0V, PG = 30dB, clamp disabled (CL = 1), LPF = 15MHz, and R
LOAD
= 1k Ω on each output to ground, unless
otherwise noted.
VCA8500
TEST
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT LEVEL
(1)
ACCURACY
20, 25,
Gain (PGA) Selectable through SPI™ dB A
27, 30
Total gain, maximum LNA + PGA gain, V
CNTL
= 1.2V 48 49.5 51 dB A
Gain range V
CNTL
= 0V to 1.2V 46 dB A
Gain range V
CNTL
= 0.1V to 1.0V 40 dB A
Gain slope V
CNTL
= 0.1V to 1.0V 44.4 dB/V A
Gain error, absolute 0V < V
CNTL
< 0.1V ± 0.5 dB A
0.1V < V
CNTL
< 1.0V – 1.5 ± 0.5 +1.5 dB A
1.0V < V
CNTL
< 1.2V ± 0.5 dB A
Gain matching Channel-to-channel ± 0.25 ± 0.5 dB A
Output offset voltage Differential – 25 ± 1 +25 mV A
Single-ended
(3)
– 50 ± 25 +50 mV A
Clamp level (V
OUT
) CL = 0 1.7 V
PP
A
CL = 1 (clamp disabled) 2.8 V
PP
B
GAIN CONTROL INTERFACE
Input voltage range (V
CNTL
) Gain range = 46dB 0 to 1.2 V A
Input resistance 25 k Ω C
V
CNTL
= 0V to 1.2V step;
Response time 0.5 µ s B
to 90% signal level, V
OUT
= 1V
PP
Gain control bandwidth 1.5 MHz C
CW SIGNAL PATH
Output transconductance (V/I) At V
IN
= 100mV
PP
14 16.4 18 mA/V A
At V
IN
= 200mV
PP
14.5 mA/V B
Dynamic CW output current, max 2.9 mA
PP
B
Static CW output current (sink) 0.9 mA B
Output common-mode voltage (V
CM0
) Supplied externally +2.5 V B
Output compliance range Symmetric around V
CMO
± 0.5 V B
Output capacitance 10 pF C
Output impedance 50 k Ω C
Input voltage noise, CW mode At f = 2MHz 1.15 nV/ √ Hz B
Signal-dependent noise (RTO) At 2kHz offset from 2MHz CW carrier +2 dB B
At 2kHz offset from 5MHz CW carrier +2 dB B
Summing of eight channels (all modes)
Output noise correlation factor 0.6 dB B
[compared to ideal 0dB]
(3) Deviation from ideal common-mode voltage (V
CM
= 1.65V).
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