Datasheet

AFE5804
www.ti.com SBOS442C –JUNE 2008–REVISED OCTOBER 2011
ELECTRICAL CHARACTERISTICS
At AVDD_5V = 5.0V, AVDD1 = AVDD2 = DVDD = 3.3V, LVDD = 1.8V, TGC mode I, single-ended input into LNA, ac-coupled
(1.0μF), V
CNTL
= 1.0V, f
IN
= 5MHz, Clock = 40MSPS, 50% duty cycle, LPF = 12.5MHz, internal reference mode, ISET = 56kΩ,
LVDS buffer setting = 3.5mA, and ambient temperature T
A
= +25°C, unless otherwise noted.
AFE5804
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
PREAMPLIFIER (LNA)
Gain A SE-input to differential output 20 dB
Input voltage (TGC, PW modes) V
IN
Linear operation (HD2 ≤ 40dB) 280 mV
PP
(CW mode) Linear operation 220 mV
PP
Maximum input voltage Limited by internal diodes 600 mV
PP
Input voltage noise (TGC) e
n
(RTI) R
S
= 0Ω, f = 2MHz 0.75 nV/√Hz
TGC mode I 3 pA/√Hz
Input current noise I
n
(RTI)
TGC mode II 1.7 pA/√Hz
Common-mode voltage, input V
CMI
Internally generated 2.4 V
Bandwidth BW Small-signal, –3dB 55 MHz
Input resistance R
IN
At 2.5MHz 8 kΩ
Includes internal ESD and clamping
Input capacitance C
IN
16 pF
diodes
FULL-SIGNAL CHANNEL (LNA + VCA + LPF + ADC)
Input voltage noise
e
n
R
S
= 0Ω, f = 2MHz, PGA = 30dB 0.89 nV/√Hz
(TGC mode I)
Input voltage noise (TGC mode II) R
S
= 0Ω, f = 2MHz, PGA = 30dB 1.23 nV/√Hz
Input voltage noise (PW mode) R
S
= 0Ω, f = 2MHz, PGA = 30dB 1.03 nV/√Hz
Noise figure NF R
S
= 200Ω, f = 2MHz 1.1 dB
Low-pass filter bandwidth LPF At –3dB, selectable through SPI 12.5, 17 MHz
Bandwidth tolerance ±10 %
High-pass filter HPF (First-order, due to internal ac-coupling) 200 kHz
Group delay variation 1MHz to 10MHz ±3 ns
≤ 6dB overload to within 3%,
Overload recovery 2 Clock Cycles
V
CNTL
= 0V to 1.2V
ACCURACY
Gain (PGA) Selectable through SPI 20, 25, 27, 30 dB
Total gain, max
(1)
LNA + PGA gain, V
CNTL
= 1.2V 47.5 49 50.5 dB
V
CNTL
= 0V to 1.2V 46 dB
Gain range
V
CNTL
= 0.1V to 1.0V 40 dB
0V < V
CNTL
< 0.1V ±0.5 dB
Gain error, absolute
(2)
0.1V < V
CNTL
< 1.0V –1.5 ±0.5 +1.5 dB
1.0V < V
CNTL
< 1.2V ±0.5 dB
Gain matching Channel-to-channel –0.5 ±0.25 +0.5 dB
Offset error V
CNTL
= 1.2V, PGA = 30dB –39 +39 LSB
Offset error drift (tempco) ±5 ppm/°C
Clamp level Level internally fixed before LPF 2.3 V
PP
GAIN CONTROL (VCA)
Input voltage range V
CNTL
Gain range = 46dB 0 to 1.2 V
Gain slope V
CNTL
= 0.1V to 1.0V 44.4 dB/V
Input resistance 25 kΩ
Response time V
CNTL
= 0V to 1.2V step; to 90% signal 0.5 μs
(1) Excludes digital gain within ADC.
(2) Excludes error of internal reference.
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