lt5524 Linear Technology Corporation, lt5524 Datasheet - Page 7

• Manufacturer Part Number: lt5524
• Description: Low Distortion If Amplifier/adc Driver With Digitally Controlled Gain
• Manufacturer: Linear Technology Corporation

BLOCK DIAGRA
PI FU CTIO S
EN (Pin 1): Enable Pin for Amplifier. When the input
voltage is higher than 3V, the amplifier is turned on. When
the input voltage is less than or equal to 0.6V, the amplifier
is turned off. This pin is internally pulled to ground if not
connected.
V
to V
for example) may be required in some applications.
GND (Pins 3, 4, 7, 8, 13, 14, 17, 18): Ground.
IN
Bias.
IN
Bias.
PGA0 (Pin 9): Amplifier PGA Control Input Pin for the 1.5dB
Attenuation Step (see Programmable Gain table). Input is
high when the input voltage is greater than 3V. Input is low
when the input voltage is less than or equal to 0.6V. This
pin is internally pulled to ground if not connected.
PGA1 (Pin 10): Amplifier PGA Control Input Pin for the 3dB
Attenuation Step (see Programmable Gain table). Input is
high when the input voltage is greater than 3V. Input is low
when the input voltage is less than or equal to 0.6V. This
pin is internally pulled to ground if not connected.
CC1
+
–
U
CC2
(Pin 6): Negative Signal Input Pin with Internal DC
(Pin 5): Positive Signal Input Pin with Internal DC
(Pin 2): Power Supply. This pin is internally connected
(Pin 19). Decoupling capacitors (1000pF and 0.1µF
U
U
5
6
LT5524
GND (3, 4, 7, 8
13, 14, 17, 18)
IN
IN
W
+
–
VOLTAGE REGULATOR
AND BIAS
2
V
CC1
19
V
Figure 1. Functional Block Diagram
CC2
ATTENUATOR
12
R
100Ω
PGA3
IN
GAIN CONTROL
11
LOGIC
PGA2
PGA2 (Pin 11): Amplifier PGA Control Input Pin for the 6dB
Attenuation Step (see Programmable Gain table). Input is
high when the input voltage is greater than 3V. Input is low
when the input voltage is less than or equal to 0.6V. This
pin is internally pulled to ground if not connected.
PGA3 (Pin 12): Amplifier PGA Control Input Pin for 12dB
Attenuation Step (see Programmable Gain table). Input is
high when the input voltage is greater than 3V. Input is low
when the input voltage is less than or equal to 0.6V. This
pin is internally pulled to ground if not connected.
OUT
with center tap tied to V
mended to source the DC quiescent current.
OUT
with center tap tied to V
mended to source the DC quiescent current.
V
nected to V
NC (Pin 20): Not Connected.
Exposed Pad (Pin 21): Ground. This pin must be soldered
to the printed circuit board ground plane for good heat
transfer.
CC2
10
PGA1
+
–
(Pin 19): Power Supply. This pin is internally con-
(Pin 16): Negative Amplifier Output. A transformer
(Pin 15): Positive Amplifier Output. A transformer
9
PGA0
AMPLIFIER
CC1
(Pin 2).
20
NC
CONTROL
ENABLE
1
EN
CC
CC
or a choke inductor is recom-
or a choke inductor is recom-
OUT
OUT
5524 F01
–
+
16
15
21
LT5524
7
5524f