HSP50216KIZ Intersil, HSP50216KIZ Datasheet - Page 23

• Manufacturer Part Number: HSP50216KIZ
• Description: IC DOWNCONVERTER DGTL 4CH 196BGA
• Manufacturer: Intersil

Specifications of HSP50216KIZ

• Function: Downconverter
• Rf Type: W-CDMA
• Package / Case: 196-BGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

†
In dB, this can be expressed as:
(AGC Mult/Shift Gain)dB = 20 log
The full AGC range of the multiplier/shifter is from 0 dB to
20log
The 16 bit resolution of the mantissa provides a theoretical
AM modulation level of -96dBc (depending on loop gain,
settling mode and SNR). This effectively eliminates AM
spurious caused by the AGC resolution.
The Cartesian to polar coordinate converter accepts I and Q
data and generates magnitude and phase data. The
magnitude output is determined by the equation:
r
Controlled via microprocessor interface.
=
(11 MANTISSA
4 EXPONENT)
IFIR
QFIR
SERIAL
1.64676 I
10
OUT
[1+(2
μP
14
2
16
19
+
24
24
-1)2
Q
2
MSB = 0
-14
] + 20log
MSB = 0
4
23
24
EXP=2
AGC MULTIPLIER/SHIFTER
24
10
10
18
(2
NNNN
EN
N
AGC LOOP FILTER
[2
[1 + (X)2
LOAD
AGC
15
FIGURE 1. AGC FUNCTIONAL BLOCK DIAGRAM
16
] = 96.329 dB.
M
U
X
MANTISSA =
01.XXXXXXXXXXXXXX
-14
LIMIT
])
DET
LIMIT
DET
μP
LOWER LIMIT
LIMIT
UPPER LIMIT
(RANGE = -2.18344 TO 2.18344)
DET
HSP50216
IAGC
24
+
QAGC
24
†
†
where the magnitude limits are determined by the maximum
I and Q signal levels into the Cartesian to polar converter.
Taking fractional 2's complement representation, magnitude
ranges from 0 to 2.329, where the maximum output is
The AGC loop feedback path consists of an error detector,
error scaling, and an AGC loop filter. The error detector
subtracts the magnitude output of the coordinate converter
from the programmable AGC THRESHOLD value. The AGC
THRESHOLD value is set in IWA register *012h and is equal
to 1.64676 times the desired magnitude of the I1/Q1 output.
Note that the MSB is always zero. The range of the AGC
THRESHOLD value is 0 to +3.9999. The AGC Error
Detector output has the identical range.
r
=
1.64676 1
AGCGNSEL
28
AGC ERROR SCALING
2
EXP
+
1
2
(RANGE = 0 TO 1)
=
4
1.64676x1.414
(RANGE = 0 TO 2.32887)
MANTISSA
4
MAGNITUDE
COORDINATE
CONVERTER
(G = 1.64676)
CARTESIAN
POLAR
TO
=
2.329
DETECTOR
ERROR
AGC
Δ
16
August 17, 2007
16
FN4557.6