19-1700; Rev 0; 4/00
Upstream CATV Amplifier
General Description
Features
The MAX3509 is a programmable power amplifier for
use in CATV upstream applications. The device outputs
up to 66dBmV QPSK through a 1:1 transformer. It fea-
tures variable gain controlled by a 3-wire digital serial
bus. Gain control is available in 1dB steps. The device
operates over a 5MHz to 65MHz frequency range.
ꢀ Ultra-Low Power-Up/Down Transients,
25mV (typ) at 66dBmV Output
ꢀ Single-Supply Operation
ꢀ Output Level Ranges from <12dBmV to 67dBmV
(QPSK)
The MAX3509 offers a transmit-disable mode, which
places the device in a high-isolation state for use
between bursts in TDMA systems. In this mode, all ana-
log functions are shut down, minimizing output noise
and power consumption. When entering and leaving
transmit-disable mode, transients are kept to 25mV
nominal at full gain. In addition, supply current is re-
duced to 7.8mA.
ꢀ Gain Programmable in 1dB Steps
ꢀ Low Transmit Output Noise Floor: -41dBmV
(160kHz BW)
ꢀ Low Transmit-Disable Output Noise: -70dBmV
ꢀ Shutdown Mode
An additional power-down mode is available. Shutdown
mode disables all circuitry and reduces current con-
sumption to less than 1µA.
Ordering Information
PART
TEMP. RANGE
PIN-PACKAGE
The MAX3509 is available in a 20-pin TSSOP-EP pack-
age for the extended-industrial temperature range
(-40°C to +85°C).
MAX3509EUP
-40°C to +85°C
20 TSSOP-EP*
*Exposed paddle
Applications
CATV Status Monitor
Telephony over Cable
OPENCATV Set-Top Box CATV Infrastructure
Cable Modems
Typical Operating Circuit
Pin Configuration
TOP VIEW
3
4
17
V
+9V
0.1µF
CC2
+9V
0.1µF
V
CC1
TXEN
1
2
3
4
5
6
7
8
9
20 SCLK
19 SDA
18 CS
GND1
SHDN
MAX3509
4700pF
16
V
CC1
1000pF
1000pF
OUT
5
6
OUT+
OUT-
IN+
IN-
GND1
IN+
17 V
CC2
T1
1:1
IN
4700pF
MAX3509
16 OUT+
15 OUT-
15
IN-
14
GND1
14
V
V
+9V
0.1µF
CC2
CC2
8
7
V
+9V
0.1µF
CC1
V
13 GND
12 GND
11 GND
CC1
GND1
GND
GND2
*
9
2
1
20
19
18
GND 10
GND
GND
GND
GND
GND
SHDN
TXEN
SCLK
SDA
CS
10
11
12
13
EXPOSED PADDLE
LOGIC
INPUTS
TSSOP-EP
*EXPOSED PADDLE
†
Covered by U.S. Patent numbers 5,748,027 and 5,994,955.
________________________________________________________________ Maxim Integrated Products
1
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