MAX3507 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Upstream CATV Amplifier with On-Chip Anti-Alias Filter

19-2092; Rev 0; 7/01
Upstream CATV Amplifier with
On-Chip Anti-Alias Filter
General Description
The MAX3507 is a variable-gain power amplifier for use
in CATV upstream transmitters. The variable-gain fea-
ture has 55dB of dynamic range and is controlled by a
3-wire SPI™ bus. The device is capable of generating
+64dBmV output (16QAM/QPSK) when driven with a
+34dBmV nominal input signal. The on-chip anti-alias
lowpass filter with 75MHz cutoff frequency saves sys-
tem design cost and space. The optional positive slope
generator provides system design flexibility.
The device operates from a single +5V supply and
draws 220mA nominal during transmit at max gain
(100% duty cycle). For burst-type transmissions, the
device is shut off between bursts to minimize noise and
save power while still maintaining a match at the output.
The device is optimized for high linearity with harmonic
levels below -55dBc.
The MAX3507 is available in a 28-pin QFN package
and operates over the extended industrial temperature
range (-40°C to +85°C).
Applications
Cable Modem Upstream Transmitter
Set-Top Box Upstream Transmitter
Telephony Over Cable
Features
o Built-In 5th-Order Elliptic Anti-Aliasing Filter
o 5MHz to 65MHz Operation
o 55dB Gain Control Range
o Optional Positive Slope Generator
o 55dB Spurious-Free Dynamic Range Over
Transmit Band
PART
MAX3507EGI
Ordering Information
TEMP. RANGE
-40°C to +85°C
PIN-PACKAGE
28 QFN
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
VCC
VCC
28
27
26
25
24
23
22
BIASF ₁
21 ^TXEN
DC+
2
BIAS
CIRCUIT
VCC
20 N.C.
DC-
3
GND ₄
VCC
VCC
5
IN+ ₆
OPTIONAL
EQUALIZER
5-POLE
ELLIPTIC
FILTER
SERIAL DATA
GAIN
CONTROL
OUT+
19
18 ^OUT-
17 N.C.
CEXT
16
4:1
IMPEDANCE
RATIO
IN-
7
MAX3507
15 N.C.
8
9
10
11
12
13
14
VCC
DIGITAL
CONTROL
LINES
SPI is a trademark of Motorola, Inc.
________________________________________________________________ Maxim Integrated Products 1
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