LTC6412 Datasheet, PDF (13/24 Pages) Linear Technology – 800MHz, 31dB Range Analog-Controlled VGA

BLOCK DIAGRAM
6 13 19 24 22
V_CC V_CC V_CC V_{CC SHDN}
21
EN
15 23
GND GND
REFERENCE AND BIAS CONTROL
+IN
2
–IN
3
V_CM
4
V_CM
5
+OUT
•••
17
BUFFER/
•••
OUTPUT
AMPLIFIER
•••
–OUT
16
ATTENUATOR
CONTROL
REFERENCE AND
BIAS CONTROL
DECL1
7
DECL2
14
EXPOSED
+V_G V_REF –V_G GND GND GND GND GND PAD
9
10 11
1 8 12 15 18 25
6412 BD
LTC6412
DC TEST CIRCUIT
0.1μF
V_CC
2.2V 0.8V
0.1μF
+IN
V_IN(DIFF) = (+IN) – (–IN)
V_IN(CM) = [(+IN) + (–IN)]/2
–IN
V_SUPPLY ≈ V_CC + 2.3V
+IN
+OUT
LTC6412
–IN
–OUT
100Ω
+OUT
V_OUT(DIFF) = (+OUT) – (–OUT)
V_OUT(CM) = [(+OUT) + (–OUT)]/2
–OUT
6412 TC
100Ω
V_SUPPLY ≈ V_CC + 2.3V
0.1μF
0.1μF
0.1μF
GAIN CONTROL
(NEGATIVE SLOPE)
6412f
13