ISL1591 Datasheet, PDF (1/18 Pages) Intersil Corporation – Fixed Gain, Dual Port, VDSL2 Line Driver

Fixed Gain, Dual Port, VDSL2 Line Driver
ISL1591
The ISL1591 provides 4 internal wideband op amps intended
to be used as two pairs of fixed gain differential line drivers.
The ISL1591’s high bandwidth, and ultra low distortion
enables the support of VDSL2 8b, 17a, and 30a in central
office modem applications. This highly versatile line driver
allows for operation from +14V to +24V nominal power
supplies, while delivering exceptional MTPR distortion
performance.
Using a single +24V supply, the ISL1591 MBPR distortion is
below -62dBc in VDSL2 8b, -63dBc in VDSL2 17a, and -60dBc
in VDSL2 30a profiles. Using a single +14V supply, ISL1591
supports 14.5dBm VDSL2 17a and 30a profiles at only a
power consumption of 425mW. This capability is ideal for
short loop, high bit rate VDSL2 applications where 14.5dBm
transmit power is all that is required. For full power VDSL2 8b
profile with 20dBm of transmit power, the line driver will
require +24V single supply.
Each of the 4 internal op amps is a wideband current feedback
amplifier offering very high slew rate intrinsic to that design
using low quiescent current levels. Each of the two pair of
amplifiers (ports) can also be power optimized to the
application using two external quiescent control logic pins. Full
power is nominally 14mA/port with options of medium power
cutback to 9.7mA/port, a low power condition at 7.4mA/port,
and an off state at <0.5mA/port.
High power push/pull line driver applications are best
supported using a low headroom, high output current device.
On +24V supplies, the ISL1591 offers a 1.6V headroom with
>360mA peak output current. Driving differentially, this gives
>42.4V_P-P swing to as low as 58Ω differential load. The four
amplifiers in ISL1591 are intended to be used as differential
pairs and not as individual amplifiers.
Features
• Internal Fixed Gain of 11.6V/V at R_LOAD
• ±360mA Output Drive Capability
• 42.4V_P-P Differential Output Drive into 82.6Ω
• -62dBc MBPR (VDSL 8b Profile)
• -65dBc US1, -63dBc US2 MBPR (VDSL2 17a Profile)
• -64dBc US1, -62dBc US2, -60dBc US3 MBPR (VDSL 30a
Profile)
• High Slew Rate of 2000V/µs Differential
• Bandwidth (170MHz)
• Supply Current Control Pins
• K.20, GR-1089 Surge Robustness Validated
• Pb-Free (RoHS Compliant)
Applications
• ADSL2+
• VDSL2 Profiles: 8MHz, 17MHz, and 30MHz
Related Literature
• AN1325 “Choosing and Using Bypass Capacitors”
TABLE 1. ALTERNATE SOLUTIONS
NOMINAL ±V_CC BANDWIDTH
PART #
(V)
(MHz)
APPLICATIONS
ISL1557
±6,+12
200
VDSL2
ISL1536
±12,+24
50
ADSL2+
ISL1539A
±12,+24
240
VDSL2
+24V
AFE
VCM 1/2
Vi
ISL1591
Rb
1:N
Vo
100Ω
LINE
Rb
Rb
=
100Ω
N²
x 0.2
x
0.5
Vo
Vi
= 11.6 ^V _V
FIGURE 1. FIXED GAIN LINE DRIVER CIRCUIT
10
0 PAR = 5.4
-10
20.2dBm
Avg. US1 MTBR = -65dBc
-20
-30
-40
-50
-60
-70
-80
-90
3.75M
4.15M
4.55M
4.95M
FREQUENCY (Hz)
FIGURE 2. MBPR VDSL2 8b PERFORMANCE
5.35M
October 31, 2012
1
FN7625.1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 |Copyright Intersil Americas Inc. 2011, 2012. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.